Use the Four-Port Network node to characterize the response of a four-port network system such as reflection and transmission using S-parameters.

A Four-Port Network can only be applied on boundaries that extend between two metallic boundaries — that is, boundaries where Perfect Electric Conductor, Impedance Boundary, or Transition Boundary conditions apply — separated by a distance much smaller than the wavelength.

Select a Type of Port — Coaxial or Uniform.

Coaxial does not support nonzero azimuthal mode number. The Azimuthal mode number in the Physics interface should be defined as zero.

Select a Type of S-parameter Definition — Matrix or Touchstone file.

Matrix defines the S-parameter by a constant matrix input. Touchstone file imports a four-port Touchstone file to characterize the four-port boundaries as a function of frequency.

Enter the Characteristic impedance Zref (SI unit: Ω) for Matrix.

Select Interpolation and Extrapolation types to obtain S-parameter values from the imported Touchstone file corresponding to the simulation frequencies.

Select a Interpolation — Nearest neighbor, Linear, Piecewise cubic (the default), or Cubic spline.

Select a Extrapolation — Constant (the default), Linear, Nearest function, or Specific value.