K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio...
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![Page 1: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/1.jpg)
K-Band Focal Plane Array:Integrated Downconverter Module #1
Matt Morgan and Tod Boyd
National Radio Astronomy Observatory
8/7/2008
![Page 2: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/2.jpg)
IDM1 is Complete
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IDM2 is Not Complete – One Key Part Missing
I mistakenly ordered the wrong size feedthru header for this module. They havebeen re-ordered, and are expected to arrive in mid-September.
![Page 4: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/4.jpg)
IDM1: Measured Gain
The bandpass is a little narrow. I will show later that it is not the filter.I probably just need to raise the lid slightly.
![Page 5: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/5.jpg)
IDM1: Measured Gain
IF Response shows a lot of ripple. I believe this is related to cavity effects onthe PCB-side – which will not be present on IDM2.
![Page 6: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/6.jpg)
IDM1: Measured Image Rejection
Image rejection at ±1.2-3 GHz offsets is better than 35 dB.
![Page 7: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/7.jpg)
IDM1: Measured Image Rejection
Image rejection at ±5.9-7.7 GHz offsets is better than 32 dB.
![Page 8: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/8.jpg)
IDM1: Measured Gain Compression
Output 1 dB compression point is about +7 dBm.
![Page 9: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/9.jpg)
IDM1: Measured LO Power Requirements
![Page 10: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/10.jpg)
IDM1: Measured Channel Isolation
There seems to be excessive crosstalk between channels (-20 dB), havinga strong IF dependance, but virtually no RF/LO dependance – this stronglysuggests that the crossover is occuring in the IF circuit inside the PCB cavity.
![Page 11: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/11.jpg)
IDM1: Measured Return Loss
Poor return loss needs investigation.
![Page 12: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/12.jpg)
IDM1: Measured Return Loss
Poor return loss needs investigation.
![Page 13: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/13.jpg)
IDM1: Measured Return Loss
Poor return loss needs investigation.
![Page 14: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/14.jpg)
Probe Measurements on Filters
Dynamic range of the measurement was limited at the high frequency end,but the passband looks perfect.
![Page 15: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/15.jpg)
Probe Measurements on Filters
Perfect.
![Page 16: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/16.jpg)
Compliance Matrix for Single Pixel Prototype
parameter symbol spec/predicted measurement comments
noise temperature Te 600 – 800 K not measured
gain G 30 dB 30 dB
gain ripple Gmax – Gmin 3 dB 8 dB presumed PCB cavity effect
output power Pout -25.5 0.5 dBm
-25.5 0.5 dBm
assuming predicted front-end gain
headroom HR +40 dB +33 dB probably ok
LO1 power required
PLO1 -3 5 dBm +1 8 dBm
LO2 power required
PLO2 +3 5 dBm +3 5 dBm
image rejection IR 25 dB 32 dB
channel isolation Iso 30 dB 20 dB presumed PCB cavity effect
return loss RF input
IF output
LO1 input
LO2 input
-17 dB
-19 dB
-12 dB
-10 dB
-11 dB
-11 dB
-6 dB
-12 dB
need to verify transition designs
mass M 250 g 316 g IDM2 will be much less, average should still meet spec
![Page 17: K-Band Focal Plane Array: Integrated Downconverter Module #1 Matt Morgan and Tod Boyd National Radio Astronomy Observatory 8/7/2008.](https://reader035.fdocuments.in/reader035/viewer/2022062423/5697bf791a28abf838c825f2/html5/thumbnails/17.jpg)
Future IDM1 Revisions
1. Modify ALH444 bias circuit for better gain repeatability.
2. Modify PCB cavity to include a metal barrier between IF circuits in bothchannels – this should improve channel isolation and IF gain flatness
3. Investigate cause of return loss problems – may require re-design ofthe transitions
4. Raise the lid above the filters to prevent de-tuning.
5. Clean up other minor PCB issues