Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Coupled Lines/Multiport Measurement/Orthogonal Calibration


This project explores multiconductor transmission line theory and

measurement methods. The project has developed a new understanding of lossy multiconductor transmission lines and modal cross powers. These theoretical developments in coupled line theory have led to accurate measurement methods for characterizing lossy asymmetric coupled lines.

This project has also developed software for performing orthogonal two-port, three-port, and four-port calibrations. Most important, the data can be corrected with any in-line calibration and standards, including the multiline TRL algorithm! No bends are required and the number of connections to the standards is kept to an absolute minimum.


The procedure corrects for all imperfect system impedances. The resulting measurements are fully calibrated to on-wafer or other transmission line reference planes. The method only requires the addition of an inexpensive switching network to a two-port vector network analyzer.

The measurements can be expressed as normal or differential scattering parameters or as normal or differential impedance parameters.

References on: Microwave Circuit Theory, Multiconductor Transmission Lines, Coupling, Orthogonal Calibrations, and Electronic Packaging Characterization


RF Technology Division

Created August 10, 2009, Updated March 25, 2020