Design of programmable digital phase shifter circuit

Based on the core requirements of programmable RF devices for multi-beam phased array technology, this study innovatively constructed a phase-adjustable and programmable digital phase-shifting system solution. Firstly, an integrated design was carried out for the FPGA control module, level conversion unit, and phase shifter RF circuit hardware system. Secondly, a dual-channel independent control system was built using Verilog HDL, and a serial port + RS232 hybrid communication protocol was adopted to provide software support for the entire system. Finally, a physical prototype was developed, and the phase-shifting effect was verified using a network analyzer. The measured data show that at the center frequency of 9.37 GHz, the Root Mean Square(RMS) phase error is 6.5°, the insertion loss is ≤ 6 dB, the switching time is < 15 μs, and the power capacity is 1.5 W. Particularly, at the phase edge value of 355°, a good VSWR performance of 1.2:1 is maintained. This study successfully achieved precise phase control of X-band (8G~12 GHz) RF signals, and its dual-channel independent programming control capability provides a hardware foundation for multi-beam forming systems. It offers an expandable technical platform for the beam control system of the next-generation phased array radar and has significant application value in satellite communication, millimeter-wave imaging, and other fields.