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Transient EM/Circuit Co-Simulation

A SPICE-based circuit solver and full-wave FDTD solver are computed simultaneously.


XF's transient EM/circuit co-simulation capability combines a time-domain circuit solver with its full wave electromagnetic solver and uses co-simulation to update complex circuit structures at each timestep in an FDTD simulation.  This improves the analysis of transient-voltage-suppression (TVS) diodes, chip components and matching networks.

  • Improve the analysis of transient-voltage-suppression (TVS) diodes, chip components and matching networks
  • Simulate realistic chip performance using measured data from manufacturers such as Murata, Coilcraft, and Taiyo Yuden 
  • Define a matching network as a SPICE model and include in a voltage source

TVS Diodes

TVS diodes are often used in the RF frontend or along data lines to protect sensitive circuitry from an ESD event. Manufacturers provide an equivalent SPICE model consisting of diodes, resistors, capacitors, and inductors to model the VI characteristics of the physical diode. XF’s nonlinear circuit solver is able to handle unidirectional diodes, bidirectional diodes, and other ESD mitigation devices which are represented as an equivalent SPICE circuit.

TVS Diodes XF Brochure

Chip Components

Two-port, surface mounted passive chip components are commonly used in PCB design.  Rather than using ideal components in an FDTD simulation, realistic chip performance can be simulated based on measured data.  Manufacturers -- such as Murata, Coilcraft, and Taiyo Yuden -- provide SPICE models for their chips, which can be imported into XF and used as circuit component definitions.  During timestepping, XF’s circuit solver updates the cell edge containing the component based on the SPICE model.

Read additional documentation on XF's Netlist Component Definition...

Matching Networks

Two-, three-, and four-port matching networks can be defined as a SPICE model and included in a voltage source within XF.  This saves users from defining each element in the matching network as an individual circuit component.

Read additional documentation on XF’s Voltage and Current Sources...


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