Reconfigurable Negative Group Delay Circuits Based on Distributed Amplifiers for Guided- and Radiated- Wave Applications

Abstract

A recent development of reconfigurable negative group delay (NGD) circuit design based on distributed amplifiers (DA) is introduced. By incorporating varactors at the input and output port of the DA-based NGD circuit, tunable non-Foster elements - negative capacitors and non-Foster T-networks, can be realized. The negative capacitor can be tuned to realize an effective capacitance between −0.5 pF and −1.0 pF within a bandwidth of 100 MHz. For the non-Foster T-network, the tuning range is from 0.0 pF to −1.5 pF for the shunt capacitor, and 0 nH to −1.875 nH for the series inductor. Furthermore, the DA-based reconfigurable NGD circuit can also be utilized as antenna feedlines to realize squint free beam steering for antenna arrays.