Innovative Transient Study of Tri-Bandpass Negative Group Delay Applied to Microstrip Barcode-Circuit

Abstract

A transient study of bandpass (BP) negative group delay (NGD) function is devoted in this paper. The transient analysis is applied to an original topology of NGD barcode-shape microstrip circuit. The performed investigation explains how to realize the transient analysis of tri-band NGD circuit. The time-domain (TD) parametrization of the test is established from the BP-NGD specifications of the circuit under test (CUT) based on the S-parameter model. The input signal is a Gaussian pulse characterized in function of the NGD bandwidth (BW) and center frequency. The feasibility of the BP-NGD transient study is illustrated with experimentation based on ultra-wide band (UWB) pulse generator. As proof-of-concept, barcode NGD circuit exhibiting tri-band NGD value-center frequency-bandwidth, (−5.9 ns, 2.128 GHz, 20 MHz), (−7.4 ns, 2.3 GHz, 14 MHz) and (−4.8 ns, 2.42 GHz, 14 MHz) has been fabricated and tested. The transient simulations and experiences confirm that the output signal envelopes of the barcode NGD prototype present leading and tailing edges in time-advance of input ones when the carrier frequency is set equal to the NGD center frequency.

Keywords

• Coupled lines (CLs)
• distributed circuit
• modelling method
• barcode topology
• bandpass (BP) negative group delay (NGD)
• microwave circuit