OSA90/hope™ User’s Manual Version 4.0 -- PC

Abstract

OSA90/hope™ is a state-of-the-art, general purpose CAD software system offering simulation, modeling, statistical analysis, nominal and yield optimization, and data visualization for linear and nonlinear RF/microwave analog circuits. Its open architecture allows you to create fully optimizable interconnections of components, subcircuits, simulators and mathematical functions. OSA90/hope is equipped with several protocols for connecting external programs through interprocess pipes. This facilitates high-speed data connections to external executable programs, even across networks. Throughout this manual, OSA90/hope is referred to as OSA90. OSA90 simulates linear and nonlinear circuits of general n-port topology. Multiple nonlinear devices and sources, both DC and AC, are allowed. Built-in simulators handle DC, small-signal AC, large-signal harmonic balance and two-tone spectral analyses. OSA90 supports oscillator analysis and design. The DC, small-signal and large-signal simulations are analytically unified through a consistent circuit description. Small-signal circuits, when needed, are automatically derived from nonlinear models. Small-signal analysis produces S, Y and Z parameters, and group delay. For 2-ports, OSA90 calculates insertion loss, stability factor and maximum available gain. Frequency, power and arbitrary multi-parameter sweeps can be defined for simulation. OSA90 supports expression composition directly in the input file. You can define constants, variables, vectors and matrices. You can create user-defined functions and postprocess responses using typical algebraic operations and a rich set of built-in mathematical functions. OSA90 is equipped with several Datapipe™ protocols for connecting external programs through interprocess pipes. This facilitates high-speed data connections to external executable programs, even across networks. Specialized Datapipe-based interfaces exist for a number of applications, including the popular analog circuit simulator SPICE and several electromagnetic simulators such as Sonnet Software’s em (Empipe) and HFSS (Empipe3D). OSA90 features powerful and robust gradient-based optimizers: L1, L2, Huber, minimax, quasi-Newton, conjugate gradient, as well as non-gradient simplex, random and simulated annealing optimizers. You can invoke OSA90 itself through Datapipe to create a simulation/optimization hierarchy of virtually unlimited depth. Space Mapping™ is a rapidly developing fundamental new theory for engineering design optimization. Exclusive to OSA90, it links “coarse” and “fine” models and is particularly useful in bringing design with CPU intensive simulators into a practical time frame. Coarse models, such as built-in OSA90 empirical models, are used for fast optimization, and the optimal solution is mapped to the fine model space. When applied to direct EM optimization, the results can be astounding! An automated algorithm for SM (Aggressive Space Mapping™) is implemented using a two-level Datapipe architecture: a generic layer of iterations creates and updates the mapping, while the parameter extraction phase aligns the specific models. OSA90 employs sophisticated one-sided L1 and one-sided Huber design centering algorithms for yield optimization. Advanced quadratic approximation is an integrated option to reduce the computer time required for large-scale yield optimization.