Design And Research Of Broadband Intelligent Microwave Digital Phase Shifter

Phase shifters are widely used in communication,radar,electronic countermeasure and microwave automatic measurement systems,especially in phased array antenna and radar systems.The agile communication radar system works at wide bandwidth while its instantaneous input signal has narrow bandwidth.It puts forward higher requirements for various technical indicators of the phase shifter including bandwidth,phase shift accuracy and pass band balance.Therefore,the design of broadband high-accuracy phase shifter has become a subject of widespread concern in academic and industry.In this thesis,a new method of combining sub-band combined vector modulation technology with intelligent detection and compensation technology is designed.And a four octave V/UHF band broadband microwave digital phase shifter is designed based on the method.The specific work is as follows:The first aspect,the sub-band combined vector modulation technique is proposed to achieve broadband digital phase shift.First,based on the analysis of the design scheme of phase shifter and discussion of employing the digital vector modulation technology to realize the phase shifter,we design a narrowband digital vector modulation phase shifter and test the phase shift error.Based on the narrowband phase shifter we designed,the sub-band combined vector modulation technology is proposed to achieve broadband phase shift,and the corresponding hardware circuits and software are designed based on the technology.The experimental results show that broadband phase shift is achieved at the operating band,but there are deficiencies in accuracy and pass band balanceThe second aspect,the thesis proposes intelligent detection and compensation technology to achieve intelligent broadband digital phase shift.In order to meet the requirements of high accuracy and good pass band balance and take the narrowband characteristics of the input signal into consideration,an intelligent detection and compensation system is proposed and designed.By detecting the frequency of the input signal,the system analyzes the verification test results using software and adjusts the parameters of the phase shift and the gain of the amplifier.The system then performs compensation and correction through the hardware to improve the phase shift accuracy and achieve intelligent error compensation in order to meet the requirements of broadband and pass band balance.The system design is mainly composed of two parts:design of frequency detection and design of amplitude compensation.The thesis introduces the implementation process of system hardware and software and gives the test results.The experimental results show that the intelligent detection and compensation technology is effective.In summary,the combination of sub-band combined vector modulation technology and intelligent detection and compensation technology proposed in this thesis solves the problem of unsatisfactory performance of the phase shifter in terms of bandwidth,phase shift accuracyand pass band balance.The scheme we proposed also provides brand-new design ideas for related engineering applications.