A high gain UWB human face shaped MIMO microstrip printed antenna with high isolation

Ultra-wideband (UWB) is the unlicensed frequency band from 3.1 GHz to 10.6 GHz and it provides the large bandwidth and high data rate communication. The antennas for UWB wireless systems require large bandwidth i.e. approximately 109 % . Microstrip antennas are suitable for many wireless systems due to their compact size, light weight, low fabrication cost etc. The major drawbacks with these antennas are low gain and narrow bandwidth. The multiple input multiple output (MIMO) systems require antennas with low coupling between the ports in order to minimize the interference due to signals of other ports. This paper presents the design, simulation, fabrication and measurement of a human face shaped (HFS) dual polarized MIMO monopole patch (MP) antenna for UWB applications. The HFS MIMO MP antenna utilizes two orthogonal HFS MP antennas. The HFS MIMO MP antenna operates in the frequency band from 2.8 GHz to 16.1 GHz with a notch band from 5 GHz to 6.4 GHz for rejecting the interference from the 5 GHz wireless local area network (WLAN) signals. The isolation between the antenna ports is high and the coupling parameter is less than -19.8 dB for the entire operating frequency band. The bandwidth of the antenna is enhanced by incorporating the slots in the modified elliptical patch along with the rectangular and triangular defects in the partial ground (PG) plane. The simulation and optimization of the HFS MIMO MP antenna is performed using the CST microwave suite. The presented HFS MIMO MP antenna provides high gain, good isolation between the two ports, and the wide impedance bandwidth. The HFS MIMO MP antenna is simple in structure and easy to fabricate. Input and radiation characteristics of the HFS MIMO MP antenna are presented and discussed. The bandwidth of the antenna (2.8-16.1 GHz) covers the entire UWB with elimination of 5-6.4 GHz WLAN signals. The simulated and measured results confirm that the proposed high gain HFS MP antenna with high isolation is suitable for UWB MIMO systems.