Broadband Phase Shifter And Switching Circuits Design For T/R Module Of Phased Array Radar

With the continuous improvement of radio technology and radio frequency integrated circuits,phased array radar has been widely used in different areas,especially in the field of military and national defense.As the front-end circuits applied to the T/R module of phased array radar,the performance of phase shifter and T/R switch directly affects the function realization of the whole T/R module.The improvement of phased array radar also makes the wideband phase shifter and T/R switch circuit covering multiple frequency bands particularly important for the multi-standard transceiver system.Firstly,the theoretical foundation of phase shifter and T/R switch as well as various common types of phase shifter structures is introduced.The advantages and defects of various topologies are compared,and the switch circuit design with different methods are discussed.Secondly,after the contrast analysis of circuits,two kinds of wideband phase shifters and T/R switches covering L/S(1.0?4.0GHz)band and L/S/C(1.0?8.0GHz)band are designed for the T/R module of phased array radar in this paper.The 6-bit digital phase shifter and switch circuit covering the L/S band and the L/S/C band are designed in different structures respectively.The L/S band phase shifter adopts a passive phase shifter which is based on the switch network phase shifter structure,and a common-source compensation amplifier is also employed in the 180 0 phase shift circuit to fine tune the insertion loss and phase error.The L/S/C band phase shifter uses active vector-synthesized phase shifter,including quadrature signal generator,gain amplifier and signal synthesizer.The various parts of the circuit are designed respectively and the overall circuit is optimized by compensation.Based on series-parallel single-pole double-throw switch structure,the matching network design and variable impedance design are employed for L/S band and L/S/C band T/R switch circuits respectively,and different improvement methods are used.Finally,the Cadence software is used in this paper to do the circuit schematic simulation,layout design and parasitic parameters extraction based on SMIC 130nm 1P8M CMOS process,and the 6-bit digital phase shifter and switch circuits design covering L/S band and L/S/C band are completed.Phase shifter circuit can achieve the required phase shift in the whole frequency range,the RMS error of phase shift is less than 2.5°,the insertion loss is less than 2dB,and the layout areas of two phase shifters are 3.1×1.7mm2 and 1.77x 1.27mm2 respectively.Both the insertion loss and isolation are considered in the switches design,and a certain power handling capacity and linearity are ensured as well.The ldB compression point is greater than 10dBm,isolation is greater than 30dB,and insertion loss is less than 2dB,the layout areas of two T/R switches are 1.17x 0.69mm2 and 0.96x 0.72mm2 respectively.The simulation results show that the circuits designed in this paper meet the performance requirements.