Design and Implementation of Multiband Noncontact Temperature-Measuring Microwave Radiometer

Area of Science:

• Biomedical Engineering
• Electromagnetics
• Non-invasive Sensing

Background:

• Accurate measurement of human core body temperature is crucial for medical diagnostics.
• Existing non-contact methods often face challenges with clothing interference and limited depth penetration.
• Multilayer human tissue exhibits complex electromagnetic properties affecting temperature sensing.

Purpose of the Study:

• To develop a multiband noncontact microwave radiometer system for measuring human core body temperature.
• To enhance measurement accuracy and sensitivity for multilayer human tissues.
• To overcome limitations of clothing and improve non-invasive temperature monitoring.

Main Methods:

• Designed a multiband microwave radiometer system operating at 4-6 GHz, 8-12 GHz, 12-16 GHz, and 14-18 GHz.
• Utilized a small, highly directional multiband angular horn antenna for enhanced signal reception.
• Proposed a novel hardware architecture for a microwave interferometric temperature-measuring radiometer.

Main Results:

• The interferometric radiometer demonstrated reduced error uncertainty compared to full-power systems.
• Achieved a maximum detection sensitivity of 215 mV/dBm and temperature sensitivity of 0.047 K/mV.
• Detection sensitivity improved 7.45-fold and temperature sensitivity 13.89-fold over full-power radiometers.

Conclusions:

• The developed multiband microwave interferometric radiometer offers a highly sensitive and accurate noncontact method for human core temperature measurement.
• The system effectively measures temperature through clothing, applicable to epidermis, dermis, and subcutaneous tissues.
• This technology presents a significant advancement in non-invasive physiological monitoring.