Research And Design Of Key Module For RF Receiver Front End Of Phased Arrays

With the development of phased array technology,it uses electronic methods to complete beam pointing scanning in all kinds of medias,and has many advantages such as high performance and multifunction,and the application range has gradually shifted from military to civilian fields such as 5G communication and vehicle radar systems The phased array of the RF phase shift architecture has the advantages of strong anti-interference ability and strong beam directivity,and has become a popular direction among them.Therefore,based on the SiGe BiCMOS process and the phased array for the RF phase-shifting architecture,a single-channel RF receiver operating at 8 to 12 GHz is designed.The channel includes a low-noise amplifier,a variable gain amplifier and a five-bit active phase shifter..For the application of phased array,the paper first introduces the common phased array architecture to determine the design direction and target,and then expands the design of the sub-module in the single channel of RF reception.Among them,the low-noise amplifier adopts Cascode structure,that is,common shot The basic structure uses parallel resistance to form negative feedback so that the output impedance tends to a fixed value in the operating frequency band.Then,a ?-type matching network is designed to achieve broadband matching.In addition,peak inductance technology is used,and the circuit is connected in parallel as a load to achieve high frequency gain It is high enough and the flatness is good.Finally,the emitter follower is used as the output stage to isolate the low noise amplifier from the variable gain amplifier.The variable gain amplifier is based on the current rudder structure,which introduces resistance-capacitance feedback,widens the bandwidth and improves the linearity.It uses a numerical control circuit to achieve five-bit gain control.The gain range is 0?-31 dB.The active phase shifter is isolated.The active phase shifter is based on the vector synthesis structure,and the required RC quadrature signal generator,vector synthesis circuit and output balun are designed separately,and finally the cascade is completed.After the phase shifter receives the differential signal output by the variable gain amplifier After passing through the quadrature signal generator,two signals of different in-phase signal I and quadrature signal Q are formed,and the vector synthesis circuit controls the amplitude of the two signals by controlling the current and then synthesizes the output to obtain equal amplitudes with different phases.The differential signal is finally converted from the output balun to a single-ended signal output to achieve five-shift phase control with a phase shift step of 11.25°.After the three sub-modules are designed and meet the requirements in the index decomposition,cascading is performed to complete the design of a single channel for RF reception.This article is designed based on the Tower Jazz 0.18?m BiCMOS process.The design time is divided into total.Under the Cadence IC software,the design and simulation of each sub-module are completed first to ensure that the requirements of prior planning are met,and then the overall single-channel integration,Layout design and simulation verification.The simulation results show that the single channel is well matched between the input and output in the required 8?12GHz working frequency band,the gain is 11.8?43.8dB,the RMS phase shift error ?3°,the RMS gain error ?0.5dB,the gain fluctuation ?1dB,noise The coefficient is ?4.5dB,which meets the design index requirements.