1 / 14

COLD FRONT END

COLD FRONT END. Stephen Muchovej Caltech. CONSIDERATIONS. RF System Itself Physical Considerations Packaging Mounting. RF System Requirements. Noise temps of < 50K from 1-18GHz 1% Amp Stability, 1 degree phase stability Polar accuracy: 15 dB isolation

nitsa
Download Presentation

COLD FRONT END

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. COLD FRONT END Stephen Muchovej Caltech

  2. CONSIDERATIONS RF System Itself Physical Considerations Packaging Mounting

  3. RF System Requirements Noise temps of < 50K from 1-18GHz 1% Amp Stability, 1 degree phase stability Polar accuracy: 15 dB isolation Ready in Fall – completely done by Summer 2013

  4. RF System Note: amp symbols are reversed.

  5. Horn Considerations - Spillover

  6. Horn Considerations - Cooling

  7. Possible Solution Well-matched optics Low spillover Free Design …only operates over factor of 6 in frequency. Means we have to split the system

  8. Telescope Focus Point 2m in front of platform. We can put the two systems side-by-side, and cool all components in a single dewar.

  9. Features Better system temp ( <50K across whole band ) Perfect beam matching between two systems. Lateral translation between 2 systems. Need 15cm Vertical Translation between two feeds. Needs to rotate to calibrate smaller dishes.

  10. Mount Proposal Replace the mechanism up there with a full, self-contained system that bolts onto the ring platform. Uses tracks for linear (and vertical -- focus) translations with actuators. Uses a gear for rotation Install whole rx system at once Adjust y once on installation

  11. Mount Proposal Replace the mechanism up there with a full, self-contained system that bolts onto the ring platform. • Allows for rotation and translation

  12. Prime Focus Inventory Rx and cryo lines. Temp Controlled (TECA) box with: Bias for amps Temp Stable noise source Temp monitoring RF switch Pre-amp module RF-optical converter Ethernet Switch Ethernet controllable power supply Small computer to control Noise Diode, Bias, and Alignment jig (rotation, x, and z)

  13. Other people involved are TomiHovatta • (most machining) and Russ Keeney • March-Mid May: Component Selection and Costing, Rx Design, and Support Jig Design • May 15: Order RF components, Quotes on Machining (that won’t happen here) • May-July: Machining (Jig, horns, cryostat), control subsystem development • August-September: Rx construction, Mechanical testing of Jig, Rx Testing • October: Buffer Month. • Nov-Dec: Installation/Commissioning Timeline

  14. Communications between small computer and control system • Amount of focus shift in pointing the telescope • Tolerances for Rx placement -- laterally and rotationally • Control of focus mechanism (distortion of dish) • Budget. Still to define

More Related