Patent ID: 7038387

Claim:
A pulse magnetron which is pulsed for oscillation, comprising: an anode having a number of vanes mounted radially on an inner wall of a cylindrical anode shell thereof; a cathode provided at a center of the anode to face an inner end of each vane; and a pair of pole pieces provided for applying a magnetic field substantially in parallel to the cathode across an interaction space defined between an outer side of the cathode and the inner ends of the vanes; wherein a radius r a of an inscribed circle defined by the inner ends of the vanes and a radius r c of the cathode surface are determined by an equation V a =942(r a 2 −r c 2 ) (10 4 b −10650 /n λ) /n λ, wherein V a is a pulsed anode voltage in volts, said radius r a and said radius r c are in cm, b is a minimum magnetic flux density in Tesla along an axial direction of the interaction space, said axial direction being parallel to said inner wall, n is given by: (a number of divisions (the number of the vanes))/2, and λ is an oscillation wavelength in cm; wherein said equation is modified such that said radius r a and said radius r c identify a point where magnetic flux density is maximum along said axial direction of the interaction space; wherein the anode and the cathode are arranged to satisfy either (i) increasing the radius of the inscribed circle defined by the inner ends of the vanes to a radius r a ′ or (ii) decreasing the radius of the cathode surface to a radius r c ′ at a point where the magnetic flux density for both cases (i) and (ii) is minimum along said axial direction of the interaction space for points corresponding to radiuses r a ′ or r c ′.