A new circularly polarized monopole antenna for 60 GHz communications

This paper presents a novel broadband unidirectional circularly polarized (CP) monopole antenna. The proposed antenna, which is based on traveling wave excitation, is compact in size and simple in structure. It consists of a ground plane, a probe, and an L-shaped strip. A 4×4-element array on low temperature cofired ceramic (LTCC) for the 60 GHz band is also presented. Simulation results of the antenna array show a 3-dB axial ratio bandwidth of 30% (51-69 GHz), which is within its -15-dB impedance bandwidth. Meanwhile, the 3-dB gain bandwidth is 27% (51.5-67.5 GHz) with a peak gain of 16.2 dBi.