Dual-band dual-polarized sub-6 GHz phased array antenna with suppressed higher order modes

Abstract This manuscript proposes a dual-band dual-polarized 64-element phased array antenna (PAA) with suppressed higher order modes (HoMs). Each array element is a microstrip patch structure with complementary split ring resonator (CSRR) loading, allowing for simultaneous dual-band and dual-polarization performance at 3. 45 GHz and 3. 87 GHz. The proposed PAA exhibits impedance matching of - 20 ≤ - 20 dB at 3. 45 GHz and 3. 87 GHz while limiting the mutual coupling below - 19 - 19 dB between the adjacent elements at both the operating bands. The proposed design includes a plated through hole placed near the CSRR loading to suppress any higher-order modes (HOMs). Two antenna prototypes, without and with HOMs suppression techniques are fabricated and measured. In addition, we demonstrate the beam steering of the proposed PAA up to 60⁰ ± 60 0 using an off-the-shelf 6-bit phase shifter module. The proposed 64 -element array achieves a gain of 23 dBi, and shows a minimal steering loss of 3 ≃ 3 dB over the steering angle.