Band Pass Negative Group Delay demonstration on a VHF RLC parallel passive lumped circuit

E J R Sambatra,Lucius Ramifidisoa,Y C Mombo Boussougou,S Ngoho,A Jaomiary,N M Murad,J.-P Kouadio

doi:10.7716/aem.v11i1.1858

E J R Sambatra, Lucius Ramifidisoa + Show 5 more

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https://doi.org/10.7716/aem.v11i1.1858

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Journal: Advanced Electromagnetics	Publication Date: Feb 18, 2022
Citations: 1	License type: CC BY 4.0

Affiliation: École Normale Supérieure

Abstract

This paper demonstrates the bandpass (BP) negative group delay (NGD) function on a passive RLC-parallel lumped network at Very High Frequencies (VHF). After the topological description of the RLC cell, the BP NGD analysis is introduced. The NGD circuit is modelled theoretical by means of voltage transfer function (VTF) expression. The analytical equations illustrating the BP NGD specifications as the NGD center frequency, NGD value, NGD bandwidth and the VTF attenuation are established in function of the R, L and C component parameters. A proof of concept is designed, fabricated as a SMD on printed circuit board, and measured. As expected, the different models (calculated, simulated and measured) present a BP NGD and are significantly corelated. The POC prototype (resp the calculated and simulated model), presents an NGD value of - 8 ns (resp -12 ns) and attenuation of - 10 dB (resp -8 dB) around a 225 MHz (resp 240 MHz) NGD center frequency. Uncertainties analysis (UA) of BP NGD specifications is also studied in order to show the influence of quality and tolerance of components for NGD circuit. The theoretical formulas of NGD specification UAs in function of R, L and C tolerances are derived. UAs with respect to 1%, 2% and 5% relative tolerances of R, L and C components constituting the POC designed circuit are performed.

Highlights

THE negative group delay (NGD) phenomenon was the first time observed with optical experimentation in 1980s [1,2]
We propose a quite easy to understand and didactical research work about BP NGD circuit engineering opens to nonspecialists as graduated students, technicians and engineers in the present article
1) uncertainty analysis (UA) CALCULATED RESULTS Table IV, Table V and Table VI highlight the influence of tolerances of R, Rn, and L element values on each BP NGD parameters

Summary

Introduction

THE negative group delay (NGD) phenomenon was the first time observed with optical experimentation in 1980s [1,2]. The counterintuitive NGD experimental demonstration attracts the attention of curious physicists in twentieth century This scientific curiosity leads to deeper investigation for the better understanding about the NGD effect meaning. By means of the equivalent transfer function, basic topologies of NGD lumped circuit in very low frequencies (VLFs) and in low frequencies (LFs) were proposed in 1990s [7,8]. With such lumped circuits, the NGD signature corresponds to the smoothed signal propagating with output in time advance compared to the corresponding input [7,8,9,10,11,12,13].

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