JPH0673278B2 - Pulse magnetron - Google Patents

Description

The present invention relates to a pulse magnetron, and more particularly to a downsized pulse magnetron for radar.

(Prior Art) For example, a pulse magnetron used for a radar of a small ship, etc., is replaced with a conventional horseshoe-shaped permanent magnet, and recently, a cylindrical permanent magnet is used and is configured by an inner magnet type magnetic circuit. As a result, the entire magnetron can be miniaturized. An example thereof is shown in, for example, Japanese Utility Model Laid-Open No. 59-79956.

As shown in FIG. 8, the structure for coupling and fixing the magnetron support substrate and the oscillator main body has a rectangular waveguide portion 12 integrally formed on the magnetron support substrate 11 as shown in FIG.
The output antenna section 14 of the oscillator main body 13 is inserted into the waveguide, and the antenna projection length into the waveguide is adjusted by advancing and retracting the main body 13 as shown by the arrow F, and then the base 15 of the output antenna section and the waveguide section. The connecting portion 16 of is connected and fixed by soldering.
In the figure, reference numeral 17 indicates the soldering portion.

(Problems to be Solved by the Invention) Conventionally, the degree of coupling between the oscillator main body and the waveguide, and hence the high-frequency coupling characteristic with the load circuit, is adjusted by adjusting the protruding length of the antenna into the waveguide as described above. Fine-tuned. After this adjustment, the base of the output antenna section and the coupling section of the waveguide section are soldered to mechanically couple and fix the support substrate and the oscillation section main body. However, according to the coupling degree adjusting method adopted from such a conventional structure,
Even if the required characteristics are obtained by adjustment in a state where the oscillator body and the waveguide portion are not soldered, the high frequency coupling characteristic may deviate from the required value when the relevant portion is soldered. This is because the pulse magnetron for radars generally has a high oscillation frequency, and a small dimensional change in the coupling and fixing portion of the two greatly affects the high frequency characteristics. Therefore, it may be necessary to release the soldered portion again and perform the adjustment again. Obviously, such complicated assembly and adjustment are not preferable, and the operating characteristics cannot be easily optimized. Further, only the portion to be soldered has to be heated up to about 350 ° C., which causes oxidation of many portions and increases restrictions on the assembly process.

The present invention eliminates the above-mentioned inconvenience, stably fixes the oscillator main body and the support substrate with a relatively simple structure, and easily and highly accurately adjusts the high-frequency coupling characteristics of the output antenna section and the waveguide section. The purpose is to provide a pulsed magnetron capable of performing.

[Structure of the Invention] (Means for Solving the Problem) The present invention provides a high-frequency coupling degree between an output antenna and a waveguide on the tip of the output antenna of the oscillator body or on the waveguide wall facing the tip. It is a pulse magnetron equipped with an adjusting rod for adjusting.

(Operation) According to the present invention, after the output antenna section of the oscillation section main body and the rectangular waveguide are coupled and fixed, the protrusion of the adjusting rod provided on the tip of the output antenna section or on the waveguide wall facing the tip section of the output antenna section. By adjusting the length from the outside, the high frequency coupling characteristic between the antenna and the waveguide can be finely adjusted. If the adjustment rod is fixedly fixed in a state where this adjustment is completed, there is no possibility that the required operating characteristics will change. Thus, highly accurate adjustment can be performed with a relatively simple structure.

(Example) Hereinafter, an example will be described with reference to the drawings. The same parts are represented by the same symbols.

A radar pulse magnetron to which the present invention is applied has a structure shown in FIGS. 1 to 4. In the figure, reference numeral 21 represents an oscillator main body, which is an anode cylinder 22 made of copper and a plurality of anode vanes 2 constituting a resonance cavity.
3. It has an electron emitting cathode 24 and an output antenna section 25.
The output antenna section 25 includes an output antenna rod 26, an outer conductor 27, a waveguide connecting flange 28, a dielectric cylinder 29, and an end plate 30 made of a disk-shaped conductor. Further, the oscillator body 21 has a pair of cup-shaped pole pieces 31 and 32 at both ends.

The magnetron supporting substrate 33 is made of aluminum or a diamond alloy thereof, and has a generally rectangular shape. The support substrate 33 also has a rectangular waveguide portion 34 that is integrally projected. A coupling hole 35 is provided in the waveguide section, and the output antenna section 25 of the oscillator main body is inserted through the coupling hole 35.

Inner magnetic poles of a pair of cylindrical permanent magnets 37 and 38 are magnetically connected to both pole pieces 31 and 32 of the oscillator body 21 through a ferromagnetic shim plate. To the outer magnetic poles of the magnets 37 and 38, the opposite end faces of a U-shaped yoke plate 39 made of a ferromagnetic material are magnetically connected. Further, the yoke plate 39 has its central portion around the outer surface of the rectangular waveguide portion 34 and abutted thereon, and is fixed by a fixing screw 39b.

Therefore, the oscillator main body 21 is a U-shaped fixing holder.
It is held and fixed to the support substrate 33 by 40. Holder 40
Is made of a high-strength aluminum alloy, has a through-hole 41 formed at one end as shown in FIGS. 2 and 3, and the portion surrounding the oscillator main body is bent at four places to form a U-shape. ing. The straight portion from one end to the first bent portion 42 is locked and fixed to the back surface of the support substrate 33 by the fixing screw 43. The second bent portion 44 and the third bent portion 45 are respectively formed with slight cuts 44a and 45a on the outer side so that they can be easily bent at these positions when the holder is tightened. A straight line is formed from the fourth bent portion 46 to the through hole 47 at the other end. As shown in FIG. 3, both ends of the holder are slightly open in advance. The holder surrounds the body of the oscillator and surrounds the other end of the holder, and the other end is tightened as indicated by arrow F to be fixed to the yoke plate 39. Tighten and fix with screws 48.
As a result, in the oscillator body 21 , the flange 28 of the output antenna portion is strongly pressed against the waveguide wall, and is stably held and fixed on the support substrate. An electrically conductive gasket (not shown) in which a metal thin wire is woven in a ring shape is interposed between the flange 28 of the output antenna portion and the waveguide wall, which are electrically coupled to each other, to electrically couple them. May be surely obtained. Although all the bent portions of the holder are in a straight line state, they are in thermal contact with the outer peripheral surface of the anode cylinder of the oscillator main body, and the heat is conducted to the supporting substrate via the holder and radiated.

Now, a disk-shaped conductor end plate 30 at the tip of the output antenna section 25
An adjusting rod 36 made of a conductor or a high dielectric material for finely adjusting the degree of high-frequency coupling by penetrating a waveguide wall facing the waveguide wall and a yoke plate 39 surrounding the waveguide wall in the vicinity of the waveguide wall.
Is screwed so that it can move back and forth. Due to the aforementioned fixed structure,
Although the protruding length of the output antenna section inside the waveguide cannot be finely adjusted, the high frequency matching between this antenna section and the rectangular waveguide can be finely adjusted by the adjusting rod 36. Then, after the output adjustment is completed, the recess S on the outer side of the adjusting rod 36
Then, a curable adhesive (not shown) is filled in to fix the adjusting rod. Since the adjusting rod 36 is screwed over both the waveguide portion and the yoke plate,
It also functions as a connecting screw for both. Therefore, the fixing screws 39b, 39b for coupling the both may be omitted. As a result, the number of parts can be reduced, and the structure can be further simplified and the price can be reduced.

FIGS. 5A and 5B show an example of adjusting the high-frequency coupling characteristics by adjusting the insertion length of the adjusting rod 36. That is, as shown in FIG. 9A, when the adjustment rod 36 is moved back and forth to change the distance L between the tip of the adjustment rod and the tip of the output antenna unit to, for example, 3 mm, 4 mm, or 5 mm, FIG. As shown in, the oscillation frequency changes only slightly, but the standing wave ratio (VSWR) changes relatively greatly. Thereby, the microwave output of the magnetron and the coupling characteristic with the high frequency load can be finely adjusted. In particular, the adjusting rod has a facing area smaller than the end plate 30 made of a disk-shaped conductor and having a certain area at the tip of the output antenna section 25.
Since the 36 is provided, the end plate 30 and the adjusting rod 36 are not likely to be electrically displaced even if there is an error in assembly. Therefore, a magnetron with uniform characteristics can be obtained even in mass production.

In addition, in the above embodiments, the oscillator main body and the waveguide are coupled and fixed by the holder. However, the invention is not limited to this, and may be coupled and fixed by soldering. In that case, soldering with an appropriate antenna protrusion length is also possible. After that, the high frequency coupling characteristic may be finely adjusted by the adjusting rod.

In the embodiment shown in FIG. 6, the tip of the output antenna rod 26 is projected from the end plate 30 toward the adjusting rod 36 facing the end plate 30 by a predetermined dimension. The antenna protruding portion 26a has a diameter smaller than the diameter of the tip portion of the adjusting rod 36, and since the high frequency electric field is concentrated on this protruding portion, the adjustment range of the high frequency coupling characteristic is widened and the adjusting sensitivity is improved. Reference numeral 51 in the figure represents a ring-shaped conductor gasket formed by knitting thin metal wires.

In the embodiment shown in FIG. 7, an adjusting rod 36a made of a dielectric material is screwed onto an external protruding portion 26a at the tip of the antenna rod 26 so that the protruding length can be adjusted. On the top surface of the adjusting rod 36a, a minute slit 36b for receiving the tip of an adjusting jig (not shown) is provided. The waveguide wall facing the adjusting rod 36a has a through hole of a minute diameter for passing an adjusting jig.
52 are formed. When adjusting, this through hole 52
Through the adjusting rod (not shown) made of dielectric
Inserted into the slit 36b of 36a and rotated to adjust the protrusion length to obtain the required coupling characteristics. Finally, the adjusting rod 36a is fixed with an adhesive or the like, and the through hole 52 is filled with the dielectric rod 53 and fixed. As a result, the coupling characteristics can be adjusted and impurities such as dust do not enter the inside of the waveguide.
A highly reliable pulse magnetron can be obtained.

[Effects of the Invention] As described above, according to the present invention, after the output antenna section of the oscillator main body and the rectangular waveguide are mechanically coupled and fixed, the tip of the output antenna section or the conductor facing the tip is provided. By adjusting the protruding length of the adjusting rod provided on the wall of the wave tube, the high frequency coupling characteristic between the antenna and the waveguide can be finely adjusted. Then, if the adjustment rod is fixedly fixed in the state where this adjustment is completed, there is no fear that the required operating characteristics will be changed. Therefore, it is possible to obtain an inexpensive pulse magnetron which is easy to assemble in mass production and has uniform operation characteristics.

[Brief description of drawings]

1 is a longitudinal sectional view of an essential part showing an embodiment of the present invention, FIG. 2 is a top view of the essential part, FIG. 3 is a sectional view thereof, and FIG.
5 is a top view of the drawings, FIGS. 5 (a) and 5 (b) are cross-sectional views and characteristic views of a main part showing the adjustment of the output characteristics thereof, and FIGS. 6 and 7 are diagrams showing other embodiments of the present invention. FIG. 8 is a sectional view of a part, and FIG. 8 is a sectional view of an essential part showing a conventional structure. 21 …… Oscillator body, 22 …… Anode cylinder, 23 …… Anode vane, 25 …… Output antenna section, 33 …… Support substrate, 34 …… Rectangular waveguide section, 36, 36a …… Adjustment rod, 37 , 38 …… Permanent magnet, 39 …… Yoke plate.

Claims (1)

[Claims] 1. An oscillator main body having a cathode, an anode vane, and a pair of pole pieces built-in, and a coaxial output antenna protruding from a side wall of an anode cylinder, and a tip portion of the output antenna of the oscillator main body. And a pair of permanent magnets magnetically connected to the pole piece of the oscillator body, and a waveguide of the support substrate connected to the permanent magnets. A pulse magnetron including a ferromagnetic yoke plate that surrounds and surrounds the outer side of the waveguide, and the waveguide wall and the yoke facing the output antenna tip of the oscillator body or facing the output antenna tip. A pulse magnetron, characterized in that an adjusting rod for adjusting the degree of high-frequency coupling between the output antenna and the waveguide is attached through the plate.