基于忆阻器的可切换带通滤波器

Switchable Bandpass Filter Using Memristors

将忆阻器作为射频开关,采用传统双模谐振器与改进式短路阶跃阻抗谐振器的组合结构,设计了一款可切换的三频带通滤波器。通过合理设计忆阻器偏置电路的位置,利用忆阻器阻抗的非易失性来实现滤波器通带的可切换功能。当滤波器工作时忆阻器处于断电的记忆状态,从而改善了可切换滤波器的互调性能。文中设计的滤波器拥有四种可切换工作状态,包括三频、双频、单频和全阻工作模式。测试结果表明,所提出的滤波器在三频情况下各通带的插入损耗分别是-1.38 dB@1.75 GHz、-0.94 dB@3.10 GHz、-3.13 dB@3.70 GHz;双频工作模式下各通带的插入损耗为-1.67 dB@1.75 GHz、-3.10 dB@3.70 GHz;单频工作模式下通带的插入损耗为-1.35 dB@3.10 GHz;全阻模式下阻带衰减高于24.85 dB。文中采用替代测试法进行测试,测试结果与仿真结果取得了较好的一致性。

Memristor is used as an RF switch in this paper.Based on a dual-mode resonator and an improved short-circuited stepped-impedance resonator,a tri-band bandpass filter is designed.The position of memristor bias circuit is optimized.The memristor′s impedance is nonvolatile,and this characteristic is used to realize the switchable function of filter passband.When the filter is working,memristor is in the memory state of power-off,which will improve intermodulation performance of filter.This filter has four switchable modes:tri-band,dual-band,single-band and full-stopband working mode.The measured results show that the insertion loss of tri-band working mode is-1.38 dB@1.75 GHz,-0.94 dB@3.10 GHz and-3.13 dB@3.70 GHz;the insertion loss of dual-band working mode is-1.67 dB@1.75 GHz and-3.10 dB@3.70 GHz;the insertion loss of single-band working mode is-1.35 dB@3.10 GHz;the rejection of full-stopband working mode is higher than 24.85 dB.The alternative test method is used in this paper,and measured results are consistent with simulated results.