JPH01307147A - Magnetron - Google Patents

Abstract

PURPOSE:To prevent the characteristic of a magnetron from varying even though its anode structure is made in small size, by forming unevenness on the surface of a resonance cavity. CONSTITUTION:A cylindrical anode body 11 has radially oriented vanes 12 installed at the bore, and this anode body 11 and vanes 12 are formed by press from a blank of oxygen free copper through a hobbing process in such a way as consolidated. Undulate surfaces are provided on the bore of the anode body 11 and at the sides of vanes 12 so that the creeping length of a unitary cavity resonator 13 will be a length necessary to oscillate high frequency electric waves of fundamental frequency. This permits making the anode structure in small size without varying its characteristics to lead to accomplishment of a small-sized magnetron.

Description

DETAILED DESCRIPTION OF THE INVENTION a) Field of Industrial Application The present invention relates to magnetrons, and more particularly to improvements in the anode structure thereof.

--) Prior Art Generally, the anode structure of a magnetron is constructed as shown in FIGS. 5 and 6. ;1) is a cylindrical anode body, and the inner peripheral surface has a plurality of vanes (2) toward the central axis of the anode body (1).
) are arranged radially, and two adjacent vanes (
A cavity resonator (3) is formed in a space surrounded by the anode body (1) and the inner peripheral surface of the anode body (1). (4) (51 is each vane (2
These are large and small strap rings that are connected every other time to the top and bottom of 1.

In order to downsize the magnetron, it is conceivable to reduce the diameter of the anode structure, but if the diameter of the anode body Il+ is reduced, the creepage length l of the unit cavity resonator (3) will be shortened n.
Cavity resonance-a (inductance L of 31 decreases, 2
450M) had the disadvantage that high frequency radio waves with a fundamental frequency of 1g could not be obtained.

fl Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned drawbacks, and an object thereof is to provide a magnetron whose characteristics do not change even if the anode structure is downsized.

B) Means for solving the problem In order to solve the above problem, the surface of the resonant cavity is formed into an uneven shape.

(E) Function Since the structure is configured as described above, the inner diameter of the anode body and the length of the vane can be reduced without changing the creeping length of the cavity resonator.

(F) Embodiment An embodiment of the present invention will be described in detail below with reference to FIGS. 1 and 2 (components that are the same as those in the prior art are given the same reference numerals and explanations will be omitted).

U is a cylindrical anode body, tta is a plurality of vanes provided on the inner periphery of the anode body αB radially toward the central axis of the anode body lID, and the anode body ttU and the pane σ2 are made of a blank of oxygen-free copper by hopper processing. Press-molded into one piece.

The inner circumferential surface of the anode body ttU and the side surface of the vane t121 are formed into wave-like uneven surfaces, and the creepage length l of the unit cavity resonator 1131 is the length necessary to oscillate high-frequency radio waves with a fundamental frequency of 2450 MHz. It is formed like this.

That is, if cavity resonator +131 is considered as an LC equivalent circuit,
Since the microwave current i flows on the surface of the cavity resonator due to the skin effect, the creepage length l of the cavity resonator is L. ) and strap ring f41 (51 corresponds to 0 minutes. In order to oscillate high-frequency radio waves with a fundamental frequency of 2450 MHz, a predetermined L minute and 0 minutes are required. Therefore, a predetermined cavity resonator (13 A creepage length l is required.

According to the present invention, the inner peripheral surface of the anode body αB and the pane u21
Since the side surface of the cavity resonator t13 is formed into an uneven shape, the cavity resonator t13
When the creepage length l of 1 is set to a predetermined length, the inner diameter of the anode body aυ and the vane 11 are
21 becomes smaller.

Incidentally, as shown in FIG. 6, only the inner peripheral surface of the anode body aυ may be formed into an uneven shape, and as shown in FIG.
Only the side surfaces may be formed into an uneven shape.

(G) Effects of the Invention As described above, according to the present invention, the anode structure can be downsized, and the magnetron can be downsized.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts of one embodiment of the present invention, FIG. 2 is a plan view of the same, FIG. 6 is a plan view of another embodiment, and FIG. 4 is a plan view of still another embodiment. FIG. 5 is a plan view of the conventional example, and FIG. 6 is an enlarged view of the main part. ul...Cylindrical anode body, α2...Pain, (13
...Cavity resonator.

Claims (1)

[Claims] (1) In a magnetron in which a plurality of vanes are provided on the inner circumferential surface of a cylindrical anode body protruding toward the central axis of the anode body to form a cavity resonator, the surface of the cavity resonator is made uneven. A magnetron formed by