Equivalent Circuit Model for Closely Spaced Patch Antenna and Microstrip Line with Loaded Defected Microstrip Structure

In this paper, a defected microstrip structure (DMS) is proposed and put on the transmission line to reduce the mutual coupling between closely spaced patch antenna and microstrip line. The equivalent circuit model of the considered structure with loading DMS are presented and extracted. The lumped elements of the equivalent circuit model are obtained from the antenna and DMS equivalent circuits by including the coupling between the patch antenna and the 50-Ω transmission line. The proposed structure is simulated by HFSS and the extracted circuit is verified by using ADS simulation. The accuracy of the circuit model agrees well with the full wave, which help to verify its effectiveness.