In this work, radio frequency (RF) micro‐electromechanical system (MEMS)‐based frequency and bandwidth tunable bandpass filter is presented for application in 24 GHz Doppler radar transceivers. The filter is fabricated on 635 μm alumina substrate using surface micromachining process. Total area of the filter is only 2.8 mm² excluding bias lines and pads. Functional building blocks of the proposed filter are fabricated and tested independently to ensure optimum filter responses. The proposed filter can be tuned to any frequency between 22 and 24 GHz based on electrostatic actuations. It demonstrates insertion loss of 1.67 dB and matching of 18.6 dB at 24 GHz with fractional bandwidth of 6.5%. Filter gives acceptable matching over a 5 GHz bandwidth (21.65‐26.65 GHz) with an average insertion loss of 4.7 dB. Filter works satisfactorily up to 10 billion cycles with 0.1 to 1 W of RF power. To the best of our knowledge, this is the first reported tunable MEMS bandpass filter at 24 GHz with 10 billion cycles reliability and with 1 W of RF power for radar applications.

中文翻译：

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频率和带宽可调的可靠MEMS带通滤波器，适用于24 GHz雷达应用

在这项工作中，提出了基于射频（RF）微机电系统（MEMS）的频率和带宽可调带通滤波器，用于24 GHz多普勒雷达收发器。使用表面微加工工艺在635μm氧化铝基板上制造滤光片。过滤器的总面积仅为2.8 mm ²不包括偏置线和焊盘。所提出的滤波器的功能构件是独立制造和测试的，以确保获得最佳的滤波器响应。可以基于静电激励将建议的滤波器调谐到22至24 GHz之间的任何频率。它显示出插入损耗为1.67 dB，在24 GHz时匹配度为18.6 dB，分数带宽为6.5％。滤波器可在5 GHz带宽（21.65-26.65 GHz）上提供可接受的匹配，平均插入损耗为4.7 dB。滤波器在0.1至1 W的RF功率下可令人满意地工作多达100亿个周期。据我们所知，这是第一个报告的可调谐MEMS带通滤波器，它在24 GHz频率下具有100亿次循环的可靠性，并为雷达应用提供1 W的RF功率。