具有均衡时延修正功能的高频跨导电容滤波器

A high-frequency G_m-C filter with equalization delay tuning

提出一种适用于高频领域的新结构跨导电容滤波器,它采用带共模反馈电路差分交叉耦合型的高频跨导放大器,稳定了输出电平和静态工作点.应用该跨导放大器设计了截止频率为160MHz的七阶跨导电容低通滤波器.针对高阶椭圆函数滤波器群时延大的缺点,设计了均衡时延修正电路来精确调节群时延大小.仿真实验表明,加入时延电路后,滤波器在通带范围内的群时延减小了83.1%.该方法可望应用于高速混合信号处理电路设计及其相关领域.

In this paper, a new structure transconductance-capacitor filter for high-fre- quency field is presented. It uses common-mode feedback circuit with differential cross- coupled high-frequency transconductance amplifier to stabilize the output voltage level and the static operating point. Based on the transconductance amplifier, a seven order low-pass Gm-C filter of cut-off frequency is 160 MHz is presented. For the defect of high-order elliptic function filter group delay, the equilibrium delay circuit which adjusts the number of group delay is designed. The simulation results show that the filter pass- band group delay decrease by 83.1% when adding group delay circuit. The method can be applied to high speed mixed signal circuit design and its related fields.