4 x 1 array antenna with harmonic suppression capability

Abstract

A 4 × 1 rectangular patch array antenna with electromagnetic bandgap (EBG) structure and filters is proposed in this work. The antenna operates at 2.45 GHz which is suitable to be used in the rectenna system and has the ability to suppress the higher order harmonics. To combine harmonic suppression and filtering functions within the antenna, two filters on the feed line and EBG structure on the ground plane are implemented into the array antenna configuration. The filter is designed such that unwanted signals are removed to achieve higher order harmonic rejection mode. The EBG structure which is located on the ground plane, act as a Defected Ground Structure (DGS). The structure provides a low pass representative with improved harmonic suppression performance in the upper frequency of the stop band. For demonstration, a 4 × 1 rectangular patch array antenna operating at 2.45 GHz is designed, fabricated, and measured. Reasonable agreements between simulated and measured results are observed. The prototype exhibited excellent suppression at 5.56 and 7.2 GHz in the presence of the EBG structure and filters. The return loss also increases to −29.99 dB at the operating frequency with increases in gain.