Dual wide band circularly polarized circular patch antenna with two half parasitic rings and defected ground structure

A design of dual wide band circularly polarized circular patch with parasitic ring and defected ground structure. By using the coaxial probe feed 45° with respect to the axis of the two stub plane of the patch then excellent circular polarization (CP) is achieved. The antenna is designed with a double-layer structure, comprising a circular patch with two rectangular stubs along the diameter direction and two half parasitic rings right above it. Both patch are separated by a circular substrate FR-4 (εr = 4.3). The ground plane also defected; two circular slots are cut away at the ground plane. By using the defected ground structure (DGS) the band width also increased. This proposed antenna work at dual wide band that are 6.90 to 7.10 GHz (200 MHz) and 8.06 to 9.22 GHz (1.16 GHz). The % band width is 2.69% and 13.42% and Gain is 6.2 dB and 8.3 dB respectively. The return loss & gain of the proposed antenna show that it has promising characteristics for various C-band and X- band (7-12 GHz) radar and satellite applications. The design is being simulated using CST (computer simulation technology) software.