Microstrip circulator made of a magnetized ferrite sphere

A new novel microstrip circulator made of a magnetized ferrite sphere is de veloped. The microstrip Y-junction is made by conventional photolithography : a ferrite sphere covered by a metal cap is placed into the hole at the ju nction center of three microstrip arms, and is fixed firmly by a low-loss a dhesive. The adhesive can be solved easily by ethyl alcohol. So it is easy to change the circulating frequency of the circulator simply by replacing t he ferrite sphere with different diameters. Experimental results at Ka-band are presented. (C) 2001 John Wiley & Sons, Inc.