Study on the Load Model of Microwave Power Detection Chip Based on MEMS Fixed Beams

To improve the performance of microwave power detection chips and address the challenge of low accuracy in theoretical models, a microwave power detection chip based on a micro-electro-mechanical system (MEMS) fixed beam is proposed in this work. The varying deformations of the beam at different positions is considered, and a load model is established. The nonlinear deformation of the beam is characterized using the deflection equation to improve the accuracy of the theoretical model. On this basis, the chip’s overload power, sensitivity, and microwave characteristics are studied. The measured results indicate that within the range of 8–12 GHz, the measured values of return loss are consistently less than −10 dB, demonstrating good microwave characteristics. The measured result capacitive sensitivity is 14.45 fF/W@10 GHz, and the theoretical result of the load model is 14.55 fF/W, and the error of the two is only 0.69%. Compared with the lumped parameter and the pivotal mechanics model, the load model has improved the accuracy by 91.56% and 43.67%, respectively. Therefore, the load model established in this work has certain reference value for the performance improvement of microwave power detection chips.