JP3213987B2 - Dielectric resonator and method for adjusting characteristics thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric resonator in which a ground electrode and a resonance electrode are formed on a dielectric substrate or a dielectric block, and a method for adjusting characteristics of the dielectric resonator.

[0002]

2. Description of the Related Art A dielectric resonator in which a resonance electrode (inner conductor) is formed inside a dielectric block and a ground electrode (outer conductor) is formed on the outer surface of the dielectric block, and a resonance electrode is formed on the surface of a dielectric substrate. (Stripline), and a stripline type dielectric resonator in which an earth electrode is formed on the opposing surface is used, for example, as a bandpass filter in a microwave band.

In the dielectric resonator having the above-mentioned structure, a so-called surface mounting type which can be surface mounted on a circuit board is a type in which a signal input / output electrode facing an electrode pattern formed on a mounting board surface is made of a dielectric material. It is provided on a block or a part of the dielectric substrate.

FIG. 7 shows a dielectric resonator provided with a signal input / output electrode capacitively coupled to a resonance electrode, taking a four-stage bandpass filter as an example. In FIG. 7, reference numeral 1 denotes a substantially hexahedral-shaped dielectric block, in which four inner conductor forming holes H are formed, and inner conductors 2a and 2 are formed on inner surfaces of the inner conductor forming holes.
b, 2c and 2d are formed. On the outer peripheral surface of the dielectric block 1, signal input / output electrodes 4a and 4b that are capacitively coupled to the inner conductors 2a and 2d are provided. Further dielectric block 1
The outer conductor 3 is formed on the entire outer peripheral surface of the six surfaces except for the regions where the signal input / output electrodes 4a and 4b are formed. With this configuration, it can be used as a surface mount type four-stage bandpass filter.

The filter as shown in FIG. 7 is surface-mounted by soldering or the like with the surface indicated by M in FIG. 7 facing the mounting substrate. Conventionally, when adjusting the coupling capacitance of the input / output unit of the filter having such a structure, the open ends of the inner conductors 2a and 2d facing the signal input / output electrodes 4a and 4b (existing inside the inner conductor forming hole). Is removed from the outside to adjust the capacitance with the signal input / output electrodes 4a and 4b, thereby adjusting the coupling capacitance of the input / output unit.

[0006]

However, if the open end of the inner conductor is cut off, the resonator length of the inner conductor also changes, and the resonance frequency changes. Therefore, it was impossible to make a significant adjustment so that the resonance frequency was out of the predetermined standard range.

An object of the present invention is to provide a dielectric resonator having a predetermined resonance frequency and a predetermined external coupling capacitance.

Another object of the present invention is to provide a method of adjusting the characteristics of a dielectric resonator which can obtain a desired external coupling capacitance without changing the resonance frequency.

[0009]

According to a first aspect of the present invention, there is provided a dielectric resonator, comprising: a dielectric electrode having a substantially hexahedral shape;
To form a ground electrode on the outer surface of the dielectric,
In the dielectric resonator according to one side as the mounting surface, the output electrodes capacitively coupled to the resonance electrode, from the mounting surface
After being provided in a part of the ground electrode forming region on the side surface that is continuous with the side surface, the side surface portion of the signal input / output electrode is partially removed together with the dielectric in order to obtain a predetermined external coupling capacitance.

According to a second aspect of the present invention, there is provided a dielectric resonator characteristic adjusting method in which a resonance electrode is provided in a substantially hexahedral dielectric.
Forming a ground electrode on the outer surface of the dielectric,
Becomes a mounting surface one surface, the mounting surface a signal input and output electrodes in a portion opposed to the resonator electrode with the ground electrode formation region
Was formed over the side surface continuous to then, a characteristic adjusting method of the dielectric resonator, the side surface of the output electrodes
The external coupling capacitance is adjusted by removing a part of the part and a part of the dielectric together with the signal input / output electrode.

[0011]

In the dielectric resonator according to the first aspect, the signal input / output electrode capacitively coupled to the resonance electrode is mounted on the dielectric resonator from the mounting surface.
After being provided in a part of the ground electrode forming region over the continuous side surface, the side surface portion of the signal input / output electrode is partially deleted to have a predetermined external coupling capacitance.

According to a second aspect of the present invention, there is provided a dielectric resonator characteristic adjusting method, wherein a resonance electrode is provided in a substantially hexahedral dielectric, a ground electrode is formed on an outer surface of the dielectric, and one surface of the dielectric is formed.
A signal input / output electrode is provided on the portion facing the resonance electrode in the ground electrode forming region from the mounting surface.
Be formed over the side surface continuous to Les, together with a part and the output electrodes of the side portions of the output electrodes with a portion of the dielectric is removed, the external coupling capacitance is adjusted. At that time, since the length of the resonator formed by the resonance electrode is constant, the resonance frequency does not change, and the coupling capacitance with the signal input / output electrode changes independently. Therefore, the external coupling capacitance can be adjusted over a wide range without changing the resonance frequency.

[0013]

1 to 3 show the structure of a surface mount type four-stage bandpass filter according to an embodiment of the present invention. FIG. 1 is a perspective view of a filter, FIG. 2 is a plan view of one dielectric substrate constituting the filter, and FIG. 3 is a cross-sectional view of a signal input / output electrode forming portion of the filter.

In FIG. 1, 1 is a dielectric block,
Four inner conductor forming holes H are provided therein, and inner conductors are formed on the inner surface thereof. Further, signal input / output electrodes 4a and 4b are formed at predetermined locations on the outer surface of the dielectric block 1, and the outer conductor 3 is formed on the entire outer surface (six surfaces) except for the region where the electrodes 4a and 4b are formed.

In FIG. 3, reference numerals 1a and 1b denote dielectric substrates, respectively. The two dielectric substrates constitute the dielectric block 1 shown in FIG. Dielectric substrate 1a, 1b
Are provided with four recesses on each of the opposing surfaces, and inner conductors 2a, 2b, 2c, 2d are provided on the inner surfaces of the recesses. In FIG. 2, reference numerals 2a, 2b, 2c, and 2d denote half inner conductors provided on the dielectric substrate 1a. The two dielectric substrates 1 having the semi-cylindrical inner conductor thus formed
By facing a and 1b, four cylindrical inner conductors are formed in the dielectric block. As shown in FIG. 3, a capacitance is generated between the signal input / output electrodes 4a and 4b and the vicinity of the open ends of the inner conductors 2a and 2d adjacent thereto.
With this configuration, it can be used as a surface mount type four-stage bandpass filter.

Next, a method of adjusting the external coupling capacitance of the filter having the structure shown in FIGS. 1 to 3 will be described.

The adjustment of the external coupling capacitance is performed by removing a part of the signal input / output electrodes 4a and 4b shown in FIGS. Here, FIG. 4 shows a cross-sectional view of the filter after adjusting the external coupling capacitance. In FIG. 4, a portion indicated by A is a portion where the signal input / output electrode 4a is partially removed from the substrate mounting surface side. A portion indicated by B is a portion where a part of the signal input / output electrode 4b in a direction perpendicular to the mounting substrate surface is deleted. By partially removing the signal input / output electrodes in this manner, the capacitance near the open ends of the inner conductors 2a and 2d decreases, and the external coupling capacitance decreases.

When a part of the signal input / output electrode is cut, a router can be used. Fine adjustment can be performed by partially removing only the dielectric.

Next, FIGS. 5 and 6 show partial perspective views of an example of a method of removing the signal input / output electrode portion. As shown in FIGS. 5 and 6, in addition to shortening the signal input / output electrode (4b), it may be partially removed from a predetermined direction as shown by C to change its shape. As shown in FIG. 6, the width may be adjusted by changing the width of the signal input / output electrode (4b).

In this embodiment, a comb-line filter is used as an example. However, an interdigital filter may be used in the same manner. In addition, the same configuration can be obtained by using a single dielectric block.

[0021]

According to the present invention, the external coupling capacitance can be independently adjusted without changing the resonance frequency of the resonance electrode capacitively coupled to the signal input / output electrode.
Therefore, the occurrence rate of characteristic failure due to the change in the resonance frequency is reduced, and the external coupling capacitance can be adjusted over a wide range.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a structure of a filter according to an embodiment.

FIG. 2 is a plan view of one dielectric substrate constituting the filter according to the embodiment.

FIG. 3 is a cross-sectional view of a filter according to an example.

FIG. 4 is a cross-sectional view of the filter after external coupling capacitance adjustment.

FIG. 5 is a partial perspective view showing an example of deleting a signal input / output electrode.

FIG. 6 is a partial perspective view showing a deletion example of signal input / output electrodes.

FIG. 7 is a perspective view of a surface mount type four-stage bandpass filter.

[Explanation of symbols]

 1-dielectric block 1a, 1b-dielectric substrate 2-inner conductor (resonant electrode) 3-outer conductor (earth electrode) 4a, 4b-signal input / output electrode A, B, C-deletion point H-inner conductor formation hole

────────────────────────────────────────────────── ─── Continuation of the front page (56) References Patent table Hei 6-505608 (JP, A) Soviet patent invention 637896 (SU, A) (58) Searched field (Int. Cl. ⁷ , DB name) H01P 1/205

Claims (2)

(57) [Claims] A resonance electrode is provided in a substantially hexahedral dielectric.
A ground electrode on the outer surface of the dielectric
Consisting of a mounting surface in the dielectric resonator, the output electrodes capacitively coupled to the resonant electrodes, mounting
After being provided in a part of the ground electrode forming region from the surface to the side surface continuing from the surface, in order to obtain a predetermined external coupling capacitance, a side surface portion of the signal input / output electrode is partially deleted together with the dielectric. Body resonator. 2. A resonance electrode is provided in a substantially hexahedral dielectric, and a ground electrode is formed on an outer surface of the dielectric.
Becomes a mounting surface one surface, the mounting surface a signal input and output electrodes in a portion opposed to the resonator electrode with the ground electrode formation region
Was formed over the side surface continuous to then, a characteristic adjusting method of the dielectric resonator, the side surface of the output electrodes
A method for adjusting the characteristics of a dielectric resonator, comprising removing a part of a part and a part of a dielectric together with the signal input / output electrode to adjust an external coupling capacitance.