A Planar All-Silicon 256-Element Ka-band Phased Array for High-Altitude Platforms (HAPs) Application

We describe the design of an active electronically steerable antenna array (AESA) enabling broadband line-of-sight communication from a high-altitude platforms (HAPs). The array is constructed using a multitude of single chip multi-channel beamforming modules capable of switched bi-directional amplitude and phase conditioning at Ka-band enabling a sharing of aperture between transmitting and receiving functions. Use of an open-ended substrate-integrated square waveguide enables wide field of regard. Measured performance of a 256-element AESA using a spherical near-field measurement technique allows for indirect characterization of both far-field gain and excitation uniformity.