A Compact Dual- and Wideband Cavity-Backed Slot Subarray

A compact design for dual- and wideband slot sub-array is presented in this letter. The cavity-backed subarray is fed by two microstrip lines on the top layer of one substrate for 900 and 1800 MHz bands, respectively. With the use of ridged slots backed by a conductor plate with three rectangular cavities, a compact design is realized for a dual- and wideband subarray with very good isolation and symmetric radiation patterns. A prototype is fabricated and tested in an anechoic chamber. The measured 10-dB return loss bandwidth of the slot subarray is 36% for 900-MHz band and 35% for 1800-MHz band, respectively. The measured gains are 7.0 dBi at 920 MHz and 10.2 dBi at 1800 MHz