Abstract: A microstrip circulator having good matching properties in the millimeter communications band. Each of three microstrip lines is shaped to interface with a metalized ferrite element in such a manner as to provide both electrical impedance matching and a contact angle with the ferrite that satisfies the magnetic coupling requirements. The end of each microstrip includes a first arcuate portion contacting the ferrite over a relatively small contact angle, to provide tangential launching of energy and good coupling properties, and a second arcuate portion spaced apart from the ferrite to allow magnetic coupling and appropriate electrical impedance matching.