1. Brillouin, L., Wave Propagation and Group Velocity, Vol. 8, Academic Press, New York, 2013.
2. Mojahedi, M., K. J. Malloy, G. V. Eleftheriades, J. Woodley, and R. Y. Chiao, "Abnormal wave propagation in passive media," IEEE Journal of Selected Topics in Quantum Electronics, Vol. 9, No. 1, 30-39, 2003.
3. Stenner, Michael D., Daniel J. Gauthier, and Mark A. Neifeld, "Fast causal information transmission in a medium with a slow group velocity," Physical Review Letters, Vol. 94, No. 5, 053902, 2005.
4. Wang, Youzhen, Yewen Zhang, Li He, Fuqiang Liu, Hongqiang Li, and Hong Chen, "Direct observation of negative phase velocity and positive group velocity in time domain for composite right/left-handed transmission lines," Journal of Applied Physics, Vol. 100, No. 11, 113503, 2006.
5. Mojahedi, Mohammad, Edl Schamiloglu, Frank Hegeler, and Kevin J. Malloy, "Time-domain detection of superluminal group velocity for single microwave pulses," Physical Review E, Vol. 62, No. 4, 5758, 2000.
6. Ibraheem, Ibraheem A., Joerg Schoebel, and Martin Koch, "Group delay characteristics in coplanar waveguide left-handed media," Journal of Applied Physics, Vol. 103, No. 2, 024903, 2008.
7. Bolda, Eric L., Raymond Y. Chiao, and John C. Garrison, "Two theorems for the group velocity in dispersive media," Physical Review A, Vol. 48, No. 5, 3890, Nov. 1993.
8. Kandic, Miodrag and Greg E. Bridges, "Asymptotic limits of negative group delay in active resonator-based distributed circuits," IEEE Transactions on Circuits and Systems I: Regular Papers, Vol. 58, No. 8, 1727-1735, Aug. 2011.
9. Kandic, Miodrag and Greg E. Bridges, "Limits of negative group delay phenomenon in linear causal media," Progress In Electromagnetics Research, Vol. 134, 227-246, 2013.
10. Kandic, Miodrag and Greg E. Bridges, "Negative group delay prototype filter based on cascaded second order stages implemented with Sallen-Key topology," Progress In Electromagnetics Research B, Vol. 94, 1-18, 2021.
doi:10.2528/PIERB21071209
11. Solli, Daniel, R. Y. Chiao, and J. M. Hickmann, "Superluminal effects and negative group delays in electronics, and their applications," Physical Review E, Vol. 66, No. 5, 056601, 2002.
12. Dorrah, Ahmed H. and Mo Mojahedi, "Nonanalytic pulse discontinuities as carriers of information," Physical Review A, Vol. 93, No. 1, 013823, 2016.
13. Kandic, Miodrag and Greg E. Bridges, "Negative group delay prototype filter based on the reciprocal transfer function of a low-pass Butterworth filter capped at finite out-of-band gain," Progress In Electromagnetics Research B, Vol. 106, 17-38, 2024.
doi:10.2528/PIERB24020602
14. Macke, Bruno, Bernard Ségard, and Franck Wielonsky, "Optimal superluminal systems," Physical Review E, Vol. 72, No. 3, 035601, Sep. 2005.
doi:10.1103/PhysRevE.72.035601
15. Macke, Bruno and B. Ségard, "Propagation of light-pulses at a negative group-velocity," The European Physical Journal D --- Atomic, Molecular, Optical and Plasma Physics, Vol. 23, 125-141, 2003.
16. Lucyszyn, S., I. D. Robertson, and A. H. Aghvami, "Negative group delay synthesiser," Electronics Letters, Vol. 29, No. 9, 798-800, Apr. 1993.
doi:10.1049/el:19930533
17. Nakanishi, T., K. Sugiyama, and M. Kitano, "Demonstration of negative group delays in a simple electronic circuit," American Journal of Physics, Vol. 70, No. 11, 1117-1121, Nov. 2002.
18. Kitano, Masao, Toshihiro Nakanishi, and Kazuhiko Sugiyama, "Negative group delay and superluminal propagation: An electronic circuit approach," IEEE Journal of Selected Topics in Quantum Electronics, Vol. 9, No. 1, 43-51, Jan.-Feb. 2003.
19. Siddiqui, Omar F., M. Mojahedi, and George V. Eleftheriades, "Periodically loaded transmission line with effective negative refractive index and negative group velocity," IEEE Transactions on Antennas and Propagation, Vol. 51, No. 10, 2619-2625, Oct. 2003.
20. Ravelo, Blaise, AndrÉ PÉrennec, Marc Le Roy, and Yann G. Boucher, "Active microwave circuit with negative group delay," IEEE Microwave and Wireless Components Letters, Vol. 17, No. 12, 861-863, Dec. 2007.
doi:10.1109/LMWC.2007.910489
21. Mirzaei, Hassan and George V. Eleftheriades, "Realizing non-Foster reactive elements using negative-group-delay networks," IEEE Transactions on Microwave Theory and Techniques, Vol. 61, No. 12, 4322-4332, Dec. 2013.
22. Chaudhary, Girdhari, Yongchae Jeong, and Jongsik Lim, "Microstrip line negative group delay filters for microwave circuits," IEEE Transactions on Microwave Theory and Techniques, Vol. 62, No. 2, 234-243, Feb. 2014.
23. Wu, Chung-Tse Michael and Tatsuo Itoh, "Maximally flat negative group-delay circuit: A microwave transversal filter approach," IEEE Transactions on Microwave Theory and Techniques, Vol. 62, No. 6, 1330-1342, Jun. 2014.
24. Wu, Yongle, Handing Wang, Zheng Zhuang, Yuanan Liu, Quan Xue, and Ahmed A. Kishk, "A novel arbitrary terminated unequal coupler with bandwidth-enhanced positive and negative group delay characteristics," IEEE Transactions on Microwave Theory and Techniques, Vol. 66, No. 5, 2170-2184, 2018.
25. Wan, Fayu, Ningdong Li, Blaise Ravelo, and Junxiang Ge, "O=O shape low-loss negative group delay microstrip circuit," IEEE Transactions on Circuits and Systems II: Express Briefs, Vol. 67, No. 10, 1795-1799, Oct. 2020.
26. Ravelo, Blaise, Fayu Wan, and Junxiang Ge, "Anticipating actuator arbitrary action with a low-pass negative group delay function," IEEE Transactions on Industrial Electronics, Vol. 68, No. 1, 694-702, Jan. 2021.
27. Wang, Zhongbao, Shipeng Zhao, Hongmei Liu, and Shaojun Fang, "A compact dual-band differential negative group delay circuit with wideband common mode suppression," IEEE Journal of Microwaves, Vol. 2, No. 4, 720-725, Oct. 2022.
28. Nair, Rekha G. and S. Natarajamani, "Design theory of compact power divider with reconfigurable power division and negative group delay characteristics," Scientific Reports, Vol. 13, No. 1, 7222, May 2023.
29. Palson, Chithra Liz, Deepti Das Krishna, and Babita Roslind Jose, "Planar tunable negative group delay circuit with low reflection loss," Progress In Electromagnetics Research Letters, Vol. 113, 53-59, 2023.
doi:10.2528/PIERL23090902
30. Ravelo, Blaise, Habachi Bilal, Sylcolin Rakotonandrasana, Mathieu Guerin, Fayrouz Haddad, Samuel Ngoho, and Wenceslas Rahajandraibe, "Transient characterization of new low-pass negative group delay RC-network," IEEE Transactions on Circuits and Systems II: Express Briefs, Vol. 71, No. 1, 126-130, Jan. 2024.
31. Zhang, Awei, Jinping Xu, and Zhiqiang Liu, "A microstrip linear-phase BPF using dual-band negative group delay equalizers," IEEE Microwave and Wireless Technology Letters, Vol. 34, No. 4, 387-390, Apr. 2024.
32. Chang, Niannan, Aixia Yuan, Ying Wang, and Junzheng Liu, "Multi-band pass negative group delay circuit with low insertion loss," International Journal of Circuit Theory and Applications, Jul. 2024.
33. Nako, Julia, Costas Psychalinos, Ahmed S. Elwakil, and Brent J. Maundy, "A note on the bandwidth of negative group delay filters," International Journal of Circuit Theory and Applications, 2024.
34. Nako, Julia, Costas Psychalinos, Brent J. Maundy, and Ahmed S. Elwakil, "Elementary negative group delay filter functions," Circuits, Systems, and Signal Processing, Vol. 43, No. 6, 3396-3409, 2024.
35. Maundy, B. J., A. S. Elwakil, and C. Psychalinos, "Systematic design of negative group delay circuits," AEU --- International Journal of Electronics and Communications, Vol. 174, 155060, 2024.
36. Nako, Julia, Costas Psychalinos, Ahmed S. Elwakil, and Brent J. Maundy, "Power-law negative group delay filters," Electronics, Vol. 13, No. 3, 522, 2024.
37. United States Patent Office (USPTO) application number: 18/491922.