Design of an Active Microstrip Antenna with High Impedance Ground Planes through a MoM-GA Optimization Procedure

The paper presents the design of an active microstrip antenna for Wi-Fi applications. The proposed antenna is backed by an High Impedance Ground Plane (HIGP) to minimize the interactions with possible radiating and transmissive microwave components residing nearby. The presence of the HIGP, made by a pattern of periodic corrugations with dimensions much smaller than the operating wavelength, makes the design procedure somewhat complicated. TheHIGP image currents, in fact, strongly affect the behaviour of the patch when it operates as an isolated component and a very extensive trial and error procedure is usually needed to obtain the final antenna layout. Due to huge number of unknowns characterizing the proposed problem, this procedure is not viable and a dedicated optimization procedure is needed. In our work, the design of the active circuitry is demanded to a commercial software (AWR Microwave Office), while the design of the radiating component is performed through an in-house hybridization of a Method of Moment (MoM) numerical tool and a Genetic Algorithm (GA) search procedure. The latter hybrid procedure allows obtaining the final layout of the active antenna in a very straightforward way. Some numerical and experimental results are also presented to show the accuracy of the proposed method and the improved features obtained through the exploitation of an HIGP