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Virtual Power Meter
Operators Manual
Model VPM2
This is a preliminary manual. Specifications, limits, and text are subject to change without notice. The information within this manual was as complete as possible at the time of printing. Bird Electronic Corporation is not liable for errors.
©Copyright 2009 by Bird Electronic Corporation Instruction Book Part Number 920-VPM2 Rev. P2
Windows and Microsoft are registered trademarks of the Microsoft Corporation
SeaLatch is a registered trademark of Sealevel Systems, Inc.
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Safety Precautions
The following are general safety precautions that are not necessarily related to any specific part or procedure, and do not necessarily appear elsewhere in this publication. These precautions must be thoroughly understood and apply to all phases of operation and maintenance.
WARNINGKeep Away From Live Circuits
Operating Personnel must at all times observe general safety precautions. Do not replace components or make adjustments to the inside of the test equipment with the high voltage supply turned on.
To avoid casualties, always remove power.
WARNINGShock Hazard
Do not attempt to remove the RF transmission line while RF power is present.
WARNINGDo Not Service Or Adjust Alone
Under no circumstances should any person reach into an enclosure for the purpose of service or adjustment of equipment except in the
presence of someone who is capable of rendering aid.
WARNINGSafety Earth Ground
An uniterruptible earth safety ground must be supplied from the main power source to test instruments. Grounding one conductor of
a two conductor power cable is not sufficient protection. Serious injury or death can occur if this grounding is not properly supplied.
WARNINGResuscitation
Personnel working with or near high voltages should be familiar with modern methods of resuscitation.
WARNINGRemove Power
Observe general safety precautions. Do not open the instrument with the power on.
Safety Symbols
The caution symbol appears on the equipment indicating there is important information in the instruction manual regarding that particular area
Note: Calls attention to supplemental information.
Warning StatementsThe following safety warnings appear in the text where there is dan-ger to operating and maintenance personnel, and are repeated here for emphasis.
On page 4.
Caution StatementsThe following equipment cautions appear in the text and are repeated here for emphasis.
On page 5.
On page 5.
On page 5.
WARNINGWarning notes call attention to a procedure, which if not correctly
performed, could result in personal injury.
CAUTIONCaution notes call attention to a procedure, which if not correctly
performed, could result in damage to the instrument.
WARNINGRF voltage may be present in RF element socket. Keep element in
socket during operation..
CAUTIONDischarge all static potentials before connecting the TPS(-EF).
Electrostatic shock could damage the sensor.
CAUTIONWhen connecting the TPS or the TPS-EF, only turn the connector
nut. Damage may occur if torque is applied to the sensor body.
CAUTIONDo not exceed 2 W average or 125 W peak power for 5 µs when using the TPS or the TPS-EF. Doing so will render the sensor inoperative.
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Safety Statements
USAGE
ANY USE OF THIS INSTRUMENT IN A MANNER NOT SPECIFIED BY THE MANUFACTURER MAY IMPAIR THE INSTRUMENT’S SAFETY PROTECTION.
USO
EL USO DE ESTE INSTRUMENTO DE MANERA NO ESPECIFICADA POR EL FABRICANTE, PUEDE ANULAR LA PROTECCIÓN DE SEGURIDAD DEL INSTRUMENTO.
BENUTZUNG
WIRD DAS GERÄT AUF ANDERE WEISE VERWENDET ALS VOM HERSTELLER BESCHRIEBEN, KANN DIE GERÄTESICHERHEIT BEEINTRÄCHTIGT WERDEN.
UTILISATION
TOUTE UTILISATION DE CET INSTRUMENT QUI N’EST PAS EXPLICITEMENT PRÉVUE PAR LE FABRICANT PEUT ENDOMMAGER LE DISPOSITIF DE PROTECTION DE L’INSTRUMENT.
IMPIEGO
QUALORA QUESTO STRUMENTO VENISSE UTILIZZATO IN MODO DIVERSO DA COME SPECIFICATO DAL PRODUTTORE LA PROZIONE DI SICUREZZA POTREBBE VENIRNE COMPROMESSA.
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SERVICE
SERVICING INSTRUCTIONS ARE FOR USE BY SERVICE - TRAINED PERSONNEL ONLY. TO AVOID DANGEROUS ELECTRIC SHOCK, DO NOT PERFORM ANY SERVICING UNLESS QUALIFIED TO DO SO.
SERVICIO
LAS INSTRUCCIONES DE SERVICIO SON PARA USO EXCLUSIVO DEL PERSONAL DE SERVICIO CAPACITADO. PARA EVITAR EL PELIGRO DE DESCARGAS ELÉCTRICAS, NO REALICE NINGÚN SERVICIO A MENOS QUE ESTÉ CAPACITADO PARA HACERIO.
WARTUNG
ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR FÜR GESCHULTES FACHPERSONAL.ZUR VERMEIDUNG GEFÄHRLICHE, ELEKTRISCHE SCHOCKS, SIND WARTUNGSARBEITEN AUSSCHLIEßLICH VON QUALIFIZIERTEM SERVICEPERSONAL DURCHZUFÜHREN.
ENTRENTIEN
L’EMPLOI DES INSTRUCTIONS D’ENTRETIEN DOIT ÊTRE RÉSERVÉ AU PERSONNEL FORMÉ AUX OPÉRATIONS D’ENTRETIEN. POUR PRÉVENIR UN CHOC ÉLECTRIQUE DANGEREUX, NE PAS EFFECTUER D’ENTRETIEN SI L’ON N’A PAS ÉTÉ QUALIFIÉ POUR CE FAIRE.
ASSISTENZA TECNICA
LE ISTRUZIONI RELATIVE ALL’ASSISTENZA SONO PREVISTE ESCLUSIVAMENTE PER IL PERSONALE OPPORTUNAMENTE ADDESTRATO. PER EVITARE PERICOLOSE SCOSSE ELETTRICHE NON EFFETTUARRE ALCUNA RIPARAZIONE A MENO CHE QUALIFICATI A FARLA.
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RF VOLTAGE MAY BE PRESENT IN RF ELEMENT SOCKET - KEEP ELEMENT IN SOCKET DURING OPERATION.
DE LA TENSION H.F. PEAT ÊTRE PRÉSENTE DANS LA PRISE DE L'ÉLÉMENT H.F. - CONSERVER L'ÉLÉMENT DANS LA PRISE LORS DE L'EMPLOI.
HF-SPANNUNG KANN IN DER HF-ELEMENT-BUCHSE ANSTEHEN - ELEMENT WÄHREND DES BETRIEBS EINGESTÖPSELT LASSEN.
PUEDE HABER VOLTAJE RF EN EL ENCHUFE DEL ELEMENTO RF - MANTENGA EL ELEMENTO EN EL ENCHUFE DURANTE LA OPERACION.
IL PORTAELEMENTO RF PUÒ PRESENTARE VOLTAGGIO RF - TENERE L'ELEMENTO NELLA PRESA DURANTE IL FUNZIONAMENTO.
v
About This Manual
This manual covers the operating and maintenance instructions for the following models:
Changes to this Manual
We have made every effort to ensure this manual is accurate. If you discover any errors, or if you have suggestions for improving this man-ual, please send your comments to our Solon, Ohio factory. This man-ual may be periodically updated. When inquiring about updates to this manual refer to the part number and revision on the title page.
Literature Contents
Chapter Layout
Introduction — Describes the features of the VPM2, lists equipment supplied and optional equipment, and provides power-up instructions.Program Interfaces — Describes the features of VPM program and interfaces with the sensors.Power Sensors — Descriptions, features, and procedures of all the 50XX series sensors.Specifications — Describes system requirements.
VPM2
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Table of Contents
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iSafety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iiWarning Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iiCaution Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iiSafety Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viChanges to this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viLiterature Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
Chapter Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Installing the VPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Connecting a Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Connecting the Directional Power Sensor (DPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Display Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Power Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Bar Graph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Limit Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Sensor Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Sensor Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Meter Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Sensor Readings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chart Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Show Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Show Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Show Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Best Fit Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Set Lower/Upper Delta Marker . . . . . . . . . . . . . . . . . . . . . . 10
Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Axis Scaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Manual Axis Scaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
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Chapter 2 Program Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13New Sensor Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Save Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Save Session As... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Close Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Recall Saved Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Recall/Review Log File... . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Preferences... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Configure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Input Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Match Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Meter Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15CCDF Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Zero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Hold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Max Hold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Match . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Add Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Remove Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Quick Save Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Label & Save Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Enable Data Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Logging Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Show/Hide Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Show/Hide Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Fullscreen Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Display Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Cascade Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
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Tile Sessions Horizontally . . . . . . . . . . . . . . . . . . . . . . . . . . 19Tile Sessions Vertically . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19User Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19About Virtual Power Meter . . . . . . . . . . . . . . . . . . . . . . . . . 19About Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Menu Label Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Forward and Reflected Power . . . . . . . . . . . . . . . . . . . . . . . 21Match . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Forward Peak Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Peak Average Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Burst Average Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Crest Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Complementary Cumulative Distribution Function (CCDF) . . . . . . . . . . . . . . . . . . . . . . . 23
Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Configure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
For Wide Band Power Sensors . . . . . . . . . . . . . . . . . . . . . . 25For Sensor 5015 and 5015-EF . . . . . . . . . . . . . . . . . . . . . . . 26For Sensor 5014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Quick Save . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Label & Save . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Analyzing Logged Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Opening .xml Files in Excel . . . . . . . . . . . . . . . . . . . . . . . . . 29Opening .csv Files in Excel . . . . . . . . . . . . . . . . . . . . . . . . . 30
Zeroing a Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Chapter 3 Power Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Sensor Uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Mismatch Uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Directional Power Sensor (DPS) Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3643 Type Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36APM/DPM Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
ix
Terminating Power Sensor (TPS) . . . . . . . . . . . . . . . . . . . . . . . . . 37Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Zeroing Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Correction Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Wideband Power Sensor Measurements . . . . . . . . . . . . . . . . . . . . 38Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Zeroing Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Chapter 4 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Minimum PC Requirements 39
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
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Chapter 1 Introduction
Power measurements verify and monitor the condition of a transmitter system. To measure transmitter power, connect an external power sen-sor to the PC then start the Virtual Power Meter program. Power sen-sors that are compatible with the VPM are the Bird 5012, 5014, 5015, 5015-EF, 5016 and the Bird 5017.
Note: ONLY sensors that have USB connections can be used with VPM2 software.The Power Meter mode has the following features:Three display formats: numerical readout, analog dial, and chart recording.Display forward power, reflected power, match efficiency, peak power, burst, and crest factor depending upon the capabilities of the sensor.Display power measurements in Watts or dBm.Display match units in either VSWR, Return Loss, Rho, or % Match efficiency.Adjust power and match readings for effects of attenuators, couplers, and cable lossLog data to a file and review Save and recall sensor configuration setups
Figure 1 VPM Compatible Sensors
Wide Band Power Sensor (WPS) Directional Power Sensor
(DPS)
Terminating Power Sensor (TPS)
1
Bird Technologies
Installing the VPM1. Insert installation CD. 2. Select Install Software when prompted.
Note: Set-up will inspect the computer for any missing operating system prerequisites. If all are present, skip to step 6.
3. Select ‘Next ‘and the install utility begins the Prerequisites Instal-lation process.
Figure 2 Install, Prerequisites Installation
4. Review the End-User License Agreement, check “I accept the terms of the License Agreement” and select “Install.”
Note: The install Utility will install the prerequisites. This may take several minutes
Note: When completed, check with Microsoft® support cen-ter for any security updates. Typically, if “Automatic Updates” are configured on the host PC, these will be automatically flagged and selected for download and installation.
Note: The VPM2 installation utility will launch after the OS prerequisites are installed.
5. Do one of the following:Accept the default installation location Select a different folder:
6. Select ‘Next’ and the installer will complete.7. Select “Finish” to launch the VPM2 program:
Note: When the VPM2 loads for the first time, the Prefer-ences Dialog will prompt for a default log file save location. Perform the following to complete the process.
8. Select the ‘Logging’ tab.9. Enter a folder local to the PC to store log file data.
Note: This can be changed at any time in the Preferenes.
�
2
Introduction
Connecting a Sensor Note: Refer to the indivdual power sensor manual for spe-
cific information regarding its sensor connections.
1. Connect a power sensor to the computers USB port with a USB cable. Note: All Bird USB sensors are HID compliant devices
and do not require any driver installation. Note: The 5014 and 5015 sensors LED will illuminate
continually when properly recognized by the host PC. Note: The 5012, 5016, and 5017 sensors LED will blink
when properly recognized by the host PC.2. Launch the VPM2.3. Select the sensor from the sensor connection manager.4. Press the Configure menu key, after VPM2 acquires the power sensor,
See “Configure” on page 25. Note: Multiple sensors can be connected and/or monitored
simultaneously through multiple USB ports or via a powered USB hub. It can take up to 30 seconds to detect a sensor.
3
Bird Technologies
Figure 3 Sensor Connection Manager
Connecting the Directional Power Sensor (DPS)
1. Connect the Bird DPS to the a USB port on the PC using the sen-sor cable provided.
2. Connect the DPS to the RF line so that the arrow on the sensor points towards the load.
Note: The arrow on the forward element should point towards the load.
Note: The arrow on the reflected element should point towards the source.
Note: Both elements must be either APM/DPM or 43 types, do not mix elements.
3. Set the power on the DPM to the forward element’s power rating.
Figure 4 DPS Element Orientation
WARNINGRF voltage may be present in RF element socket. Keep element in
socket during operation.
4
Introduction
Connecting the Wideband Power Sensor (WPS)
1. Connect the Bird WPS to the a USB port on the PC using the sen-sor cable provided.
2. Connect the WPS to the RF line so that the arrow on the sensor points towards the load.
Connecting the Terminating Power Sensor (TPS)
Note: Connections are the same for the Bird 5011 and 5011-EF.
1. Connect the Bird TPS to the a USB port on the PC using the sen-sor cable provided.
Note: An attenuator or directional coupler should be used with the TPS in most applications. Example - For an RF source with output between 0.1 and 50 W, use a 40 dB, 50 W attenuator.
2. Connect the TPS RF input to the source (using an attenuator, if appropriate).
Note: Only connect the TPS directly to a source if the RF power will be less than 10 mW.
CAUTIONDischarge all static potentials before connecting the TPS(-EF).
Electrostatic shock could damage the sensor.
CAUTIONWhen connecting the TPS or the TPS-EF, only turn the connector
nut. Damage may occur if torque is applied to the sensor body.
CAUTIONDo not exceed 2 W average or 125 W peak power for 5 µs when using the TPS or the TPS-EF. Doing so will render the sensor inoperative.
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Display Types
Typical functions are selecting the type of measurement, type of ele-ment, units of measure, measurement scales, offset values, and zero-ing the sensor.
When a power sensor is properly connected (and detected), a status message, located at the top of the Power Meter screen, will indicate the model number of the power sensor (i.e., Bird model number). A popup with all decimals in the reading will display when a mouse icon hovers over the specific reading.
Power Display
The selected measurement type is displayed in the main power dis-play and ancillary readings are displayed under the bar graph.
Bar GraphThe bar graph gives a visual indication of the main reading as well as displaying the preset limits for the currently selected measurement. The scale of the graph can be set to auto or full-scale.
Limit Indicators'Virtual LEDs' indicate when pre-set limits have been exceeded.
Sensor DetailsProvides a comprehensive display of all readings provided by the sensor as well as all relevant configuration parameters
Sensor StatusIndicates the sensors connection status and zeroing progress.
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Introduction
Figure 5 VPM Screen, Power Display
Item Description1 Model of connected power sensor2 Softkey Labels3 Display Type4 Menu Label Keys5 Sensor Status6 Sensor Details7 Power Display8 Main Power Display
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Meter Display
Provides for a more traditional, analog-style view of main power dis-play. The selected measurement type is displayed in the analog meter as well as the preset limits for the currently selected measurement. The scale of the graph can be set to auto or full-scale.
Sensor Readings
Numerical readout of selected measurement type and ancillary read-ings is displayed under the meter display.
Figure 6 VPM Screen, Meter Display
Item Description
1 Model of connected power sensor
2 Softkey Labels
3 Display Type
4 Menu Label Keys
5 Sensor Status
6 Sensor Readings
7 Power Meter
8 Limit Indicators
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Introduction
9
Chart DisplayUsed to display running time trace of all data collected by a sensor session or to review data saved to a log file.
Note: Displaying the time trace does not automatically log data to a file. Logging must be active to store data. See “Log-ging” on page 29.
Figure 7 VPM, Chart Display
Note: Only data stored in Extensive Markup Language format (.xml) can be recalled using the VPM2. See “Logging” on page 29.
Both Type and Units may be changed at any time in chart display.Right clicking in chart will change display options:
Show MarkersToggles markers on & off. See “Markers” on page 10.
Item Description1 Model of connected power sensor2 Softkey Labels3 Display Type4 Menu Label Keys5 Sensor Status6 Sensor Readings7 Marker Readout8 Time Chart Display9 Scroll Buttons
Bird Technologies
Show GridTurns major & minor grid on/off
Show PointsToggles points on each data location
Best Fit DataAdjust scales to show entire range of data
Set Lower/Upper Delta MarkerMoves the marker to the location of the mouse pointer & automati-cally sets the position in time for the marker.Figure 8 Chart Display, Options Menu
MarkersClick on marker & slide, also can type time in display to move mark-ers to exact time location.Markers always stay in their current time reading.
Note: If the chart moves the markers off-screen, simply select ‘Set Upper or Lower Delta Marker’ to return the markers to the current displayed time interval.
Figure 9 Chart Display, Markers
Options Menu
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Introduction
Axis Scaling
Right click on Y or X axis to change scale from Auto to user-defined.Figure 10 Chart Display, Changing Scale
Manual Axis ScalingChange Time axis to ‘Manual’ allows scroll keys to be activated<< , >> - Moves chart to start, end of log< , > - Moves chart one span to the left or right Auto Scroll - When checked, the chart will automatically advance forward in time maintaining the same interval specified in the manual scale entry.Figure 11 Chart Display, Manual Axis Scaling
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Chapter 2 Program Interfaces
Menu Bar
Sessions
New Sensor SessionOpens a new sensor session.
Save SessionSaves the selected session.
Save Session As...Saves the selected session under a different name or file type.
Close SessionCloses the selected session.
Recall Saved SessionOpens a recently saved session from a drop down menu.
Recall/Review Log File...Opens a saved log file.
Preferences...Sets the location of a saved files directory.
ExitCloses the program and all open sessions.
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Configure
Input OffsetTo read the true power when using a coupler or attenuator, enter (in dB) the attenuation or coupling factor. To convert percentages to dB, use the equation:
Note: The Bird 5015-EF uses frequency-dependent correc-tion factors to provide more accurate measurements that are entered here. For more information, refer to the owners manual for the 5015-EF.
Match OffsetThe masking effect of cable loss can cause significant error when mea-suring antenna VSWR or return loss levels. This masking can make an antenna to “appear” to perform more efficiently than is actually the case. The offset error may be corrected with the following equation:RL at Antenna = RL at Transmitter - (2 x CL)RL = Return LossCL = Cable Loss or Match Offset.In the Match Offset dialog, enter the total insertion loss of the cable connected between the power sensor and antenna, in dB. The VPM2 will correct the displayed match values according this equation.
FilterSets the video filtering of a measurement. See “Video Filter -” on page 25. It can be set at:
Full400 kHz4.5 kHz
Duty CycleSets the duty cycling of a measurement. If sensor is capable, the duty cycle will be inferred by the sensor hardware and reported. A user-defined duty cycle can be entered to override the sensor provided value.
Note: If zero is entered, the duty cycle automatically sets to Auto.See “Specifications” on page 39 for more information on how duty cycle is calculated and used for each sensor that has the feature.
Attenuation dB( ) 10 Log10 Attenuation percent( ) 100⁄[ ]×=
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Program Interfaces
Meter RangeToggles the meter range between Auto and Full.Auto - Scales the bar graph or analog meter according to the main measurement type displayed in multiples of 10X for power or 1,2,5X scales for Match.Full - Scales the bar graph or meter to the full measurement range of the sensor.
CCDF Limit
Allows specification of the CCDF limit.
TypeDependant on sensor type.
AmplitudeZero
Performs a zero calibraion on the selected sensor. See “Zeroing a Sen-sor” on page 31.
Note: One or more of the following Amplitude menu keys will be available depending upon the capabilities of the sensor being used:
SmoothingEnables smoothing and sets the number of readings to use for smoothing.
HoldHolds a trace until a Run is selected.
RunStarts a trace for the selected session.
Max HoldHolds and displays the highest trace data points.
UnitsPower
Toggles the power measurement between Watts and Decibels.Match
Allows selection of match measurement units. Note: This is dependant on the sensor attached.
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Limits
By default, limits are turned on & set to lower accuracy limit & maxi-mum power level for a particular sensor. When a limit is exceeded, a ‘virtual LED’ indicator in the upper right side of the display session will blink red. The lower ‘LED’ corresponds to a lower limit & the top ‘LED’ corresponds to an upper limit.To add, change, or disable limits, select ‘Limits’ from the menu.The configuration of a limit can be interpreted by each column.Enabled - Checked to turn onMeasurement - List the type of measurement to monitor. Choices are sensor dependent & will match options found in the Type menu.Limit Type - The state the ‘Measurement’ reading must be. For exam-ple ‘Lower’ means the reading must be below the ‘Value’ to trip.Units - Current unitsValue - The value for the particular limit.Type the unit label of uW, mW, W, kW, or dB after the numerical entry.
Example - The first row, limit would be tripped if the Forward Average power is less than 150 mW, exceeds 150 W, or the peak power exceeds 400W.
Figure 12 VPM, Limit Settings
Add Limit1. Select the Measurement, Limit Type and unit. 2. Enter the limit value in the ‘Value’ column.Figure 13 VPM, Add Limit
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Program Interfaces
Remove Limit1. Select the limt to be removed. 2. Select “Remove Limit”.
Note: To disable a limit, uncheck it in the ‘Enabled’ column.
Figure 14 Power Limit Indicators
Figure 15 Meter Limit Indicators
Figure 16 Chart Limit Indicators
Limit Lines
Limit Lines
Limit Lines
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File
Quick Save DataSee “Quick Save” on page 28.
Label & Save DataSee “Label & Save” on page 28.
Enable Data LoggingStarts monitoring the selected Measurement type. See “Logging” on page 29.
Logging SettingsSee “Logging” on page 29.Log Format - set whether the log file will be in Extensive Markup Language (.xml) or comma-separated (.csv) format.Sample Time - Sets the time interval between readings. Select a number of seconds, minutes, or hours for how long to wait before taking another reading.
Example - Select '5' 'Minutes' to get 1 reading every 5 minutes. Monitor - Sets which measurement type will be monitored and the value to trigger logging.
Note: Enter the type of units after the numerical value entry: uW, W, kW, dBm, or %.
Note: All data provided by the sensor will be stored to the log file, regardless of what Monitor, Measurement type is selected.
Trigger, Result - Logical condition between the Monitored Measure-ment and Value and the result.Logging Enabled,Start Continuous Logging – Continuous logging will start as soon as ‘Enable Data Logging’ is selected from the dialog or File menu.Monitor Below Value, Start Continuous Logging - Continuous logging will start as soon as the Measurement Type reading falls below the ValueMonitor Above Value, Start Continuous Logging - Continuous logging will start as soon as the Measurement Type reading rises above the ValueMonitor Below Value, Log Single Reading - Whenever the Measure-ment Type reading falls below the Value, one reading will be logged. Continuous readings are not taken.Monitor Above Value, Log Single Reading - Whenever the Measure-ment Type reading rises above the Value, one reading will be logged. Continuous readings are not taken.
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Program Interfaces
Figure 17 VPM, Logging Settings
View
Show/Hide ButtonsToggles the display of the buttons on and off.
Show/Hide DetailsToggles the display of the details on and off.
Fullscreen ModeToggles the display to full screen on and off.
Display StyleChanges the display into one of three settings:
Digital DisplayAnalog DisplayChart Display
WindowCascade Sessions
Organizes the sessions in a cascading, offset display.Tile Sessions Horizontally
Organizes the sessions horizontally.Tile Sessions Vertically
Organizes the sessions vertically.
HelpUser Manual
Opens a html version of the user manual.About Virtual Power Meter
Displays version info about the VPM and any attached sensors.About Sensor
Displays model information of the selected sensor.
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Menu Label KeysType
Note: Specific measurement types depend upon the power sen-sor being used. Not all power sensors have the Type selection option.
When the Type menu key is pressed, the soft key functions that select the primary measurement to be made (such as forward average power, reflected average power, match) are enabled. The selected measure-ment will be displayed in large characters above the bar graph. The remaining measurements will display in smaller characters below the bar graph. If one of the measurements is not available or does not apply to the current application, it will be identified as N/A (not applicable).Figure 18 VPM, Type, WPS
Figure 19 VPM, Type, DPS
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Program Interfaces
Forward and Reflected Power
Average power is a measure of the equivalent “heating” power of a sig-nal, as measured with a calorimeter. It measures the total RF power in the system, and does not depend on number of carriers or modula-tion scheme. Average power is the most important measurement of any transmis-sion system since the average power is normally specified on the oper-ating license. It is also valuable as a maintenance tool, showing overall system health, and for calibration.
Match
Match measures the relation between forward and reflected average power. The health of the feedline and antenna systems can be moni-tored using Match, or VSWR, measurement under full power operat-ing conditions. High VSWR is an indicator of feed line damage, overtightened cable or feed line clamps, or antenna changes/damage due to weather conditions, icing, or structural damage to the tower.Rho and Return Loss are also the same measurement, but in different units:
Rho ρ( ) PR PF⁄=
VSWR 1 p+1 p–------------=
ReturnLoss dB( ) 20 plog×=
Rho -
VSWR -
Return Loss (dB) -
Figure 20 Average and Peak Envelope Power, Square Wave Signal
Forward Peak Power
Peak power measurements detect amplitude changes as a signal mod-ulates the carrier envelope. Transmitter overdrive can be detected with peak measurements. Com-mon problems are overshoot at the beginning of burst packets, ampli-tude modulation, and excessive transients. These damage system components with excessive peak power and also cause data degrada-tion, increasing the Bit Error Rate. For TDMA applications, Peak and Burst Power measurements are used to detect overshoot in single timeslots. Other timeslots must be turned off for this test.
Average Power
Peak Envelope Power
0 W
50 W
100 W
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Peak Average Power
This displays the average of the positive and negative peak power readings.
Burst Average Power
Burst width (BW) is the duration of a pulse. Period (P) is the time from the start of one pulse to the start of the next pulse. Duty cycle (D) is the percentage of time that the transmitter is on. To calculate the duty cycle simply divide the burst width by the period (D = BW / P). Low duty cycles mean that the burst width is much less than the period; a large amount of dead time surrounds each burst. For low duty cycles, the burst average power will be much larger than the average power.After peak power is measured, a threshold of ½ the peak is set. The sampled power crosses that threshold at the beginning and end of each burst. The time between crossings is used to calculate the duty cycle. Burst Average Power is calculated by dividing the Average Power by the Duty Cycle.Burst power measurements provide accurate, stable measurements in bursting applications such as TDMA and radar. Accurately measuring the output signal strength is essential for optimizing radar coverage patterns. Actual transmitted power in a single timeslot can be deter-mined in TDMA. The other timeslots must be off during this test.
Figure 21 Burst Average Power
Crest Factor
Crest factor (CF) is the ratio of the peak and average powers, in dB. The WPS calculates the Crest Factor from the Forward Peak and Average Power measurements.
Average Power
Burst Average Power
Peak Envelope Power
0 W
100 W
50 W
Burst Width
Period
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Program Interfaces
Crest factor is becoming one of the most important measurements as communication systems move into the digital age. For CDMA and sim-ilar modulation types the CF may reach 10 dB. If the crest factor is too large, the transmitter will not be able to handle the peak powers and amplitude distortion will occur. Crest factor can also detect overdrive and overshoot problems. Knowing the CF allows end-users to more accurately set base station power and lower operating costs.
Figure 22 Crest Factor, 10 dB CDMA Signal, 100 W Peak, 10 W Ave
Complementary Cumulative Distribution Function (CCDF)CCDF measures the amount of time the power is above a threshold. This threshold is set in the Configure, CCDF Factor menu. Equiva-lently, it is the probability that any single measurement will be above the threshold. The WPS samples the power over a 300 ms window and compares it to a user-specified threshold, in Watts. The time above the threshold relative to the total time is the CCDF.CCDF measurements are most useful for pseudo-random signals, such as WCDMA, where a high CCDF means that the transmitter is being overdriven. CCDF can also detect amplitude distortion within an envelope caused by unwanted modulating signals. In TDMA systems, CCDF indicates the health of power amplifier stages and their ability to sustain rated power over an appropriate timeframe. As a trouble-shooting aid, CCDF allows tracking of trends such as amplifier over-drive (which can cause dropped calls and high bit error rates).Figure 23 CCDF, 100 W Signal, 80 W Threshold, 20% CCDF
Units
When the Units menu key is pressed, the soft key functions that select the units of measure are enabled. For power measurements, Watts or dBm can be selected. For match measurements, VSWR, dB, rho, and percent (%) can be selected.
Average Power
Peak Envelope Power
0 W
100 W
50 W
80 W
0 W
50 W
100 W
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Figure 24 VPM, Units, WPS
Figure 25 VPM, Units, TPS
Figure 26 VPM, Units, DPS
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Program Interfaces
Configure Note: Specific configuration features depend upon the
power sensor being used.When the Configure menu key is pressed, the soft key functions that specify the setup information about the sensor and the measurements are enabled. What type of element in the power sensor, offsets for input and match, duty cycle, and the scale for forward and reflected power is displayed at this time.
Note: For DPS sensors, element scales have pre-defined values and an “Other” category for arbitrary values.
Note: The 5015-EF offset factors are used for frequencies above 4 GHz.
For Wide Band Power Sensors
Video Filter - Except for average power and VSWR measurements, all WPS measurements rely on a variable video filter to improve accu-racy. This filter can be set to either 4.5 kHz, 400 kHz, or full band-width. It should be as narrow as possible while still being larger than the demodulated signal bandwidth (video bandwidth). Narrowing the filter limits the noise contribution caused by interfering signals. Listed below are some common modulation schemes and the appropri-ate video filter.
Figure 27 Video Filter Settings, 300 kHz Signal
1. Press the Input Offset soft key and use the key pad to enter the amount of attenuation then press the Enter key.
2. Press the soft key to select Auto Duty Cycle.3. Press the soft key to select Auto Range.
Video Filter Modulation Type4.5 kHz CW Burst (Burst width > 150 µs), Voice Band AM, FM, Phase
Modulation, Tetra400 kHz CW Burst (b.w. > 3 µs), GSM, 50 kHz AM, DQPSKFull Bandwidth CW Burst (b.w. > 200 ns), CDMA, WCDMA, DQPSK, DAB/DVB-T
FilterToo Small
FilterToo Wide
CorrectFilter
Noise
Signal
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Figure 28 VPM, Configure, WPS
For Sensor 5015 and 5015-EF
1. Press the Power: Watts soft key.2. Press the Input Offset soft key and use the key pad to enter the
amount of attenuation then press the Enter key.Figure 29 VPM, Configure, TPS
For Sensor 501443 Peak - Refer to the 5014 owner’s manual.DPM - Refer to the 5014 owner’s manual.1. Press the soft key to select the type of element.2. Press the Forward Scale to enter the watt rating of the forward element.3. Press the F/R Scale 10:1 Ratio soft key to select ON.4. Press the Input Offset soft key and use the key pad to enter the
amount of attenuation then press the Enter key.
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Program Interfaces
Figure 30 VPM, Configure, DPS
AmplitudeWhen the Configure menu key is pressed, the settings for controlling the smoothing effect and holding of a specified reading are displayed.It also allows for Zero calibrating a sensor. See “Zeroing a Sensor” on page 31.Figure 31 VPM, Amplitude
File
Quick Save and Label & Save captures the most recent measurement readings. It will not store the time-chart information. To store time chart display, ensure logging is enabled. See “Logging” on page 29.
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Quick Save
Press this soft key to create a snapshot of the readings displayed on the screen. That snapshot is saved in the log file folder “Setup” in the Preferences under the File menu item. Each quick save is stored in a separate file that is named using the date-time file naming format:
Label & Save
Same as Quick Save, only the program will request a title to save the trace under.Figure 32 VPM, File
MMMM_NNNNNNNN_YYYYMMDD_HHMMSS.xml
ModelSerial Number
Year
MonthDay Hour
MinuteSeconds
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Program Interfaces
LoggingMeasurement logging is a powerful tool for monitoring and tracking sys-tem performance. Storing the readings enables the ability to graph the output over time, know the exact time of a failure, or compare systems.The VPM2 can be set up to take many readings over a short test period, to take a few readings a day for long-term monitoring, to log only while the transmitter is on, or to log when power spikes or drops below a critical value, depending on specific needs. To begin logging:1. Configure the logging options.2. Begin logging by selecting Enable Logging, under the File tab.
Note: When logging is active, in the upper right of the sen-sor session will display “Logging On.”
3. Stop logging by selecting Enable Logging, under the File tab.After logging is complete, the data can be reviewed in the a VPM2 log-file recall/review session or imported into Microsoft Excel or another spreadsheet program for analysis.
Note: Log files are stored in the default log file directory under ‘Sessions, Preferences’
Analyzing Logged DataThe simplest way to view logged data is to recall in VPM2. See “Chart Display” on page 9.
Note: Only log files saved as .xml can be opened and viewed in the VPM2. Files saved in comma-separated format (CSV) can be read by most common spreadsheet programs.
Since logged data is stored in a text file in an .xml or comma-separated text file where each line is one data record. Fields are separated by com-mas format, it is also readable by most spreadsheet programs. Each log file is stored in a separate file that is named using the same date-time file naming format as for quick-save.
Opening .xml Files in Excel
1. Open the file in Microsoft Excel. Note: The file will appear in Microsoft Excel with each
field in its own column. 2. Filter the data, since the Extensive Markup Language format is a
hierarchical format.a. In the Measurement column, select the drop-down and
check only the Forward Average labelb. In the Limit Type column, select the drop-down and check
only the Lower label
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Note: This will now show data in a time vs. power format. Additional filtering and sorting can be applied using the options in the column headers.
Opening .csv Files in Excel1. Open the file in Microsoft Excel.
Note: The file will appear in Microsoft Excel with each field in its own column. If all the data is in a single column, follow these steps to convert it:
a. Click on the column name, to select the entire column.b. Select Text To Columns, under the Data tab.
Note: A conversion wizard should open.c. Select Delimited, under Original Data Type. d. Click Next.e. Check Comma, under Delimiters.
Note: All other delimiters should be unchecked. Treat Consecutive Delimiters as One should be unchecked.
f. Click Next.g. Click Finish.
2. Create a graph of the forward and reflected average power as a function of time:
a. Select row 1 by clicking on the row name.b. Select Delete, under the Edit tab.
Note: The first line of header information will be deleted.c. Click on cell B1.d. While holding down the Ctrl key, select columns B (Time),
H (Avg Fwd W), and J (Avg Rfl W).e. Select Chart, under the Insert tab.
Note: The chart wizard should open.f. Select XY (Scatter). g. Select the Line subtype. h. Click Next.i. Click Next in the data range, which should already be set.j. Enter a title and names for the X and Y axes. k. Click Finish.
Note: Other data can be graphed by selecting the appropri-ate columns in step d.
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Program Interfaces
Zeroing a Sensor1. Check that no RF is in the system.
Note: The sensor will read “~0.”2. Do one of the following:
Press the Amplitude menu button.Go to the Amplitude menu item.
3. Press the Zero menu key. Note: Calibration will take about 40 seconds. Do not inter-
rupt the calibration. A progress bar for the calibration will be displayed on the screen.
Note: Some soft key features will not be available for cer-tain power sensors.
4. Press “Run” to resume data collection with the new Zero offset.Figure 33 Zeroing Sensor
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Chapter 3 Power Sensors
AccuracyThe Bird power sensors are highly accurate. Accuracy is specified for each sensor type is typically given as a percent of reading or of full-scale.
Example - If a sensor has a specified accuracy of 5% of read-ing + 1.0 uW, then for a 10 mW signal the uncertainty is ± 0.501 mW. For a 1 mW signal the measurement uncertainty is ± 0.051 mW.
Sensor UncertaintyWhile this value is a good estimate, the sensor is actually more accu-rate. The sensor’s accuracy also depends on the temperature, and the power and frequency of the source; Table 1 lists some examples of uncertainty factors. If an uncertainty is given as a power, divide this value by the measured RF power and convert to a percentage. For example, an uncertainty of ± 0.25 µW with a RF power of 10 µW is a 2.5% uncertainty. Table 2 lists external factors, such as using attenu-ators or using a cable to connect a sensor to the transmitter, which could affect the measurement uncertainty.Table 1 - Example Uncertainty Factors
Table 2 - External Factors
Error Source Conditions UncertaintyCalibration Uncertainty ± 1.13%Frequency Response 40 MHz to 4 GHz ± 3.42%Temperature Linearity –10 to +50 °C ± 3.43%Other*
*. Above 40 °C, when making measurements at frequencies between 40 and 100 MHz, add 1.1%.
< 40 °C or > 100 MHz ± 0.50%Resolution ± ½ smallest displayed digit
(e.g. for a mW scale, three decimal places are displayed. ½ the smallest is 0.5 µW)
Zero Set† ± 0.125 µWNoise†
†. After a 5 minute warm-up, measured over a 5 minute interval and 2 standard deviations
above 1.05 mW ± 0.7 µW105 µW to 1.05 mW ± 0.4 µWbelow 105 µW ± 0.2 µW
Error Source ConditionsAttenuator Uncertainty Frequency dependentCable Uncertainty Frequency and length dependent (± 5% at
1 GHz for a ‘reasonable’ 1.5 m cable)
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The root sum square (RSS) uncertainty is the industry standard method for combining independent uncertainties. To determine the TPS's RSS uncertainty:1. Square each uncertainty factor.2. Add these values together.3. Take the square root of this sum.Table 3 has two examples of uncertainty calculations. The first is a 10 mW signal at room temperature. The second is a 10 µW, 40 MHz sig-nal at 50°C. Since this measurement is at both low frequency and high temperature, the uncertainty will be increased. Note that the RSS uncertainties are smaller than the values from the rough estimate. This will always be the case.Table 3 - Uncertainty Examples
Mismatch UncertaintyAnother factor of measurement accuracy is mismatch uncertainty. When a source and a load have different impedances, some signal will be reflected back to the source. This uncertainty depends on both the VSWR of the TPS and the VSWR of the rest of the system. For a system VSWR of 1.0, the mismatch uncertainty would be 0. For a VSWR of 5.0, the mismatch uncertainty would be 12.5%. Given the VSWR of the TPS and the source, the mismatch uncertainty can be calculated as follows.Mismatch uncertainty (MU) is related to the reflection coefficient (ρ) by the formula:
Note: where ρs = reflection coefficient of the source, and ρl = reflection coefficient of the load (the TPS)
Example 1(10 mW, Room Temp)
Example 2(10 µW, 40 MHz, 50°C)
Error Source
Percent Uncert.
RSS Term
Percent Uncert.
RSS Term
Cal. Uncert. 1.13 % 1.28 1.13 % 1.28Freq. Resp. 3.42 % 11.70 3.42 % 11.70Temp. Lin. 3.43 % 11.76 3.43 % 11.76Other 0.5 % 0.25 1.6 % 2.56Res. 0.005 % 0.00 0.5 % 0.25Zero Set 0.00125 % 0.00 1.25 % 1.56Noise 0.007 % 0.00 2 % 4.00Sum Uncert. 24.99 33.11RSS Uncert. 5.00 % 5.75 %Quick Uncert. 5.01 % 16 %
MU percent( ) 1 ρsρ1+( )2 1–[ ] 100×=
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The reflection coefficients can be calculated from the VSWR by the formula:
Example - If a source with a 1.50:1 VSWR with the Terminat-ing Power Sensor was used, which has a max VSWR of 1.20:1, the mismatch uncertainty would be calculated as follows:
ρs 1.50 1–( ) 1.50 1+( )⁄ 0.200= =
ρ1 1.20 1–( ) 1.20 1+( )⁄ 0.091= =
MU 1 0.200 0.091×+( )2 1–[ ] 100 3.67±=×=
If a source with a 1.30:1 VSWR was used instead, the mis-match uncertainty would be:
Using a lower VSWR source can drastically reduce the mismatch uncertainty. Keep in mind that the typical VSWR of the Model 5011 is 1.03:1, which gives a much lower mismatch uncertainty.
Example - With the 1.50:1 source, the mismatch uncertainty would be:
ρs 1.50 1–( ) 1.50 1+( )⁄ 0.200= =ρ1 1.03 1–( ) 1.03 1+( )⁄ 0.015= =
MU 1 0.200 0.015×+( )2 1–[ ] 100 0.59±=×=
To determine the total uncertainty of the measurement, combine the RSS uncertainty with the mismatch uncertainty using the RSS method. Square the RSS uncertainty, add it to the square of the mis-match uncertainty, and take the square root.Using Example 1 in Table 3 with a source VSWR of 1.50 and a TPS VSWR of 1.20, the total uncertainty would be:
For example 2, the total uncertainty would be 6.82 %.
ρ VSWR 1–( ) VSWR 1+( )⁄=
ρs 1.30 1–( ) 1.30 1+( )⁄ 0.130= =
ρ1 1.20 1–( ) 1.20 1+( )⁄ 0.091= =
MU 1 0.130 0.091×+( )2 1–[ ] 100 2.39±=×=
5.002 3.672+ 6.20 percent( )=
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Directional Power Sensor (DPS) Measurements
Description
The DPS series sensors utilize elements in order to make power mea-surements. Each element has an arrow on it that represents the direc-tion in which it measures power. The elements ignore power in the opposite direction with a directivity of at least 25 dB. The DPS series can make power measurements using either 43 type or APM/DPM ele-ments, and the readings available vary, based on which elements are being used.
Since the DPS uses two elements, it can measure the quality of the system by comparing the forward and the reflected power. This is usu-ally presented in the form of VSWR (voltage standing wave ratio) or Return Loss.
43 Type Elements
The 43 type elements are normally used to measure peak power. These elements can measure the peak power of a system with an accu-racy of +/-8% of full scale as long as the signal meets the following requirements:
At least 15 pps (pulses per second)Minimum pulse width of 15 µs (800 ns if frequency is greater than 100 MHz)Minimum Duty Cycle of 0.01%
In addition, 43 type elements can be used to measure average power in signals with a peak-to-average ratio close to 1, like a CW or FM sig-nals. In these cases, the average power is measured with an accuracy of +/- 5% of full scale.
APM/DPM Elements
The APM/DPM elements are used to measure true average power. True average power means the sensor provides equivalent heating power of the signal, regardless of modulation or number of carriers. These elements can measure average power with an accuracy of +/-5% of reading from full scale down to 2.5% of full scale.
Note: The equivalent heating power is dependent on the duty cycle of a signal. If a system puts out 50 watts with a 50% duty cycle, the APM/DPM elements will measure 25 watts.
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Power Sensors
Terminating Power Sensor (TPS)Description
The Bird Terminating Power Sensor (TPS) and 5015-EF extended fre-quency TPS are a diode-based power sensors that measures true aver-age power. For best results, wait 5 minutes after applying power to the sensor before taking readings.Zeroing SensorOver time, the sensor’s “zero value” (reading with no applied RF power) can drift, making all readings inaccurate by this value. For example, if the zero value is –0.02 W, measuring a 50 W signal will give a reading of 49.98 W, a 0.04% error. Measuring a 1 W signal will give a reading of 0.98 W, a 2% error. If the drift would be a significant error, rezero the sensor:1. Ensure the sensor has reached a stable operating temperature.2. Ensure no RF power is applied to the sensor.3. Press “Zero” to begin Calibration.
Note: Calibration will take about 40 seconds. Do not inter-rupt the calibration! A bar on the screen will display calibra-tion progress.
Correction Factors
The Bird TPS-EF uses frequency-dependent correction factors to improve its accuracy. To use the correction factors:1. Look at the Correction Factor Table on the side of the TPS and find
the correction factor corresponding to the frequency under test.2. Add the correction factor to all other necessary offsets (for exam-
ple, the coupling factor of a directional coupler).3. Enter the total offset into the power meter. 4. Input the Offset on the VPM2. See “Input Offset” on page 14.
Note: Correction factors are only required above 4 GHz. Below 4 GHz, the TPS-EF can be used as a normal TPS. See “Terminating Power Sensor (TPS)” on page 37.
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Wideband Power Sensor Measurements Note: WPS Firmware V1.45 or latter is required to operate
on the VPM2.
Description
The Bird Wideband Power Sensor (WPS) is a Thruline sensor that can measure average, peak, or burst power, VSWR, crest factor, and Com-plementary Cumulative Distribution Function (CCDF).
Note: Firmware upgrades extending the WPS’s capabili-ties may be periodically released. For the latest firmware upgrade, contact Bird Customer Service at (866) 695-4569 or visit the Bird website at http://www.bird-technologies.com (Mousing over http://www.bird-technologies.com shows a link to http://bird-electronic.com).
Zeroing Sensor
Over time, the sensor’s “zero value” (reading with no applied RF power) can drift, making all readings inaccurate by this value. For example, if the zero value is –0.02 W, measuring a 50 W signal will give a reading of 49.98 W, a 0.04% error. Measuring a 1 W signal will give a reading of 0.98 W, a 2% error. If the drift would be a significant error, rezero the sensor:1. Ensure the sensor has reached a stable operating temperature.2. Ensure no RF power is applied to the sensor.
Press “Zero” to begin Calibration. See “Zeroing a Sensor” on page 31.
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Chapter 4 Specifications
Minimum PC Requirements
* - These values represent the maximum disk space required to install the VPM2. Memory requirements for .NET prerequisites will vary depending on components that are pre-viously installed
Example - On XP if .NET 2.0 & 3.0 were previously installed, then the requirement is only an additional 48MB plus the 6MB for the VPM2).
Operating System Microsoft Windows 2000 with service pack 4Microsoft Windows XP and XP Professional with service pack 2 Microsoft Windows Vista with service pack 1Microsoft Internet ExplorerAdobe Acrobat reader
Processor 256 MB RAM & Pentium III or equivalent processor (512 MB & Pentium 4/M or higher recommended)
Display 800x600, 256 color display (1280x720, 16 bit or higher resolution recommended)
Memory*Windows 2000Windows XPWindows Vista
.Net prerequsites90 MB506 MB 40.8 MB
VPM24.2 MB6 MB6 MB
TOTAL94.2 MB512 MB46.8 MB
Connections 1 available USB port
Drives Hard drive, CD-ROM (for installation)
Accessories Mouse or other pointing device
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Limited Warranty
All products manufactured by Seller are warranted to be free from defects in material and workmanship for a period of one year, unless otherwise specified, from date of shipment and to conform to applica-ble specifications, drawings, blueprints and/or samples. Seller’s sole obligation under these warranties shall be to issue credit, repair or replace any item or part thereof which is proved to be other than as warranted; no allowance shall be made for any labor charges of Buyer for replacement of parts, adjustment or repairs, or any other work, unless such charges are authorized in advance by Seller.If Seller’s products are claimed to be defective in material or work-manship or not to conform to specifications, drawings, blueprints and/or samples, Seller shall, upon prompt notice thereof, either examine the products where they are located or issue shipping instructions for return to Seller (transportation-charges prepaid by Buyer). In the event any of our products are proved to be other than as warranted, transportation costs (cheapest way) to and from Seller’s plant, will be borne by Seller and reimbursement or credit will be made for amounts so expended by Buyer. Every such claim for breach of these warranties shall be deemed to be waived by Buyer unless made in writing within ten days from the date of discovery of the defect.The above warranties shall not extend to any products or parts thereof which have been subjected to any misuse or neglect, damaged by acci-dent, rendered defective by reason of improper installation or by the performance of repairs or alterations outside of our plant, and shall not apply to any goods or parts thereof furnished by Buyer or acquired from others at Buyer’s request and/or to Buyer’s specifications. Rou-tine (regularly required) calibration is not covered under this limited warranty. In addition, Seller’s warranties do not extend to the failure of tubes, transistors, fuses and batteries, or to other equipment and parts manufactured by others except to the extent of the original man-ufacturer’s warranty to Seller.The obligations under the foregoing warranties are limited to the precise terms thereof. These warranties provide exclusive remedies, expressly in lieu of all other remedies including claims for special or consequential damages. SELLER NEITHER MAKES NOR ASSUMES ANY OTHER WARRANTY WHATSOEVER, WHETHER EXPRESS, STATUTORY, OR IMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS, AND NO PERSON IS AUTHORIZED TO ASSUME FOR SELLER ANY OBLIGATION OR LIABILITY NOT STRICTLY IN ACCORDANCE WITH THE FOREGOING.
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