Microstrip Patch Antenna for Single Resonant Frequency Using Various Types of Slots

Microstrip patch antennas are widely utilized in WLAN applications, and body-centric wireless communication relies on multiple network links to get messages through. But the existing antenna size is big with less bandwidth, which increases the cost. This paper has taken a rigorous approach to design an antenna that will provide a single resonant frequency at the targeted bandwidth (2.45GHz). The patch size in the proposed antenna is 28mm by 27mm and energized by a 50 ohm microstrip feed line with dimensions 3.137mm by 18.35mm. The dielectric substrate of permittivity Er = 4.3 is used in the fabrication process. The optimal size and other antenna characteristics are found by finite difference time domain method based CST Studio Suite. Other parameters like return loss, input impedance, and bandwidth of the microstrip patch antennas are calculated using VNA and WATS software to verify the proposed work. Finally, the proposed slot-loaded antenna attains an improved bandwidth and gain while providing a single resonant frequency.

I. Introduction

In the digital era, communication plays an influential role in well-known places, and the communication system could be classified into wireless and wired according to the medium. The antenna is essential to transmit and receive signals efficiently in wireless communication. Though regular microstrip antennas have many benefits, they have three significant disadvantages: low gain, narrow bandwidth, and relatively larger antenna size. But the top problem for these antennas is narrow or limited bandwidth [1]. The conventional microstrip antennas’ operation frequencies depend on the electrical size of the antenna, specifically at the lowest microwave frequencies; for this reason, these antenna’s sizes are relatively larger than others. So, the larger size is the main limitation of these antennas. Typically, the rectangular microstrip antenna size should be the order of a half-guided wavelength. Wheeler [2] and Chu [3] studied the mathematical limitations and discussed them in their papers.