3D Model of the Thermoelectric Microwave Power Sensor by MEMS Technology

In this paper, a novel 3D model of the thermoelectric microwave power sensor is proposed to describe the temperature distribution. In the 3D model, the heat flux density decreases from the upper surface to the lower surface of the substrate while it is assumed to be a constant in the 2D model. FEM by ANSYS software is applied to verify the proposed 3D model. The microwave performance experiment shows that the return loss of the fabricated sensor is less than -26dB over the frequency band of 1-10GHz. The power response experiment demonstrates that the output voltage increases from 0mV to 27mV while the incident power varying from 1mW to 100mW. The measured sensitivity is about 0.27mV/mW and the calculated result from the 3D model is 0.28mV/mW. The relative error has been reduced from 7.5% of 2D model to 3.7% of 3D model.