Phased Array Antenna Structure Based on Novel 6-Bit Phase Shifter for Wi-Fi Communication Systems

This paper proposes a structure for a 6-bit loaded-reflection phase shifter based on short-circuited stubs loaded with varactor diodes, designed for phased array antenna applications. The structure prototype is created by combining a stage of a new 4-bit loaded-reflection phase shifter structure with a cell of transmission line loaded with a shorted stub and a varactor. The different phases are produced by tuning the capacitances of varactor diodes across different values. The proposed 6-bit phase shifter structure has demonstrated 64 different phases with a phase shift of 5.625° ± 1° over 2.4-2.5 GHz in simulation results. The reflection coefficient results vary between -25 dB and -10 dB over the 2.4-2.5 GHz Wi-Fi band, while the insertion losses are tuned between -0.2 dB and -3 dB. The design of the structure is compact, measuring approximately 40 mm by 30 mm at 2.45 GHz. A phased array antenna, based on the proposed 6-bit phase shifter, has been developed to cover a scanning range of ±30° with a scan angle of 7° at 2.45 GHz. Simulated results demonstrate the production of eight scan beams around the broadside at [-30°, -22°, -14°, -7°, +7°, +14°, +22°, +30°].