JPH07283608A - Dielectric filter and its production - Google Patents

Abstract

PURPOSE:To obtain dielectric resonators constituting a dielectric filter as one body of elements different by resonance frequencies. CONSTITUTION:A dielectric substrate 11 provided with recessed grooves and a plane dielectric substrate 12 are stuck to each other, and a conductor film 19 extended from aperture end faces of recessed grooves is formed in one of adhesion surfaces and is connected to a short-circuit conductor. By this conductor film 11, effective dimensions of resonators are reduced to raise the resonance frequencies of dielectric resonators. The dielectric filter unified into one body is obtained by the structure where resonance frequencies in both ends of plural resonance elements can be raised.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure and a manufacturing method of a dielectric filter, and more particularly to a dielectric filter in which a plurality of resonant elements are integrally formed by bonding dielectric substrates.

[0002]

2. Description of the Related Art Various dielectric filters are used as high frequency filters. The one using a quarter-wave coaxial TEM resonator in which an inner conductor, an outer conductor, and a short-circuit conductor are formed in a dielectric having a through hole is often used for mobile stations for mobile communication. A strip line type and a laminated LC type are also used for downsizing.

When a filter is formed by using a plurality of resonators, the resonance frequency of each resonance element may be different. In particular, the resonance frequency of the resonant element at the input / output end needs to be set higher than the resonant frequency of the intermediate resonant element. In the integrated type dielectric filter, as shown in FIG. 5, it is necessary to shorten the length of the element portions at both ends, and for that purpose, the opening surface of the through hole of the resonance element is processed. .

[0004]

However, due to problems such as man-hours and accuracy of processing for adjusting the resonance frequency,
Problems arise in terms of cost and characteristics of the dielectric filter. The present invention makes it possible to obtain a dielectric filter which is easy to manufacture and has stable characteristics, without requiring the above-mentioned processing steps.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a dielectric filter, which is proposed by the inventor in Japanese Patent Application No. 4-186099, in which two or more dielectric substrates are bonded together to form a plurality of resonance elements. The above problem is solved by using a conductor film formed on the surface to be bonded.

That is, a flat dielectric substrate is adhered to the grooved surface of a dielectric substrate having a plurality of parallel grooves, or a plurality of dielectric substrates having a groove and a plurality of flat dielectrics are attached. Bond the body substrate so that the concave grooves are arranged at a predetermined interval,
A conductor film is formed inside the groove and on the surface of the flat dielectric substrate facing the groove to form an inner conductor, and a conductor film is formed on the outer peripheral surface in a direction parallel to the extending direction of the groove to form an outer conductor, In a dielectric filter, which is a short-circuit conductor by forming a conductor film on one of the open end faces of the groove, it is connected to the short-circuit conductor adjacent to at least one groove and extends from the short-circuit end face to the open end face. Is characterized in that it has a conductor film formed on at least one of the adhesive surfaces of the dielectric substrate.

Further, a flat second dielectric substrate is provided on each grooved surface of a plurality of first dielectric substrates having a plurality of parallel grooves extending linearly, and at least a part of the dielectric substrate is provided. A conductive film is formed on the adhesive surface of the body substrate so as to extend from the end face where the groove is opened and adjacent to a part of the groove, and the first dielectric substrate and the second dielectric substrate are connected to each other by the second dielectric substrate. Arranged so as to be parallel so that the concave grooves are located at a predetermined interval and bonded, and form a plurality of dielectric blocks by cutting the concave groove and the intermediate portion of the concave groove in a direction perpendicular to the bonding surface, A conductor film is formed inside the groove and on the surface of the flat dielectric substrate facing the groove to form an inner conductor, and a conductor film is formed on the outer peripheral surface in a direction parallel to the extending direction of the groove to form an outer conductor, A conductor film is formed on one of the end surfaces of the recessed groove to form a short-circuit conductor, and the short-circuit conductor and the adhesive surface are formed. And those having features to connect the conductor film.

[0008]

Since the conductor film extending from the short-circuited end surface to the adhesive surface is connected to the short-circuited conductor, the distance from the open end surface to the short-circuited end surface is substantially reduced, and the resonance frequency of the resonance element can be increased.

[0009]

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

FIG. 1 is a perspective view showing an embodiment of the present invention, showing a state before assembly of a dielectric filter. A flat second dielectric substrate (12) is attached to the surface of the first dielectric substrate (11) in which parallel concave grooves are formed at predetermined intervals to form a dielectric block having a plurality of through holes. It is what constitutes. An inner conductor is formed in the through hole, an outer conductor is formed on the outer peripheral surface parallel to the extending direction of the through hole, and a short-circuit conductor is formed on one of the end surfaces of the through hole, thereby forming a quarter-wave TEM resonator.
A dielectric filter including elements is constructed.

In the dielectric filter according to the present invention,
The conductor film 19 is formed on the surface to be bonded. This conductor film
A short-circuit conductor is formed on the side on which the conductor film 19 is formed.
Connected with. In the case of three elements, this conductor film is formed in the portions adjacent to the concave grooves at both ends, and is not formed in the central concave groove portion. The size of the conductor film 19 is set according to the difference in resonance frequency of the resonance element.

The conductor film 19 is a flat second dielectric substrate.
It is preferable to form it on the surface of 12, but it may be formed on the surface of the first dielectric substrate 11 having a groove or on both surfaces. Since the input / output conductor pattern and the coupling adjusting conductor pattern may be formed on this adhesive surface, these conductor films can be formed at the same time.

FIG. 2 is a perspective view showing another embodiment of the present invention. Dielectric substrates 21, 23, 25 with concave grooves and flat dielectric substrates 22, 24, 26 are bonded together.
A single resonant element is configured by each one. As described above, the through holes formed by the grooves are arranged at equal intervals, and the inner conductor, the outer conductor, and the short-circuit conductor are formed after the bonding.

A conductor film 29 is formed on one end of each of the flat plate dielectric substrates 22 and 26 constituting the resonant elements located at both ends, and the bonding and assembly are performed. The short-circuit conductor is formed on the side where the conductor film 29 is formed, as in the above example.

FIG. 3 is a perspective view showing another embodiment of the present invention. Dielectric substrates 31, 33 having concave grooves on two opposite surfaces
And the flat dielectric substrates 32a, 32b, 34a, 34b are bonded together, and one dielectric substrate having concave grooves and two flat dielectric substrates constitute one resonant element. . As described above, the through holes formed by the grooves are arranged at equal intervals, and the inner conductor, the outer conductor, and the short-circuit conductor are formed after the bonding.

A conductor film 39 is formed on one end of each of the flat dielectric substrates 32a and 34b forming the resonance elements located at both ends, and the conductor films 39 are bonded and assembled. The short-circuit conductor is formed on the side where the conductor film 39 is formed, as in the above example.

FIG. 4 is a perspective view showing an embodiment of the manufacturing method according to the present invention, and shows an example of manufacturing the dielectric filter shown in FIG. A dielectric substrate 41, 43, 45 having a plurality of parallel grooves is bonded to a flat dielectric substrate 42, 44, 46, and a large number of resonant elements are vertically and horizontally integrated, and a through hole formed by the grooves. Are arranged so as to be lined up at equal intervals and bonded. After the bonding, the grooves are cut in a direction perpendicular to the surface to be bonded between the concave grooves to obtain the dielectric filter shown in FIG. , After bonding, inner conductor, outer conductor,
The short-circuit conductor is formed as described above.

A flat dielectric substrate 4 constituting the elements on both ends
A conductor film 49 is formed on one end of each of the wires 2, 46, and after cutting, a short-circuit conductor is formed on the end surface of the conductor film 49 to make them conductive.

The dielectric filter to which the present invention can be applied is not limited to the one having the above structure, but can be applied to any dielectric filter constructed by bonding two or more dielectric substrates together. It can be applied to all cases where resonant elements having different resonant frequencies are formed in a block.

[0020]

According to the present invention, the number of steps for polishing the dielectric for adjusting the resonance frequency is reduced, the number of steps can be significantly reduced, and the cost can be reduced.

Further, since the conductor film can be formed simultaneously with the formation of other conductor films, there is an advantage that it can be dealt with only by changing the mask for printing and no special process is required.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing another embodiment of the present invention.

FIG. 3 is a perspective view showing another embodiment of the present invention.

FIG. 4 is a perspective view showing an embodiment of a manufacturing method according to the present invention.

FIG. 5 is a perspective view showing a conventional dielectric filter.

[Explanation of symbols]

11, 21, 23, 25, 31, 33, 41, 43, 45: Dielectric substrate with concave groove 12, 22, 24, 26, 32, 34, 42, 44, 46: Flat dielectric substrate 19 , 29, 39, 49: Conductor film

Claims (5)

[Claims] 1. A flat dielectric substrate is adhered to a concave surface of a dielectric substrate having a plurality of parallel concave grooves, and the flat dielectric substrate is bonded to the inside of the concave groove and the surface of the flat dielectric substrate facing the concave groove. A conductor film is formed as an inner conductor, a conductor film is formed as an outer conductor on the outer peripheral surface in a direction parallel to the extending direction of the concave groove, and a conductor film is formed on one of the end surfaces of the concave groove to form a short-circuit conductor. In the dielectric filter, the conductive film formed on at least one of the bonding surfaces of the two dielectric substrates, which is adjacent to at least one concave groove, is connected to the short-circuit conductor, and extends from the short-circuit end face to the open end face. A dielectric filter characterized by being provided. 2. The dielectric filter according to claim 1, wherein the conductor film formed on at least one of the two dielectric substrates is formed adjacent to the concave grooves located at both ends. 3. A plurality of dielectric substrates having concave grooves and a plurality of flat dielectric substrates are adhered to each other so that the concave grooves are arranged at a predetermined interval, and the dielectric substrates in the concave grooves and the flat dielectric substrate are concave. An inner conductor is formed by forming a conductor film on the surface facing the groove, and an outer conductor is formed by forming a conductor film on the outer peripheral surface in a direction parallel to the extending direction of the groove.
In a dielectric filter, which is a short-circuit conductor by forming a conductor film on one of the open end faces of the groove, it is connected to the short-circuit conductor adjacent to at least one groove and extends from the short-circuit end face to the open end face. A dielectric filter comprising a conductor film formed on at least one of the adhesive surfaces of the dielectric substrate. 4. The dielectric according to claim 3, wherein the conductor film formed on at least one of the two dielectric substrates adjacent to the concave grooves on both ends is formed adjacent to the concave grooves located on both ends. filter. 5. A flat second dielectric substrate on each grooved surface of a plurality of first dielectric substrates having a plurality of linearly extending parallel grooves, and at least a part of the dielectric substrate. A conductive film is formed on the adhesive surface of the body substrate so as to extend from the end face where the groove is opened and adjacent to a part of the groove, and the first dielectric substrate and the second dielectric substrate are connected to each other by the second dielectric substrate. Arranged and bonded so that the concave grooves are parallel to each other and are positioned at a predetermined interval, and a plurality of dielectric blocks are formed by cutting the concave groove and an intermediate portion of the concave groove in a direction perpendicular to the bonding surface, An inner conductor is formed by forming a conductor film in the groove and on the surface of the flat dielectric substrate facing the groove.
A conductor film is formed on the outer peripheral surface in a direction parallel to the extending direction of the groove to form an outer conductor, and a conductor film is formed on one of the end surfaces of the opening of the groove to form a short-circuit conductor. A method of manufacturing a dielectric filter, which is connected to a conductor film formed on a substrate.