Square Microstrip Antenna with T-Shape Slots for Wide Band Response

Abstract

Wide band designs of square microstrip antenna by employing four T-shape slots is proposed. The appropriate placement of proximity feed and T-shape slots modifies the modal current vectors at TM₁₁ mode that along with its mutual coupling with diagonal TM₁₀ mode yields wide band characteristics. The antenna yields impedance bandwidth of around 470 MHz (>40%) with radiation pattern in broadside direction along with peak gain close to 8 dBi. Further pair of T-shape slots cut square patch is presented. The additional slots maximize current vector on the surface along patch length which yields improved radiation pattern characteristics with impedance bandwidth of larger than 480 MHz (>43%). A rectangular slot cut variation shows broadside pattern and 8 dBi of maximum gain. Proposed designs are optimized in 900 MHz frequency band which will make them suitable in mobile and wireless communication designs in 800–1200 MHz spectrum.