Design and Analysis of Wideband Stair Step-Shaped Rectangular Ring Microstrip Antenna with DGS for IoT Applications

A novel miniature wideband rectangular ring antenna is proposed for 4.6–6.2 GHz which is compatible with IoT applications. The wideband response of the proposed antenna is achieved by a partial ground and stair step structure. Because modifying the width and etching the ground plane does not improve the impedance matching over a large bandwidth, a triangular shape DGS is inserted in the partial ground plane to increase the antenna bandwidth with enhanced return loss. The wideband features of the antenna were explored here by incorporating different DGS shapes such as triangles, rectangle, pentagon, circle, and oval in the partial ground. The results have been successfully verified through measurement. The simulated fractional bandwidth is greater than 29% at 4.6–6.2 GHz whereas the measured fractional bandwidth is 27.6% at 4.75–6.2 GHz. In both cases, the maximum return loss is greater than 55 dB. The gain of the antenna is greater than 2.6 dB with good efficiency and nearly omnidirectional radiation pattern in shape. Due to its compact size and outstanding performance, the suggested stair stepshaped rectangular ring antenna could be a promising choice for IoT and wireless applications.