An X-band Microwave Thermoelectric Power Detector in 0.18-μm CMOS Technology

This article presents a root mean square (RMS) microwave thermoelectric power detector operating in the X-band and implemented in standard 0.18-μm CMOS technology. The working principle of the designed device is mainly to convert the incident microwave power into Joule heat through the terminal resistor. The output voltage is further measured by a number of thermocouples made of aluminum (Al) and p-type polysilicon electrically connected in series. The experimental results demonstrate that the output DC voltage and incident microwave power exhibits inherent linearity over a dynamic range of 1mW to 200 mW. The slopes of the linear relationship between incident power and output DC are 3.82 μV/mW, 3.27 μV/mW and 2.76 μV/mW at 8GHz, 10GHz, 12GHz, respectively. The measured return loss is no greater than -20dB over an operating bandwidth (BW) of 8 to 12 GHz. Overall die area is only 0.103 mm
²
, including all pads. The proposed microwave-thermal-electric RMS power detector shows great potential for advanced radars and wireless communication systems due to its large operating BW, high power handling capability, good RF-DC linearity and cost-efficiency.