New Structure for High-Sensitivity Coaxial Thermal Power Sensor in the Frequency Range from DC–50 GHz

This paper presents the design and development of a new thermal microwave power sensor for a frequency range spanning from DC to 50 GHz. The purpose of this new design is to propose a high-sensitivity thermoelectric power sensor suitable for microcalorimeter application that is a primary method of microwave power calibration. The core structure of the power sensor comprises a Grounded Coplanar Waveguide (GCPW) transmission line, two load resistors, a thermopile, and output pads for DC measurements. The optimized power sensor demonstrates promising simulation performance, with a return loss better than 20 dB across the frequency range and an efficiency exceeding 80%. At 50 GHz, the sensitivity of the power sensor reaches well over 0.240 mV/mW.