Ryan S. Adams

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—Although the potential for wideband double-negative metamaterials using non-Foster circuit elements was described more than a decade ago, progress has been somewhat limited. Therefore, the analysis and simulation of a wideband microwave metamaterial are presented, where non-Foster elements are used as loads on split rings and on electric resonators. Using(More)
— Current conveyors are an important component for implementing non-Foster circuits such as negative capacitors and negative resistors. However, different topologies exist for implementing negative capacitance using a current conveyor, and the performance of such topologies can vary greatly. Therefore, this paper considers two competing realizations of(More)
Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works, must be obtained from the IEEE. Abstract— A novel unit cell and(More)
Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works, must be obtained from the IEEE. Abstract— Left-handed materials(More)
—There is renewed interest in the use of non-Foster circuit elements in a variety of important applications such as wideband impedance matching and artificial magnetic conductors. Although non-Foster devices such as negative capacitors and negative inductors can be realized using current conveyors and Linvill circuits, a digital design approach may offer an(More)
— Although microwave metamaterials may seem unrelated to gamma-ray astrophysics, it is shown that both phenomena may be expressed using left-handed extensions to Maxwell's equations. For metamaterials, such extensions represent the left-handed behavior of materials. For gamma-ray bursts, such extensions represent unknown dispersive processes, such as(More)
—Digital discrete-time implementations of non-Foster circuit elements offer an alternative to conventional analog circuit approaches. In particular, the design of a discrete-time negative capacitor is investigated, since such non-Foster circuit elements offer significant potential in wideband antenna, metamaterial, and artificial magnetic conductor(More)
— Current conveyors can be used as building blocks for implementing non-Foster circuits such as negative capacitors and negative inductors that are useful in extending bandwidth in metamaterials. In the present paper, measured results are presented for a prototype integrated circuit current conveyor negative capacitor. This circuit has been fabricated in a(More)
— This paper presents an effective approach for reducing parasitic resistance of a CMOS negative inductor with a single compensating resistor. A compensating resistor is used to mitigate the effect of parasitic resistance with quadratic frequency dependence. The undesired parasitic effect is induced by the inevitable finite drain-source resistance of the(More)