A novel microwave power sensor using MEMS fixed-fixed beam

In this paper, a novel MEMS microwave power sensor employing the coplanar waveguide (CPW), which is consist of the linearly graded signal line and ground planar, is presented to avoid step discontinuity. Then the design of the proposed power sensor is described in detail. Through compared to the simulation results of the device with the abrupt signal line and ground planar, the proposed device can obtain better microwave performances. The fabrication process is compatible with GaAs MMIC technology completely and also described in this paper. The capacitance change, return and insertion losses have been measured. The measurement results indicate that the proposed power sensor is characterized by a sensitivity of 20 aF mW^-1 for 400×200 μm² fixed-fixed beam and superior return and insertion losses (S₁₁ and S₂₁), which are less than -25 dB and -0.35 dB, respectively, up to 14 GHz.