1. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 1 EVLA Front-End CDR Plans for S (2-4), X (8-12) & Ku (12-18 GHz) Receiver Bands

2. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 2 Contents S-Band Receiver –EVLA Design X-Band Receiver –EVLA Design –EVLA Transition Ku-Band Receiver –EVLA Design

3. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 3 EVLA S-Band 2.0 – 4.0 GHz Schedule: starting builds in 2008 Critical design issue –OMT scaled from L Band quad-ridge Possible reuse L Band dewars CTI 350 cryopump is allocated

4. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 4 Block Diagram Quad hybrid OMT Cal injection 2 stage balanced LNA +32 RF Postamp module

5. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 5 Estimated EVLA T Rx, Output Power & Headroom

6. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 6 16K performance –Tamp = 4K –Gain = 32 dB CDL’s Low Noise Amplifiers S21 S11 S22 295K performance –S11: -15dB –S22: -13 dB 4K

7. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 7 Polarizer Design scaled up in frequency from L Band quad- ridge OMT full length = 13.25”, ridge width = 0.25”.085” coax for probes

8. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 8 EVLA X-Band 8.0 – 12.0 GHz Schedule: Transition receivers until 2008, new receivers 2009-2012 Only critical design issue – Polarizer CTI 22 cryopump allocated

9. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 9 Block Diagram polarizer undetermined cal injection cooled isolators single LNA RF postamp module

10. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 10 Estimated EVLA X-Band T Rx, Output Power & Headroom

11. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 11 CDL’s Low Noise Amplifiers “CX” 4-12 GHz 3-stage, all InP C-band X-band

12. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 12 Polarizer Design Options Quad-ridge OMT + hybrid –full length = 3.975” –ridge width = 0.075” –.047” coax for probes

13. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 13 Polarizer Design Options Corrugated phase shifter + Bøifot OMT –length of phase shifter 9.1” –length of Bøifot OMT 8.8” –better phase and amp balance than 8-12 hybrid

14. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 14 Polarizer Design Options Cooled dielectric phase shifter + Bøifot OMT –length of PS: shorter than corrugated PS –better phase and amp balance than 8-12 hybrid

15. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 15 EVLA Ku-Band 12.0 – 18.0 GHz Schedule: 2007 – 1 prototype, 2010 – 2012 production No critical design issues Polarizer has been designed

16. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 16 Block Diagram cooled phase shifter + Boifot OMT cooled isolators single LNA RF postamp module

17. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 17 Estimated EVLA Ku-Band T Rx, Output Power & Headroom

18. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 18 CDL’s Low Noise Amplifiers CDL model 8-18 GHz used in VLBA W Band’s second stage S21 30dB -15dB -10dB 35dB S22 S11 818 8 Noise (K) Gain (dB) 295K performance 16K performance

19. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 19 Polarizer Design S. Srikanth’s corrugated phase shifter shifted down in frequency from K Band model Wollack & Gundersen have designed a Ku-Band OMT Overall lengths –phase shifter: 6.0” –OMT: 4.6”

20. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 20 More OMT Information

21. Lisa LockeEVLA Front-End CDR – S, X & Ku-Band Receivers April 24, 2006 21 Conclusions S Band (2008) –needs L Band OMT to scale X Band (2009) –transition receivers until 2009 –needs polarizer design resolved Ku Band (2007) –no design issues