1-Bit Programmable Circularly Polarized Beam Scanning Array Based on PB Phase

A low-profile 1-bit programmable circularly polarized (CP) beam scanning array based on PB phase is proposed in this paper. The current direction can be changed by regulating the PIN diodes to achieve 0° and 180° phase, i.e. 1-bit. Furthermore, the CP antenna can be rotated in-plane to obtain different initial PB phases. The initial PB phase of each array element is optimized by a genetic algorithm (GA), which effectively eliminates the 1-bit array grating lobe to achieve a single beam scan. The introduction of the PB phase simplifies the way in which the initial phase is fed through the phase shifter. This greatly simplifies the design complexity of the power division and improves the scalability of the array. Simulation results confirm that the proposed 1-bit CP array has no grating lobes and the side lobes are below -10 dB for beam scans of (θ, φ), where φ = [0°,45°, 90°, 135°] and θ = [0°, 15°, -15°, 30°, -30°, 45°, -45°].