Negative Group Delay Theory of a Four-Port RC-Network Feedback Operational Amplifier

Autor: Fayu Wan, Taocheng Gu, Blaise Ravelo, Binhong Li, Jing Cheng, Qingyun Yuan, Junxiang Ge
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: IEEE Access, Vol 7, Pp 75708-75720 (2019)
Druh dokumentu: article
ISSN: 2169-3536
DOI: 10.1109/ACCESS.2019.2922422
Popis: An innovative negative group delay (NGD) theory based on a unity direct chain feedback (UDCF) circuit topology is developed in this paper. This NGD circuit is an active cell constituted by an operational amplifier in feedback with a four-port RC-network. This NGD circuit theory is developed based on the S-parameter model analytically established from the equivalent impedance matrix. The UDCF group delay frequency response is expressed as a function of the feedback RC-cell and the operational amplifier parameters. The NGD analysis of the developed UDCF cell is introduced. According to theoretical analysis, under a certain condition, the UDCF topology is susceptible to behave as a low-pass NGD function. The UDCF cell NGD characteristics are defined theoretically. The theoretical prediction is verified numerically and experimentally in both the frequency- and time-domain by designing and fabricating an active PCB prototype. The simulations and experimentations show that the UDCF circuit exhibits an NGD of approximately -38 ns with NGD cut-off frequency of about 5.5 MHz. More importantly, it is demonstrated in the time-domain that the low-pass NGD effect enables the UDCF cell to generate advanced output with sinc waveform input voltages.
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