The Study on the Effect of Frequency Selective Surface to the Return Loss of Microstrip Array Antenna at 28 GHz Frequency

Abstract

Microstrip Array Antenna has been operated at 28- GHz because of the basic features of the famous microstrip patch. The purpose of this research is to study the effects of Frequency Selective Surface (FSS) on the return loss of microstrip array antenna. In this research, Rogers Duroid RT5880 with a dielectric constant r is 2.2 and the thickness is 0.254 mm is chosen to be the based substrate. Frequency Selective Surface (FSS) is used with air gap separation, which is 1-wavelength is 10.7143 mm. This research proposed a triangle shape rather than a circle, which is a conventional shape that significantly enlarges the fringe capacitance to compress the overall size of unit cell. The CST Microwave Studio 2016 software has been used. By selecting optimum parameters, the simulated return loss of the proposed antenna with and without FSS is -64.677 dB and -37.621 dB respectively. The results for both simulations fall at 28 GHz. After the fabrication and measurement, the result shifted forward by 1 GHz. At 29 GHz, the result with FSS and without FSS is -43.55 dB and -36.71 dB respectively. Both of result simulation and measurement can be used since the results of both are more than 1 GHz.