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Frequency Coverage and RFI Observations at Effelsberg K. Grypstra, R. Keller, Max-Planck-Institut für Radioastronomie, Bonn, Germany

Frequency Coverage and RFI Observations at Effelsberg

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Frequency Coverage and RFI Observations at Effelsberg. K. Grypstra, R. Keller, Max-Planck-Institut für Radioastronomie, Bonn, Germany. Overview. Frequency coverage and protected bands RFI at low frequencies Observations in an RFI polluted environment. Frequency coverage. Frequency coverage. - PowerPoint PPT Presentation

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Page 1: Frequency Coverage and RFI Observations at Effelsberg

Frequency Coverage and RFI Observations at Effelsberg

K. Grypstra, R. Keller, Max-Planck-Institut für Radioastronomie, Bonn, Germany

Page 2: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

2

Overview

• Frequency coverage and protected bands

• RFI at low frequencies• Observations in an RFI polluted

environment

Page 3: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

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Frequency coverage

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Protected Bands

Page 4: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

4

Frequency coverage

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zReceivers at Effelsberg

Page 5: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

5

Frequency coverage

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E-VLA RX

Page 6: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

6

RFI at 18cm

• RFI Signal

• Spectral Lines(same scale)

Page 7: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

7

RFI examples: TV

• Analogue– High level

carriers– Low spectral

density in between

• Digital– No carriers– High

spectral density

– Lower power level

Page 8: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

8

RFI by Radar Signals

• Radar Spectrum at Effelsberg

• 1.0 – 1.2 GHz • Setup:

Log Periodic+ 120K LNA+ Spectrum Analyzer

Page 9: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

9

RFI at 21cm

Setup:• 100m RT• 15K RX• 9x20MHz

Source:• PCs?• Media

Converters?• WebCam?• Radar?• ?

Page 10: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

10

RFI at 18cm

Setup:• 100m RT• 20K RX

Source:• PCs?• Media

Converters?• WebCam?

Page 11: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

11

RFI at 18cm

BackendArtefacts

Setup:• 100m RT• 20K RX• FFT-Spectr.

Page 12: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

12

Airplane Radar Altimeter

• Airplanes over Effelsberg

• 4.2-4.4GHz• 2hrs• Aaronia

Spectrum Analyzer(2k€)

Page 13: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

13

RFI examples: UMTS

• UMTS• On the field• Setup:

– LogPer– 200K LNA– R&S FSH6

Page 14: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

14

RFI examples: Wireless

• WLAN 2.4GHz• Spectrum

50MHz

• Setup:– LogPer– 200K LNA– R&S FSH6

Page 15: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

15

RFI examples: Wireless

• WLAN 5.28GHz

SAPOS-GSM

WLAN

Page 16: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

16

RFI examples: Wireless

• WLAN 5.28GHz• Time Series• OFDMA

Orthogonal Frequency Division Multiple Access

• Setup:– LogPer– 200K LNA– R&S FSH6

Page 17: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

17

RFI: Electric Fences

• Distances0,5-1km

Page 18: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

18

RFI: Electric Fences

• ‚Pulsar‘1.382sec

• Setup:– 100m RT– 20K L-Band RX– FFT Anal.

Page 19: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

19

Ultra Wide Band

• UWB Generator

• @ 0-5GHz• Spurious up to

18GHz

Page 20: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

20

RFI and Measurements

• GSM900• Setup:

– LogPer.– 120K LNA– 30dB

Gain– R&S FSH6

Page 21: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

21

RFI and Measurements

• GSM900• Setup:

– LogPer.– 200K LNA– 12dB

Gain– R&S FSH6

Page 22: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

22

RFI and Measurements

• GSM900• Setup:

– LogPer.– 200K LNA– 12dB

Gain– R&S FSH6– Pointed

to zenith

Page 23: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

23

Observations through RFI

• 3C28618.6Jy

• @21cm

Page 24: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

24

Usable Frequencies

• 50cm: 608-614MHz protected; TV band IV narrow BW

• 21cm: 1.4-1.427GHz protected, outside critical

• 13cm (S): 2.2-2.29GHz prot. (no observation / experience)

• 11cm: 2.69-2.7GHz protected, surrounded by radar

• 9cm: 3.26-3.267GHz & 3.332-3.339GHz narrow BW

– 4-4.2GHz Airplane Radar Altimeter

• 6cm: 4.8-5GHz prot.; free in wide bands

– 5.1-5.5GHz earth bound radar, WLAN

Page 25: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

25

Usable Frequencies

• 5cm: 5.7-6.7GHz nothing prot.; free in wide bands

• 3.6cm (X): 8.215-8.4GHz prot.; >9GHz classical radar

• 2.8cm: 10.6-10.7GHz; not usable in practice → TV-sat

• 1.9cm: 14.47-14.5 & 15.35-15.4GHz prot.; radar @ 16.7

• 1.3cm: 22.01-24GHz prot. with gaps; ptp comm. @ 24

• Above: more or less free (cloudsat @ 86)

Page 26: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

26

Usable Frequencies

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Don't use!

Page 27: Frequency Coverage and RFI Observations at Effelsberg

Wettzell;March 18-20, 2009

Frequency Coverage and RFI in EffelsbergK. Grypstra, R. Keller, MPIfR

27

Don‘t suppress!

Setup:

• 100m RT, 15K RX, 20MHz BW, 1420MHz CF.