Open AccessStable multiple non‐Foster circuits loaded waveguide for broadband non‐dispersive fast‐wave propagation
Author(s) -
Long J.,
Sievenpiper D.F.
Publication year - 2014
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2014.2612
Subject(s) - broadband , microwave , electronic circuit , waveguide , bandwidth (computing) , materials science , acoustics , electronic engineering , optoelectronics , optics , electrical engineering , computer science , physics , telecommunications , engineering
Periodically loading non‐Foster circuits (NFCs) in a conventional waveguide has been proved to be possible for achieving broadband non‐dispersive fast‐wave (FW) propagation. However, the unconditional stability of such structures has been argued due to the multiple NFC loadings. Despite the potential instability, it is demonstrated that the NFC‐loaded waveguide can still be stable for specific terminations, in particular, with the 50 Ω load that is commonly used in radio frequency/microwave applications. For purpose of demonstration, a NFC‐loaded waveguide that contains substantially more unit cells than in prior work has been designed and measured, showing a stable and causal FW propagation with a 1.2 c phase velocity over the bandwidth of 80–120 MHz.