Enhancing the bandwidth of rectangular microstrip antennas through design optimization of feeding methods

Abstract

Antenna is one of the most critical component for wireless communication systems. The antenna must also be adaptive to act as a directional device to optimize or accentuate the transmitted or received energy in some directions while suppressing it in others. A good design of the antenna can be very useful in improving the overall system performance. Microstrip antennas have many attractive features which has considerable attention for wireless communication applications. Researchers are engaged in removing this limitation and many techniques have been proposed for the design of wideband antennas for wireless communication systems. Methods for increasing the bandwidth of microstrip antenna are continuously getting upgraded. Undoubtedly the simplest microstrip antenna configuration is rectangular microstrip parch antenna. Hence this investigation deals with rectangular microstrip antenna. The prototype antenna 2 demonstrates that a broadband rectangular microstrip patch antenna with narrow slots and parasitic element. This antenna is excited by an L-probe fed. The bandwidth is improved by two parallel narrow slots on the main patch and parasitic patch. The design provides a simulated impedance bandwidth of 71.33% with gain of 8.6dbi. It has been observed that additional gap-coupled parasitic element yields considerably wider impedance bandwidth. This antenna configuration can be used in applications where wider impedance bandwidths are needed and variations in the radiation pattern are tolerated. The main patch is excited by proximity coupling. This antenna provides a dual frequency response with the simulated impedance bandwidth of 63.35% and 33.48% with a gain of 6 dBi. The design demonstrates that all the three antennas overcome the inherent narrow bandwidth of the conventional microstrip antenna. The main advantages of these antennas are their improved bandwidth with the acceptable performance of low return loss, good gain and radiation characteristics. newline newline newline