Characteristic mode analysis of wideband microstrip antenna

In this paper, a wideband antenna is designed systematically based on characteristic mode analysis (CMA). The antenna consists of a rectangle, a semi-annular ring, and a microstrip line. The radiating behavior and resonant frequencies of the radiating element are analyzed by using first four characteristic modes. First two modes only have wideband behavior and are excited by CPW feeding technique. The proposed antenna is printed on a low cost FR4 substrate with a size of 35×50×1.6mm3 and impedance bandwidth ranging from 1.6 to 3.8 GHz for the applications of GSM, DCS, LTE, and WIMAX. To validate the proposed approach, the wideband antenna is fabricated and tested. A wide impedance bandwidth of 81% with |S11| < −10 dB is achieved for both simulation and measurement results. © 2019, Electromagnetics Academy. All rights reserved.