Abstract—Since its introduction 25 years ago, the probe-fed Uslot patch antenna has remained popular. Recently, Characteristic
Mode Analysis (CMA) revealed these devices are governed by
Coupled Mode Theory (CMT). Although this principle is
conceptually simple, achieving this understanding is only possible
through a systematic analysis using CMA. This paper uses the Uslot patch to illustrate a general process for analyzing electrically
small antennas using CMA with the software package FEKO.