Low-Cost, Dual Circularly Polarized 2-bit Phased Array Antenna at X-Band

A low-cost, dual-circularly-polarized (CP) 2 bit antenna working at 10 GHz is reported in this work. The antenna element utilizes a square-ring patch as a radiator. By selecting the feeding direction of the T-shaped coupling microstrip line and the position of the perturbation corner, the 2 bit phase of 0°, 90°, 180°, 270° and the CP reconfigurability can be realized. An eight-element linear array is used to verify the beam scanning performance. By controlling the “ON” or “OFF” of the p-i-n diodes, the prototype array can steer the main beam from 0° to 40°. Within these steering beams, simulated and measured results have a good agreement, which verifies the functions of the antenna.