Abstract: The design, fabrication, and experimental results of an MEMS microwave frequency detector are pre-sented for the first time. The structure consists of a microwave power divider, two CPW transmission lines, a mi-crowave power combiner, an MEMS capacitive power sensor and a thermopile. The detector has been designed and fabricated on GaAs substrate using the MMIC process at the X-band successfully. The MEMS capacitive power sensor is used for detecting the high power signal, while the thermopile is used for detecting the low power signal. Signals of 17 and 10 dBm are measured over the X-band. The sensitivity is 0.56 MHz/fF under 17 dBm by the capac-itive power sensor, and 6.67 MHz/V under 10 dBm by the thermopile, respectively. The validity of the presented design has been confirmed by the experiment.

Key words: MEMS,  frequency,  detector,  microwave,  power divider,  frequency measurement