Y Circulator

Abstract

It is well known that the field distribution in a rectangular wave guide containing a magnetized ferrite can be asymmetrical even though the physical configuration is symmetrical. By properly choosing the ferrite, its shape, and location, it is possible to concentrate the energy on one side of the wave guide. Reversing the field or changing the direction of propagation will cause the energy to concentrate on the other side of the wave guide. This phenomenon has been utilized to construct a new type of circulator. A ferrite post has been placed at the junction of three wave guides intersecting at 120 degrees. The dc field is applied transverse to the broad side of the wave guide. Circulator action can be obtained by using a ferrite rod of the correct size and applying a dc field of the proper magnitude. Similar results have been obtained by using single and double slab configurations as well as with wedges. A wave-guide switch can be obtained by reversing the direction of the applied field. Results to date indicate that it is possible to build this Y-type circulator with a loss less than 0.5 db and isolations and reflections of greater than 20 db over a 300-megacyle band at X band. A four-port junction operating on this same principle is also under investigation.