A New Design of a Wideband Low-Profile Monopole Patch Antenna Based on SIW Resonator

A wideband low-profile monopole patch antenna is designed by utilizing substrate integrated waveguide (SIW) resonator. The proposed antenna is constructed on a single center-fed square patch working under the operation of TM20 mode. Originating from an investigation on the field distributions of the square patch, the center-fed square patch antenna is analyzed to prove that the undesired modes are removed completely, based on the cavity mode theory. Thereafter, the wideband operation is realized by utilizing the TM20 mode of the patch and the TE110 mode of the SIW cavity resonator. A prototype of the proposed antenna is fabricated and measured. Measured results and the simulated results are found in reasonably good agreement. With a low profile of $0.024\boldsymbol{\lambda}_{0}$, the antenna has a 10-dB return-loss impedance bandwidth of nearly 12.1% (3.41-3.85 GHz) and a peak gain of 6dBi.