Nathan Bushyager

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— Modern RF-MEMS device design is difficult due to the lack of tools capable of simulating highly integrated structures. This paper presents methods in which the FDTD technique can be used to model a reconfigurable RF-MEMS tuner. A new method of modeling a conductor intersecting a cell is presented. In addition, code parallelization and variable gridding(More)
— This paper introduces a novel full wave technique for modeling MEMS tunable capacitors that is based on the coupling of physical motion of the MEMS device with Maxwell's equations through the modification of the MRTD/FDTD techniques. The difficulties of modeling MEMS devices are discussed, and ways to compensate for several of these are presented. The(More)
—Future wireless communications systems require better performance, lower cost, and compact RF front-end footprint. The RF front-end module development and its level of integration are, thus, continuous challenges. In most of the presently used microwave integrated circuit technologies, it is difficult to integrate the passives efficiently with required(More)
Methods to model metamaterial structures consisting of lumped elements embedded into transmission lines using multiresolution time-domain (MRTD) are presented in this paper. Specifically, this paper presents the modeling of lumped elements in MRTD, including elements that are smaller than a cell (subcell modeling). Using this technique, several lumped(More)
— This paper presents techniques that can be used with the Haar MRTD method for time and space adaptive gridding. For the first time, absolute and relative thresholds for wavelet functions are used to change the resolution as a function of time and space. This technique is applied to the composite cell Haar MRTD scheme, which is capable of representing(More)
— Four DSP-based digital predictors (Prony's, covariance, forward-backward, matrix pencil), that are commonly used to enhance the time-domain modeling and design of highly complex RF MEMS structures, are evaluated in terms of computational efficiency and accuracy as a function of the model order, the decimating factor, and the size of sample train. For a(More)
— The modeling of RF integrated structures with fine metallic details using time-domain simulators is addressed. The key features identified as difficulties in modeling metallic structures in these techniques are dielectric and metal loss and complexity of geometry. A method to model loss that involves the use of a quasi-static simulator to identify(More)
This paper deals with some of the most important issues in modern packaging design and simulation of structures for use in wireless communications systems. The focus of the discussion is on the integration of novel complex device parameters, specifically the inclusion of MEMS devices and solid-state circuit elements, and on the mathematically correct(More)
As RF technologies mature designing complex RF systems is becoming an increasingly difficult task. Modern systems include components that cannot be modeled with traditional simulators. This paper introduces a modeling technique for use in RF systems that combines Maxwell's, mechanical, and solid-state equations. The resulting simulator can be used to(More)