1. US SKA TDP DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC Overview Of DVA-1 Optics Lynn Baker Bill Imbriale German Cortes

2. US SKA TDP DVA-1 DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

3. US SKA TDP DVA-1 DVA-1 Ray Trace Diagram June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

4. US SKA TDP DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC Offset Advantage: Electromagnetic Performance Clear optical path, no blockage or scattering Combined with shaped optics, leads to very low spillover (~ -50db wide angle) Very low spillover yields very low antenna noise temperature (<6 K ground) Very low spillover results in high rejection of RFI and strong sources Shaped optics yield high efficiencies, total result is a high Aeff / Tsys

5. US SKA TDP DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC Offset Advantage: Payload Capability Ample space and load capability to mount multiple feeds Feeds, receivers and interchange mechanism out of optical path Access to payload area with out impacting either reflector PAF can be mounted at either secondary or primary focal area For structural cost reasons, DVA-1 is “feed arm high” Easy, effective maintenance access with a standard scissors lift truck

6. US SKA TDP DVA-1 DVA-1 Beam Pattern, Perfect Feed June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

7. US SKA TDP DVA-1 DVA-1 Low Frequency Performance.35 To 2.8 GHz. June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

8. US SKA TDP DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC Low System Noise, Now & Future Lowering Tsys is the most cost effective way to increase sensitivity Present LNA’s need cryogenics to minimize noise contribution, expensive Ongoing trend is ever lower noise and future cryogenics should be lower cost. Conclusion: Reduce antenna noise contribution to absolute minimum now. Deep edge tapers improve antenna noise but usually lower efficiency Shaping restores the efficiency and optimizes Aeff / Tsys

9. US SKA TDP DVA-1 DVA-1 Antenna Temperature June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

10. US SKA TDP DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC DVA-1 Modeled Performance With A Corrugated Horn Lynn Baker Bill Imbriale German Cortes

11. US SKA TDP DVA-1 Corrugated Horn Used In Modeled Performance June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

12. US SKA TDP DVA-1 DVA-1 Wide Pattern, Corrugated Horn June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

13. US SKA TDP DVA-1 DVA-1 Near Pattern, Corrugated Horn June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

14. US SKA TDP DVA-1 DVA-1 Efficiency, 3 Corrugated Horns June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

15. US SKA TDP DVA-1 DVA-1 Antenna Temperature, 3 Corrugated Horns June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

16. US SKA TDP DVA-1 DVA-1 Aeff/Tsys, 3 Corrugated Horns Assume 15K Receiver June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

17. US SKA TDP DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC Far Field Beam Patterns From Modeled Distortions At 10 GHz & 18 GHz. Bill Imbriale

18. US SKA TDP DVA-1 Beam Pattern at 10 GHz. Undistorted Optics, Ideal Feed June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

19. US SKA TDP DVA-1 Beam Pattern at 10 GHz. 25 Celsius Thermal Change (Blue) Undistorted (Red) June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

20. US SKA TDP DVA-1 Beam Pattern at 10 GHz. Gravity Deformation at 15 degree Elevation (Blue) Undistorted (Red) June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

21. US SKA TDP DVA-1 Beam Pattern at 10 GHz. Gravity Deformation at 55 degree Elevation (Blue) Undistorted (Red) June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

22. US SKA TDP DVA-1 Beam Pattern at 10 GHz. Gravity Deformation at 90 degree Elevation (Blue) Undistorted (Red) June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

23. US SKA TDP DVA-1 Beam Pattern at 10 GHz. 25 kph Wind at 15 degree Elevation (Blue) Undistorted (Red) June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

24. US SKA TDP DVA-1 Beam Pattern at 10 GHz. 25 kph Wind at 55 degree Elevation (Blue) Undistorted (Red) June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

25. US SKA TDP DVA-1 Beam Pattern at 10 GHz. 25 kph Wind at 90 degree Elevation (Blue) Undistorted (Red) June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

26. US SKA TDP DVA-1 Beam Pattern at 18 GHz. Gravity Deformation at 55 degree Elevation (Blue) Undistorted (Red) June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

27. US SKA TDP DVA-1 Beam Pattern at 18 GHz. Gravity Deformation at 15 degree Elevation (Blue) Undistorted (Red) June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC

28. US SKA TDP DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC Freq Peak Scan Scan On-axis Peak Peak Beam Width Case Gain Offset Orthogonal Gain Sidelobe X-pol X Y (GHz) (dB) mdeg mdeg (dB) (dB) (dB) (deg) (deg) 10.000 63.270 0.51 0.00 63.270 20.857 41.954 0.133 0.133 Undistorted 10.000 63.253 -2.97 -0.18 63.247 20.317 42.196 0.133 0.133 Thermal 10.000 63.162 32.49 0.17 62.482 19.076 43.200 0.134 0.132 Gravity 15 degrees 10.000 63.250 12.82 0.12 63.145 20.674 42.092 0.134 0.133 Gravity 55 degrees 10.000 63.107 -9.29 0.03 63.052 19.501 41.046 0.134 0.134 Gravity 90 degrees 10.000 63.268 5.09 0.15 63.251 20.689 42.014 0.134 0.133 Wind 15 degrees 10.000 63.270 0.23 0.03 63.270 20.834 41.951 0.133 0.133 Wind 55 degrees 10.000 63.270 1.30 -0.11 63.269 20.804 41.954 0.133 0.133 Wind 90 degrees Calculated Performance Of Each Distortion Case

29. US SKA TDP DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC Conclusions Shaped, offset gregorian reflectors yield very high performance Cost increment for offset design is modest Very low noise performance maximizes Aeff/Tsys Mechanical design with single piece reflectors is very stiff Equivalent RMS error from all sources is.45 mm., worst case

30. US SKA TDP DVA-1 June 28-29, 2012Dish Verification Antenna No. 1 Critical Design Review, Penticton, BC End