A Wideband Dual-Circularly Polarized Transmitarray Antenna Based on Magnetoelectric Dipole Elements and Source

A dual-circularly polarized (dual-CP) transmitarray (TA) antenna with the capability of providing independent beamforming for each polarization across a wide bandwidth is proposed in this paper. To achieve such functionality, a novel wideband magnetoelectric (ME) dipole TA element simultaneously processing a 360° transmission geometric phase coverage, and a 160° transmission propagation phase coverage is designed. The element is composed of two back-to-back dual-polarized (DP) ME dipoles and a transition structure. The geometric phase is related to the element rotation angle and the propagation phase is controlled by the transition structure. Based on the hybrid phase compensation technique, the left-/right-hand CP waves from the ME dipole feed can be independently manipulated by the TA and reradiated out with the opposite handedness through two separated channels. For validation, a wideband Ku-band TA antenna with the left-hand CP (LHCP) beam pointing to 15° at the xoz plane and the right-hand CP (RHCP) beam pointing to -15° at the yoz plane is designed, fabricated, and measured. A full metal ME dipole integrated with a dielectric polarizer is used as the feed. The experimental results demonstrate an effective bandwidth of 35.7% (for the reflection coefficient ≤ -10 dB, gain variation ≤ 3 dB, and axial ratio (AR) ≤ 3 dB) with a peak realized gain of 22.2 dBic with a RHCP feed and of 34.6% with a peak realized gain of 22.7 dBic with an LHCP feed. With the merits of wideband performance and independent beam controllability for each CP polarization, the proposed dual-CP ME dipole TA antenna is promising for satellite communication systems. © 2025 IEEE.