JP3020295B2 - Combined cavity filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter for microwaves and millimeter waves, and more particularly to a combined cavity filter in which a cavity of a cavity resonator and an iris plate are made of different kinds of metals.

[Summary of the Invention] In the present invention, in a combined cavity type filter in which a plurality of cavities and an iris plate constituting a cavity resonator are made of different kinds of metals, the iris plate is heated. When
The inner diameter of the thick portion of the iris plate is set so that the inner circumference of the thick portion of the iris plate is slightly larger than the outer circumference of each cavity portion, and the thick portion of the iris plate and the hollow portion are heated while the iris plate and the cavity portion are heated. An iris plate is sandwiched and fixed between the cavity portions so that the inner periphery of the cavity faces the outer periphery of the cavity portion. That is, it is integrally formed so as to have a thin plate portion formed of a thin plate having a coupling hole opening, and an inner periphery which is in close contact with the outer periphery of the end portion of the cavity portion in a high-frequency input state on the outer peripheral portion of the thin plate portion. By forming the iris plate with the thick portion, the high frequency power is supplied to the filter so that the iris plate is not deformed even if the temperature of the iris plate changes, and the iris plate and the cavity are joined together. The relationship can be kept from changing, thereby stabilizing the electrical characteristics.

[0004]

2. Description of the Related Art A coupled cavity type filter used as a filter for microwaves, millimeter waves and the like can obtain a high no-load Q value, and is therefore used in a place where the power is large, such as a channel combiner mounted on a satellite.

In this case, since it is necessary to adjust the size of the opening of the coupling hole of the iris plate in such a coupling cavity type filter, the cavity portion and the iris plate are separately formed, and as shown in FIG. Each flange 102 provided on the cavity 101 and each iris plate 103, 104 are fixed by screws 105, and a iris plate having the most suitable coupling hole opening is selected from various iris plates. Is connected to each cavity 101 to adjust the size of the coupling hole openings 106 and 107.

[0006] Since the length of the cavity 101 determines the frequency of the filter, a coupled cavity filter for high power usually uses an invar or a super invar that is less likely to expand and contract due to heat as a material for the cavity. Used, and in each iris plate 103, 104, each iris plate 103, 10
Since heat is generated in the vicinity of the coupling hole openings 106 and 107 on the substrate 4, the temperature rise becomes very large when using Invar or Super Invar having poor heat conduction. In many cases, materials such as silver and copper are used.

[0007]

However, in the above-described conventional combined cavity type filter, each cavity 10
1 and the respective iris plates 103 and 104
The required characteristics are ensured by changing the type of metal constituting the iris plate 1 and the iris plate 1.
The expansion and contraction of heat and the way of heat transfer to and from the heat exchangers 03 and 104 are different, and mechanical distortion is partially generated due to a temperature change due to a loss of a transmission signal.

Thus, each of the iris plates 103, 10
4 only greatly expands and contracts in the radial direction, and the fixed state of the screwed portions of each iris plate 103, 104 and each cavity portion 101 changes, or each iris plate 103, 104 bends, and the filter characteristics are degraded. It often changed.

Therefore, as a method for solving such a problem, for example, “Dietmar J. Rosowskyand Dieter Wolk,
“A 450-W Output Multiplexer for Direct Broadcasti
ng Satellites "IEEE Trans. Microwave Theory Tech.,
vol.MTT-30,1982, pp.1317-1323 ”
A method using a silver plate with a thickness of “4 mm” as 3, 104 or “Ali E. Atia,“ A 14-GHz High-power Filte
r ", IEEE MTT-S Digest, 1979, pp. 261-263", each iris plate 103, 104 is formed by using a copper plate having a thickness of "0.065 inch (about 1.65 mm)". There has been proposed a method for solving the above-mentioned problem by increasing the thickness of the plates 103 and 104 to improve heat conduction.

However, in such a method, since each of the iris plates 103 and 104 is made thick, the loss around the coupling hole openings 106 and 107 increases, and further heat is generated by the loss. There was a problem that it was not a very effective method.

In view of the above circumstances, the present invention can prevent the shape of the iris plate and the bonding relationship between the iris plate and each cavity portion from changing even when the temperature of the iris plate changes. It is an object of the present invention to provide a coupled cavity filter capable of stabilizing electric characteristics.

[Structure of the Invention]

[0013]

In order to achieve the above object, the present invention provides a combined cavity type in which a plurality of cavities and an iris plate constituting a cavity resonator are formed of different kinds of metals. In the filter, a thin plate portion formed of a thin plate having a coupling hole opening and an inner periphery which is in close contact with an outer peripheral portion of the thin plate portion in close contact with an outer periphery of an end portion of the cavity portion in a high frequency input state are integrally formed. The iris plate is constituted by the thick portion to be formed.

[0014]

In the above construction, a thin plate portion formed of a thin plate having a coupling hole opening and an inner periphery which is in close contact with the outer periphery of the end portion of the cavity portion in a high-frequency input state at the outer peripheral portion of the thin plate portion. The iris plate is constituted by a thick portion integrally formed so as to have, so that the iris plate is not deformed even if the temperature of the iris plate changes due to the presence or absence of high frequency input, and the iris plate and the cavity portion The electrical characteristics are stabilized by not changing the bonding relationship with the semiconductor device.

[0015]

FIG. 1 is a sectional view showing a first embodiment of a combined cavity filter according to the present invention.

The combined cavity filter shown in FIG. 1 includes two cavities 1 and 2 and three iris plates 3 to 5a. A high frequency input signal is inputted to the cavity 1 on the input side. In this case, a signal in a frequency band corresponding to the length of each of the cavities 1 and 2 is selected and output from the cavity 2 on the output side.

Each of the cavities 1 and 2 has a length "nλg /
A cylindrical portion 6 of 4 ", a flange portion 7 integrally formed at one end of the cylindrical portion 6, and a flange portion 8 integrally formed at a position slightly away from the other end of the cylindrical portion 6; These are integrated so that the iris plate 5a is sandwiched between the flange portions 8, and the flange portions 7 of the cavity portions 1 and 2 are integrated.
The cavities 1 and 2 are connected to the waveguides 9 and 10 by screws 13 in a state where the iris plates 3 and 4 are interposed between the waveguides 9 and 10 and the flanges 12 of the waveguides 9 and 10 respectively. You.

Of the iris plates 3 to 5a, the two iris plates 3 and 4 at both ends have the same outer diameter as the outer diameter of the flange 7 constituting each of the cavities 1 and 2. And a silver plate or the like having a coupling hole opening 11, and a flange portion 7 of each cavity portion 1 and 2 and each waveguide 9, 10
Screw 13 while being sandwiched between the
Thus, it is fixed between the respective cavity portions 1 and 2 and the respective waveguides 9 and 10.

The iris plate 5a at the center has the same outer diameter as the outer diameter of the cylindrical portion 6 constituting each of the cavities 1 and 2, and has a coupling hole narrower than the coupling hole opening 11. A thin plate portion 15 made of silver (or a material such as copper) having an opening 14
And a thick portion 16 integrally formed on the outer periphery of the thin plate portion 15.
The thick portion 16 is slightly larger than the outer diameter of the cylindrical portion 6 constituting each of the cavities 1 and 2 when the iris plate 5a and each of the cavities 1 and 2 are heated. And, when the temperature of the iris plate 5a is low, the inner diameter is set so as to be smaller than the outer diameter of each cylindrical portion 6, and the thickness of the thin plate portion 15 is set so as to reduce the loss as a filter. Have been.

When the iris plate 5a is connected to each of the cavities 1, 2, the temperature of the iris plate 5a is higher than the temperature rise when a high-frequency input signal is inputted (for example, a hundred or more). Iris plate 5
a and the cavity portions 1 and 2 are heated, and in this state, the thick portion 16 is heated.
The inner peripheral surface of the iris plate 5a is fitted into the outer periphery of the end portion of each of the cavity portions 1 and 2 until the respective surfaces of the thick portion 16 abut against the flange portion 8. After that, the screws 17 are inserted into the holes formed in the flanges 8 to connect and fix the cavities 1, 2 to the iris plate 5a.

As described above, in this embodiment, the thick portion 16 is formed on the outer periphery of the iris plate 5a having the coupling hole opening 14 so that the thin plate portion 1 in which the coupling hole opening 14 is formed is formed.
5, the outer peripheral portion of the iris plate 5a is made thicker, and the thick portion 16 and each of the cavities 1 and 2 are fitted and connected while the iris plate 5a and each of the cavities 1 and 2 are heated. Therefore, even when a high-frequency input signal is input to the cavity 1 on the input side and the vicinity of the coupling hole opening 14 of the iris plate 5a generates heat, thereby connecting and fixing the iris plate 5a even if the temperature rises. The temperature will never be higher than at times. Therefore, the extension of the iris plate 5a is suppressed, and the iris plate 5a can be prevented from being bent. Further, even when the high-frequency input signal input to the cavity 1 on the input side is cut off and the iris plate 5a cools and the iris plate 5a tries to contract, each cavity 1 and 2 suppresses this and the deflection is suppressed. Can be prevented. As a result, even if the iris plate 5a repeatedly changes in temperature, deformation of the iris plate 5a can be prevented, and the connection between the iris plate 5a and each of the cavities 1, 2 can be kept constant. Can be stabilized.

In this embodiment, the thin plate portion 15 of the iris plate 5a is made thinner, and the thicker portion 16 thicker than the thin plate portion is formed on the outer peripheral portion. When a high-frequency input signal is input to the cavity 1 on the side, the loss at the coupling hole opening 14 can be reduced, whereby the temperature rise of the iris plate 5a can be reduced.

FIG. 2 is a sectional view showing a second embodiment of the combined cavity filter according to the present invention. In this figure, the same parts as those shown in FIG. 1 are denoted by the same reference numerals.

The difference between the combined cavity type filter shown in FIG. 1 and that shown in FIG. 1 is that a flange portion 20 is formed at the end of each of the cavity portions 1 and 2 and the outer diameter of the thin plate portion 15 is increased. Correspondingly, a thick portion 16b having a large inner diameter is provided on the outer periphery of the thin plate portion 15, and when the iris plate 5b is heated, the inner diameter of the thick portion 16b is slightly smaller than the outer diameter of each of the flange portions 20. When the iris plate 5b becomes large and the temperature of the iris plate 5b becomes low, the thick portion 16b is formed such that the inner diameter of the thick portion 16b becomes smaller than the outer diameter of the flange portion 20.
b, the inner diameter of the iris plate 5b and each of the cavities 1 and 2 are heated, and the iris plate 5b and the respective cavities 1 and 2 are heated.
After they are brought into contact with 0 and pushed in, they are connected by screws 17.

Also in this case, as in the first embodiment, the temperature of the iris plate 5b does not become higher than that at the time of connection and fixing, so that even if the temperature of the iris plate 5b increases, The extension of the iris plate 5b is suppressed.
Deflection can be prevented from occurring. Further, even if the high-frequency input signal input to the cavity 1 on the input side is cut off and the iris plate 5b cools down and the iris plate 5b tries to contract, the flange portion 20 prevents the iris plate 5b from contracting, thereby preventing the deflection from occurring. it can. Thereby, even if the iris plate 5b repeatedly changes in temperature, the iris plate 5b can be prevented from being deformed, and the connection between the iris plate 5b and each of the cavities 1, 2 can be kept constant. Can be stabilized. Further, since the thin plate portion 15 of the iris plate 5b can be thinned, the loss at the coupling hole opening 14 can be reduced, and the temperature rise of the iris plate 5b can be reduced.

FIG. 3 is a sectional view showing a third embodiment of the combined cavity filter according to the present invention. In this figure, the same parts as those shown in FIG. 2 are denoted by the same reference numerals.

The difference between the combined cavity type filter shown in FIG. 2 and that shown in FIG. 2 is that a thick wedge-shaped portion 16c is provided on the outer periphery of the thin plate portion 15 constituting the iris plate 5c, and the iris plate 5c and each The thick portion 16c is brought into contact with the flange portion 20 of each of the cavities 1 and 2 while the cavities 1 and 2 are heated, and the thick portions 16c are connected by tightening them with screws 17.

Also in this case, as in the first and second embodiments, the temperature of the iris plate 5c does not become higher than that at the time of connection and fixing, so that even if the temperature of the iris plate 5c rises. Elongation is suppressed, and it is possible to prevent the iris plate 5c from being bent. Further, even if the high-frequency input signal input to the cavity 1 on the input side is cut off and the iris plate 5c cools and contracts, the flange 20 suppresses the contraction and prevents deflection. Thus, even if the iris plate 5c repeatedly changes in temperature, deformation thereof can be prevented, the connection between the iris plate 5c and each of the cavity portions 1, 2 can be kept constant, and the electrical characteristics as a filter can be stabilized. be able to. The thin plate portion 15 of the iris plate 5c
Can be reduced, so that the loss at the coupling hole opening 14 can be reduced and the temperature rise of the iris plate 5c can be reduced.

FIG. 4 is a sectional view showing a fourth embodiment of the combined cavity filter according to the present invention. In this figure, the same parts as those shown in FIG. 2 are denoted by the same reference numerals.

The difference between the combined cavity type filter shown in this figure and that shown in FIG. 2 is that the thick portion 16b of the iris plate 5d
Is provided with a connecting portion 26 having a flange 25, and a screw 27 is inserted into a hole formed in the flange 25 to fix the iris plate 5d to a base plate 28 constituting a mission panel such as a communication satellite. is there.

In this case, as in the first and second embodiments, the temperature of the iris plate 5d does not become higher than that at the time of connection and fixing, so that the temperature of the iris plate 5d rises. The extension of the iris plate is also suppressed, and it is possible to prevent the iris plate 5d from being bent. Further, the high frequency input signal input to the cavity 1 on the input side is cut off and the iris plate 5d is cut off.
However, even if it cools and shrinks, it can be prevented from being bent by the flange portion 20. by this,
Even if the iris plate 5d repeats a temperature change, its deformation is prevented, the connection between the iris plate 5d and each of the cavities 1, 2 can be kept constant, and the electrical characteristics as a filter can be stabilized. . The thin plate portion 1 of the iris plate 5d
Since the thickness of the iris plate 5d can be reduced, the loss at the coupling hole opening 14 can be reduced and the temperature rise of the iris plate 5d can be reduced.

Further, since the connecting portion 26 is formed in the thick portion 16b of the iris plate 5d and is fixed to the base plate 28, the heat of the iris plate 5d is conducted to the base plate 28 side, and the iris plate 5d Can be prevented from suddenly changing.

In each of the above-described embodiments, the thick portions 16 to 16d are formed only on the iris plates 5a to 5d provided between the hollow portions 1 and 2. However, other irises are formed. The plates 3, 4 and each flange portion 7 may have the same structure as the iris plates 5a to 5d and the flange portions 8, 20 so that the electrical characteristics are further stabilized against a temperature change.

[0034]

As described above, according to the present invention, even if the temperature of the iris plate changes, the shape of the iris plate and the joining relationship between the iris plate and each cavity portion do not change. Therefore, electrical characteristics can be stabilized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a combined cavity filter according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the combined cavity filter according to the present invention.

FIG. 3 is a sectional view showing a third embodiment of the combined cavity filter according to the present invention;

FIG. 4 is a sectional view showing a fourth embodiment of the combined cavity filter according to the present invention;

FIG. 5 is a cross-sectional view showing an example of a conventionally known combined cavity filter.

[Explanation of symbols]

 1, 2 cavity part 5a iris plate 14 opening of coupling hole 15 thin plate part 16 thick part 17 screw

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 1-126604 (JP, U) JP-A 63-147002 (JP, U) JP-A 62-8703 (JP, U) US Pat. , A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01P 1/208 H01P 1/30 WPI (DIALOG)

Claims (1)

(57) [Claims] 1. A combined cavity filter in which a plurality of cavities and an iris plate constituting a cavity resonator are formed of different kinds of metals, wherein a thin plate having a thin plate having a coupling hole opening is provided. ,
The iris plate is constituted by a thick portion integrally formed so as to have an inner periphery in close contact with an outer periphery of an end portion of the cavity portion in a high-frequency input state on an outer peripheral portion of the thin plate portion. Combined cavity filter.