In this paper, high-power up to 4000 mW electro-mechanical behavior of a capacitive micro-electromechanical systems (MEMS) microwave power sensor using cantilever beam is investigated. Due to residual stress gradients, the power sensor is proposed for a warped cantilever beam connected to coplanar waveguide (CPW) structure. The proposed sensor is fabricated using the GaAs monolithic microwave integrated circuit (MMIC) process. It is demonstrated that the output response of this sensor exhibits non-linear characteristics under high power levels (more than 1000 mW). The measurement results can be classified as three regions: linear region (1–1000 mW), saturated region (1000–2500 mW), and over-saturated region (2500–4000 mW). Their corresponding sensitivities are 2.8 fF/W, 1.03 fF/W, and 0.32 fF/W at 10 GHz, respectively. The non-linear output response of the power sensor is mainly caused by impedance mismatch at X-band (8–12 GHz). Furthermore, an electro-mechanical model of power sensor based on warped cantilever beam is proposed. The results are well in agreement with the calculated ones using this model by software that employs the finite element method (FEM), which provides the potential prospect for the design of capacitive power sensor.

本文研究了使用悬臂梁的大功率，高达4000 mW的电容式微机电系统（MEMS）微波功率传感器的机电性能。由于残余应力梯度，建议将功率传感器用于连接到共面波导（CPW）结构的弯曲悬臂梁。所提出的传感器是使用GaAs单片微波集成电路（MMIC）工艺制造的。结果表明，该传感器的输出响应在高功率水平（超过1000 mW）下表现出非线性特性。测量结果可分为三个区域：线性区域（1-1000 mW），饱和区域（1000-2500 mW）和过饱和区域（2500-4000 mW）。它们在10 GHz时的相应灵敏度分别为2.8 fF / W，1.03 fF / W和0.32 fF / W。功率传感器的非线性输出响应主要是由X波段（8–12 GHz）的阻抗失配引起的。提出了基于弯曲悬臂梁的功率传感器机电模型。结果与使用有限元法（FEM）的软件使用该模型计算的结果非常吻合，这为电容式功率传感器的设计提供了潜在的前景。