设计了一款X波段压控可调梳状线带通滤波器, 通过调整加载变容二极管的偏置电压改变电容值大小, 从而达到调整滤波器中心频率的目的。根据恒定带宽条件对滤波器耦合系数以及外部Q值的要求, 确定梳状线滤波器的尺寸参数, 并对其进行电磁仿真优化, 最终制作的X波段可调滤波器尺寸为16 mm×20 mm×21 mm, 控制电压7.6~15.4 V, 实现滤波器中心频率8~10 GHz连续可调。在调谐频率范围内, 滤波器通带宽度15%, 回波损耗小于–10 dB, 矩形系数小于2.8。

An X-band combline tunable bandpass filter is proposed. Through adjusting the bias voltage of the loaded varactor, the central frequency of the filter is tuned. According to the constant bandwidth requirements on coupling coefficients and external Q factor, the initial dimension parameters of the combline filter are determined and then optimized with an electromagnetic field simulator. The completed X-band voltage controlled tunable filter is 16 mm×20 mm×21 mm in size and has a controlled voltage range of 7.6-15.4 V by which the center frequency of the filter is tuned continuously within the range between 8 GHz to 10 GHz. The passband width of the filter is 15%, the return losses are below -10 dB and the rectangle coefficient is less than 2.8 within the tuning frequency range.