Equivalent Circuit of an Aperture Coupled Patch Antenna for Beam Control Applications

In this paper, an exhaustive study of different equivalent circuits of an aperture coupled patch permits to develop a suitable circuit model. The vast majority of these models are able to reproduce the antenna behavior around the first resonance frequency, but the proposed equivalent circuit is also capable of duplicating the radiator input impedance in the two next harmonics. Over such model two different approaches have been carried out for beamsteering purposes: a variable capacitor has been added to control the resonant frequency and a left-handed (LH) structure has been introduced at the patch input to obtain two variable operating bands. The agreement shown in the results obtained using the proposed circuit structure, electromagnetic simulations and experimental measurements validates the model. Furthermore, simulations and measurements over the resonance control show very promising results