Modelling the effect of a thin shorting post in an arbitrary position along the outer radiating edge of a rectangular patch antenna

An extended transmission-line model is proposed for a shorted rectangular patch antenna. The transmission-line model represents the effect of a thin shorting post placed at an arbitrary position along the outer radiating edge of the patch antenna. A comparative study has been conducted with a 3D full-wave solver. An example patch antenna having a resonance frequency of 2280 MHz without any shorting post, can be re-tuned between 2375 MHz and 2511 MHz by varying the location of the shorting post. A special case with the post at one of the outer vertices is also considered. Maximum deviation between results obtained from the extended transmission-line model and the full-wave solver is 0.74% for the example patch antenna.