V-band monolithically integrated four-arm spiral antenna and beamforming network

A V-band four-arm spiral antenna with monolithically integrated feed bundle and modified Butler matrix beamforming network designed and fabricated utilizing surface micro-machining is discussed. Basic layout and fabrication are shown for both the feed network and the spiral itself. Measurements are compared with simulations for both the impedance and co-polarized far-field radiation patterns. A VSWR <; 2:1 for modes 1 and 3 (-1), realized gain between 0 and 5dBic, and axial ratio <; 2dB are demonstrated across the 50 to 75GHz range.