Proposal of wide bandwidth and very miniaturized having dimension of μm range slotted patch THz microstrip antenna using PBG substrate and DGS

Abstract

In this paper, a wide bandwidth (26.4 GHz) and very small sized (180×210×10 μm3) slotted patch terahertz (THz) rectangular microstrip antenna using photonic band gap (PBG) substrate and defected ground structure (DGS) has been proposed and analyzed. At first a very compact with dimension of μm range rectangular microstrip patch antenna (RMPA) was designed by using computer simulation technology microwave studio (CST-MWS) at the operating frequency of 0.685 THz, which shows return loss of −30.552 dB, wide bandwidth of about 26 GHz, gain of 5.145 dBi, directivity of 6.727 dBi and VSWR of 1.061. Then we introduced PBG structure as substrate by creating same distant as well as same sized air gaps on the substrate. In that case the performance of the antenna is improved significantly than the previous one. Its return loss decreased to −38.973 dB at resonating frequency 0.701 THz. Its gain and directivity get increased to 5.156 dBi and 6.833 dBi respectively. Bandwidth is also enhanced compared to the previous one with a VSWR of 1.023. Next we have done some experiment by creating defects in ground plane. We optimized the dimensions of the defects and got better performance of the antenna having 0.704 THz resonant frequency with more minimized return loss of −47.862. Gain of this antenna is 5.090 dBi and directivity is increased to 6.835 dBi. Its VSWR is of 1.008 with the improved bandwidth. Finally, we have made some circular slots on the radiating patch and got best results. The final design of antenna resonates at center frequency of 0.703 THz with a return loss of −50.948 dB. The gain and directivity of the proposed antenna are of 5.075 dBi and 6.833 dBi respectively. The antenna shows VSWR of 1.006 which is very much close to unity (1) with the enhanced bandwidth compared to the all previously designed antenna.