Dual Polarized Multiband Stub and Slot Loaded Semicircular Microstrip Antenna

A multiband configuration using semicircular patch fabricated on glass epoxy at height of 1.58mm was reported. The patch was loaded with a stub and a slot. Three bands were observed respectively at 3.5GHz with gain of 1.5dBi due to patch, 2.45 GHz with gain of 1.2dBi due to stub and 5.5GHz with gain of 1.8dBi due to slot. However detailed explanation of various resonant modes for getting multiband dual polarized response was not given in the reported work. In this paper a detailed analysis using resonance curve plots, return loss plot and vector surface current distributions explaining the multiband dual polarized response of reported work is presented. It is observed that length variations of stub and slot modify various modes of semicircular patch in such a way that results into multiband band dual polarized response. The dimension along with position of slot and stub with given feed location causes matching input impedances of TM10, TM31 and TM32 modes which results in multiband dual polarized response.