Dual-mode dielectric loaded cavity filter with nonadjacent mode couplings

An electromagnetic filter comprising at least three cavities defined by electrically conductive walls, said cavities having substantially the same dimensions, with each adjacent pair of cavities electromagnetically coupled via a common wall;

• wherein the angle formed by the midpoints of any three contiguous cavities is an integral multiple of 90.degree.;
• at least one of the cavities has two orthogonal modes of electromagnetic radiation resonating therewithin;
• each pair of coupled cavities is coupled by an intercavity coupler comprising an elongated iris opening in the common wall and an electrically conductive probe protruding into each of the coupled cavities;
• at least one of the cavities has an initial mode generated outside the filter and brought into the cavity via a port penetrating a cavity wall;
• and
• a derivative electromagnetic mode is excited within the same cavity in a direction orthogonal to that of the initial mode by means of perturbation applied at an angle of substantially 45.degree. with respect to the characterizing vector defining the initial mode.

An electromagnetic filter comprising at least three cavities defined by electrically conductive walls, said cavities having substantially the same dimensions, with each adjacent pair of cavities electromagnetically coupled via a common wall;

• wherein the angle formed by the midpoints of any three contiguous cavities is an integral multiple of 90.degree.;
• at least one of the cavities has two orthogonal modes of electromagnetic radiation resonating therewithin;
• each pair of coupled cavities is coupled by an intercavity coupler comprising an elongated iris opening in the common wall and an electrically conductive probe protruding into each of the coupled cavities;
• and
• each cavity surrounds a dielectric resonator, with all the dielectric resonators having substantially the same size, shape, and dielectric constant.