Design, fabrication and testing of well-matched microwave array antennas with greater than 2.5:1 bandwidth

A connected array antenna architecture composed of multiple fragmented metallic surfaces over a ground plane has been used for a number of ultra-wideband applications. In this paper we apply design procedures developed for ultra-wideband operation but emphasize extremely low impedance mismatch to enable operation at high power levels in the Ultra High Frequency (UHF) range. The design evaluation includes simulations to assess robustness to manufacturing tolerances. An S-band prototype test article was fabricated with dummy elements terminated in matched loads made of etched resistive material. Measurements of the prototype confirmed suspicions that impedance variability in the resistive layer limits the ability of the test coupons to validate the designs. A comprehensive test plan to mitigate risk is developed that will culminate in demonstration of a fully populated array. The paper concludes with a summary of plans for future tests.