eldo_user

• Simulation of passive networks using an electromagnetic solver.
Working with S, Y, Z Parameters
Basic Functionality
• Measurements from a passive network (interconnects, transmission lines, passive filters,
and so on).
• Frequency-domain simulation of passive networks (AC analysis).
• Data sheets of active or passive devices.
The major applications of S-model are as follows:
• Transient simulation of microwave linear circuits originally described by its response in
frequency domain.
• Transient simulation of interconnects together with non-linear drivers/loads, either for
VLSI or GaAs integrated circuits, using either their calculated or measured scattering
parameters.
• Lossy transmission-line transient simulation in the presence of either linear or non-linear
drivers/loads.
• Transient simulation of arbitrary (or user-defined) passive microwave circuits after
extracting their S parameters (using a standard electromagnetic solver).
Basic Functionality
The S-model implemented in Eldo is a building block that makes possible DC, AC, and
transient simulation of circuits with any number of N-ports described by their S (Scattering), Y
(Admittance), or Z (Impedance) parameters, in the form of tabulated data in the frequency
domain.
The tabulated data is contained in an ASCII data file in the Touchstone® format. This format is
briefly described in “Touchstone Data File Format” on page 705. When giving the instance of
the model in the Eldo netlist file, you can specify the data file either by setting an index
associated with the file’s name, or by explicitly defining the name of the file. The optimal of the
three algorithms discussed above, Complex Pole Fitting (CPF), Digital Signal Processing
(DSP), and System Identification (SI), is selected by the internal Eldo monitor that enables great
flexibility of simulation. You can also specify this method directly.
Detailed Functionality
Eldo supports S parameters as follows:
• Simulation of N-ports with no restriction on N. N is determined automatically by the
Eldo parser according to the number of pins.
• Any number of instances of the same model, any number of different models.
• All SST, PSS and MODSST simulation types are supported.
Eldo® User's Manual, 15.3 697