Patent ID: 8173943

Claim:
A waveguide element, wherein the waveguide element is in form of a rectangular pipe made of electrically conducting material, the waveguide element comprising an input port having a standard rectangular cross-section with the width of the input port being b A in a direction of an electric field of the fundamental mode propagating in the waveguide element, the direction of the electric field being perpendicular to a propagation direction of a microwave power, an output port having an enlarged rectangular cross-section, the width of the output port being C*b A in the direction of the electric field of the fundamental mode, wherein C is an enlargement factor greater than one, a plurality of intermediate waveguide segments cascaded in the propagation direction of the microwave power and arranged to split the waveguide element into two symmetrical waveguide branches which are combined at the output port, the waveguide branches terminating to symmetrical horn-shaped waveguide segments of width C*b A /2 which are arranged to open to the output port, and wherein each one of the intermediate waveguide segments comprise a first intermediate waveguide segment having width b B in the direction of the electric field of the fundamental mode, wherein b B >b A , a second intermediate waveguide segment having width b C in the direction of the electric field of the fundamental mode, wherein b C >b B , third and fourth intermediate waveguide segments located in parallel to each other with a spacing b G to form first segments of said symmetrical waveguide branches, the third and fourth intermediate waveguide segments each having width b D in the direction of the electric field of the fundamental mode, wherein (2*b D +b G )>b C .