JPS62214701A - Dielectric filter - Google Patents

Abstract

PURPOSE:To attain the miniaturization and light weight of the titled filter by connecting a capacitor and an input/output terminal connected to a conductor film and arranged near the opening of an open face by means of a conductor wire through the inside of a resonance hole. CONSTITUTION:An inner conductor film 12a of a couple of resonance holes 12 is prolonged to the opening peripheral of an upper face 11a to form a prolonged conductor film 12b as a resonance element. Since an upper face 11a of a block 11 is formed as a non-metallized face being a part except the prolonged conductor film 12b, the part is formed as an open face of an electromagnetic field. A capacitor 14 is connected on the prolonged conductor film 12b of a couple of the resonance holes 12 placed at both ends and the capacitor 14 is formed as a doughnut type parallel capacitor by providing conductor films 14b, 14c respectively at both faces of an insulator 14a and the through hole at the middle part is used as a guide 14d of the conductor wire 16.

Description

[Detailed Description of the Invention] [Table of Contents] - Overview, industrial application field, conventional technology (Figure 7) - Problems to be solved by the invention, means for solving the problems, actions, and implementation Examples [First embodiment (Fig. 1.2) Second embodiment (Fig. 3) Third embodiment (Fig. 4) Fourth embodiment (Fig. 5) Fifth embodiment (Fig. 6)] - Effects of the invention [1 Already required] In the dielectric filter, the inner conductor film (12a) of a pair of resonance holes (12) located at both ends of a plurality of resonance holes (12) is blocked (11). ) is provided with an extended conductor film (12b) extending to the periphery of the opening of the open surface (11a);
A capacitor (14) is connected to this conductor film (12b) and placed near the opening on the open side (11a), and a capacitor (14) is placed near the opening on the short-circuit side (11C> side) of the pair of resonance holes (12). By connecting the input/output terminal (15) with the conductor wire (16) passing through the resonance hole (12), the filter can be made smaller and lighter.

[Industrial application field]

The present invention relates to a dielectric filter in which a plurality of resonance holes are arranged in a corner of a single dielectric block at predetermined intervals, and the resonance holes are also integrally formed in the dielectric block as a WR element. In particular, it relates to a coupling structure between a resonance hole and an input/output terminal.

In wireless equipment, depending on the frequency used, ViF band, t
A filter for the 11lF band or microwave band is used. Filters used in mobile radio devices such as in-vehicle radios or portable radios are required to be electrically and mechanically stable, small and lightweight in terms of usability and installation space. Dielectric filters have been developed as filters that meet these demands. However, in recent years, as wireless devices have become more densely packaged, dielectric filters are also required to be further miniaturized.

[Conventional technology]

FIG. 7 is a side sectional view showing a conventional dielectric filter. In the figure, a plurality (four in this case) of resonance holes 2 are formed vertically through a dielectric block l formed in the shape of a rectangular parallelepiped, with openings arranged longitudinally at predetermined intervals. A metallized inner conductor film 2a is provided on the inner surface of the resonance hole 2, and a metallized outer conductor film 1b is provided on the entire surface other than the top surface 1a of the block l including the opening of the resonance hole 2, The bottom IC is set as a shorting surface. Thereby, the resonance hole 2 is formed as a resonance element. Since the upper surface 1a of the block l is a non-metalized surface, it is formed as an open surface to the electromagnetic field. By setting the length of the resonant hole (resonant element) 2 (substantially the length of the portion having the internal conductor film) to two wavelengths of the operating frequency, or to a size approximately equal to the two wavelengths, the χ wavelength or Each wavelength filter is configured. The block 1 is housed and fixed in the housing 7 with its lower IC fixed on the bottom plate 7b of the housing 7. This casing 7 is composed of a box-shaped casing main body 7a having an opening on the top surface and a shield cover 8 disposed on the top surface. A cylindrical metal block 3 is inserted and fixed into the upper end (open surface side) of a pair of resonance holes (resonance elements) 2 located at both ends, and a capacitor 4 is fixedly connected onto the metal block 3. On the other hand, the side plate 7c of the housing 7
Input/output terminals (hermetic terminals) 5 are arranged in the upper part, corresponding to the capacitors 4, respectively. Capacitor 4 is connected to input/output terminal 5 via conductor wire 6 .

This conventional example has a coupling structure between the resonance hole (resonance element) 2 and the input/output terminal 5 as described above.

[Problem that the invention seeks to solve]

In the above conventional example, the input/output terminals 5 are arranged on the side plate 7C of the casing 7, and the capacitor 4 provided at the upper end of the resonance hole (resonance element) 2 via the metal block 3 is connected to the conductor wire 6. Block 1 is connected to input/output terminal 5 via
It is necessary to set the distance H1 between the top surface (open surface) 1a and the cover 8 large, and the block I is connected to the housing 7.
In order for the block l to avoid the input/output terminals 5 when housed in the housing, it is necessary to provide a certain margin in the distance H2 between the side plate 7C of the housing 7 and the side surface of the block 1, and also to Since the input/output terminals 5 are attached to Fi and 7C, the wall thickness of the side plate 7C needs to be thickened, and for other reasons, the entire filter becomes larger and weighs more. There was a problem that it was not possible to reduce the size and weight.

The present invention was created in view of these problems, and an object of the present invention is to provide a dielectric filter that can be made smaller and lighter.

[Means for solving problems]

In the present invention, as a means to solve the above problems,
A plurality of resonance holes (12) are arranged in a single dielectric block (11) at predetermined intervals, and one surface (11a) of the block (11) containing the openings of the resonance holes (12) is open. conductor films (11b, 12a) on the ground surface except for the one surface (11a) and on the inner surface of the resonance hole;
), and in the dielectric filter comprising the resonance holes (12 formed as a resonance element and the back surface (11C) opposite to the one surface (11a) formed as a short-circuit surface, the plurality of resonance holes The internal conductor film (12a) of the pair of resonance holes (12) located at both ends of (12) is formed to extend to the opening periphery of the open surface (11a), and
A capacitor (14) connected to the extended conductor film (12b) is arranged near the opening of the pair of resonance holes (12) in 11a), and An input/output terminal (15) is arranged near the listening port, and the extended conductor film (12) of the capacitor (I4) is connected to the input/output terminal (15).
Connect one end of the input/output conductor wire (16) to the surface opposite to the connection surface with b), and connect the other end of the conductor wire (16) to the resonant hole (
12) and connected to the input/output terminal (15) via the resonance hole (12).

[For production]

Open surface 1 of a pair of resonance holes (12) located at both ends
The extended conductor film (12a) provided around the opening on the (11a) side
b)) and the input/output terminal (15) arranged near the opening on the short-circuit surface (11C) side of the pair of resonance holes (12), by connecting the inside of the resonance hole (12). Since the connection structure between the connected resonance hole (resonance element) and the input/output terminal can be configured via the conductor wire (16), the entire filter can be made smaller.

Weight reduction can be achieved.

〔Example〕

1 to 6 are diagrams for explaining the present invention in detail. Incidentally, in these figures, the same or equivalent parts are indicated by the same reference numerals.

Figures 1 (fal, b), fc) show the first embodiment, (a) is a side sectional view thereof, and (bl is (
An enlarged perspective view of the arrow P section of al, (C1 is the arrow Q of (a)
FIG.

In the figure, a dielectric block I formed in the shape of a rectangular parallelepiped
A plurality of resonance holes 12 (four in this case) having openings arranged in the longitudinal direction at predetermined intervals are formed vertically through I. A metallized inner conductor film 12a is provided on the inner surface of the resonance hole I2, and an outer conductor film is metalized on all other surfaces except for the upper surface (one surface) 11a of the block 11 including the opening of the resonance hole L2. 11b is provided,
The lower surface (direction) 11c is set as a short-circuit surface, and in the present invention, an extended conductor film 12b formed by extending the internal conductor film 12a of the pair of resonance holes 12 located at both ends to the periphery of the opening of the upper surface 11a is provided. It is being Thereby, each resonance hole 12 is formed as a resonance element. block 1
Since the upper surface 11a of 1 is a non-metallized surface except for the extended conductor film L2b, it is formed as an open surface to the electromagnetic field.

A two-wavelength filter is constructed by setting the length of the resonance hole (resonance element) 12 (substantially the length of the internal conductor film) to be approximately the same as the wavelength A of the frequency used. Accommodation case 1
7 is a bottom +ji17a formed from a metal plate, and a bottom plate 17
a and a box-shaped shield cover 18 which is placed and fixed on top of the box and has an opening on the bottom surface. The block 11 is housed and fixed in the casing 17 with its lower surface (shorting surface) 11c fixed on the bottom plate 17a of the casing 17. A capacitor 14 is connected to the extended m-body membrane 12b of the pair of resonance holes 12 located at both ends. The capacitor 14 is shown in FIG.
As shown in the enlarged view el, conductor films 14b and 14c are provided on both sides of the insulator 14a to form a donut-shaped parallel plate capacitor, and the r\ communicating hole in the center is set as a guide portion 14d for the conductor wire 1G. has been done. Block lower surface (short circuit surface) IIC of a pair of resonance holes 12 at both ends
The input/output terminal 1 is located on the bottom plate 17a of the housing 17 corresponding to the opening of
5 are inserted and fixed respectively. The input/output terminal 15 is
FIG. 1 (as shown in C1, the center conductor 15a and the insulator 1
5b and an outer conductor 15C as a hermetic terminal. One end side of the conductor wire 16 is connected to the upper surface of the capacitor 14, that is, the surface opposite to the connection surface with the extension conductor film 12b, and the other end side is connected to the guide portion 14 of the capacitor 14.
d and is connected to the input/output terminal 15 via the resonance hole 12. In this example, the conductor wire 16 connected to the capacitor 14 passes through the inside of the resonance hole 12 and connects to the resonance hole 1.
The main feature is that it has a coupling structure that connects to the input/output terminal I5 provided on the lower surface side of 2. In addition, input/output terminal I5
For example, it is plugged into a socket (not shown) provided on a printed board of a wireless device.

In this example, by configuring as described above, the block upper surface (open surface) 11a and the ceiling plate 18a of the shield cover 18
The distance H3 between the block II and the side plate 18b of the shield cover 18 can be reduced to a greater width than before, and the distance H4 between the side surface of the block II and the side plate 18b of the shield cover 18 can be reduced to such an extent that they almost contact each other. The housing 17 is made smaller, and the entire filter can be made smaller and lighter.

2(a), 2(b') and 2(C) are diagrams showing a modification of the capacitor 14 of FIG. 1. The capacitor 14 shown in (a) is formed into a semi-doughnut shape.

The capacitor 14 shown in (b) has a rectangular outer surface and can have a large capacity. The capacitor 14 shown in (C) is formed into a rectangular parallelepiped, and is easy to manufacture and can have a large capacity.

FIG. 3 is a diagram showing the main parts of the second embodiment. In this example, the attachment part of the input/output terminal 15 on the bottom plate 17a of the housing casing 17 is bent and formed toward the inside of the resonance hole 12, and the input/output terminal 15 is inserted and fixed in this bent part 17b. The other configurations are the same as the first embodiment (FIG. 1). In this example, the height of the entire filter including the input/output terminals can be made slightly lower than in the first embodiment, but other effects are the same as in the first embodiment.

FIG. 4 is a diagram showing the main parts of the third embodiment. This example differs from the first example (Fig. 1) only in that the input/output terminal 15 is placed directly inside the lower end of the resonance hole 12, and the shield cover 18 is directly attached to the block 11. The rest of the structure is the same as that of the first embodiment. This example has a slightly smaller number of parts than the first example, but other effects are the same as the first example.

FIG. 5 is a diagram showing the main parts of the fourth embodiment. This example is different from the third example (Fig. 4) described above in that the capacitor 4 is disposed inside the upper end of the resonance hole 12, and the other points are the same as those in the third example. Constructed similarly to the example. In this example, the height of the shield cover 18 from the top surface of the block can be set slightly lower than in the third example, and other effects are the same as in the third example.

FIG. 6 is a diagram showing a fifth embodiment, and is an end sectional view of the block 11 viewed from the longitudinal direction. In this example, block 1
A step extending in the longitudinal direction on the top surface 11a of 1? 111d, the bottom surface lie of this stepped groove 11d is formed as an open surface, the capacitor 14 is disposed on this open surface (11e), and the shield cover 18 is bonded and disposed on the block top surface ita. This embodiment is different from the third embodiment (FIG. 4) described above, but has the same structure as the third embodiment in other respects.

In this example, the bottom surface he of the stepped groove 11d and the shield cover 18
The distance between the block upper surface 11a and the shield cover 18 can be set slightly smaller than the distance between the block top surface 11a and the shield cover 18 in the third embodiment, and other effects are the same as in the third embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, the internal conductor film (12) provided in the pair of resonance holes (12) located at both ends.
a) to the opening periphery of the open surface (11a) of the dielectric block (11) to form an extended conductor film (12b).
A capacitor (14) is arranged in the vicinity of the opening of the open surface (11a) so as to be connected to the extension conductor Jlff (12b), and the short-circuit surface (I) of the pair of resonance holes (12) is
The input/output terminals are arranged near the opening on the IC) side, and the conductor wire (1
6) is connected to the capacitor (1) via the resonance hole (12).
4) and the input/output terminal (15), the dielectric filter can be made smaller and lighter.

[Brief explanation of drawings]

FIG. 1 (at, (b), fcl are the first
FIG. 2 is a diagram showing a modification of the capacitor (14) in FIG. 1, FIG. 3 is a diagram showing a second embodiment of the present invention, and FIG. 4 is a diagram showing a third embodiment of the present invention. FIG. 5 is a diagram showing a fourth embodiment of the present invention, FIG. 6 is a diagram showing a fifth embodiment of the present invention, and FIG. 7 is a diagram showing a conventional example. In Figures 1 to 6, 11 is a dielectric block, Ila is the top surface (open surface), 1
1b is the outer conductor film, 11C is the lower surface (short circuit surface), l
id is the step groove, lie is the bottom surface (open surface) of the step/g (11d), 12 is the resonance hole (resonance element), 12a is the internal conductor film, 12b is the extension conductor film, 14
15 is a parallel plate capacitor, 15 is an input/output terminal (hermetic terminal), 16 is a conductor wire, 17 is a housing case, 17a is a bottom plate, and 18 is a shield cover.

Claims (1)

[Claims] 1. A plurality of resonance holes (12) are arranged in a single dielectric block (11) at predetermined intervals, and the resonance holes (12)
One surface (11a) of the block (11) including the opening is formed as an open surface, and a conductive film (11b, 12a) is provided on the other surface other than the one surface (11a) and on the inner surface of the resonance hole, and A resonance hole (12) is formed as a resonance element,
In a dielectric filter in which a back surface (11c) opposite to the one surface (11a) is formed as a shorting surface, a pair of resonance holes (12) located at both ends of the plurality of resonance holes (12). an internal conductive film (12a) is formed to extend to the periphery of the opening of the open surface (11a), and the pair of resonance holes (1) in the open surface (11a)
A capacitor (14) connected to the extension conductor film (12b) is arranged near the opening of 2), and an input/output terminal (15) is arranged near the opening on the back side (11c) of the pair of resonance holes (12). one end of an input/output conductor wire (16) is connected to the opposite surface of the capacitor (14) to the connection surface with the extension conductor film (12b), and the other end of the conductor wire (16) is connected to the Resonance hole (12)
A dielectric filter characterized in that the dielectric filter is introduced into the interior of the resonant hole (12) and connected to the input/output terminal (15) via the inside of the resonance hole (12).