A Parasitic Patch Antenna System with High Isolation for Full Duplex Application

This paper proposes a D-Shaped parasitic patch antenna fed with a 180° hybrid coupler for full duplex communication. This antenna has three layers of substrates. Over the top layer, there are three parasitic patches one is D shaped and the other two are rectangular shapes which are used to improve the bandwidth. A Hybrid coupler is on the bottom of the third layer. The proposed antenna has a bandwidth of 130 MHz from 2.31 GHz to 2.44 GHz with less than -50 dB isolation. It has gain over 4 dB for both TX and RX in 2.375 GHz which is the center frequency for this antenna.