The Design Of Microwave Sensor For Materials Uniformity Test

With the maturation of microwave technology,the microwave non-destructive testing as a new detection technology,compared to other detection technology has many significant features.One of the important areas of application is the detection of dielectric material properties.In this paper,the test method for uniformity of large-sized plate-like media is studied.The microwave test sensor is designed to realize the rapid extraction of the measurement parameters,which greatly improves the detection efficiency.This test program as a means of product quality monitoring with high practical value can be widely used in industrial production.The main content includes the following aspects:First,access to the relevant literature,the various types of microwave non-destructive testing methods and their characteristics were analyzed.Select the transmission method as the basic test method,the basic scheme of using the multi antenna probe array and the microwave switch to realize the fast measurement of the electric scanning is determined.And designed the experiment to verify the program,the results show that this test program is feasibleSecond,using Vivaldi antenna as a sensor probe unit which has broadband,end shot,high gain characteristics,just to meet the needs of the sensor.The antenna designed in this paper is loaded with corrugated periodic structure on two radiation arms,which effectively improves the low frequency gain and the radiation characteristics of the antenna.The gain of the designed antenna in the 3~8GHz band is greater than 8dB,and the VSWR is less than 2,which meets the requirement of application.In addition,a single pole sixteen throws microwave switch is designed by using HMC345 switch chip.The switch is the key device to realize the electric scanning test by control 4 channel TTL signal.Third,set up a sensor testing system with the design of the key components and a conveyor belt,write a switch control and vector network analyzer measurement data reading software.Different kinds of samples were tested.Based on the test results,the performance of the sensor is analyzed,including the sensitivity of the sensor to various types of nonuniformity and the range resolution of the sensor.Finally,the results show that the design of the test system can effectively test the uniformity of the material,the test speed is greater than 1m/min,the size of more than 4cm*4cm of the non-uniform area detection effect is obvious.