采用Hilbert分形缺陷地结构单元和并联枝节串联设计制作了一种微带低通滤波器。HFSS仿真结果表明:设计的滤波器通带回波损耗小于–20 dB,通带范围为0~5 GHz,阻带带宽能达到10 GHz以上。实物测量结果与仿真结果基本吻合。实现了回波损耗和通带内的纹波小、过渡带陡峭、阻带宽、结构紧凑、尺寸小的微带低通滤波器。 A kind of microstrip low pass filter was designed by using Hilbert fractal defect structure unit and parallel branch series connection. The HFSS simulation results show that the designed passband return loss of the filter is less than -20 dB, the passband range is 0 ~ 5 GHz and the stopband bandwidth can reach above 10 GHz. Physical measurement results and simulation results are basically consistent. It achieves low return loss and small ripple in passband, steep transition band, narrow band-stop, compact structure and small size of microstrip low-pass filter.