A Compact, Low-Profile Dual-Band Patch Filtering Antenna for Off-Body Communications

A compact dual-band filtering antenna operating in the 5.0-GHz WiFi and 5.8-GHz ISM bands for wearable applications is investigated. The proposed filtering antenna is composed of a rectangular patch that etched with two pairs of rectangular slots and two notch ring slots. In addition, a set of curved parasitic patches with metallic pins are placed inside the two notch ring slots. Four rectangular slots and the curved parasitic patches generate three radiation nulls at the edges of lower and upper bands, and in the middle of the two working bands, leading to an enhanced suppression level in the stop-band. The proposed filtering antenna has the dimensions of 41.5 mm × 33.9 mm × 1.524 mm with a simulated in-band gain of about 6.5 dBi. Due to the merit radiation patterns with the front-to-back ratios of more than 15 dB, the proposed filtering antenna is suitable for the off-body communications.