Butler Matrix

A Butler matrix is a type of beamforming network used in antenna arrays and phased array systems. Its main functions are:

● Beam steering – It can steer the antenna beam to different angles by switching the input port. This allows the antenna system to electronically scan its beam without physically moving the antennas.
● Multi-beam formation – It can feed an antenna array in a way that produces multiple beams simultaneously, each pointing in a different direction. This increases coverage and sensitivity.
● Beam splitting – It divides an input signal into multiple output ports with specific phase relationships. This enables the connected antenna array to form directive beams.
● Beam combining – The reciprocal function of beam splitting. It combines signals from multiple antenna elements into a single output with higher gain.

The Butler matrix achieves these functions through its structure of hybrid couplers and fixed phase shifters arranged in a matrix layout. Some key properties:

● The phase shift between adjacent output ports is usually 90 degrees (a quarter wavelength).
● The number of beams is limited by the number of ports (N x N Butler matrix produces N beams).
● Beam directions are determined by the matrix geometry and phasing.
● Low loss, passive, and reciprocal operation.

So in summary, the main function of a Butler matrix is to feed an antenna array in a way that allows dynamic beamforming, beam steering, and multi-beam capabilities through electronic control with no moving parts. It is an enabling technology for electronically scanned arrays and phased array radars.

Concept Microwave is a worldwide supplier of the butler matrix,supporting multichannel MIMO testing for up to 8+8 antenna ports, over a large frequency range .

For more details , Pls visit our web:www.concept-mw.com or mail us at:sales@concept-mw.com.