Analysis and Design of a Low-Cost Circularly Polarized Horn Antenna

A millimeter-wave wideband circularly polarized (CP) horn antenna with no requirement of an orthogonal mode transducer feeding is reported. The horn antenna has a simple structure, which consists of an antipodal curvedly tapered slot antenna and a circular waveguide. The CP principle of the horn is explained. A series of parametric studies was carried out to estimate the effect of key parameters, and the design procedure is also presented. The measured results are in reasonable agreement with the simulation results. The experimental results indicate that the proposed antenna can achieve a bandwidth of 40% (50-75 GHz) for both the axial ratio <; 3.2 dB and the reflection coefficient S
₁₁
<;-10 dB. The proposed antenna is easy to manufacture and is a good candidate for the low-cost wideband CP horn antenna.