Nathan Bushyager

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The FDTD and the Haar-based MRTD algorithms are applied to the full-wave modeling of high-frequency structures that require the combination of differential equations with time-constants of different orders. The numerical coupling of Maxwell's and mechanical equations for the simulation of a MEMS capacitor and of Maxwell's and solid-state equations for a pn(More)
The modeling of MEMS structures using MRTD is presented. Many complex RF structures have been inadequately studied due to limitations in simulation methods. The space and time adaptive grid, as well as the ability to handle intracell feature variations, makes MRTD an ideal method for modeling these structures. MRTD is shown to be able to handle the complex(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)
—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)
— 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)
The successful use of the Design of Experiments (DOE) and Response Surface Modeling (RSM) approaches in an optimization study for a multilayer interdigitated passband filter is presented. The medium of interest is Liquid Crystal Polymer (LCP) and the frequency band is in the 60 GHz range. The two figures of merit chosen are the resonating frequency f o and(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)
The successful use of the Design of Experiments (DOE) approach in an optimization feasibility study for two microwave balanced to unbalanced transformers (baluns) is presented. The medium of interest is the multi-layer Low Temperature Cofired Ceramic (LTCC) and two different topologies, one microstrip and one stripline, are investigated. The design goals(More)
This paper presents methods using time domain electromagnetic modeling techniques to characterize passive devices in packaging structures. Particularly, the Q of a novel multilayer inductor is predicted. The inductor uses a " hollow ground plane " configuration to increase performance. The modeling techniques employed include dielectric loss modeling to(More)