| Microwave power measurements have taken an important role in electromagnetics. As the developing of economy and the progressing of science, microwave power meter has been used to measure output/input of transmitter/ receiver,output of signal generator and output of monofier, it has many uses in national defence, communication and scientific research. Microwave power sensor is the core component of microwave power meter,and it has been researched by many domestic and overseas research institutions, but micro-structure microwave power sensor developed by using MEMS technology is few yet. In this paper, Design and fabrication of a new chip of microbridge structure thermocouple type microwave power sensor developed by using MEMS technology were recommended."Heat" measure(i.e. to transform microwave power to heat energy)is the most familiar way to measure microwave power. the chip of microbridge structure thermocouple type microwave power sensor is designed by using Seeback domino offect of thermocouple. Ta2N of relatively low resistor-temperature coefficient and Si of relatively high thermoelectric power Seebeck coefficient are used as thermocouple materials in the chip. Microwave power dissipated in Ta2N resistive film generates heat to raise the temperature of the hot junction above that of the cold junction, thereby producing a dc voltage across the thermocouple. We can measure microwave power through measuring this dc voltage. The temperature rises and the dc voltage are proportional to the power dissipated, which is equal to the power of the source being measured if the input impedance is suitably matched to the source impedance.The chip is fabricated by using semiconductor technics and MEMS technics. The fabricative technics is complex and difficult, every step can be done repeatedly after doing a lot of experiments, and the figuration of chip is nice. The chip has sensitivity as high as 1.1mV/mW over a frequency range of DC to 18GHz at a power lever from 10μW to 100μW.
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