Compact Absorptive Dual-Beam Patch Antenna by Fusing Resistor-Terminated Defected Microstrip Structure

A compact absorptive dual-beam patch antenna is proposed by fusing the absorptive branch inside the patch antenna. The defected microstrip structure (DMS) with a meander slot and the T-shaped shorted stub can make the absorptive branch achieve the absorptive function in a small size, so that it can be fused into the dumbbell-shaped slot of the patch antenna. Furthermore, the dumbbell-shaped slot extends the current path of the patch operating at TM 20 mode. Thus, the overall size of the patch antenna doesn't increase, but decreases. Compared with other absorptive antennas, the proposed one realizes the out-of-band reflectionless characteristic in a compact size and dual-beam radiation. For demonstration, a prototype operated at 5.8 GHz was measured with the compact size of 0.31λ 0 ×0.48λ 0 , the out-of-band reflectionless bandwidth of 49.5% (3.50-5.72 GHz and 6.46-7.11 GHz), and the dual radiation beams directed at ±42 o .