Negative Group Delay Circuit for Feed-Forward Amplifier

Abstract

We present a design and an implementation of a negative group delay circuit, which consists of lumped parameter element. It is very small and simple circuit. The circuit is composed of three resonators with resisters, which are arranged to pi type circuit to improve the reflection. We discuss the principle of a negative group delay circuit and apply the circuit to the feed-forward amplifier. It is confirmed that the delay line of the distortion cancellation loop is shortened 40% by connecting the circuit to the driver stage of the error amplifier. The efficiency of the feed-forward amplifier has been improved from 9% to 12%.