Enhancement of Higher Order Modes Using Characteristic Mode Analysis

This paper presents a design approach to enhance the excitation modes on a rectangular patch using characteristic mode analysis (CMA). The design begins with a rectangular patch of 18×20 mm2 dimensions. Thereby introduced a truncation on the bottom edge of the patch which excites an additional two higher-order modes from the basic lower-order modes. By arranging truncation in a step-like pattern with extended slot produces four modes at 7.3 GHz, 9.7 GHz, 12.12 GHz, and 12.21 GHz is concerning Mode1, Mode2, Mode4, and Mode5, respectively. The excited modes and their surface current distribution will provide physical insight into the design of either wideband or multiband operation. This can be achieved with proper optimization of the feed line.