IdEM Versions Comparison

Main Feature	Detailed Feature	Description
Import	Transient Data Import	Transient data import from CST Microwave Studio has been upgraded in order to support recent versions. Support is now available for all transient data formats from MWS version 3 up to version 2008.
	Touchstone Import	The Touchstone import module has been improved and optimized for handling huge data files with a size larger than 100 MBytes. In particular, memory requirements are now significantly reduced during file read and data storage in IdEM workspace.
Causality	Data Causality Check	The causality check tool included in IdEM implements one of the most advanced and accurate techniques for frequency data validation. Through a series of different tests, the causality check tool can detect the presence of measurement/simulation errors that compromise the physical consistency of the raw data.
	Causality Plots	A novel visual representation for data causality check results is now available, allowing for an intuitive interpretation and understanding of the results.
Data Operations	DC Point Extrapolation	This feature allows to add the missing DC point to frequency-domain responses via advanced and causality-constrained extrapolation schemes.
	Data Conversion	This feature allows conversion between differen network parameters. When dealing with N-port structures, it may be necessary or convenient to convert them into specific matrix representations, depending on the applications. IdEM can perform conversion from and to Impedance (Z), Admittance (Y) and Scattering (S) formats.
	Variable Port Impedance	Since IdEM R2009b, it is possible to re-normalize Scattering representations using different reference impedances for individual ports. This feature improves accuracy and model robustness for mixed Signal-Power integrity applications.
	Reciprocity	Since R2009b, full support for reciprocity in data and models is available, leading to several optimizations, including speed up in all steps of model extraction and reducing memory requirements.
Fitting Algorithm	Fast Fitting Algorithms	New optimized implementations of the frequency-domain fitting algorithms are now available. Main advantage is runtime, which is reduced up to two orders of magnitude with respect to previous IdEM versions. This suprising performance increase has been achieved with state-of-the-art matrix compression techniques in the numerical solution of the fitting equations.
	Automatic Fitting Order Estimation	Automated order estimation and initialization has been added to the frequency-domain fitting tool. Using default settings, no User input is now required to construct a macromodel. Of course, all (and even more) advanced control settings are still available to the User, for a complete configuration of the algorithm behavior and for fine-tuning the output model.
	Model Refinement	This feature allows to refine a model that is already available in the workspace, by tuning its complexity until the desired accuracy level is reached.
IdEMXpress	IdEMXpress Wizard	Since IdEM R2009b, the IdEMXpress Wizard has been introduced for automation of the most common data and model operations (data passivity check - data causality check - model build - model passivity enforcement). No user intervention is now required for performing repeated modeling tasks on a possibly large number of structures.
Passivity	Hamiltonian (HAM) Scheme	This scheme achieves passivity via perturbations of the so-called Hamiltonian matrices associated to the model.
	SOC Scheme	This scheme achieves passivity by enforcing local passivity constraints at carefully selected frequencies. Global passivity is achieved by iterations. The passivity equations are formulated as Second-Order-Cone constraints, leading to a particularly efficient numerical solution.
	SOC+HAM Scheme	This scheme combines the advantages of SOC and HAM schemes, by selecting the best algorithm to be run at each iteration, based on the specific model being processed.
	SOC and HAM Optimizations	New and improved formulations of both passivity algorithms have been applied, leading to a reduction of passivity enforcement time by at least a factor of 2 with respect to previous algorithms.
	SOC Weighting	Advanced frequency-weighting schemes are now used in SOC scheme to preserve in-band model accuracy while enforcing global passivity. Main advantages are more accurate results, combined with better and faster convergence properties even in the most challenging multiport cases.
	HAM Weighting	Advanced frequency-weighting schemes have been extended to the Hamiltonian passivity solver, with major improvement in convergence properties, in-band accuracy preservation, and processing speed.
	Asymptotic Passivity Enforcement	A new strategy for asymptotic passivity enforcement is now available and applied for handling sparsified scattering-based models. Sparsified models are obtained by processing raw data with some of the small couplings removed. This is accomplished by using either energy-based or topology-based sparsification. In previous releases, asymptotic passivity (hence, global passivity) could not be enforced for these models. It is now possible to process also sparsified models, provided that the raw data is in scattering form.
	Sparse SOC Scheme	A new and optimized SOC passivity enforcement scheme is available. This scheme exploits an internal sparse representation of the Gramian matrices and fully supports reciprocity. Main advantage is faster processing time. Backward compatibility is also retained for convenience.
	Advanced Sampling	An pptimized frequency sampling scheme for SOC-based passivity enforcement has been introduced, leading to a faster and more robust algorithm.
Model Operations	DC Point Enforcement	This feature allows to enforce the DC point of the model to a prescribed value. In particular, DC point enforcement is useful as a post-processing step after a fitting or a passivity enforcement operation. It is possible to extract the DC value to be used as reference from any dataset in the workspace, provided that the number of ports matches.
Model Export	HSPICE® Laplace/Foster	Model export is now available as equivalent circuits in Laplace/Foster form (available for HSPICE® only).
	Verilog-A	Model export is now available in Verilog-A language.
	Spectre®	Model export is now available as equivalent circuits in native Cadence Spectre® language.
	VHDL-AMS	Model export is now available in VHDL-AMS language.
	MAST®	Model export is now available in MAST® Hardware Description Language.
GUI	Interface	The IdEM Graphical User Interface has been drastically improved, both for algorithm and configuration controls. More intuitive interfaces are now available, leading to a simpler and more effective macromodeling experience.
	Abort Control	A new control has been added in the GUI, allowing for user interruption of any IdEM calculation. When a simulation is taking longer than expected or is not leading to the expected results, a simple mouse click returns control to the User, resetting IdEM to its previous state.
	IdEMXpress Link	A new control for accessing the IdEMXpress Wizard is now available in the IdEM toolbar.
	Export Link	A new control for direct model Export is now available in the IdEM toolbar.
	Figure Auto-Close	An auto-close switch is now available for configuring the behavior of IdEM with respect to figures and plots that are automatically generated during modling steps. The User can choose whether retaining these figures for further inspection or automatically close these figures at the end of processing. This control is available in main IdEM toolbar.
Settings	Installation Settings	IdEM installation files and folders are accessed by each user only in read mode. This allows for centralized installations in a multi-user environment. This feature was available on Linux platforms in previous releases and it has been extended to Windows platforms in R2008b.
	Personal settings	Each User has now its private log file and configuration settings. These are created with defaults at the first IdEM run after installation in a private folder. Each User can then modify these private configuration options without affecting other Users. In addition, each User can configure its preferred working folder and the locations where data, models, and configuration settings are located.
	Fitting/Passivity Options	General Preferences and advanced Fitting and Passivity options have been enriched and reorganized. It is now possible to import and export predefined or user-defined configuration settings and options, thus enabling a single-click reconfiguration of IdEM for different working modes or tasks.
	Exception Handling	An advanced system for exception handling has been implemented, allowing to recover smoothly from various unexpected situations, including out-of-memory errors. When such exceptions occur, IdEM interrupts immediately the action causing the problem and returns control to the User. In particular, it is now possible to save workspaces, data and models even after blocking exceptions.
	Plotting Options	Several options are now available for controlling plotting and figure generation, including configurable default plotting profiles.
	Backward Compatibility Mode	The User can switch between most recent or previous implementations of the algorithms through a dedicated switch in main GUI. Performance improvement can thus be easily assessed.