P.A. Grobelny

Yield-driven electromagnetic optimization via multilevel multidimensional models

The authors present the foundation of a sophisticated hierarchical multidimensional response surface modeling system for efficient yield-driven design. The scheme dynamically integrates models and database updating in real optimization time. The method facilitates a seamless, smart, optimization-ready interface. It has been specially designed to handle circuits containing complex subcircuits or components whose simulation requires significant computational effort. This approach makes it possible, for the first time, to perform direct gradient-based yield optimization of circuits with components or subcircuits simulated by an electromagnetic simulator. The efficiency and accuracy of the technique are demonstrated by yield optimization of a three-stage microstrip transformer and a small-signal microwave amplifier. The authors also perform yield sensitivity analysis for the three-stage microstrip transformer. >

Electromagnetic design of high-temperature superconducting microwave filters

We present novel approaches to electromagnetic design of high-temperature superconducting quarter-wave parallel coupled-line microstrip filters. The dielectric constant of substrate materials used in high-temperature superconductor technology is too large to be accurately treated by traditional microwave circuit design software packages with analytical/empirical models. We employ electromagnetic field simulation and develop a look-up table method and a powerful space mapping optimization technique, which dramatically reduce the CPU time for the design process.<<ETX>>

Integrated harmonic balance and electromagnetic optimization with geometry capture

This paper presents an integrated approach to nonlinear circuit optimization. Electromagnetic simulations are seamlessly integrated into harmonic balance simulation and optimization. For the first time, complicated planar structures can be made fully optimizable through the parameterization process of this geometry capture technique. They are then treated as individual elements in electromagnetic simulations and are embedded into the overall nonlinear circuit to be optimized. A comprehensive class B frequency doubler design demonstrates our approach.<<ETX>>

Exploitation of coarse grid for electromagnetic optimization

Direct, optimization-driven electromagnetic design is studied. Focusing upon a double folded stub microstrip filter, we explore design characteristics for coarse grids. EM models: coarse grid (EMC) for fast computations and the corresponding fine grid (EMF) for more accurate simulations are compared. The EMC model,useful when circuit-theoretic models may not be readily available, permits rapid exploration of different starting points, solution robustness, local minima, parameter sensitivities, yield-driven design, and other design characteristics within a practical time frame.<<ETX>>

A CAD environment for performance and yield driven circuit design employing electromagnetic field simulators

In this paper we describe a CAD environment for performance and yield driven circuit design with electromagnetic (EM) field simulations employed within the optimization loop. Microstrip structures are accurately simulated and their responses are incorporated into the overall circuit analysis. We unify the component level interpolation technique, devised to handle discretization of geometrical parameters, and the modeling technique used to lighten the computational burden of statistical design centering. We discuss the organization and utilization of the data base system integrated with the modeling technique. We demonstrate the feasibility and benefits of performance and yield optimization with EM simulations.<<ETX>>

Multilevel multidimensional quadratic modeling for yield-driven electromagnetic optimization

Powerful multilevel multidimensional quadratic modeling has been developed for efficient yield-driven design. This approach makes it possible to perform direct yield optimization of circuits with microstrip structures simulated by an electromagnetic simulator. This approach is particularly useful for circuits containing complex subcircuits or components whose simulation requires significant computational effort. The efficiency and accuracy of this technique are demonstrated by yield optimization of a small-signal amplifier.<<ETX>>

Heterogeneous parallel yield-driven electromagnetic CAD

Within an integrated parallel optimization framework, we are able, for the first time, to apply electromagnetic (EM) optimization to the yield-driven design of microstrip circuits of arbitrary geometries. Parallel optimization handles the massive demand on computer resources, due to the large number of designable parameters describing an arbitrary geometry and the large number of simulations involved in yield optimization. Our parallel strategy can be implemented over local and wide area networks supporting heterogeneous workstations.<<ETX>>