1. Antenna, Reflector and Radome

2. Antenna
Initial single-wavelength (W band) system will use a 15” diameter lens antenna
A dual-wavelength feed and lens antenna is planned for the Phase C system
Expected performance:
Beamwidth
0.6 degrees
Gain
48 dBi
Sidelobes
-24 dB
Cross-pol. isol.
-30 dB
f/D
~ 1.0

3. HIAPER Pitch Envelope

5. Reflector Plate
Reflector plate rotates independently, nose cone/radome stationary
Design to compensate for aircraft pitch envelope: 1° < pitch < 5°
Locate plate pivot point at near-field beamwaist a distance, f (15”) from back of lens
At beamwaist: beam is 10” 1/e2 (13.5%) power loss
Plate flatness: 0.005” rms to have negligeable effect on far-field beam pattern
Elliptical design: 15.5” x 0.8% power loss

6. Pod Beam Projections: Top and Side Views

7. Radome Sandwich design ensures:
structural integrity (FEA req’d) as well as high transmissivity (one way loss ~ 0.5 dB)
functionality at both W-band (94 GHz) and Ka-band (35 GHz)
Compensate for radome induced phase errors distorting far-field beam pattern by applying low-loss SAN (styreneacrylonitrile) foam to reflector plate
Use ray tracing to determine above compensation

8. Expected Radome Performance
94 GHz

9. Expected Radome Performance
35 GHz