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 .