A Compact $W$ -Band Substrate-Integrated Cavity Array Antenna Using High-Order Resonating Modes

A planar W-band array antenna is presented in this communication with a high gain and compact footprint. In order to simplify the feed network and reduce the feeding loss, a high-order resonating mode, i.e., the TE560-like mode, is employed for radiations. Thus, a single-element antenna can support 30 radiation slots on the top surface of the substrate-integrated cavity. Full-wave analysis along with measured results is given to explain the operational principle and performance of the proposed antenna. A 20 × 24 and 40 × 48 slot arrays based on the proposed high-order resonating mode element antenna are fabricated and measured to demonstrate array applications. The measured results show that these two arrays have a -10 dB impedance bandwidth from 91 to 97 GHz. The measured peak gain is 26.39 dBi at 95.3 GHz and 30.36 dBi at 95.2 GHz for the 20×24 and 40×48 slot arrays, respectively.