Antenna, Reflector and Radome

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

HIAPER Pitch Envelope

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” diameter @ 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 22.4” @ 0.8% power loss

Pod Beam Projections: Top and Side Views

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

Expected Radome Performance 94 GHz

Expected Radome Performance 35 GHz