1 / 31

EVLA Front-End CDR

EVLA Front-End CDR. The New EVLA Receiver Card Cage. Overview. The EVLA Card Cage shall: Provide 8 stages of conditioned LNA bias Control and monitor cryogenic sensors Interface to Monitor/Control system (But allow stand-alone bench testing) Mount to EVLA receivers Minimize EMI

brick
Download Presentation

EVLA Front-End CDR

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EVLA Front-End CDR The New EVLA Receiver Card Cage EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  2. Overview • The EVLA Card Cage shall: • Provide 8 stages of conditioned LNA bias • Control and monitor cryogenic sensors • Interface to Monitor/Control system • (But allow stand-alone bench testing) • Mount to EVLA receivers • Minimize EMI • Minimize assembly time and cost EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  3. Block Diagram EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  4. Pseudo-passive Scheme • 96 available analog monitor points, selectable in banks of 3 • Default critical diagnostic parameters • Gate voltage sums (RCP, LCP) • 15K stage temperature • MIB mounted remotely • No digital signal traffic during observation EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  5. Card Cage:EVLA vs. VLA/VLBA EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  6. Chassis: VLA EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  7. Chassis: EVLA Interim only EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  8. Wiring: VLA • 250-300 individual solder points • Wire directions hand- randomized to prevent EMI due to AC EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  9. Wiring: EVLA • 6 IDC connections • 8 solder points • 16 crimps • No AC, clocks EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  10. Enclosure • COTS Stamped Al VME Chassis • Pre-assembled with hardware • 1/3 the weight of extruded aluminum • 1/4 the cost! EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  11. Minimizing Assembly • IDC/Crimp vs. hand-soldering • Pre-assembled chassis • Modular, universal design EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  12. Control/Sensor Card • Replaces VLA: • Control, • Sensor and • Monitor cards • Altera CPLD • No fast clock! • 4” x 6” Eurocard EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  13. Control PLD • Communication registers for Digital IO • 32 x 4 latching input registers • 32 x 4 output registers • SPI-compatible EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  14. Cryogenic State Machine • 9 sensor comparators • 4 user-set state commands • 14-way LED state indicator • Local/remote control EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  15. Cryogenic Control EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  16. AC Relay Box • Removes AC & its EMI from Card Cage • Allows logicbypass for Fridge • Separate LEDfor each request EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  17. 8-Stage Bias Card • Based on GBT 6-stage design • Allows disabling of stages in banks of 2 • VD, ID, and VGare monitored • 4” x 6” Eurocard EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  18. LNA Diode Protection Board • Accommodates 8 bias stages • Drain voltage clamped to +6V/-1V • Gate voltage clamped to +1V/-2V • Soldered to hermetic feedthrough EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  19. Receiver ID • Band code, Receiver S/N, and revision stored in 64kB EEPROM • Spare capacity for text—CAL files, bias settings, etc. • Follows receiver, not Card Cage EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  20. RF/IF Box Interface • Accommodates VLA and EVLA solar calibration • 28V noise cal is not switched in Card Cage EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  21. RF/IF Box Interface • SPI for logic, step attenuators • LVTTL from Card Cage to external switching circuit • Separate voltage regulation for Room-TempRF components EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  22. DC Power • +17, -17, +7, +32V from DC distribution • Through to RF/IF interface • +15, -15, +5, +3.3V for Card Cage, AC Relay Box EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  23. Monitor & Control • Up to 35’ cable run  Differential ( 25 STPs) • +/-5V analog range • LVDS for digital • Monitor 3 of 96 possible analog points • Select with 5-bit address from F317 • Change only when data will not be corrupted EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  24. Production Costs EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  25. Summary • Eliminates EMI from fast clocks/AC • Universal to all receivers • Minimizes assembly time & cost • Leverages existing NRAO designs (where possible) EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  26. Questions? EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  27. Effect of Bias Card on Receiver Performance EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  28. Effect of Bias Card on Receiver Performance EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  29. Monitor and Control EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  30. Monitor & Control: Digital Monitors EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

  31. Monitor & Control: Analog Monitors EVLA Front-End CDR – New EVLA Receiver Card Cage April 24, 2006

More Related