Terminology » RF Components » Branch Line Coupler S-Matrix Explained

Branch Line Coupler S-Matrix Explained

branch line coupler s-matrix rf device quadrature hybrid rf component

This page describes the Branch Line Coupler S-Matrix (scattering matrix).

It also covers the basics of a Branch Line Coupler along with its S-matrix.

What is a Branch Line Coupler?

  • It is a lossless 4-port hybrid device.
  • All four ports are matched.
  • The device is reciprocal, and hence the S-matrix is symmetric.
  • Port-1 is the input port, port-2 is the output port, port-3 is the coupled port, and port-4 is the isolated port.

Branch Line Coupler

  • Figure 1 depicts a Branch Line Coupler.
  • It is also known as a quadrature hybrid or 90° hybrid.

Branch Line Coupler S-Matrix

The Branch Line Coupler S-matrix is as follows:

Branch Line Coupler S-Matrix