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DSA Receiver [email protected] , Dec 31, 2016
1. Title, Contents2. DSA Receiver Block Diagram 3. DSA Receiver
Linearity Measurements4. Output Spectrum of Complete Receiver in
Caltech Lab, Moore 3505. Output Spectra for System on Caltech Roof,
Dec 30, 20166. Feed Photograph and Pattern Measurement7. Feed S
Parameters8. Feed Dimensions9. Feed Assembly10. LNA Data Sheet and
Photograph11. S Parameters and Noise of LNA‘s SN01 and SN02, Oct
26, 201612. LNA Interior Views and Schematic13. Temperature
Coefficients of LNA Gain, Phase, and Noise14. Front-End Box, FEB,
Interior View15. Lab Tests of FEB Module16. FEB Schematic17. FEB
Parts List18. Back-End-Box, BEB, Dual Polarization Receiver
Module19. BEB1A and BEB1B Output Spectra When Driven by FEB1A and
LNA20. BEB Schematic, Dec 23, 201621. BEB Parts List22. BEB Printed
Circuit Board
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mailto:[email protected]
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DSA Receiver Block Diagram The DSA receiver consists of 4
assemblies – Feed, LNA, Front-End Box, FEB, (2),
and Back-End Box, BEB.
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CW Pin at 1405MHz connected to FEB driving BEB with measurement
of output with E4418/E4413 broadband and at monitor port with Field
Fox at 375 MHzE4418 Field Fox Gain
Pin Pout 1MHz RBW B-A C-A-60 -12.63 -36.88 47.37 23.12-55 -7.62
-31.9 47.38 23.10-50 -2.75 -26.9 47.25 23.10-45 2.29 -21.99 47.29
23.01-42 5.19 -19.12 47.19 22.88-40 7.02 -17.29 47.02 22.71-35
10.86 -13.52 45.86 21.48-30 12.58 -11.84 42.58 18.16-27 13.04
-11.39 40.04 15.61
P1dB out is +8dBmNoise output with 32 dB LNA and 300K
termination is -8.3dBmNoise output with 30 dB LNA, 2 dB cable loss
and 60K Tsys will be -19 dBmY factor measurement of Trcvr with
HP346A, ENR=5.18dB, Tex=956K, Thot=1259KNS off -8.34 YdB Y TnNS on
-2.13 6.21 4.178 -2.2K ENR would need to be 5.7dB to give 40KZero
-41.8Using the Field Fox SA for power measurement at 375 MHz, 1 MHz
bandwidth NS off -32.4 6.11 4.083 7.0K Unrealistic Tn
measurementsNS on -26.29 LNA Tn measured at 32K on N8975AZero
-80.6
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
-60 -55 -50 -45 -40 -35 -30 -25 -20
Po
ut,
dB
m
Pin, dBm, 1405 MHz CW
Pout vs Pin for FEB1B+BEB1BShows output 1dB compression at +8
dBm
Broadband Power Meter SA 375 MHz on -24 dB Monitor Port
DSA Receiver Linearity MeasurementsAlso unrealistic and
unexplained Y factor results, Dec 29, 2016
Table is Pout vs Pin for FEB-BEB CascadeMain results are 47 dB
gain and P1dB output of +8 dBm
LNA adds another 30dB gain to give 75 dB including 2 dB for
antenna cable losses, This gives an output noise power of -15 dBm
in 250 MHz for 300K input.
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Output Spectrum of Complete Receiver in Caltech Lab, Moore
350
Bottom trace is with 300K termination of LNA input, Top trace is
with 956K injected from a noise source. Noisy, blue trace is with
the feed connected
and picking up RFI in the room
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Output Spectra for System on Caltech Roof, Dec 30, 2016Black
trace is for 50 ohm, 300K termination and blue trace is for feed
pointed at
zenith. Optical attenuator, 3dB, between FEB and BEB.Local
oscillator was Anritsu synthesizer, -15 dBm at 1030 MHz
Port1, FEB1A, BEB1A, Yfactor at 1405 MHz is 5.7dB which gives
Tsys=91K
Total power at 300K was -11dBm
Port2, FEB1B, BEB1B, Yfactor at 1405 MHz is 8.dB which gives
Tsys=52K
Total power at 300K was -15dBm
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Round Feed Pattern Tests at Caltech Roof, Dec 23, 2016
Feed Port
Setup Oriention
Feed Plane
Freq GHz
S21 on Axis
S21 at 64 deg
64 deg Taper
S21 HV
Cross Pol
S21 on Axis
S21 at -64 deg
-64 deg Taper
2HH E-Plane 1.280 9.4 -2.6 12.0 -7.0 -16.4 8.9 -1.8 10.71.405
9.2 -3.7 12.9 -9.5 -18.7 9.2 -2.6 11.8
1.530 6.3 -3.9 10.2 -14.0 -20.3 7.8 -3.0 10.81VV E-Plane 1.280
10.3 -4.7 15.0 nm nm 10.2 -2.3 12.5
1.405 8.2 -2.8 11.0 nm nm 8.3 -3.2 11.51.530 7.4 -4.9 12.3 nm nm
7.4 -3.8 11.2
1VV H-Plane 1.280 8.7 -3.0 11.7 nm nm 8.7 -2.1 10.81.405 9.3
-4.6 13.9 nm nm 9.2 -3.9 13.11.530 8.2 -6.7 14.9 nm nm 8.3 -5.0
13.3
Feed Photograph and Pattern MeasurementFeed design by Jun Shi,
[email protected]
In 1.28 to 1.53 GHz range the feed taper at the edge of an
F/D=0.4 dish is in the range of 10.7 to 14.9 dB for both
polarizations and both E and H planes.
The on axis cross-polarization is 16 to 20 dB down.
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Feed S ParametersS21=S12 is the Coupling Between Polarizations
and averages -30dB with a peak of -17dB. The return loss of port 1
averages 15dB with a peak of 9dB. The return loss of port 2
averages 18 dB with a peak of 6.6 dB at 1280 but 12.4dB at 1300
MHz.
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Feed DimensionsAluminum pipe, 6”OD, 5.75”ID, 19.1” inch long
with 6.5” D end cap and 15” mounting disk welded 3.12” from top
end. Cake pans, 15” OD and 8” OD are attached to the mounting disk
with four 8-32 screws.. The flats for the connectors must be 90 +/-
1 degree apart.
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Feed Assembly
Bracke BM60807N jack connector
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LNA Data Sheet and PhotographDesign and manufacture by Martyn
Gawthorpe, [email protected]
Powered by +12V, 100mA into SMA output connector
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S Parameters and Noise of LNA‘s SN01 and SN02, Oct 26, 20168 to
12V DC at 105mA, at 1400 MHz, S21=30dB, Tn = 32 to 35K, S11=-10dB,
S22= -14dB, P1dB=-13 dBm
Noise measurements made with N4000ASW noise source calibrated
with LN2 coaxial noise standard.
SN01
S Par
Gain,Noise
SN02
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LNA Interior Views and Schematic
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Temperature Coefficients of LNA Gain, Phase, and
NoiseMeasurements performed by heating SBA1400/1700 (www.g8fek.com)
SN02 with hot airConclusions: Gain: -.015 dB/C or -0.6dB/40C,
Phase: -.13 deg/C or -5.2 deg/40C, Noise Temperature: 0.24K/C or
9.6K/40C
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http://www.g8fek.com/
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Front-End Box, FEB, Interior ViewLNA is at left and is powered
by +12V, 100mA, from the FEB. DC block is required for FEB tests
Absorber block and absorber on cover are needed to prevent cavity
modes inside box which cause variation in frequency response and
instability. One FEB is required for each polarization and consumes
+12V at 260mA (including the LNA) and -9V at 40mA/
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S[1,1] S[2,1] S[2,2]
|S|(d
B)
S Parameters of FEB3 Into Photodiode Test Module, Dec 13,
2016
Freq (GHz)
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
1.15 1.20 1.25 1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65
1.28GHz19.12dB
1.53GHz20.52dB
Lab Tests of FEB Module
Temperature Coefficients: Gain, -0.12 dB/C, -3.6 dB/30C, Phase,
0.48deg/C,Noise Temperature: 600K at 30C, increases Tsys by 0.9K
with 30dB LNA and 2dB cable loss
3530K at 65C, increases Tsys by 5.6K with 30dB LNA and 2dB cable
lossGain Compression, 1dB, Input/Output:, -32/+18.4 dBm @ 1.28 GHz,
-33/19.4 dBm @1.405 GHz, -28/+15.3 dBm @ 1.53 GHz. (System gain
compression limited by LNA and BEB)
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FEB Schematic
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FEB Parts List
3
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Back-End-Box, BEB, Dual Polarization Receiver Module
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BEB1A and BEB1B Output Spectra When Driven by FEB1A and LNATop
trace is HP346A on, ENR=5.18dB, Tx=956K, middle trace is with 300K
termination and
bottom trace is with optical fiber disconnected.
BEB1A Output BEB1B Output
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BEB Schematic, Dec 23, 2016
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BEB Parts ListDec 23, 2016
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BEB Printed Circuit Board
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