Dual-Wideband Hollowed Substrate-Integrated Stacked Antenna for Vertically Mounted Low-Elevation Scanning Array

A novel hollowed substrate-integrated stacked antenna (SISA), with self-package, dual-wideband, high-efficiency, low-weight, and low-cost characteristics, is introduced for vertically mounted low-elevation scanning array. The total efficiency of the proposed antenna is close to 100% in the operational bands although a lot of high-loss substrates (HLSs) are applied. This antenna has wide fractional bandwidths of 25% and 22% in two commonly used frequency bands, X-band and Ku band, respectively. In order to verify the performance of the proposed antenna in phased arrays, a 16-element array is designed, which has a good beam-scanning performance in the typical low-elevation range of vertically mounted arrays.