US 2004/0104679 A1Published application

Pulse magnetron

AssigneeNew Japan Radio Co., Ltd.

InventorsHideyuki Obata, Naoki Tsuji

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Abstract

The object of the present invention is to provide a pulse magnetron which can inhibit unwanted oscillation at an operation point lower than the rated level in the rise or decay of a pulse, attenuate spurious radiation at lower frequencies than the fundamental oscillation frequency, and produce an improved symmetrical profile of output spectrum. The pulse magnetron of the present invention includes an anode, a cathode provided at the center of the anode, and a pair of pole pieces provided for applying a magnetic field to an interaction space where the outer side of the cathode is opposed to the inner ends of the vanes. The radius ra of the inscribed circle defined by the inner ends of the vanes and the radius rc of the cathode surface satisfy the operation theory equation for the minimum value of the magnetic flux density along the axial direction of the cathode at both ends of the inner end of the height of the vanes in the interaction space. The anode and the cathode are arranged to satisfy at least either (i) increasing the radius of the inscribed circle defined by the inner ends of the vanes or (ii) decreasing the radius of the cathode surface as the magnetic flux density along the axial direction of the cathode at both ends of the inner end of the height of the vanes.

Claims1

Dependent claims

Pulse magnetron which is pulsed for oscillation comprising:

an anode having a number of vanes mounted radially on the inner wall of a cylindrical anode shell thereof;
a cathode provided at the center of the anode to face the 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 the outer side of the cathode and the inner ends of the vanes;
wherein a radius ra of the inscribed circle defined by the inner ends of the vanes and a radius ra of the cathode surface are determined by equation (1);
wherein said radius ra and radius rc are measured at a point where the magnetic flux density is maximum along the axial direction of the cathode and the height of the vanes;
wherein the anode and the cathode are arranged to satisfy at least either (i) increasing the radius of the inscribed circle defined by the inner ends of the vanes or (ii) decreasing the radius of the cathode surface as the magnetic flux density is declined along the axial direction of the cathode and the height of the vanes;
wherein the equation (1) is represented as follows:
Va=942(ra2−rc2)(104b−10650/nλ)/nλ (1)
where Va is the pulsed anode voltage (in V), ra is the radius of the anode (the radius in cm of an inscribed circle defined by the inner ends of the vanes), rc is the radius of the cathode surface (in cm), b is the minimum of the magnetic flux density T along the axis of the interaction space, n is the (number of divisions (the number of the vanes))/2, and λ is the oscillation wavelength (in cm).

7 more elements

Dependencies are inferred from the claim text.