How does Spark3D work?

The Spark3D corona module is based on a numeric algorithm that uses an adapted FEM technique to solve the free electron density continuity equation. The Spark3D multipactor module is based on a full 3D electron tracker that employs a Leap-Frog algorithm for the path integration and the Vaughan model for SEY characterization of materials. These allow breakdown analysis in complicated structures that involve arbitrary shapes in short computational times.

How does breakdown analysis of a RF system work?

Breakdown analysis models electric fields inside a device, taking into account particle behavior and the breakdown properties of the media inside the component, in order to identify possible multipactor and corona discharge risks.

Spark3D

What is Spark3D?

Spark3D is a unique simulation tool for determining the Radiofrequency (RF) breakdown power level in a wide variety of passive devices, including cavities, waveguides, microstrip and antennas. Spark3D can import field results from CST Studio Suite simulations directly to analyze vacuum breakdown (multipactor) and gas discharge. From this, Spark3D calculates the maximum power that the device can handle without causing discharge effects.

Typical approximate approaches to determine the RF breakdown power level of any component are intentionally conservative. Spark3D is based on advanced methods which analyze the breakdown phenomena numerically, predicting more realistic breakdown power levels, and thus improving the design margins.

Spark 3D Key Features

Import the electromagnetic (EM) fields from different EM solvers.
Automatic determination of the breakdown power threshold.
Definition of analysis boxes to choose the critical regions for analysis.
Output interface with rich simulation data, in table, plot and 3D view forms.

Spark3D is an optional part of CST Studio Suite® and is also available as a stand-alone offering.

Multipactor Analysis
Gas Discharge Simulation

Multipactor Analysis

RF Breakdown in Vacuum

The multipactor effect is a microwave breakdown discharge occurring at high frequencies in vacuum conditions caused by the formation of an electron cloud. High-energy electrons collide with the walls of the device, releasing secondary electrons, eventually creating an electron avalanche. The continuous release of electrons results in the creation of electron plasma which degrades the response of the component.

With Spark3D, the user can perform full numerical simulations of the multipactor effect considering the 3D EM field distribution. To perform this simulation, Spark3D emits electrons in the component, tracking their trajectories and checking the evolution of the electron number with time.