A Filtering Antenna Based on Etched Interdigital Structure for Dual-Band High Selectivity

Abstract

A dual-band filtering antenna, comprising a quasi-Yagi antenna and similar etched interdigital structures featuring high selectivity and wide impedance bandwidth, is proposed and analysed in this paper. Differing from the existing filtering antennas, the performance of the novel one can be improved with the help of the proposed interdigital structure etched on metallic ground instead of adding parasitic strips connected to the feedline of the top layer. Moreover, the proposed low-profile antenna performs as expected; the peak gain is 5.1 dBi and relative impedance bandwidth surpasses 36.4% in the former band within 3.6–5.2 GHz compared to conventional antennas. Meanwhile, it will work with the similar performance in multi-band due to the arrangement of symmetric etched interdigitals. For verification, a 35 × 55 × 1-mm3 prototype operating in dual-band is fabricated and experimented to compare with simulated results. In the end, the measured results are found in a good agreement with those of the simulated ones in designed band.