Abstract: Compactness and substantially optimum electrical performance are realized in a microwave filter incorporating a housing (21, 22) including an interior surface that forms an enclosed cavity having planar cross sections substantially elliptical in shape (FIG. 3). At least one axis of each ellipse monotonically increases in length with perpendicular distance from a first surface (23) toward a second surface (24). A dielectric resonator (11) is positioned in a predetermined relationship within the cavity and at least two terminal members (30,35) extend from outside the housing (21,22) into the cavity. Electromagnetic coupling between the housing (21,22) and the dielectric resonator (11) is minimized to afford substantially optimum electrical performance of the microwave filter.