Effect of Finite Dimension of the Substrate on the Performance of Microstrip Antenna

Present wireless communication systems needed high gain, low profile, low volume, low fabrication cost, easy to implement, high-efficiency antenna. A microstrip antenna can provide all these mentioned features [1]. A microstrip antenna consists of four elements. The conducting patch that acts as radiator, substrate that acts as base material, conducting ground plane and strip line that provide interface between source and antenna. The prime disadvantage of the microstrip antenna is narrow bandwidth, which restricts it for many applications, where wider bandwidth is required [2]. Therefore, the big challenge designing of microstrip antenna is to increase the bandwidth. Various methods have been studied [3, 4] and reported to increase the antenna’s bandwidth. The effect of slots is also presented in many literatures [5, 6]. The substrate has a vital role in the characteristic of microstrip antenna. The height of substrate with low dielectric constant offers good efficiency and wide bandwidth, but it needs larger element [7] and hence increases the size of antenna. Simplicity in structure and of the antenna finds many wireless applications for X-band frequency range.