Experimental Studies on Microstrip Patch Antenna with Superstrate

The paper describes the effect of with and without dielectric superstrates on bandwidth, beamwidth, gain, resonant frequency, input impedance, return loss, Voltage Standing Wave Ratio (VSWR) and radiation pattern of rectangular microstrip patch antenna. It is found that there is a slight degradation in the performance of the antenna when the superstrate is touching the patch antenna. In particular, the resonant frequency decreases with increase in the dielectric constant of the superstrate thickness. In addition, it has also been observed that return loss and VSWR increase, however, bandwidth and gain decrease with the dielectric constant of the superstrate thickness. The microstrip patch antenna without dielectric superstrate achieves an impedance bandwidth of 0.203 GHz (SWR < 2) at 2.4 GHz, compared to microstrip patch antenna with dielectric superstrate, which shows that the resonate frequency is decreased to 2.31 GHz from 2.40 GHz, impedance bandwidth to 0.040 GHz from 0.200 GHz (SWR < 2) at 2.30 GHz and the gain to 2.80 GHz from 7.30 GHz. The optimum gain is obtained at Îr2 = 2.2. This type of antenna is mainly used in wireless and Bluetooth applications.