MIMO antenna with UWB characteristics and sharp multi-stop band characteristics

Abstract

Abstract With multi-band rejection characteristics, a new low profile antenna of size 34x34 mm2 is conferred in this article. It consist of quad identical monopole elements (originated orthogonally), contributing ultra-wide band characteristics in the system. The single unit of the proposed design consists of modified spinning-top shape radiator (MSTSR), excited by tapered micro strip line feed (TMLF) and semi-circular ground. An excellent bandwidth of 3-12.9GHz (where S11<-10dB) is obtained at each port. By inserting structure of four spirals coils, a sharp notch ranges from 7.9- 8.5GHz is achieved to filter X-band satellite communication uplink. In addition, a circular spiral slot in radiator near the ground plane create stop band at 7.35- 7.565GHz band (satellite communication downlink band). Furthermore, symmetrical rectangular trapezoids resonators and inverted symmetrical rectangular trapezoid structures near the feed line are responsible for elimination of interferences at 5.5GHz lower WLAN and 3.5GHz WiMAX respectively. The FR-4 substrate used for UWB-MIMO design fabrication process and fabricated results are found in good match with the simulated results. Also, the design provides good performance metrics such as total active reflection coefficient, diversity gain, channel capacity loss, isolation, and envelope correlation coefficient.