基于VDTA的混合多模式双二阶滤波器的设计

Design of Mixed Multi-mode Bi-quad Filters Based on VDTA

针对各类核探测仪的供电电源系统和核能谱测量仪的前端电子线路广泛采用的滤波技术,提出了一种设计混合多模式双二阶滤波器的新方法。首先通过分析新的有源元件——电压差跨导放大器(VDTA)的一般工作原理,提出了一种采用CMOS晶体管实现VDTA的电路;然后基于实现的VDTA模块,设计了采用两级VDTA模块实现单输入、三输出或三输入、单输出电子可调混合多模式双二阶滤波器。通过选择输入端,该滤波器可以产生5种不同的电压和跨导纳模式滤波器功能,实现低通、带通、高通、带阻和全通5种不同的滤波信号。同时对滤波器的有限频率效应、稳定性条件和寄生元件效应进行了分析;仿真实验结果验证了所设计滤波器的性能,表明了理论设计的正确性和有效性。

Aiming at the filtering technology widely used in the power supply system of various nuclear detectors and the front-end electronic circuit of nuclear spectrum measurement instruments,a new method for designing mixed multi-mode bi-quad filter is proposed.Firstly,by analyzing the general operating principle of a newly active element—voltage differencing transconductance amplifier(VDTA),a CMOS transistor circuit is proposed to realize VDTA.Then,based on the obtained VDTA module,a two-stage VDTA module is designed to achieve single-input,three-output or three-input,single-output electronically tunable mixed multi-mode bi-quad filters.By selecting the input terminals,the filter can generate five different voltage and transadmittance modes filter functions,and achieve five different filter signals of low pass,band pass,high pass,band stop and all pass.The limited frequency effect,stability condition and parasitic element effect of the filter are analyzed simultaneously.The simulation experimental results verify the performance of the designed filter and demonstrate the correctness and effectiveness of the theoretical design.