scholarly journals Negative Group Delay Circuit Based on Microwave Recursive Filters

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Ashraf Ali ◽  
Chung-Tse Michael Wu
Keyword(s):  
Transmission Lines ◽  
Group Delay ◽  
Characteristic Impedance ◽  
Negative Group ◽  
Recursive Filters ◽  
Novel Approach ◽  
Quarter Wavelength ◽  
Quarter Wave ◽  
The Given ◽  
Negative Group Delay

This work presents a novel approach to design a maximally flat negative group delay (NGD) circuit based on microwave recursive filters. The proposed NGD circuit is realized by cascading N stages of quarter-wavelength stepped-impedance transformer. It is shown that the given circuit can be designed to have any prescribed group delay by changing the characteristic impedance of the quarter-wave transformers (QWTs) cascaded with each other. The proposed approach provides a systematic method to synthesize NGD of arbitrary amount without including any discrete lumped component. For various prescribed NGD, the characteristic impedance of QWT has been tabulated for two and three stages of the circuit. The widths and lengths of microstrip transmission lines can be obtained from characteristic impedance and the frequency of operation of the transmission line. The results are verified in both simulation and measurement, showing a good agreement.

scholarly journals Reconfigurable Negative Group Delay Circuit with a Low Insertion Loss Using a Coupled Line

2020 ◽  
Vol 20 (1) ◽  
pp. 73-79
Author(s):  
Girdhari Chaudhary ◽  
Yongchae Jeong
Keyword(s):  
Insertion Loss ◽  
Group Delay ◽  
Characteristic Impedance ◽  
Center Frequency ◽  
Pin Diode ◽  
Negative Group ◽  
Coupled Line ◽  
Coupled Lines ◽  
Low Insertion Loss ◽  
Negative Group Delay

This paper presents a design of a transmissive-type, low insertion loss (IL) negative group delay (NGD) circuit with a reconfigurable NGD. The proposed circuit consists of a series transmission lines (TLs) and shunt short-circuited coupled lines where an isolation port is terminated with a parasitic compensated PIN diode. Analytical design equations are derived to obtain the circuit parameters for the predefined NGD and IL. The low IL can be achieved because of the very high characteristic impedance of the short-circuited coupled lines. The TL terminated with a PIN diode is used to achieve the constant center frequency of reconfigurable NGD circuit. For experimental validation, the NGD circuit is designed and fabricated at a center frequency (<i>f</i><sub>0</sub>) of 2.14 GHz. In the measurement, the NGD varies from -0.5 ns to -2 ns with an IL variation of 2.08 to 3.60 dB at <i>f</i><sub>0</sub> = 2.14 GHz. The NGD bandwidth (bandwidth of GD less than 0 ns) varies from 90 MHz to 50 MHz. The minimum input/output return losses are higher than 10 dB for the overall tuning range.

Negative group delay experimentation with tee connector and cable structures

2020 ◽  
Vol 91 (1) ◽  
pp. 10903
Author(s):  
Fayu Wan ◽  
Xiaoyu Huangi ◽  
Preeti Thakur ◽  
Atul Thakur ◽  
Sébastien Lalléchère ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Group Delay ◽  
Characteristic Impedance ◽  
Existence Condition ◽  
Proof Of Concept ◽  
Negative Group ◽  
S Parameter ◽  
High Figure ◽  
Good Agreement ◽  
Negative Group Delay

The unfamiliar negative group-delay (NGD) phenomenon is experimented with structure constituted by tee-connectors and coaxial cables. The topology of the NGD generator is described. It consists of two parallel 50-Ω characteristic impedance cables. The S-parameter model in function of the cable physical lengths is established. The existence condition enabling to understand the NGD phenomenon is defined. A proof of concept simply is constituted by two three-port SMA connectors, three SMA transitions and 13-cm length cables. The NGD experimentation is performed from 1.5 GHz to 3.5 GHz. Tri-band NGD aspects in good agreement with the theory and simulation is observed experimentally. Particularly, high figure-of-merit NGD circuit with −3 ns NGD level, less than 2 dB insertion loss and 12 dB return loss around 3 GHz centre frequency is measured.

Electromagnetic Cavity Resonance Equalization With Bandpass Negative Group Delay

2021 ◽  
pp. 1-10
Author(s):  
Blaise Ravelo ◽  
Sebastien Lallechere ◽  
Wenceslas Rahajandraibe ◽  
Fayu Wan
Keyword(s):  
Group Delay ◽  
Cavity Resonance ◽  
Negative Group ◽  
Negative Group Delay

scholarly journals Negative Group Delay Theory on Li Topology

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 47596-47606
Author(s):  
Blaise Ravelo ◽  
Lili Wu ◽  
Fayu Wan ◽  
Wenceslas Rahajandraibe ◽  
Nour Mohammad Murad
Keyword(s):  
Group Delay ◽  
Negative Group ◽  
Negative Group Delay

scholarly journals Design of resonant mirrors with negative group delay

2014 ◽  
Vol 22 (23) ◽  
pp. 29213 ◽  
Author(s):  
Antonio Gellineau ◽  
Yu-Po Wong ◽  
Olav Solgaard
Keyword(s):  
Group Delay ◽  
Negative Group ◽  
Negative Group Delay
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