Wideband circularly polarized modified trapezoidal-shaped monopole antenna

A novel-shaped monopole antenna is proposed for wideband circularly polarized radiation and wireless systems. The antenna consists of a trapezoidal-shaped radiator and a microstrip feed line. A wideband circularly polarized radiation is achieved with modified trapezoidal-shaped radiator and ground plane. Impedance matching of the antenna is achieved by using quarter-wave transformer in tandem with microstrip feed line. The antenna prototype shows a 47% (2.84-4.58 GHz) for VSWR of 2 with a 3-dB axial ratio bandwidth of 36% (3.2 to 4.6 GHz). Overall antenna size is 38.0 mm× 40.0 mm× 0.8 mm with a maximum gain of 2 dBic.