Design and fabrication of triple frequency microstrip patch antenna by attaching tuning stub element

This effort aims to design and fabricate a triple frequency rectangular patch antenna, by attaching a single stub element of a varying length (rectangular-shaped), to the top left corner of radiating edge of the patch, to act as a tuning network. The patch and the stub are excited through a 50 Ohms insert-fed line, connected to a midpoint of the patch. The whole structure is embedded on a single FR4_epoxy substrate. Methodology of this work is based on trial and error. Behavior of proposed prototype antenna was discussed in terms of three simulated and measured analytical parameters, return loss, Voltage Standing Wave Ratio and input impedance of the patch. Three measured resonant frequencies are 4.71 GHz (C band), 10.6 GHz (X band) and 11.85 GHz (X band) were achieved for 7 mm stub length. HFSS13.0 was used as a software tool.