一种新型宽线性低灵敏度通用滤波器设计

Design of multifunctional filter with wide linear and low sensitivity

提出了一种基于双极工艺实现跨导线性电可调的跨导运算放大器(EOTA)电路模型,采用EOTA和接地电容实现了多输入单输出的通用滤波器设计。该滤波电路具有在高输入阻抗节点处提供低通、高通、带通、带阻的电压响应,同时容易级联生成任意阶高阶滤波器。该滤波器通过调整EOTA的偏置电压或电流来设置独立电控参数ω0或Q,且参数灵敏度低,线性范围宽且无需考虑电路参数匹配等特点,文中分析了利用EOTA实现通用双二次滤波器的工作原理及生成高阶滤波器的方法,讨论了两种滤波功能的特点,结果证实了理论分析的正确性。

A circuit model of electronically tunable operational transconductance ampli？ er （EOTA） based on bipolar technology is described. Multi -input and single - output universal filter used by EOTA and grounded capacitors has been designed. The proposed circuit provides lowpass, highpass, bandpass, bandstop voltage responses at a high impedance input terminal. The arbitrary high order filters are easy to generate by cascading the filter. The circuit parameters tOo and Q can be set orthogonally by adjusting the bias current or voltage. The filter has high sensitivity, wide linearity and the circuit parameters matching are eliminated. The working principle of Biquadratic Filters and the method of generating high order fil- ters with EOTA are analyzed. The two filter functions are discussed. The theoretical analyses are verified by experiments.