Wideband high-efficiency unit-cell for 1-bit and 2-bit transmit-arrays operating in X-band

A new attractive elementary cell is proposed for 1-bit and 2-bit transmit-arrays in X-Band, where the wideband and low loss characteristics are crucial. The proposed unit cell consists of two identical square patch antennas include C-loop slot and interconnected in their centers by a metalized via hole. The unit cell exhibits a simple three-layer metallic structure and allows standard printed-circuit board fabrication technology. The elementary cell is designed and verified using finite element method simulation. A waveguide measurement system (WGMS) has been utilized for S-parameters characterization. An excellent agreement has been obtained between the simulations and the measurements in terms of impedance matching (S₁₁<;-10dB for the range 9.39 GHz -10.26 GHz, 8.8% around 9.85 GHz) and insertion loss (0.36 dB at 9.85 GHz). The proposed unit cell is an excellent candidate for a 1-bit active cell by integrating two PIN diodes in the order to control its transmission phase (E-field opposite orientation).