Latest Enhancements in XFdtd

Current Version: Release 7.5.1


Remcom continues our tradition of customer-responsive design with XFdtd Release 7.5.

  • We identified a bottleneck in the processes of our customers working on mobile device design, and created a new add-on module that simplifies and speeds the process of matching the antenna. The Circuit Element Optimizer is an industry first and promises to transform antenna matching circuit applications.
  • We have introduced a new electrostatic solver for XFdtd. The electrostatic solver enables the use of XF’s Capacitance Matrix Simulation, a critical feature for designing electronics with Touchscreen Panel (TSP) technology.

Read on to learn how XF 7.5's new features will speed your processes and assist your company in releasing products to the market faster.

New Modules

Circuit Element Optimizer

Matching network with two feeds for dual band antenna.Initially designed for matching circuit optimization, the Circuit Element Optimizer determines optimal component values while considering the multitude of EM effects on the real circuit’s physical layout.

Using XF’s full wave FDTD solver, the optimizer is able to take the following EM effects into account:

  • Parasitic effects within the matching network layout
  • Coupling between the matching network and antenna being tuned
  • Coupling between antenna being tuned and other antennas
  • Physical configurations (free space, held in hand, held near head)


Reflection coefficient for a matched and unmatched antenna.   The following types of components can be optimized:
  • Fixed resistor, capacitor, inductor
  • Ideal resistor, capacitor, inductor
  • Realistic capacitor, inductor with user defined equivalent series resistance
  • Standard *.s2p file definitions downloaded from component manufacturer
  • Passive tunable integrated circuits (PTIC or “tuners”) in the MDIF format of *.s2p files

System efficiency, radiation efficiency, and S-parameters are used as the goal function to determine the final component values.

Additional Learning:
Whitepaper: Overview of XFdtd’s Circuit Element Optimizer
Application Example: Matching Network Design for GPS/Bluetooth Antenna
Circuit Element Optimizer Brochure


Electrostatic Solver with Capacitance Matrices

Remcom’s Electrostatic Solver has been enhanced to increase its accuracy and expand the applications for which it can be used.  The Electrostatic Solver utilizes the XF user interface and is available as a stand-alone product or as an add-on to XF.

Create an Electrostatic simulation.The improvements within the calculation engine include the following abilities:

  • Consider dielectric materials while computing fields.
  • Compute charge. Charge is used in capacitance calculations so self- and mutual- capacitance are available in the Spice and Maxwell formulations.
  • Handle variable cell sizes in the grid.

3D view of voltage for touchscreen electrodes.New features in the UI allow users to do the following:

  • Apply a voltage to a Part or an Assembly. This means that a single Part with multiple, unconnected bodies can have the same potential.
  • View volumetric results for voltage or electric field.


Additional Learning:
Application Example: Touchscreen 3x4 Diamond
Touchscreen Capacitance Computation Brochure


Other Enhancements

Optenni Lab Integration

Matching network in Optenni Lab.

Data from XF can be directly transferred to Optenni Lab through the Results Browser. Optenni Lab is a software package that synthesizes and optimizes matching network topologies and component values based on S-Parameter and efficiency results from an XF simulation. Included in this integration is the ability to:

  • Analyze single and multi-port devices
  • Select inductors, capacitors, and tunable components
  • Optimize over multiple bands
  • Choose matching network layouts based on targets for S-Parameters or efficiency

Additional Learning:
Optenni Lab Integration Video

Three Pole Debye/Drude Material on XStream

The GPU kernel has been updated to support dispersive three pole Debye/Drude material equations (previously only the single pole representation was supported). This update allows simulations containing the three pole Debye/Drude material type to utilize the speedups from GPU hardware. Identical to non-dispersive materials, users can specify the number of GPUs to utilize through the Queue dropdown in the Simulations window.

Softkill Termination for Timestepping

Terminate the timestepping stage of a simulation.An FDTD simulation proceeds through the following stages: initialization, timestepping, steady state post processing, and writing output. The softkill feature allows the user to terminate the timestepping stage of a simulation and proceed to the steady state post processing.

Through the UI, timestepping can be terminated by right clicking on the simulation in the Simulations window and choosing Stop | End Simulation Gracefully.

Alternatively, create a file named project.softkill in the *.xf/Simulations/### directory to kill a simulation or create the file in …/Simulations/###/Run### to kill the run, but continue the simulation.

Time Dependent Material

Material with time varying conductivity.A new material type has been added to XF that allows a user to specify a material’s permittivity and conductivity as a function of time. The inputs can be specified as a constant value, loaded from a file, or entered as an equation. As the timestepping stage of a simulation proceeds through time, the material properties will be modified accordingly.