基于枝节加载开环谐振器的带阻滤波器设计

提出了一种具有良好谐波抑制功能的双枝节加载开环谐振器,加载枝节采用均匀阻抗结构,与同尺寸的开环谐振器相比,结构更紧凑,能够更好地抑制寄生模,而且可以达到更低的谐振频率。分析了加载枝节参数对带阻滤波器抑制二次谐波的影响。通过在加载的双枝节间引入集总可变电容,可以使谐振器具备谐波抑制性能的同时,实现中心频率可调的功能。基于双枝节加载环谐振器设计出一种可调带阻滤波器,中心频率可以在900MHz ~2. 65GHz 范围内调节,而且最低寄生阻带能够抑制到8GHz。

Design of Compact Band-Stop Filter Based on Stub-Loaded Open-Loop Resonator

In this paper, open-loop resonators loaded by shunt uniform open stubs are proposed to design compact bandstop filters with improved out-of-band rejection characteristics. ompared to open-loop resonators without open stubs, the stub-loaded resonator of the same size possesses lower resonant frequency. Then we analyze the stub parameters affects to the second harmonic suppression of the bandstop filter. A novel resonator with a tunable center frequency and better suppression to harmonic wave can be constructed with lumped variable capacitors between two stubs. In the end, a tunable bandstop filters based on the proposed resonator is designed and fabricated. The center frequency is tunable from 900MHz-2. 65GHz with a lowest parasitic stopband restrained to 8GHz.