1. Feed/Receiver Developments ATA-TAP December 17, 2002 WJW

2. Prototype Wideband Feeds 0.5 – 11 GHz

3. Second Model H-Plane

4. Second Model E-Plane

5. Cross-Polarization Both Models

6. Gain Tables

7. Feed Tests Excellent (16 dB) matchExcellent (16 dB) match Agrees with EM calcs on Impedance Gain Internal Loss

8. Feed Measurements

11. Measured LNA Temperature Measured and simulated noise for WBA13 at 300K, 77K and 4K MMIC InP PHEMT.18  m Design by S. Weinreb

12. Tip Circuit Board

13. Dewar Layout

14. Input Match and Cross Talk

15. Feed Properties Input impedance – =206 Ohms –S max =1.35  Spillover 42 o 18% 90 o 8.5% 135 o 3% Spillover

16. Odd Mode Resonances: No Cover

17. Odd Mode Resonances: w. Cover

18. Resonances w. & w/o. Cover: Absorber Added

19. Spillover vs. Zenith Angle Zenith Angle T sys

20. Noise Summary for 10 GHz ItemTemperatureNotes Feed (3%) 9.0Const w freq Tip Circuit Bd 3.0Varies w freq Transition Line 2.6 (20mil)Varies w freq Cold Line 2.4Varies w f req Spillover 3.0Const w freq Tbb 2.7Const Atmosphere 7.04.0 @ 4GHz LNA 12.0 Total 42.036.0 @ 4GHz