Journal ArticleDOI
Negative-Impedance Converters
TLDR
In this article, the conditions under which an active device exhibits an input impedance at one terminal pair which is exactly the negative of the load impedance connected to the other terminal pair are discussed.Abstract:
The conditions under which an active device exhibits an input impedance at one terminal pair which is exactly the negative of the load impedance connected to the other terminal pair are discussed. There are an infinite number of ways by which such a device, which is called a negative-impedance converter (NIC), can be made. One of the limits of this set is represented by a transistor circuit which was discussed previously by Linvill; the other limit, by a new circuit introduced recently. Practical negative-impedance converters are not exact; however, they may be made so by the addition of a pair of compensating impedances. The parameters of the NIC which most affect circuit performance are indicated as a guide to NIC design. Two typical transistor NIC circuits are compared on this basis. Experimental results are given.read more
Citations
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Journal ArticleDOI
Realisation of gyrators using operational amplifiers, and their use in RC-active-network synthesis
TL;DR: The realisation of negative-impedance convertors and invertors using the bridge-type circuit using the nullor to infinite-gain controlled sources is briefly surveyed and a relevant theorem concerning passivity is proved.
Journal ArticleDOI
Broadband, Efficient, Electrically Small Metamaterial-Inspired Antennas Facilitated by Active Near-Field Resonant Parasitic Elements
Peng Jin,Richard W. Ziolkowski +1 more
TL;DR: In this paper, the possibility of using an active internal matching element in several types of metamaterial-inspired, electrically small antennas to overcome their inherent narrow bandwidths is demonstrated.
Journal ArticleDOI
A New Theory of Cascade Synthesis
TL;DR: In this article, a new result generalizing Richards' theorem is presented, which leads to a complete, simple and unified theory of cascade synthesis which yields the types A, B, Brune, C and D sections in a direct and natural manner.
Journal ArticleDOI
Superluminal Waveguides Based on Non-Foster Circuits for Broadband Leaky-Wave Antennas
TL;DR: In this paper, negative capacitors are used to create superluminal waveguides for broadband leaky-wave antennas, which cancels part of the dielectric constant within the waveguide to provide a broadband relative permittivity between 0 and 1.
Journal ArticleDOI
Robust and efficient wireless power transfer using a switch-mode implementation of a nonlinear parity–time symmetric circuit
Sid Assawaworrarit,Shanhui Fan +1 more
TL;DR: It is shown that robust and efficient wireless power transfer can be achieved by using a power-efficient switch-mode amplifier with current-sensing feedback in a parity–time symmetric circuit.
References
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Journal ArticleDOI
Transistor Negative-Impedance Converters
TL;DR: The physical characteristics of transistors, compactness, long life, simple power requirements, plus constancy of pertinent electrical parameters enhance their practical utility in the production of negative impedances.
Journal ArticleDOI
RC Active Filters
TL;DR: In this article, a class of active RC filters is described in which one active component, a transistor negative-impedance converter, is employed, and simple unbalanced network configurations are obtained in which the number of capacitors in the RC circuits is equal to the total number of reactive elements in the corresponding LC filter.
Journal ArticleDOI
Theory of the negative impedance converter
TL;DR: In this paper, a relatively new approach to the solution of negative impedance problems related to vacuum tube circuits is presented, which consists of reducing the vacuum tube circuit of a device for producing negative impedance to an electrically equivalent four-terminal network from which the stability and the operation of the device as an element in a system can be predicted accurately.