An apparatus, system, and method of and for a microwave circulator. The apparatus, system, and method includes a non-reciprocal element for coupling microwaves from an input port to at least one output port, wherein the non-reciprocal element is capable of isolating at least one of the at least one output port, and a plurality of fillers, wherein each of the plurality of fillers is corresponded to a portion of the non-reciprocal element, and wherein each of the plurality of fillers is substantially adjacent to the corresponded portion of the non-reciprocal element and at least substantially fills a span between the corresponded portion of the non-reciprocal element and a proximate conductor surface.