A Broadband Circularly Polarized Printed Monopole Antenna With Parasitic Strips

A novel printed monopole antenna is presented for circular polarization (CP) operation with broad axial-ratio (AR) bandwidth. The antenna is composed of a monopole, a ground plane, and two parasitic strips. By utilizing two spiral strips coupled by the monopole, broadband CP radiation is achieved. The measured results show the 10-dB impedance bandwidth is 2.75 GHz (1.75-4.5 GHz) and the antenna also has a 3-dB AR bandwidth of 64.7% (2.2 GHz, 2.3-4.5 GHz). The proposed antenna features simple structure and broad AR bandwidth, which is desirable for various wireless communication systems.