JP2869335B2 - Dielectric filter and method of manufacturing the same - Google Patents

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 resonance elements are integrally formed by bonding a dielectric substrate.

[0002]

2. Description of the Related Art Various dielectric filters have been used as high frequency filters. The use of a quarter-wavelength 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 widely used for mobile stations of mobile communication. For downsizing, a type using a strip line, a laminated LC type, and the like are also used.

When a filter is formed using a plurality of resonators, the resonance frequency of each resonance element may be different. In particular, the resonance frequency of the resonance element at the input / output end needs to be set higher than the resonance frequency of the middle resonance element. In the integrated dielectric filter, as shown in FIG. 5, it is necessary to shorten the length of the element at both ends, and for this purpose, processing such as cutting the opening surface of the through hole of the resonance element is performed. .

[0004]

However, due to such problems as man-hours and accuracy of processing for adjusting the resonance frequency,
Problems arise in the cost and characteristics of the dielectric filter. An object of the present invention is to obtain a dielectric filter which is easy to manufacture and has stable characteristics by eliminating the above-mentioned man-hours for processing.

[0005]

SUMMARY OF THE INVENTION The present invention provides a dielectric filter proposed by the present inventors in Japanese Patent Application No. 4-186099 or the like, in which two or more dielectric substrates are laminated to integrally form a plurality of resonance elements. An object of the present invention is to solve the above problem by using a conductive film formed on a surface to be bonded.

That is, a flat dielectric substrate is bonded to the surface of a dielectric substrate having a plurality of parallel concave grooves, or a plurality of dielectric substrates having a plurality of parallel grooves are provided. Adhere the body substrate so that the grooves are arranged at predetermined intervals,
A conductor film is formed on the surface facing the groove in the groove and on the flat dielectric substrate to be an inner conductor, and a conductor film is formed on an outer peripheral surface in a direction parallel to a direction in which the groove extends to form an outer conductor, In a dielectric filter in which a conductor film is formed on one of the open end surfaces of the concave groove to be a short-circuit conductor, the dielectric filter is connected to the short-circuit conductor adjacent to at least one concave groove, and extends from the short-circuit end surface to the open end surface. And a conductive film formed on at least one of the bonding surfaces of the dielectric substrate.

[0007] Further, a flat second dielectric substrate is formed on at least a part of the surface of the first dielectric substrate provided with a plurality of parallel concave grooves extending linearly, and at least a part of the dielectric substrate is provided. A conductor film extending from the open end of the groove on the bonding surface of the body substrate and forming a conductor film adjacent to some of the grooves is formed, and the first dielectric substrate and the second dielectric substrate are formed by the second dielectric substrate. A plurality of dielectric blocks are formed by arranging and bonding the parallel grooves so that the grooves are positioned at predetermined intervals, and cutting the intermediate portion between the grooves and the groove in a direction perpendicular to the bonding surface. A conductor film is formed on the surface facing the groove in the groove and on the flat dielectric substrate to be an inner conductor, and a conductor film is formed on an outer peripheral surface in a direction parallel to a direction in which the groove extends to form an outer conductor, A conductor film is formed on one of the open end faces of the concave groove to form a short-circuit conductor, and the short-circuit conductor is formed on the bonding surface. And those having features to connect the conductor film.

[0008]

Since the conductor film extending from the short-circuit end surface to the bonding surface is connected to the short-circuit conductor, the distance from the open end surface to the short-circuit end surface is substantially reduced, and the resonance frequency as a 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 and shows a state before a dielectric filter is assembled. A flat plate-shaped second dielectric substrate 12 is attached to the surface of the first dielectric substrate 11 having the parallel grooves formed at predetermined intervals, and a dielectric block having a plurality of through holes is formed. Make up. An inner conductor is formed in the through-hole, an outer conductor is formed on the outer peripheral surface parallel to the direction in which the through-hole extends, and a short-circuit conductor is formed on one of the open end faces of the through-hole.
A dielectric filter having elements is configured.

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 where 19 is formed.
Connected to In the case of three elements, this conductor film is formed in a portion adjacent to the concave grooves at both ends, and is not formed in a central groove portion. The dimensions of the conductor film 19 are set in accordance with the difference between the resonance frequencies of the resonance elements.

The conductor film 19 is a flat second dielectric substrate.
Although it is preferable to form it on the surface of the substrate 12, it may be formed on the surface of the first dielectric substrate 11 having the concave groove or on both. Since a conductor pattern for input / output and a conductor pattern for coupling adjustment are preferably formed on the bonding surface, these conductor films can be formed simultaneously.

FIG. 2 is a perspective view showing another embodiment of the present invention. The dielectric substrates 21, 23, 25 having concave grooves and the flat dielectric substrates 22, 24, 26 are bonded together.
One resonance element is constituted by each sheet. The through holes formed by the concave grooves are arranged at equal intervals, and the inner conductor, the outer conductor, and the short-circuit conductor are formed after bonding as described above.

A conductor film 29 is formed on one end of flat dielectric substrates 22 and 26 constituting the resonance elements located at both ends, and bonded and assembled. The short-circuit conductor is formed on the side where the conductor film 29 is formed, as in the above-described example.

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

A conductor film 39 is formed on one end of the flat dielectric substrates 32a and 34b constituting the resonance elements located at both ends, and is bonded and assembled. The short-circuit conductor is formed on the side where the conductor film 39 is formed as in the above-described 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 and a flat dielectric substrate 42, 44, 46 are bonded together. Are arranged and adhered at equal intervals. After the bonding, the dielectric filter shown in FIG. 2 is obtained by cutting in a direction perpendicular to the surface to be bonded at a portion between the concave grooves. , After bonding, inner conductor, outer conductor,
The short-circuit conductor is formed as described above.

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

The dielectric filter to which the present invention can be applied is not limited to the above-described structure, but can be applied to all types of dielectric filters formed by laminating two or more dielectric substrates. The present invention can be applied to all cases where a resonance element having a different resonance frequency is 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, so that the number of steps can be greatly reduced and the cost can be reduced.

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

[Brief description of the 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 the 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: Conductive film

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01P 1/20-1/219 H01P 7/00-7/10 H01P 11/00

Claims (5)

(57) [Claims] 1. A flat dielectric substrate is adhered to a surface of a dielectric substrate having a plurality of parallel grooves, the surface of the dielectric substrate having a plurality of parallel grooves. A conductor film is formed as an inner conductor, a conductor film is formed on an outer peripheral surface in a direction parallel to a direction in which the concave groove extends, and an outer conductor is formed, and a conductor film is formed on one of the open end surfaces of the concave groove. In the dielectric filter which is a short-circuit conductor, a conductor film is provided on at least one of the adhesive surfaces adjacent to the concave groove, which is connected to the short-circuit conductor and extends from the short-circuit end surface to the inside of the adhesive surface of the dielectric substrate. Dielectric filter. 2. The dielectric filter according to claim 1, wherein the conductive film formed on at least one of the two dielectric substrates is formed adjacent to the concave grooves located at both ends. 3. A flat dielectric substrate is adhered to a surface of a plurality of dielectric substrates having parallel grooves so that the grooves are arranged at predetermined intervals. A conductive film is formed on a surface of the dielectric substrate facing the concave groove to be an inner conductor, and a conductive film is formed on an outer peripheral surface in a direction parallel to a direction in which the concave groove extends to be an outer conductor. In a dielectric filter in which a conductor film is formed on one of the open end surfaces and is a short-circuit conductor, the dielectric filter is connected to the short-circuit conductor and extends from the short-circuit end surface to the inside of the bonding surface of the dielectric substrate, adjacent to at least one concave groove. A dielectric filter comprising a conductive film on at least one of the adhesive surfaces. 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 at both ends is formed adjacent to the concave grooves located at both ends. filter. 5. A flat second dielectric substrate on at least one grooved surface of a plurality of first dielectric substrates provided with a plurality of linear grooves extending linearly, and at least a part of the dielectric substrate. A conductor film extending from the open end of the groove on the bonding surface of the body substrate and forming a conductor film adjacent to some of the grooves is formed, and the first dielectric substrate and the second dielectric substrate are formed by the second dielectric substrate. A plurality of dielectric blocks are formed by arranging and bonding the parallel grooves so that the grooves are positioned at predetermined intervals, and cutting the intermediate portion between the grooves and the groove in a direction perpendicular to the bonding surface. A conductor film is formed on the surface facing the concave groove of the flat dielectric substrate in the concave groove to form an internal conductor,
A conductor film is formed on the outer peripheral surface in a direction parallel to the direction in which the concave groove extends to form an outer conductor, and a conductive film is formed on one of the open end surfaces of the concave groove to form a short-circuit conductor. Of manufacturing a dielectric filter to be connected to a conductive film formed on a substrate.