JP2001160702A - Triple mode spherical dielectric filter and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To provide a triple mode spherical dielectric filter excellent in vibration / shock resistance and a method of manufacturing the same. SOLUTION: This triple mode spherical dielectric filter 100 is provided.
Is a metal cavity 2 having a cubic space,
A spherical dielectric ceramic 1 disposed at the center of the space in the cavity 2, and first, second, and third frequency adjusting screws 4 attached to respective wall surfaces of the cavity 2;
5, 6, first and second coupling adjusting screws 9, 10, input / output probes 7, 8, and fluororesin 3 filled and filled with spherical dielectric ceramics 1 to fill space inside cavity 2. And the main part is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to a filter or an oscillator in a microwave band or a millimeter wave band.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual mode spherical dielectric filter and a method of manufacturing the same, and more particularly to a triple mode spherical dielectric filter having excellent vibration and shock resistance and an improvement of a method of manufacturing the same.

[0002]

2. Description of the Related Art As a triple mode spherical dielectric filter of this kind, for example, as shown in FIG. 4, a metal cavity 2 having a cubic space and a spherical cavity fixed at the center of the space inside the cavity 2 are shown. Dielectric ceramics 1
And a rod-shaped support 11 made of a fluororesin that supports the dielectric ceramics 1, and its central axis set on axes X, Y, and Z that are attached to the wall surface of the cavity 2 and that are orthogonal to each other. At the same time, the first frequency adjusting screw 4, the second frequency adjusting screw 5, and the third frequency adjusting screw 6 whose intersections of the respective central axes are set at the central points of the dielectric ceramics 1 and the second frequency adjusting screw 5, A first surface formed by the one frequency adjustment screw 4 and the second frequency adjustment screw 5, a second surface formed by the second frequency adjustment screw 5 and the third frequency adjustment screw 6, and a third frequency adjustment screw 6, Two surfaces selected from a third surface formed by the first frequency adjustment screw 4 (a first surface formed by the first frequency adjustment screw 4 and the second frequency adjustment screw 5 and a second frequency adjustment in FIG. 4) Screw 5 and third round The central axis is present on one of the surfaces (the second surface formed by the number adjusting screw 6) and these central axes are the first, second and third frequency adjusting screws 4, 5, 6 respectively. Are not set on the same axis as the respective center axes, and the first coupling adjusting screw 9 whose tip direction is directed to the center or substantially the center of the dielectric ceramic 1 (the center axis exists on the first surface in FIG. 4). And the second coupling adjusting screw 10
(The center axis is present on the second surface in FIG. 4), and two frequency adjustment screws selected from the first, second and third frequency adjustment screws 4, 5, and 6 with the dielectric ceramic 1 as the center. A rod-like shape which is attached to the cavity wall opposite to the first frequency adjusting screw 4 and the third frequency adjusting screw 6 in FIG. 4 and whose central axis is set to be the same as the central axis of the opposing frequency adjusting screw. It is known that an output terminal (output probe) 7 and a rod-shaped input terminal (input probe) 8 constitute a main part thereof.

In the spherical dielectric ceramics (spherical dielectric resonator) incorporated in the triple mode spherical dielectric filter, a resonance mode called TE101 mode is a lowest-order mode, and this resonance mode is most industrially used. Easy to use. For example, Nakakita et al.'S literature (Proceedings of the 1989 IEICE Spring Conference, Volume 2-p54)
6, According to Hisamio Nakakita and Kazuo Imai, "Millimeter-wave spherical dielectric resonator"), using a spherical dielectric ceramic having a diameter of 1.6 mm and a relative dielectric constant of 24, a TE101 mode 38G.
A Hz band rejection filter is realized.

[0004] Spherical dielectric ceramics (spherical dielectric resonators) can realize a high no-load Q value because the ceramics have no corners as compared with a cylindrical dielectric resonator that has been widely used in the past. It has the feature of. Further, in the millimeter wave band, the processing of the spherical ceramic is easier than the processing of the columnar ceramic, so that the application in the millimeter wave band is advantageous.

Incidentally, the above-mentioned spherical dielectric ceramic (spherical dielectric resonator) has a symmetric structure with respect to three orthogonal axes, so that many resonance modes including the TE101 mode are triple degenerate. Mode. Therefore, if a mechanism for adjusting the resonance frequency of each of the three degenerated modes and a mechanism for adjusting the electrical coupling between the resonance modes are provided, a three-stage dielectric filter can be realized with one spherical dielectric ceramic. It is possible to do.

The first frequency adjusting screw 4, the second frequency adjusting screw 5, and the third frequency adjusting screw 6 shown in FIG. 4 play a role of adjusting respective resonance frequencies in each of the three reduced modes. , The first coupling adjusting screw 9 and the second coupling adjusting screw 10 play a role of adjusting the electrical coupling between the respective resonance modes.

[0007]

However, in the triple mode spherical dielectric filter shown in FIG. 4, the spherical dielectric ceramic 1 must be fixed at the center position of the space inside the metal cavity 2. In addition, it is necessary to use the bar-shaped support 11 having an unstable structure, which has a problem that it is susceptible to vibration and impact.

The present invention has been made in view of such a problem, and an object thereof is to provide a triple mode spherical dielectric filter excellent in vibration and shock resistance and a method of manufacturing the same. It is in.

[0009]

That is, according to the first aspect of the present invention, there is provided a cavity having a cubic space, a spherical dielectric ceramic fixed at a center position of the space in the cavity, and First, second, and third axes whose center axes are respectively set on axes indicated by X, Y, and Z axes that are attached and that are orthogonal to each other, and whose intersections are set at center points of the dielectric ceramics. A third frequency adjustment screw, a first surface attached to the cavity wall surface and formed by a first frequency adjustment screw and a second frequency adjustment screw, a second surface formed by a second frequency adjustment screw and a third frequency adjustment screw The center axis is present on one of the two surfaces selected from the surface and the third surface formed by the third frequency adjusting screw and the first frequency adjusting screw, and the center axes thereof are respectively located on these surfaces. However, the first and second coupling adjustment screws are not set on the same axis as the respective central axes of the first, second, and third frequency adjustment screws, and the tip ends thereof are directed toward the center or substantially the center of the dielectric ceramic, The center axis of the frequency adjusting screw which is mounted on the cavity wall opposite to the two frequency adjusting screws selected from the first, second and third frequency adjusting screws with the dielectric ceramic as the center and whose central axis is opposed Assuming a triple mode spherical dielectric filter having a rod-shaped input terminal and a rod-shaped output terminal respectively set on the same as above, the spherical dielectric ceramic is filled with a fluorine resin filled to fill the cavity space. It is characterized by being fixed.

In the triple mode spherical dielectric filter according to the first aspect of the present invention, the spherical dielectric ceramic is fixed by the fluorine resin filled so as to fill the cavity space. In addition, since it is not necessary to use a rod-shaped support to support the dielectric ceramics, it is possible to dramatically improve the vibration and shock resistance characteristics of the dielectric filter.

Next, the second and third aspects of the invention relate to an invention which specifies a method for manufacturing a triple mode spherical dielectric filter according to the first aspect.

That is, the invention according to claim 2 is based on the method of manufacturing a triple mode spherical dielectric filter according to claim 1, and includes first, second, and third frequency adjusting screws on the cavity wall surface. First, the second coupling adjustment screw and the first and second support screws corresponding to the rod-shaped input terminal and the rod-shaped output terminal are attached, and the spherical dielectric ceramic is arranged at the center position of the cavity space. The first, second, and third frequency adjusting screws, and the first and second coupling adjusting screws and the first and second supporting screws sandwich the dielectric ceramic at the respective distal ends of a plurality of screws selected from the screws. A step of filling an uncured fluorine-based resin so as to fill the space in the cavity and curing the same to fix the dielectric ceramic, and pulling out the first and second supporting screws to remove the portion thereof To And a step of attaching a rod-shaped input terminal and a rod-shaped output terminal, respectively. The invention according to claim 3 is based on the method of manufacturing a triple mode spherical dielectric filter according to claim 1. The third, fourth, and fifth supporting screws corresponding to the first, second, and third frequency adjusting screws on the cavity wall surface, and the sixth and seventh supporting screws corresponding to the first and second coupling adjusting screws. Screws and first and second support screws corresponding to the rod-shaped input terminal and the rod-shaped output terminal are attached, and the spherical dielectric ceramic is arranged at the center position of the space in the cavity. A step of sandwiching the dielectric ceramic at each end of the screw from the screw to the seventh supporting screw, and filling an uncured fluorine-based resin so as to fill the cavity, and curing the resin to cure the dielectric ceramic. Fixing step, and withdrawing a seventh supporting screw from the first supporting screw, a rod-shaped input terminal corresponding to the part, a rod-shaped output terminal, first, second, third frequency adjusting screws and first and second screws. And a step of attaching a coupling adjusting screw.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic perspective view showing the structure of a triple mode spherical dielectric filter according to the present invention, in which the inside of a metal cavity is shown in a transparent manner, with the illustration of the upper side wall surface omitted.

That is, as shown in FIG. 1, the triple mode spherical dielectric filter 100 includes a metal cavity 2 having a cubic space, and a spherical dielectric member disposed at the center of the cavity 2. Ceramics 1,
The center axes are respectively set on axes indicated by X, Y and Z axes which are attached to the wall surface of the cavity 2 and are orthogonal to each other.
The first frequency adjustment screw 4 (center axis is set on the X axis), the second frequency adjustment screw 5 (center axis is set on the Y axis), and the third frequency adjustment A screw 6 (center axis is set on the Z-axis) and a central axis is present on a first surface mounted on the cavity 2 wall surface and formed by the first frequency adjusting screw 4 and the second frequency adjusting screw 5. The center axis of the first frequency adjusting screw 4 and the center axis of the second frequency adjusting screw 5 are not set on the same axis, and the tip of the first axis adjusting screw faces the center point of the dielectric ceramic 1. 9, a second frequency adjusting screw 5 and a third frequency adjusting screw 6 attached to the wall surface of the cavity 2 and having a central axis on a second surface formed by the second frequency adjusting screw 5 and the third frequency adjusting screw 6. The center axis of the third frequency adjustment screw 6 is set on the same axis. Second coupling adjustment screw 1 is not the together the distal direction toward the center point of the dielectric ceramic 1
0, which is mounted on the cavity wall opposite to the first frequency adjustment screw 4 with the dielectric ceramics 1 as the center, and whose central axis is set to be the same as the central axis of the first frequency adjustment screw 4 facing the same. The output probe 7 is mounted on the cavity wall opposite to the third frequency adjusting screw 6 with the dielectric ceramics 1 as the center, and its central axis is the same as the central axis of the third frequency adjusting screw 6 facing the same. The main part is composed of an input probe 8 set to the above and a fluororesin 3 filled to fill the space inside the cavity 2 and fixing and supporting the spherical dielectric ceramics 1.

According to the triple mode spherical dielectric filter 100, the spherical dielectric ceramics 1 is fixed by the fluorine resin filled so as to fill the space in the cavity 2, so that the conventional dielectric ceramic filter 1 has a structure similar to the conventional one. Since it is no longer necessary to support the dielectric ceramics 1 using a rod-shaped support, there is an advantage that the vibration and shock resistance characteristics of the dielectric filter can be dramatically improved.

In the triple mode spherical dielectric filter 100, the spherical dielectric ceramics 1 needs to be fixed at the center position of the space in the cavity 2, so that the dielectric ceramics 1 is formed by the following procedure. Fixation is made.

First, as shown in FIG. 2, the first, second, and third frequency adjusting screws 4, 5, 6
And holes (not shown) to which the first and second coupling adjusting screws 9 and 10 and the output probe 7 and the input probe 8 are attached, respectively, and the first, second and third frequency adjusting screws 4 are provided. The third, fourth and fifth supporting screws 204, 205 and 206 are inserted into the holes corresponding to 5 and 6, respectively.
Sixth and seventh support screws 209 and 210 are inserted into holes corresponding to the first and second coupling adjustment screws 9 and 10, respectively.
First and second support screws 207 and 208 are inserted into the holes corresponding to the output probe 7 and the input probe 8, respectively, and the spherical dielectric ceramics 1 is disposed at the center of the space in the cavity 2. Thus, the dielectric ceramics 1 is sandwiched between seven screw tip portions of the first support screw 207 to the seventh support screw 210 (claim 3).

Next, an uncured fluororesin [for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (PFEP), tetrafluoroethylene- Perfluoroalkyl vinyl ether copolymer (PFA), etc.] and cure. When the uncured fluororesin is filled, one of the walls of the cavity 2 is selected (however, a wall surface to which the seventh support screw 210 is not attached from the first support screw 207 is selected).
, And after filling the fluorocarbon resin from the opening,
The opening may be closed, or an opening for injection may be opened in one of the wall surfaces of the cavity 2, and after the opening is filled with a fluororesin, the opening may be closed in the cavity 2. Alternatively, a method of closing with the same material may be adopted.

Here, it is known that a fluorine-based resin is not generally bonded to a metal or the like after curing. Therefore,
After the fluororesin is cured, the dielectric ceramic 1
The seven screws of the seventh support screw 210 can be rotated and extracted from the first support screw 207 that has sandwiched and supported the. As a result, the first support screw 207
Except for the portion where the seventh supporting screw 210 is located, the other portion is completely filled with the fluorine-based resin, and the spherical dielectric ceramics 1 is fixed to the center position of the space inside the metal cavity 2.

Thereafter, the removed first support screw 207
, The first, second and third frequency adjusting screws 4, 5, 6 corresponding to the respective holes of the seventh supporting screw 210, the first and second coupling adjusting screws 9, 10, the output probe 7, and the input probe. 8 and these are appropriately moved to be fixed at an optimum position, whereby the triple mode spherical dielectric filter 100 shown in FIG. 1 is manufactured.

As shown in FIG. 3, the first support screw 207 and the second support screw 208 corresponding to the output probe 7 and the input probe 8, and the first frequency adjustment screw 4 and the third frequency adjustment screw 6 are provided. The dielectric ceramic 1 is supported using the four screws described above, and the other components, the second frequency adjusting screw 5 and the first and second coupling adjusting screws 9 and 10, are assembled as they are and the dielectric ceramic 1 is assembled. The ceramics 1 is fixed with the above-mentioned fluororesin, and then the first support screw 2 which has been removed is removed.
07 and the output probe 7 in each hole of the second support screw 208.
The triple mode spherical dielectric filter 100 may be manufactured by mounting the first and second frequency adjusting screws 4 and 6 while rotating the first frequency adjusting screw 4 and the third frequency adjusting screw 6 and fixing them at an optimum position. (Claim 2).

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a spherical dielectric ceramic, the diameter is 1.
8 mm, using Ba, Mg, Ta oxide-based ceramics (relative dielectric constant 24), and as a metal cavity,
A triple mode spherical dielectric filter was experimentally manufactured using a brass having a cubic space having an inner size of 5 mm × 5 mm × 5 mm and having a silver plated surface.

The first, second and third frequency adjusting screws and the first and second coupling adjusting screws are M1.6 brass silver-plated screws, and are used as input / output probes. Using a rod-shaped probe made of a metal (beryllium copper alloy) having a diameter of 0.5 mm.
TFE was applied.

The prototype triple mode spherical dielectric filter produced a pass band at 37.5 GHz, and was confirmed to operate as a 3 dB bandwidth, 50 MHz band pass filter.

A vibration test was performed on the triple mode spherical dielectric filter based on MIL-STD883D. That is, when the vibration of the acceleration 10G was applied for three hours in each of the three directions and the changes in the filter characteristics such as the center frequency and the pass bandwidth were measured, there was no change in these characteristics.
It was confirmed that it had excellent vibration and shock resistance.

[0027]

According to the triple mode spherical dielectric filter according to the first aspect of the present invention, the spherical dielectric ceramic is fixed by the fluorine resin filled so as to fill the cavity. In addition, since it is no longer necessary to support the dielectric ceramics using the rod-shaped support table as in the related art, there is an effect that the vibration and shock resistance characteristics of the dielectric filter can be drastically improved.

According to the method for manufacturing a triple mode spherical dielectric filter according to the second and third aspects of the present invention, it is possible to easily and easily manufacture the triple mode spherical dielectric filter according to the first aspect. Have.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing the structure of a triple mode spherical dielectric filter according to the present invention.

FIG. 2 is a schematic perspective view showing one step of a method for manufacturing a triple mode spherical dielectric filter according to the present invention.

FIG. 3 is a schematic perspective view showing one step of a method for manufacturing a triple mode spherical dielectric filter according to a modification of the present invention.

FIG. 4 is a schematic perspective view showing the structure of a conventional triple mode spherical dielectric filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spherical dielectric ceramic 2 Cavity 3 Fluororesin 4 First frequency adjusting screw 5 Second frequency adjusting screw 6 Third frequency adjusting screw 7 Output probe 8 Input probe 9 First coupling adjusting screw 10 Second coupling adjusting screw 100 3 Double mode spherical dielectric filter

Claims (3)

[Claims] 1. A cavity having a cubic space;
A spherical dielectric ceramic fixed at the center position of the space in the cavity, and its central axes set on axes X, Y, and Z axes attached to the wall surface of the cavity and orthogonal to each other, are set. The first, second, and third frequency adjusting screws are formed at the center point of the dielectric ceramic, and the first frequency adjusting screw and the second frequency adjusting screw are attached to the cavity wall surface. 2 selected from a first surface, a second surface formed by the second frequency adjustment screw and the third frequency adjustment screw, and a third surface formed by the third frequency adjustment screw and the first frequency adjustment screw
The central axis is present on any one of the two surfaces, and these central axes are not set on the same axis as the central axes of the first, second, and third frequency adjustment screws, and the tip direction thereof A first and a second coupling adjustment screw heading toward the center or substantially the center of the dielectric ceramic, and two frequency adjustment screws selected from the first, second, and third frequency adjustment screws with the dielectric ceramic as a center. Is a three-mode spherical dielectric filter having a rod-shaped input terminal and a rod-shaped output terminal which are mounted on the opposite cavity wall surface and whose central axis is set to be the same as the central axis of the frequency adjusting screw facing the spherical cavity. The dielectric ceramic is fixed by a fluorine resin filled so as to fill a cavity space.
Double mode spherical dielectric filter. 2. The method of manufacturing a triple mode spherical dielectric filter according to claim 1, wherein first, second, and third frequency adjusting screws, first and second coupling adjusting screws, and the rod-shaped member are provided on a cavity wall surface. First, second, and third screws are attached to the input terminal and the rod-shaped output terminal, so that the spherical dielectric ceramic is disposed at the center position of the space in the cavity. A frequency adjusting screw, a step of sandwiching the dielectric ceramic with each tip of a plurality of screws selected from the first and second coupling adjusting screws and the first and second supporting screws, and filling the cavity space. Filling an uncured fluororesin and curing the same to fix the dielectric ceramics, and pulling out the first and second support screws, and a rod-shaped input terminal and a rod-shaped output terminal corresponding to the portion. Step of attaching each triple mode spherical method for manufacturing a dielectric filter characterized by comprising the steps of. 3. The method of manufacturing a triple mode spherical dielectric filter according to claim 1, wherein third, fourth, and fifth supports corresponding to the first, second, and third frequency adjusting screws are provided on the cavity wall surface. Screws, the first and second support screws corresponding to the first and second coupling adjustment screws, the sixth and seventh support screws, and the first and second support screws corresponding to the bar-shaped input terminals and the bar-shaped output terminals, and the cavity space A step of sandwiching the dielectric ceramic at each tip of the first support screw to the seventh support screw so that the spherical dielectric ceramic is disposed at the center of the cavity, and filling the cavity interior space. A step of filling the uncured fluorine-based resin and curing the same to fix the dielectric ceramics, and pulling out a seventh supporting screw from the first supporting screw and a rod-shaped input terminal corresponding to the portion, rod Output terminal, first,
A method of mounting the second and third frequency adjusting screws and the first and second coupling adjusting screws, respectively.