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Matching network design using non‐Foster impedances
Author(s) -
SussmanFort Stephen E.
Publication year - 2006
Publication title -
international journal of rf and microwave computer‐aided engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.335
H-Index - 39
eISSN - 1099-047X
pISSN - 1096-4290
DOI - 10.1002/mmce.20118
Subject(s) - impedance matching , reactance , variable capacitor , antenna (radio) , computer science , electrical impedance , antenna tuner , converters , broadband , electronic engineering , electrical engineering , dipole antenna , capacitor , antenna efficiency , engineering , telecommunications , voltage
Non‐Foster synthesis bypasses the gain‐bandwidth limitations of conventional LC matching and achieves superior broadband performance by employing negative circuit elements, which are realized via negative impedance converters. The idea is to construct a negative‐image model of an antenna, which cancels the antenna's parasitic reactance and transforms its frequency‐dependent radiation resistance to a constant value. Successful implementation of negative‐image modeling requires the realization of stable, low‐loss negative elements. After a discussion of the basic ideas of non‐Foster matching, we present experimental results for broadband, stable, high‐ Q , grounded negative capacitance. Next, in the first experimental confirmation of non‐Foster impedance matching for signal reception, we use a floating negative capacitor to cancel a substantial portion of the reactance of a 6‐in. monopole antenna. Over 20–110 MHz, the signal‐to‐noise ratio improved by up to 6 dB as compared to the same antenna with no matching, or to a lossy‐matched blade antenna of twice the size. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.