Four-way beam steering monopole array antenna with switched feeding network

Abstract

A simple four-element monopole array antenna is presented for four-way electronic beam steering. All four identical elements operate as a radiator or reflectors through the centre fed coplanar waveguide feeding network with an offset switching structure. This enables the easy optimization for gain, front to back ratio and the input return loss. The designed antenna shows the measured return loss below −14 dB in 2.35 GHz–2.55 GHz band and the 5.7 dBi gain with the front to back ratio (FBR) of 11 dB.