A broadband stacked patch antenna with enhanced antenna gain by an optimized ellipsoidal reflector for X-band applications

A broadband stacked patch antenna, based on an aperture coupled feeding with two patch elements is presented. The transmission line model is introduced as one possibility for the design of an aperture coupled antenna. 3D electromagnetic field simulations are used for optimization and allow a detailed investigation of the influence of the different antenna parameters on the return loss and the antenna gain. To minimize the effect of an undesired formed opposite side lobe of the antenna, resulting in a poor front-to-back ratio, an optimized ellipsoidal reflector is presented to focus the radiation in one main direction. A good return loss in a bandwidth of more than 4 GHz, i.e. 42%, with a maximum antenna gain of 18.1 dBi is achieved. A first prototype verifies the simulation results and the functionality of the developed antenna design.