New transmission lines of negative refractive index based on periodically loaded negative-impedance-converted inductors and capacitors

¹ Division of Electromagnetic Theory, School of Electrical Engineering, Royal Institute of Technology, 100 44 Stockholm, Sweden
² Centre for Optical and Electromagnetic Research, Zhejiang University, Hangzhou 310058, P.R. China

Corresponding author: sailing@kth.se

Received: 4 February 2008
Revised: 18 March 2008
Accepted: 7 April 2008
Published online: 19 June 2008

Abstract

A new class of negative refractive index (NRI) transmission line is proposed. Differential operational amplifiers are used to form the required lumped elements, i.e., negative-impedance-converted (NIC) inductors and capacitors. When the gain of the differential operational amplifiers in the NIC circuits is very large over the entire frequency band, the equivalent material parameters are non-dispersive, and the phase response of the new NRI transmission line can be complimentary to that of a conventional transmission line over the entire frequency band. As an application example, a broadband 1:4 power divider based on the proposed NRI transmission line is studied.