Sonnet EM Research Articles

Implicit Space Mapping Optimization Exploiting Preassigned Parameters

We introduce the idea of implicit space mapping (ISM) and show how it relates to the well-established (explicit) space mapping between coarse and fine device models. Through comparison, a general space mapping concept is proposed. A simple algorithm based on the novel ISM concept is implemented. It is illustrated on a contrived "cheese-cutting problem" and is applied to electromagnetics-based microwave modeling and design. An auxiliary set of parameters (selected preassigned parameters) is extracted to match the coarse model with the fine model. The calibrated coarse model (the surrogate) is then (re)optimized to predict a better fine model solution. This is an easy space mapping technique to implement since the mapping itself is embedded in the calibrated coarse model and updated automatically in the procedure of parameter extraction. We illustrate our approach through optimization of a high-temperature superconducting filter using Agilent ADS with Momentum and Agilent ADS with Sonnet's em.

Simulation study on the mechanical tuning of high-T/sub c/ superconducting microwave filters

We tried to apply the mechanical tuning method to lumped-element superconducting filters and investigated the tunability by simulation. This tuning method is the same as we previously adopted for tuning microstrip-line-type resonators, i.e., tuning by the displacement of a dielectric floating plate with an actuator above the resonator. We considered band pass filters with a center frequency in a GHz range and a bandwidth of a few tens to a few hundreds MHz. The inductors and the capacitors were designed and simulated using an electromagnetic analysis simulator, Sonnet EM. We assumed MgO for the substrate and the floating plate. We investigated the properties of the filters and their tunability.

Design of coplanar waveguide multilayer square spiral inductors for monolithic microwave integrated circuits

A square indicator using multilayer coplanar waveguide transmission lines on a GaAs fabricated by using monolithic microwave integrated circuits (MMIC) technology is presented. The polyimide layer formation, curing and dry etching processes are used in an attempt to obtain high quality dielectric layers suitable for MMIC applications. The experimental fabrication progress provides two metal layers with two polyimide spacer dielectric layers. A brief overview of the electromagnetic design process is included. The performance of the proposed spiral inductor is investigated experimentally and with electromagnetic simulations (Sonnet em) up to 20 GHz using RF-on-water measurements. A very good agreement is achieved, despite the highly three-dimensional nature of the structure. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 86–92, 1999

A trust region aggressive space mapping algorithm for EM optimization

A robust new algorithm for electromagnetic (EM) optimization of microwave circuits is presented. The algorithm (TRASM) integrates a trust region methodology with the aggressive space mapping (ASM). The trust region ensures that each iteration results in improved alignment between the coarse and fine models needed to execute ASM. The parameter extraction step is a crucial part of the ASM technique. The nonuniqueness of this step may result in the divergence of the technique. To improve the uniqueness of the extraction phase, we developed a recursive multipoint parameter extraction. This suggested step exploits all the available EM simulations for improving the uniqueness of parameter extraction. The new algorithm was successfully used to design a number of microwave circuits. Examples include the EM optimization of a double-folded stub filter and of a high-temperature superconducting (HTS) filter using Sonnet's em. The proposed algorithm was also used to design two-section, three-section, and seven-section waveguide transformers exploiting Maxwell Eminence. The design of a three-section waveguide transformer with rounded corners was carried out using HP HFSS. We show how the mapping can be used to carry out Monte Carlo analysis using only coarse model simulations.

Some experimental results of printed antennas for the benchmarking of sonnet em electromagnetic simulator

Recently, a significant amount of research has concentrated on printed antennas and their applications using either commercial or in-house electromagnetic simulators to evaluate performance prior to construction. It has now become clear that such 2.5-D/3-D simulators play a unique role in the development of precise microwave or millimeter-wave printed antennas. This article describes some of the experimental results and benchmarking of printed antennas designed using the Sonnet Software em electromagnetic simulator. Discussions about em's accuracy and problems and comparisons to other analytical methods are presented. © 1996 John Wiley & Sons, Inc.