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)
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)
— 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— 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)
The process of developing optimal parallel applications is computationally expensive. The goal of this work is to design and validate a Markov chain based system-level performance prediction models to efficiently optimize parallel applications on shared memory multicore processors with coarse-grain thread level parallelism (TLP) like Intel Xeon Clover town.(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)
The primary purpose of the current paper is to design a fast and accurate performance model framework for exploring various thread-to-core mapping strategies (MS) and estimating steady state cycles per instruction (CPI). It is directed towards efficiently exploring these performance metrics for large parallel applications for shared memory multicores. This(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)