A Low-Profile Dual-Polarized Transmitarray with Enhanced Gain and Beam Steering at Ku Band

A low profile dual polarized transmitarray antenna, made of three identical layers, is proposed in this paper for Ku-band applications. The transmitarray comprises 22 × 22 symmetrical unit cells. A 3-bit phase compensation layer with less than αT = 1.3 dB transmission loss and 2π transmission phase coverage for both linear polarized components at the central frequency f0 = 12 GHz is designed. Moreover, for an incidence angle θ = 30°, the unit cell transmission loss is less than 2 dB; the transmission phase is close to the transmission phase at zero incidence angle θ = 0°. The fabricated transmitarray exhibits a measured peak gain of Gm0 = 21 dB at the frequency f0 = 12 GHz. The corresponding measured 1 dB gain bandwidth is BWg = 10.8% (11.1–12.4 GHz). The measured peak side lobe levels are SLL0 = −20.8 dB at f0 = 12 GHz. The transmitarray antenna can be used for beam steering up to an angle of γmax = ±30° with a measured scan loss △GMSL1 = 2.73 dB at f1 = 12.4 GHz.