Design of Variable Bandwidth Phase Modulation Signal Generator Based on FPGA

ZHANG Wenduo; WANG Chuang; SUN Hongyue

doi:10.3969/j.issn.1672-9730.2023.11.014

Abstract：Broadband signal is a kind of signal commonly used in communication field,and spread spectrum bpsk based on DSSS principle is also a kind of phase modulation method commonly used in extended frequency band.This paper studies the princi-ple of pn code and binary phase shift keying modulation,and designs the hardware circuit with FPGA as the core,including power supply,clock and storage.The program of PLC is compiled,including the specific algorithm and the communication between them.The design of variable bandwidth phase modulation signal generator is completed.The signal generated by the signal generator has a wide bandwidth,and the pbrs order of the signal can be selected from order 2 to order 25.The signal width can vary up to 100MHz,and the carrier can reach 3GHz at this time.The carrier frequency is variable and can reach 4.1 GHz at 40 MHz bandwidth.There are four phase modulation modes available.Users can input corresponding information for modulation as required.The designed out-put signal is flexible.The output signal is very stable and can be modulated on a carrier with a higher frequency.Compared with the common signal generator,it is more flexible and can output not only narrowband signals but also wideband modulated signals.It can replace some broadband modulation modules,can be used in communication fields such as high frequency and short wave,and can also be used to provide signals for other equipment during normal measurement and experiment.