gsm forum

Do you have the some material about a butler maxtrix for RADAR System.

Please, advise me of it.

Thank you.

What are butler matrix? Algebra structures?

Butler matrix are feeding network structures for multiple beam antennas. Assume you have an antenna array with N elements and you want to generate M independent beams with your array. The butler matrix allows you to make that: the feed network is composed of interconnections between several raws of 3db directional couplers with phase adjustments between connectrions.

the Blass Matrix is also an alternative for the design of multibeam antennas.

I have only this material.

An original chapter written by Butler can be found in the book:
Hansen, Microwave scanning antennas, Peninsula Publishing

Hi, dear friends,

As I know, Butler matrix performs a spatial fast Fourier transform and provides orthogonal beams.

But what does orthogonal beams mean here?

Thanks!

saryee

yxc0458@exchange.uta.edu

Orthogonal beams,

means that them constitute an orthogonal set function in terms of L2 norm.
In other words, if fp(u) and fq(u) are two beams generated by the butler matrix,
then

∫fq(u)*fp(u) du = δpq

this results directly from the lossless nature of the network (only hybrids and phase shifters).


Hope this help

Satellite

So what's the advantage of the orthogonal beams?

PS: why is here no "helped me" button?

If a network is lossless, it generate orthogonal beams and viceversa.

The advantage is not in the orthogonality of the beams but in the lossless nature of the network.

If amplifier are at input port, lossless means no loss of power!

Reversing: if power amplifiers are at the imput of the BFN and you want to avoid power wast you must generate orthogonal beams.

Bye,

Satellite