Simplified Transmitarray Unit Cell for 1-Bit Beam-Steering Operation

In this paper, a simplified design of transmitarray unit cell for 1-bit beam steering operation is proposed. It can provide 1-bit phase quantization by switching on/off the loading capacitors, which could be realized by using varactors and switching the dc bias voltages between a predetermined value and zero. The proposed unit cell is made of two identical, back-to-back rectangular patch antennas, coupled through a ground slot. Each patch is cut into halves by a transverse slit, at the middle of which the varactor is loaded. For preliminary verification, two test pieces of fixed-beam X-band transmitarray (0° and 20° from broadside, respectively) based on the proposed unit cell (loaded with and without capacitors) are fabricated and tested. The agreement between the simulated and measured results is satisfactory.