Mesh-Network Equivalent Model for Unified Rectangular Microstrip Antenna Analysis

A generalized mesh-network equivalent model for a microstrip rectangular patch antenna (RPA), which is simple yet efficient is proposed, studied, and demonstrated in this article. The mesh-network equivalent model is established through the segmentation of RPA width and radiation parameters into M sections, as well as the segmentation of RPA length into N sections. A general design procedure to realize the mesh-network equivalent model is addressed and described for any number of RPA segmentations, as desired by specific applications. Subsequently, the proposed mesh-network equivalent model is used to accurately evaluate the input impedance responses at various feed positions along the length of RPA. In addition, to include the effects of a slot etched inside the RPA geometry, a generalized microstrip coupled line equivalent model is proposed, analyzed, and discussed in detail. Eventually, the microstrip coupled line model in conjunction with the proposed mesh-network equivalent model can accurately estimate the input impedance response of a slotted RPA, and has been verified for RPA with center slot, edge slot, and multiple slots as examples in this work. Two cases with multiport excitation of RPA are also analyzed and presented as a part of this work. For demonstration purposes, all these prototypes are designed, fabricated, and measured at 28 GHz. The proposed equivalent model-based results are validated by measured and simulated counterparts. Furthermore, the extension of the proposed mesh-network model to accommodate slots of smaller size inside RPA, RPA loaded with via, inverted-F antenna, and multimode operation are demonstrated and discussed through a comparison between mesh-network modeling results and simulation results.