基于开槽技术的双模带通滤波器设计

Design of Double-Mode Bandpass Filter Based on Slotting Technology

文章利用开槽技术改变微带贴片式谐振器原本的电流分布以分离简并模,从而实现谐振器的双模传输特性,并基于该双模谐振器设计了一款双模带通滤波器。通过软件仿真,分析对比了不同开槽尺寸下滤波器的传输特性。采用直接耦合的馈电方式设计了基于该开槽型双模谐振器的带通滤波器。最后,对该双模带通滤波器进行了仿真优化,实现了带内衰减达到26dB以上,带内平坦,3dB相对带宽达到14%,同时,带外具有一个传输零点,可有效提高边带陡峭度,使滤波器具有较好的通带选择性和阻带抑制能力。

In this paper, a slotting technique is used to change the original current distribution of the microstrip patch resonator to separate the degenerate mode, so as to realize the dual-mode transmission characteristics of the resonator, and a dual-mode bandpass filter is designed based on the dual-mode resonator. Through software simulation, the transmission characteristics of the filter under different slot sizes are analysed and compared. A direct coupled feed mode is used to design the bandpass filter based on the slotted dual-mode resonator. Finally, the dual-mode bandpass filter is simulated and optimized. The band attenuation reaches more than 26 dB, the band is flat, and the fractional bandwidth of 3 dB is over 14%, with a transmission zero outside the band, the filter has better band selectivity and stopband suppression.