Group delay distortions are critical for high quality transmissions in today's communication system. In this paper, we have proposed design and analysis of defected microstrip line-based Negative Group Delay Circuits (NGDCs) to compensate for group delay distortions. Initially, a tunable pulse shaped defection based NGD structure is designed wherein a variable resistor connection allows group delay tunability. The proposed design is able to generate a group delay (GD) tuning from 0 to -4.8 ns at 2.7 GHz as the resistance is varied from 1 kΩ to 1 MΩ. Further, we embedded two stubs to implement the switchable multi-band feature on the proposed NGDC design. The NGDCs are fabricated, and the measured results confirm the proposed concept. Lastly, we designed a tunable compact NGDC with inverted-U stubs inscribed inside a microstrip line. It generated GD tunability at different frequency bands with the aid of a variable resistor and switched the frequencies as required.
2. Xiao, J. K., Q. F. Wang, and J. G. Ma, "Negative group delay circuits and applications: Feedforward amplifiers, phased-array antennas, constant phase shifters, non-foster elements, interconnection equalization, and power dividers," IEEE Microwave Magazine, Vol. 22, No. 2, 16-32, 2021.
3. Choi, H., G. Chaudhary, T. Moon, Y. Jeong, J. Lim, and C. D. Kim, "A design of composite negative group delay circuit with lower signal attenuation for performance improvement of power amplifier linearization techniques," IEEE MTT-S Int. Microw. Symp. Dig., 1-4, Jun. 2011.
4. Choi, H., Y. Kim, Y. Jeong, and J. Lim, "A design of size-reduced negative group delay circuit using a stepped impedance resonator," Proc. Asia-Pacific Microw. Conf., 118-1121, Dec. 2010.
5. Kitano, M., T. Nakanishi, and K. 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.
6. Brillouin, L., Wave Propagation and Group Velocity, Academic, Cambridge, MA, USA, 1960.
7. Choi, H., Y. Jeong, C. D. Kim, and J. S. Kenney, "Efficiency enhancement of feed forward amplifiers by employing a negative group-delay circuit," IEEE Trans. Microw. Theory Techn., Vol. 58, No. 5, 1116-1125, May 2010.
8. Oh, S. S. and L. Shafai, "Compensated circuit with characteristics of lossless double negative materials and its application to array antennas," IET Microw. Antennas Propag., Vol. 1, No. 1, 29-38, 2007.
9. Shao, T., Z. Wang, S. Fang, H. Liu, and Z. N. Chen, "A full-passband linear-phase band-pass filter equalized with negative group delay circuits," IEEE Access, Vol. 8, 43336-43343, 2020.
10. Choi, H., Y. Jeong, C. D. Kim, and J. S. Kenney, "Bandwidth enhancement of an analog feedback amplifier by employing a negative group delay circuit," Progress In Electromagnetics Research, Vol. 105, 253-272, 2010.
11. Ravelo, B. E. G., A. Pérennec, and M. Le Roy, "Synthesis of frequency-independent phase shifters using negative group delay active circuit," International Journal of RF and Microwave Computer- Aided Engineering, Vol. 21, No. 1, 17-24, Wiley, 2011.
12. Ravelo, B., M. Le Roy, and A. Pérennec, "Application of negative group delay active circuits to the design of broadband and constant phase shifters," Microw. Opt. Technol. Lett., Vol. 50, 3078-3080, 2008.
13. Wan, F., et al., "Design of multi-scale negative group delay circuit for sensors signal time-delay cancellation," IEEE Sensors J., Vol. 19, No. 19, 8951-9962, 2019.
14. Ravelo, B., "Similitude between the NGD function and filter gain behaviours," Int. J. Circ. Theor. Appl., Vol. 42, No. 10, 1016-1032, Oct. 2014.
15. Chaudhary, G., Y. Jeong, and J. Lim, "Miniaturized negative group delay circuit using defected microstrip structure and lumped elements," 2013 IEEE MTT-S International Microwave Symposium Digest (MTT), 1-3, 2013.
16. Choi, H., et al., "A compact DGS load-network for highly efficient class-E power amplifir," 2009 European Microwave Conference (EuMC), 492-495, 2009.
17. Radisic, V., et al., "Novel 2-d photonic bandgap structure for microstrip lines," IEEE Microwave and Guided Wave Letters, Vol. 8, No. 2, 69-71, 1998.
18. Kandic, M. and G. 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.
19. Chaudhary, G., Y. Jeong, and J. Lim, "Microstrip line negative group delay filters for microwave circuits," IEEE Trans. Microw. Theory Techn., Vol. 62, No. 2, 234-243, Feb. 2014.
20. Xiao, J.-K. and Q.-F. Wang, "Individually controllable tri-band negative group delay circuit using defected microstrip structure," 2019 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC), 1-3, 2019.
21. Zhao, G. and B. You, "A tunable negative group delay filter using memristors," 2020 IEEE MTT-S International Wireless Symposium (IWS), Shanghai, China, 2020.
22. Palson, C. L., R. K. Sreelal, D. D. Krishna, and B. R. Jose, "Memristor based tunable negative group delay circuit," 2021 International Conference on Advances in Computing and Communications (ICACC), 1-4, 2021.
23. Chaudhary, G., Y. Jeong, and J. Lim, "Miniaturized dual-band negative group delay circuit using dual-plane defected structures," IEEE Microwave and Wireless Components Letters, Vol. 24, No. 8, 521-523, Aug. 2014.
24. Chaudhary, G., P. Kim, J. Jeong, Y. Jeong, and J. Lim, "Dual-band negative group delay circuit using defected microstrip structure," 2015 IEEE Radio and Wireless Symposium (RWS), 129-131, 2015.
25. Wan, F., N. Li, B. Ravelo, and J. 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. Chaudhary, G., Y. Jeong, and J. 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.
27. Meng, Y., Z. Wang, S.-J. Fang, and H. Liu, "A tri-band negative group delay circuit for multiband wireless applications," Progress In Electromagnetics Research C, Vol. 108, 159-169, 2021.
28. Meng, Y., Z. Wang, S. Fang, and H. Liu, "Reconfigurable negative group delay circuit with tunable group delay flatness," Int. J. RF Microw. Comput. Aided Eng., Vol. 32, No. 6, e23159, 2022.
29. Chaudhary, G., Y. Jeong, and J. Lim, "Realization of negative group delay network using defected microstrip structure," International Journal of Antennas and Propogation, Vol. 2014, 1-5, 2014.
30. Kandic, M. and G. 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, Sep. 2021.
31. Wan, F., N. Li, B. Ravelo, W. Rahajandraibe, and S. Lalléchère, "Design of shape stub-based negative group delay circuit," IEEE Design & Test, Vol. 38, No. 2, 78-88, Apr. 2021.