Research Of Mems Microwave Communicated Signal Detection And Demodulation Monolithic Integrated System For Adaptive Radar

The adaptive radar system plays an extremely important role in today's communication systems,especially in frequency-hopping communications.In the frequency-hopping communications,microwave signals have the characteristics of large power dynamic range and real-time hopping of phase and frequency values.The working frequency of the adaptive radar system is becoming wider and wider,which greatly increases the design difficulties of adaptive radar systems.Generally speaking,to measure an unknown microwave signal,you need to know three parameters: power,frequency,and phase.The most existing sensors that can detect microwave power,frequency and phase are basically independent devices,which can not realize the measurement of these three major parameters at the same time.In addition,these sensors usually can only work in a narrow frequency band,which limits its application in adaptive radar systems.For this reason,a microwave signal monolithic integrated system capable of realizing a wide frequency band,a large dynamic detection range,and simultaneously detecting three parameters of the microwave signal is urgently needed to meet the application requirements of the adaptive radar system in frequency hopping communication.In view of the above requirements,this paper designs four different types of MEMS microwave power sensors to compare their power sensing mechanisms in different environments.At the same time,a wideband MEMS microwave frequency sensor and a wideband MEMS microwave phase sensor based on the dual-frequency power divider/combiner are studied.At last,this paper finally proposed a single chip integrated system for detection and demodulation of microelectronic mechanical microwave communication signals covering X-band.The main innovations in this subject include:(1)A series of MEMS thermoelectric microwave power sensors with different terminal load sizes are designed and the effects of load size changes on microwave performance are studied.A MEMS capacitive microwave power sensor with a curved cantilever beam is designed to study the nonlinear compensation in a high power environment.A cascaded microwave power sensor based on a MEMS cantilever beam and a MEMS thermoelectric microwave power sensor is designed to increase the dynamic detection range of microwave power.A new MEMS bridge-type microwave power sensor is designed.Compared with the traditional thermal resistance power sensor,its sensitivity and stability have been greatly improved.Through analysis and comparison,MEMS thermoelectric microwave power sensors have the advantages of good linearity,high reliability,and easy integration.This paper will use this structure as the terminal sensor of the microelectronic mechanical microwave communication signal detection and demodulation monolithic integrated system.(2)A RF receiving front-end model based on MEMS online frequency detection is researched.Through the coupling characteristics of MEMS fixed beams,the output frequency of the VCO can be controlled at the same time as frequency detection.So it can achieve the adaptive oscillation frequency output of MEMS microwave receivers.Furthermore,a microwave frequency sensor based on the dual-frequency power divider/combiner and the MEMS thermoelectric microwave power sensor is designed.The dual-frequency characteristic of the dual-frequency power divider/combiner is employed to broaden the entire microwave bandwidth of the frequency sensor.(3)A microwave phase sensor based on the dual-frequency power divider/combiner and the sandwich-type MEMS thermoelectric microwave power sensor is designed.The the dual-frequency power divider/combiner can effectively broaden the operating bandwidth,while the sandwich type MEMS thermoelectric microwave power sensor can effectively improve the power capacity through the optimization of the thermopile structure.Finally,the phase detection function in a wide frequency band and high power environment can be realized.(4)A single-chip integrated system for detecting and demodulating microelectronic mechanical microwave communication signals based on the dual-frequency power divider/combiner is proposed.The integrated system employs a one-to-four topology to integrate MEMS microwave power sensors,wideband MEMS microwave frequency sensors and wideband MEMS microwave phase sensors.Among them,MEMS microwave power sensors can both realize power detection and direct demodulation of microwave modulated signals,while wideband MEMS microwave frequency sensors and wideband MEMS microwave phase sensors can achieve frequency and phase detection in a wider frequency band.Furthermore,in order to better target adaptive radar systems,peripheral design circuits including amplification,filtering,calibration,and LCD display are specifically designed.The power,frequency and phase values of the microwave signal to be measured can be displayed more intuitively.