This paper presents a design technique to realize fractional order (FO) immittance in the second quadrant of the impedance plane, using Bruton’s generalized immittance converter (GIC). Design guidelines are developed based on a sub-optimal analysis of phase error resulted by non-ideal op amps. The analysis takes into account finite open-loop dc gain and finite unity-gain frequency of practical op amps and aim to maximize the constant phase zone for a given phase band specification. The fractance of the realized fractor can also be tuned to a desired value by varying one of the GIC resistances. Several simulations and experimental validations are demonstrated. Also, high Q, FO bandpass filter with wide tuning range is presented as an application of the designed obtuse angle fractor.

本文提出了一种使用Bruton的通用阻抗变换器（GIC）在阻抗平面的第二象限中实现分数阶（FO）阻抗的设计技术。基于非理想运算放大器引起的相位误差的次优分析，制定了设计指南。该分析考虑了实际运放的有限开环直流增益和有限的单位增益频率，旨在针对给定的相带规格，使恒定相位区域最大化。也可以通过改变GIC电阻之一将已实现的分光系数调整为所需值。演示了一些模拟和实验验证。此外，提出了具有宽调谐范围的高Q，FO带通滤波器，作为设计的钝角分光器的应用。