Millimeter-Wave Wideband Magnetoelectric Complementary Source Circularly Polarized Antenna

A millimeter-wave wideband circularly polarized (CP) antenna based on magnetoelectric complementary source is proposed. The antenna element is composed of an x-polarized magnetoelectric complementary source antenna (MECSA) and a y-polarized microstrip dipole antenna (MDA). Circular polarization is achieved by controlling the phase difference between the two antennas. The axial ratio (AR) bandwidth of the antenna is further extended by the introduction of a microstrip loop. Based on the proposed antenna element, a 1×4 antenna array is designed to achieve higher gain. Finally, the antenna element and array are fabricated and measured to verify the proposed design. The measurement results of the proposed CP antenna element show -10-dB impedance bandwidth of 63.2% (26–50 GHz), and 3-dB AR bandwidth of 47.4% (29–47 GHz) with peak gain of 9.6 dBi. While the antenna array has -10-dB impedance bandwidth of 45.2% (26.4–41.8 GHz), 3-dB AR bandwidth of 46.8% (26.7–43 GHz), and 3-dB gain bandwidth of 47.1% (26-42 GHz). The proposed design has several advantages, such as wide overlap bandwidth and easy integration, which makes it suitable for wideband applications in millimeter-wave communication systems.