Sensing Depth Study of Microwave Radiometer

• Main Authors: HUANG,SHIH-ZHAN, 黃士展
• Other Authors: WU,JANNE-WHA
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/t3ebpr

碩士 === 國立中正大學 === 電機工程研究所 === 106 === Body temperature is one of the figure-merit for reflecting the physical and mental condition of the subject. On physical condition , body temperature will change when the human body is affected by disease or the external environment. ; ForOn mental condition , body temperature will change when subject's mood changes , so body temperature is a good figure index for reflecting condition of subjectto present the personal status. The core internal temperature of the human body reflects the condition of the subject morecan instantly and significantly shows the human body status as compared to that bythan the surface temperature. The purpose of this thesis is to design a design system for measuring the deep tissue temperature of the human body. The goal of thesis is to design and implement a radiometer system. The operating principle of the radiometer is to convert the black body radiation signal to a voltage signal and derivateso as to represent the temperature of target by the aoutput voltage. Compared to the infrared frequency band, the wavelength of the signal in the microwave band is longer. So the signal in the microwave band can measure deeper tissue layer. The thesis choose 3.2 GHz is adopted to be the center frequency of system finallyoperation. Since the measurement situation requires high precision and must decrease the influence of system variation , it choose a Dicke radiometer architecture is usedto implement. The first half of this thesis will explain the research motivation、, state-of-art current temperature measurement techniques ,and various radiometer types. It also explores the condition of using microwave frequency to measure the temperature of the human body, discuss and the detail operation of design the a Dicke radiometer. The second half will shows the implementation of sub-circuit and measured results, test the radiometer system, confirm system operation, and discuss the measurement problem. On final measurement result, the thesis use metal to be object and use baking tray to heat it. When the distance between metal and antenna is 0mm and 1mm, the system output slope is 0.1mV/℃.The maximum temperature error of measurement result is 3℃. The system output voltage is positively correlated with the temperature of object.