Independent Reference Planes

When ports have independent reference planes:

•  The length of each reference plane may be set independently.
•  Calibration standards are composed of single (uncoupled) lines as shown below.
•  Coupling between the fringing fields of the ports is not removed. Thus, ports must be far apart to ensure an accurate result.
•  Coupling between feedlines is not removed. Therefore, you should not use independent reference planes when the lines are close enough to couple.
•  Sonnet calculates a Z0 or Eeff for each feedline without the influence of the nearby lines.

Diagonal box-wall ports, and diagonal co-calibrated ports are always independent. Thus, they should not be used if the ports or feedlines are close to each other. This concept is shown below:

Orthogonal box-wall ports on a given box wall may be set to independent or shared. For instructions on how to change an orthogonal box-wall port from shared to independent, please see Applying the Diagonal Port Feature to a Port.

Ports on different box-walls are always treated as independent from one another as shown below.