EVLA Front-End CDR. EVLA K-Band (18-26 GHz) Receiver

Transcription

1 EVLA Front-End CDR EVLA K-Band (18-26 GHz) Receiver 1

2 EVLA K-Band Receiver Overview 1) EVLA Upgrade - Existing VLA Configuration - Required Modifications - New Upgraded EVLA Block Diagram 2) Block Converter Scheme 3) Noise & Headroom Model 4) Upgrade Details 5) Test Results - Swept LO1 vs. Block Converter Mode - Equalization - Ellipticity 2

3 VLA K-Band Receiver Current Configuration (No WVR) Po = +8 dbm GHz Po = +9 dbm GHz 35 db LNA 38 db NF < 4 db GHz Pol Noise Diode LO Ref 16-2 GHz +15 dbm IF Out GHz LNA NF < 4 db 35 db 38 db Po = +8 dbm GHz Po = +9 dbm GHz 3

4 K-Band Receiver VLA to EVLA Modifications Switch to High-side LO injection Requires new Mixers (Miteq RF/LO=4-4 GHz, IF=DC-2 GHz) Requires new Limiting Frequency Doubler for LO Reference Adopt Block Converter Scheme ( GHz) Remove narrow GHz IF components Replace 38 db Miteq post-amps with 32 db Quinstar units To avoid compromising Headroom Already have 47% (28 out of 6) of the Quinstar QLN-224J amps that will be required Add Isolators on RF, IF & Cal signals To reduce passband and T Cal ripple 4

5 EVLA K-Band Receiver Baseline Configuration (without WVR capability) Dewar RF/IF Box WVR Box RCP Pamtech KYG2121-K2 (w/g) NRAO CDL 35dB MICA T-318S3 K&L Filter 13FV1-2225/U85 MICA T-318S3 Quinstar QLN-224J Po>+1dBm NF < 2.5 db 32dB MICA T-318S2 Miteq TB44LW1 Po>+9dBm CL < 1dB MICA T-78S4 TTT Filter K G 8-16 GHz MICA T-78S35 RCP IF Out 8-18 GHz GHz Old Some New New LNA Pol LCP Krytar GHz Pamtech KYG2121-K2 (w/g) T Cal 35dB NRAO CDL LNA MICA T-318S2 MDL 42AC26 Noise/COM NC 5242 (w/g) R. Hayward EVLA Front-End CDR EVLA NF < K-Band 2.5 db Receiver WR-42 To SMA MICA T-318S3 Atlantic Microwave AB42 K&L Filter 13FV1-2225/U85 Noise Diode MICA T-318S3 Doubler 18 dbm Doubler 32dB Quinstar QLN-224J Po>+1dBm x GHz dbm MICA T-318S2 x2 Miteq TB44LW1 Po>+9dBm CL < 1dB Norden Doubler MICA T-78S4 MAC Tech PA8272H (2F) GHz ( GHz) 8-16 GHz TTT Filter K G Ditom DF GHz MICA T-78S GHz LO Ref 3 dbm LCP IF Out 8-18 GHz

6 K-Band Block Conversion Frequency Diagram LO Ref = GHz IF Out GHz K-Band Rx GHz LO = 34.5 GHz Freq (GHz) Translation of GHz down to GHz LO Ref GHz x 2 = 34.5 GHz Closest L31 Lock Point is actually GHz 6

7 Estimated EVLA K-Band T Rx, Output Power & Headroom EVLA K-Band Rx P (1dB) P (1%) Temp NF/C Loss/Gain Loss/Gain Delta T Trx BW Pnoise Pnoise Headroom (RHH : 28 March 26) (dbm) (dbm) (K) (db) (db) (linear) (K) (K) (MHz) (dbm) dbm/ghz (db) for Tsky of 25. (K) Weather Window Feed Horn Vacuum Window Phase Shifter OMT W/G or Coax Cal Coupler (IL) Cal Coupler (Branch) Isolator LNA Stainless Steel Coax Isolator Coax Cable Isolator Filter ( GHz) Isolator Post-Amp WVR Coupler+Iso+Coax Isolator Mixer (Level 15) Isolator Filter (8-16 GHz) Isolator

8 Old vs. New K-Band Longer legs New Card Cage Block Converter New bottom Feed section Easy access to fridge & manifold EVLA VLA 8

9 Feed Horn & Receiver Mounting Modifications In the EVLA configuration the receiver is essentially hung from the Vertex Cabin roof by the feed. New bottom section of feed is more robust to carry the receiver s weight. New thicker Top Plate. New anti-cocking flange addresses the problem with the old boss/deboss mating system which caused large broad bumps in T Rx. New Ring-Load section has improved compression system to eliminate their distortion. 9

10 EVLA GHz Receiver Thermal Gap 15ºKelvin Cold Stage Cold Straps LCP LNA Cryo Isolator Cal Coupler Stainless Steel Coax Phase-Shifter RCP LNA Cryo Isolator Cal Coupler Ortho-Mode Transducer 1

11 CDL K-Band LNA Cryo-3 Device in 1 st Stage Noise Temperature (K) CDL K-Band LNA LNA Noise Temperature (KM-66) Frequency (GHz) Noise Temperature (K) Replace old-style GaAsFET cooled amplifiers with new MAPstyle InP units as well several existing MAP units which have inferior performance. 28 new LNA s Upgrade existing 4-stage MAP amps by returning to them to CDL for substitution of Cryo-3 device in the first stage 24 upgraded LNA s 11

12 The New RF/IF Box 12

13 K-Band SN 27 - First EVLA Prototype Swept LO1 vs. Block Converter Mode 27 May 24 Swept LO 1 Mode : LO1 = 29. to 37. GHz, LO2 = 11. GHz Block Converter Mode : LO1 = 34. GHz, LO2 = 16. to 8. GHz Receiver Temperature (K) T Rx LCP Swept LO1 Mode (KL273C29.373) BC Mode 34 GHz (KL273C29.545) LNA Noise Temperature (KM-64) Gain L Receiver Gain (db) Receiver Temperature (K) Original MAP LNA 4 design 2 7T Rx only intended to cover GHz RCP Swept LO1 Mode (KR273C29.423) BC Mode 34 GHz (KR273C29.463) LNA Noise Temperature (KM-65) Gain L Receiver Gain (db) Frequency (GHz) Frequency (GHz) 13

14 K-Band SN 27 - First EVLA Prototype Gain Flatness in 2 GHz Bandwidths - No Equalization Swept LO1 Mode (LO1 = GHz, LO2 = 11 GHz) 27 May Normalized Gain Frequency & Gain Slope Equalization 18-2 GHz with db 2-22 GHz with db GHz with db GHz with db LCP (KL273C29.373) Normalized Gain Frequency & Gain Slope Equalization 18-2 GHz with db 2-22 GHz with db GHz with db GHz with db RCP (KR273C29.423) Normalized Gain (db) Normalized Gain (db) Frequency (GHz) Frequency (GHz) 14

15 +15 db 1 db +13 db 2 db IL=2.5 db +11 db +9 db 3 db 4 db IL=2.5 db Input 2-4 GHz IL=1.5 db +7 db +5 db +3 db +1 db -1 db -3 db 5 db 6 db 7 db 7 db IL=1.5 db 15 db Output 2-4 GHz -5 db 6 db -7 db 5 db IL=2.5 db -9 db -11 db -13 db 4 db 3 db 2 db 1 db -15 db IL=2.5 db Planned T34 Downconverter Programmable ±15 db Equalizer 15 with 2 db Steps

16 K-Band SN 27 - First EVLA Prototype Gain Flatness in 2 GHz Bandwidths - Simulated T34 Equalizer Swept LO1 Mode (LO1 = GHz, LO2 = 11 GHz) 15 March Normalized Slope Frequency & Gain Slope Equalization 18-2 GHz with -7 db 2-22 GHz with +3 db GHz with -5 db GHz with +3 db LCP (KL273C29.373) Normalized Gain Frequency & Gain Slope Equalization 18-2 GHz with -11 db 2-22 GHz with +3 db GHz with -3 db GHz with +3 db RCP (KR273C29.423) Normalized Gain (db) Normalized Gain (db) Frequency (GHz) Frequency (GHz) 16

17 Typical K-Band Axial Ratio Measurement 3 Axial Ratio (db) Measured Axial Ratio on K#22 LCP & RCP Channels using the Iso-KETF versus Calculated Axial Ratio for Phase-Shifter #23 based on Differential Phase Shift Test Data (Assumes db Amplitude Inbalance) 15 April 25 1 db Axial Ratio Spec LCP (Unsmoothed) LCP Smoothed RCP (Unsmoothed) RCP (Smoothed) Phase-Shifter # Frequency (GHz) 17

18 EVLA K-Band Summary Incremental upgrade to an existing VLA receiver band EVLA design improves sensitivity and broadband performance New/upgraded LNA s will provide even more improvement M&S Budget - $289.1K already spent out of $445.5K allotment Remaining large ticket items - LNA s -Cables - New Card Cages To keep within the EVLA Project spend profile, it was felt that the upgraded design was low risk and that we could confidently proceed with mass production We hope the FE CDR Panel agrees 18

19 Questions? 19

20 Backup Slides 2

21 Frequency Doubler Norden Millimeter Limiting Doubler N3-284 Input Frequency GHz Output Frequency 3-36 GHz P In (min) -3 dbm P In (max) +3 dbm P Out (min) +17 dbm P Out (max) +19 dbm O/P Variation over I/P Drive (max) ".5 db Power Flatness with Freq (max) ".5 db Max Input No Damage +13 dbm Fundamental Rejection (min) -5 dbc Harmonic -4 dbc Spurious -65 dbc 21

22 IF Filter ( GHz) TTE K495-8/16.5G-A Insertion Loss 1 db Flatness.5 db Rejection - 1 db 8. & 16.5 GHz - 3 db 7.8 & 16.7 GHz - 3 db 6.11 & GHz - 5 db 4.4 & 19.6 GHz Upper -5 db Stopband 35 GHz 22

23 VLA/EVLA K-Band Receiver SN 26 (28 April 23) LCP Receiver Temperature Receiver Gain RCP Receiver Temperature Receiver Gain 6 Receiver Temperature (K) Gain Receiver Gain (db) Receiver Temperature (K) Gain Receiver Gain (db) 2 1 T Rx T Rx Frequency (GHz) Frequency (GHz) 23