A Low-Cost, Single-Layer, Dual Circularly Polarized Antenna for Millimeter-Wave Applications

摘要

This letter presents a low-cost, single-layer, dual circularly polarized (CP) series-fed antenna based on the sequential rotation technique for millimeter-wave (MM-wave) applications. The series-fed working form endows the proposed antenna with more compact structure and lower ohmic, dielectric losses caused by the feeding network compared with parallel-fed antennas. The curved microstrip transmission lines are adopted as radiation elements; therefore, the whole antenna can be etched on a single-layer laminate using standard printed circuit board technology. These characteristicsmake the antenna a competitive candidate for MMwave applications. To validate the proposed design, a dual-CP antenna operating at 30 GHz is fabricated. Based on the measurement, the proposed antenna has a 3 dBgain bandwidth of 1.97 GHz, the measured vertical bar S-21 vertical bar is lower than -20 dB, and the axial ratios are lower than 3 dB in the aforementioned frequencies.