Broadband FFT Spectrometer Broadband FFT Spectrometer

ARGOSARGOSFirst results

ETHZInstitute of Astronomy Christian MonsteinScheuchzerstrasse 7CH-8092 Zürichmonstein@astro.phys.ethz.ch ARGOS-GG.ppt, 14.04.2005

ContentContent

• Specifications, block diagrams• FPGA, VHDL, resource table• Schedule, cost, additional information• KOSMA block diagram, measurement methods • Gornergrat impressions• Measurements in the laboratory• Spectrum results• Software, GUI• RF-overview Gornergrat 3100m, Bleien 420m and Diavolezza 3000m

• Conclusions

FPGA = Field Programmable Gata ArrayVHDL = Very High Speed Integrated Circuit Description LanguageKOSMA = Kölner Observatorium für SubMillimeter AstronomieGUI = Graphical User InterfaceRF = Radio Frequency

SpecificationsSpecificationsParameter Value Comment

2 x AD-conversion 2 x 1GS/sec Interlaced 500ps → 2GS/s

Rate : programmable

Input resolution 8 bit voltage → 48.1 dB power

Max number of channels 16’384 fixed

Channel spacing 61.035KHz At full sampling rate

Conversion time 16.384µsec → 1 single integration step

Internal data width 18 bit Twiddle factors etc.

Minimum accumulation time

Maximum accumulation time

1ms (64 integrations)

70’000 sec (≈ 1 day)

At PC duty cycle ≈ 50%

Windowing Programmable filter Kaiser, Hanning, etc.

Output data PCI interface 32bit x 33 MHz Internally 36bit

PCI = Peripheral Component Interconnect (local bus standard)AD = Analog Digital Converter

Block diagram AC240Block diagram AC240

Digital processing UnitFPGA

Xilinx Virtex-2 pro XC2VP70

Preamp1GHz

Trigger

CrossPoint

Switch

ADC 11Gs/s8 bit

ADC 21Gs/s8 bit

Demux 18 bits x 16

Demux 28 bits x 16

TimeBase

Preamp1GHz

ControllerPCI

Interface

PCIBus

Opt.DRAM

Opt.SRAM

Additional digital l/Ofrom/to telescopeAnalog output

Ch1

Ch2

Exttrigger

Extclock

2 x

128

bits

Δt=0.5nsec

PCB AC240 with FPGAPCB AC240 with FPGA

Block diagram AC240Block diagram AC240

16 k FFTPipeline

complex inputcomplex output

PostProcessing

UnitΣ

j

2 Gs/sreal

even

odd

2 x 1 Gs/sreal

1 Gs/scomplex 1 Gs/s

complex

1 Gs/scomplex

Redundantdata

32K FFT with 2Gs/sec throughput32K FFT with 2Gs/sec throughput

125MHz 125MHz

Overview of AC240 FDK coreOverview of AC240 FDK core

D D R C o ntro ller A

WR Buffe r RD Buffe r

DDR SDRAMExte nsio n (512M B)

D ua l Po rt In terfa ce

Dua l Po rt SRAMExte nsio n

Lo c a lBus

M AC 100 M AC 100

Use r-De fine d Pro c e ssing Blo c k

I/O Exte nsio n

Da ta Link

Da ta Link

Trig g e r

D D R C o ntro ller B

WR Buffe r RD Buffe r

DDR SDRAMExte nsio n (512M B)

VHDL design with MENTOR toolVHDL design with MENTOR tool

Design Entry : HDL Desinger 2004.1aSimulation    : ModelSim 5.8cSynthese     : Precision RTL 2004.a1Place & Route: Xilinx ISE 6.2i

Utilization FPGA resourcesUtilization FPGA resources

• No use of internal Power-PC (gray area) foreseen• Purple = input structure and programmable window• Yellow = pipeline #1, green = pipeline #2• Violet = output structure • horizontal structure = Block-RAM and multipliers

Xilinx FPGA Virtex II XC2VP70-6 Xilinx FPGA Virtex II XC2VP70-6 resourcesresources

– Slices 29‘24788.4%– Flip Flops 38‘27257.2%– Block-RAM 300 91.5%– Multiplier 192 58.5%– fmax 138 MHz (required: 125 MHz)

ScheduleSchedule

Planned In fact

1. Start of KTI-project: 2003-11-01 2004-11-

01

2. Decision system architecture: 2004-03-18 2004-03-18

3. Preliminary tests of 1st implementation: 2004-08-30 2004-09-30

4. System ready for Radio Astronomy: 2004-12-20 2005-03-18

5. Scientific analysis, fist results: 2005-03-07 2005-04-05

6. End of project, closing report to KTI: 2005-04-02 2005-05-31

CostsCosts

Acqiris sampler 2Gs/s AC240 20’000 EuroOption FFT (Bitfile) 4’000 EuroPCI-interface IC414 1’400 EuroBlanking panel XB200 100

Euro3-slot crate CC103 2’500 EuroDriver (Win/Linux) free of charge 0

EuroStandard-PC with one free PCI-slot 2’000

Euro

FFT – spectrometer 30’000 Euro

Some statistics to remember….:

1,8 Euro per FFT-channel or33KHz bandwidth for every single Euro

Actual prices to be negotiated with Acqiris!

Additional informationAdditional information

Additional information: http://www.astro.phys.ethz.ch/instrument/argos/argos_nf.htmlhttp://www.acqiris.com

Project management & tests: ETH Zurich:- Prof. A. O. Benz- Chr. Monstein

- Hansueli Meyer

Algorithms: FHS (Fachhochschule Solothurn):- Bruno Stuber

VHDL design: ZMA (Zentrum für Mikroelektronik Aargau):- Prof. K. Schenk

- D. Zardet

Industry: Acqiris company Geneva:- Dr. V. Hungerbühler et. al.

Block diagram KOSMABlock diagram KOSMA

Receivers200…900GHz

Local oscillatorunit

Positioningunit

IFunit

AOS LRS1000MHz/1450

AOS MRS300MHz/1800

AOS HRS59MHz/2048

ETH-FFT1GHz/16384

PC Win XPArgos,FTP, VNC

KOSMADSP

KOSMAcontrol

Laptop LINUXIDL

PC Win XPOffice, VNC Printers

ToInternet

Intranet

DigitalI/O -Data ready

-Wobbler controlIF = 350MHz±150MHz

KOSMA measurement methodsKOSMA measurement methodsMeasurement

Mode

Mirrors involved Local

oscillatorSecondary Tertiary

Continuous recording fixed fixed const

Beam switched (wobbler) √ fixed const

Beam switched (telescope) fixed fixed const

Dual beam switched

(reference = sky)

√ fixed const

Dual beam switched

(reference = hot load)

√ √ const

Frequency switching fixed fixed √

KOSMA 3m-parabolaKOSMA 3m-parabola

KOSMA Control roomKOSMA Control room

Ilona Miller

KOSMA clock generationKOSMA clock generation

ARGOS, IF-units & AOSARGOS, IF-units & AOS

Allan time hot noise sourceAllan time hot noise source

Data: 3.6 GByte in total,(extraction of Saturday, 02.04.2005.Used for analysis 08:15 - 21:00)FPGA: 52.8°C ±0.2KPlace : Library SECRange: 50mVpp[sec]

Channel test 10MHz combChannel test 10MHz comb

Receiver temperature 230GHzReceiver temperature 230GHz

Birdies < 200MHz and > 500MHz are out of KOSMA-IF (red shaded area)!

DR21K DR21K 1212CO 2CO 2→→11

Some single spectra 15sec each↑ = source - reference↓ = reference - source

DR21K DR21K 1212CO 2CO 2→→11

230.537994GHz Ti = 179secBW = 47KHz

Ti = 90secBW = 61KHz

DR21K DR21K 1212CO 3CO 3→→22

Channel width 60KHzTi = 200sec

Channel width 560KHzTi = 400sec

ORION A ORION A 1212CO 2CO 2→→11

Channel width 240KHzTi = 10sec

Channel width 560KHzTi = 20sec

AFGL 2591 AFGL 2591 1212CO 3CO 3→2→2

Channel width 240KHzTi = 160sec

Channel width 560KHzTi = 320sec

IRC 10216 IRC 10216 1212CO 2CO 2→→1 Observation 3h1 Observation 3h

SNR with BW=240KHz, Ti=3420sec Ta with BW=560KHz, Ti=5700sec

Sun in absorption Sun in absorption 1212CO 3CO 3→→22

1212CO 2CO 2→→1 Line1 Line

Dual beam switched modeDual beam switched mode

Tamax ≈ 1Kelvin

Frequency switching Frequency switching 1212CO 2CO 2→→11

Fo = 230’537.994MHz ± 10.5MHz

Ozone in the atmosphereOzone in the atmosphere

AOS saturated

ARGOS-GUI Windows XPARGOS-GUI Windows XP

ARGOS on-line graphicsARGOS on-line graphics

Sky noise Zero noise

Comb noise

The ADC-range has to be adjusted suchthat peak amplitudes don’t strike maximumvalues but, the ADC should be set to maximum gain while observing a hot load.

Base band overviews DC-1GHzBase band overviews DC-1GHz

Time- & frequency domain Time- & frequency domain Gornergrat 3100m aslGornergrat 3100m asl

10sec base band dc-1GHz 30sec IF (230GHz - RX)

Time- & frequency domain duringTime- & frequency domain duringVP Diavolezza 3000m aslVP Diavolezza 3000m asl

Radar pulse 1028...1030MHzusing an L-band down converter

Echo of ionosphere sonder 16…30Mhzwhile doing Jupiter/Io observations.

ConclusionsConclusionsParameter FFT using AC240 AOS

Dynamic range ~ 48dB ~ 24dB

Number of channels 2^14 = 16’384 1’000 … 2’048

Observation bandwidth 1GHz 50MHz …. 1GHz

Channel bandwidth 61KHz 50KHz … 1MHz

Allan time >2’000sec (±0.2°C) 50 …200sec

Output digits 36 bit 12 bit

Integration on board 16.384µsec … ~ 1day 10ms … 100ms

Frequency stability Very good Regular calibration necessary

Lifetime Very high High

Shock resistance Very high, no optics Low

Electrical power & cooling 100 Watt comparable

Weight 7.8kg comparable

Price ~ 28’000Euro >30’000Euro