A Broadband Low-Profile Circular-Polarized Antenna on an AMC Reflector

A broadband low-profile circular-polarized (CP) antenna on an artificial magnetic conductor (AMC) reflector is proposed in this letter. The basic wideband circular polarization radiation characteristic of the antenna is achieved by feeding broadband crossed dipole through a 90° phase shifter. An AMC reflector is further introduced to realize a broadband low-profile CP antenna. The impedance bandwidth (VSWR <; 2) of the present CP antenna is about 1.19-2.37 GHz (66.3%), and the axial-ratio (AR) bandwidth (AR <; 3 dB) is about 1.25-1.97 GHz (44.7%). The antenna has a low profile of 20.1 mm (about 0.12 λ
₀
at the center frequency of 1.78 GHz). The simulated and measured results show that the proposed CP antenna has wide impedance and AR bandwidth in the condition of low profile.