Magic-T waveguide transition

Image of the Magic-T waveguide transition.

The Magic-T is a popular hybrid or 3 dB splitter/coupler used in many microwave systems. It was originally developed during World-War II and typically used in pulsed radar applications. One advantage of the Magic-T is when combining multiple power amplifiers, the input or output ports are well isolated from each other.

Like all other coupler and splitter structures, the Magic-T can be used as a power combiner or a divider. It is ideally lossless, so that all power into one port can be assumed to exit the remaining ports. Power entering the sigma port (port 1 ; also commonly referred to as the sum, H-plane, P or Parallel port) is divided equally between ports 3 and 4, with the resulting output signals being in phase. Power entering the delta port (port 2 ; also commonly known as the difference, E-plane, S or Series port) also divides equally between ports 3 and 4, BUT the resulting signals are 180° out of phase. Ports 3 and 4 are sometimes called the co-linear ports as these two ports are physically in line with each other.

Antenna Magus provides pre-optimised designs in popular waveguide bands (S, X, Ka and W bands) as well as a design group for any specific operating frequency.

Estimated |S11| performance showing reflection, coupling and isolation between ports for a Magic-T operating at Ka-Band.