Nathan Bushyager

Learn More
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)
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)
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 are(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)
A method that allows the intracell modeling of a PEC/dielectric interface using MRTD is presented in this paper. This approach involves zeroing scaling and wavelet functions that intersect the metal, and results in the decoupling of the fields on either side of the metal. Applications of this technique to EBG patterned ground planes and RF-MEMS are(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)
This paper details some of the basic issues that arise when designing a Beowulf cluster for particular types of scientific simulations. The general problems of interest are partial differential equations (PDEs). These equations describe natural phenomenon and can be numerically solved. Finite differencing is used to solve the system of equations. This(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)