JP2852689B2 - Dielectric resonator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a dielectric resonance device used for a dielectric resonance type electrostatic sensor or the like.

[Conventional technology]

2. Description of the Related Art In recent years, video disk devices such as a VHD system that detects information recorded on an information medium as a change in capacitance have become widespread. In a signal pickup device used in this device, a dielectric resonator having a large Q is used as a resonator instead of a coaxial resonator using a strip line. The use of the dielectric resonator has an advantage that the pickup device can be simply and smallly configured. [Problems to be Solved by the Invention] However, when the device is used for a small-sized video disk device or a similar device, a very small space is required. It is conceivable to use the device in such a way that it moves inside.To meet the demands of such a use mode, it is necessary to further reduce the size of the electrostatic sensor. For this purpose, a case, a circuit board, a dielectric resonator and It is necessary to further reduce the size of the dielectric resonator composed of

In order to miniaturize this dielectric resonator, first,
What is necessary is to shorten the length of the dielectric resonator.
The resonance frequency becomes extremely high, and the influence of the impedance with the peripheral circuit such as a transistor connected to the dielectric resonator, the floating distribution capacitance, and the like becomes large, and this also has a limit. Also, when the cross-sectional area of the dielectric resonator is reduced, Q is reduced, and the frequency characteristics are deteriorated. Furthermore, if the dielectric constant of the dielectric resonator is increased, the length of the dielectric resonator can be shortened, and the device can be miniaturized. However, this also has a limit in terms of material. Because of these various limitations, the minimum dimension of the dielectric resonator was considered to be 4 mm square.

The present inventor has repeated the trial production and experiments, and has been working on miniaturization of the dielectric resonator, and has arranged the dielectric resonator on the ground plane of the circuit board, and has set the dielectric resonator facing the ground plane. Is connected to the ground potential,
Can be prevented from decreasing. The present invention has been made in view of this point, and an object of the present invention is to provide a dielectric resonator device capable of miniaturizing a dielectric resonator.

[Means for solving the problem]

The present invention is configured as described below to achieve the above object. That is, the present invention provides a dielectric resonator in which a dielectric resonator is mounted on a ground mounting surface of a conductor patterned on a surface of a circuit board by soldering a bottom surface thereof. Is provided around the periphery of the dielectric resonator, and a conductive case having an upright conductive surface opposed to both side surfaces of the dielectric resonator is provided, and a ground mounting surface on which the dielectric resonator is mounted is a ground lead formed on a circuit board. One or more points are soldered to the conductor case via a pattern, and the plane of the dielectric resonator facing the mounting bottom surface on the ground mounting surface is via an auxiliary electrode soldered to the plane. The conductive case is electrically connected to the conductive case by soldering, and the conductive case is connected to a chassis ground.

[Action]

In the present invention, a dielectric resonator is connected and fixed to the upper side of the ground mounting surface formed on the surface of the circuit board by soldering, and a lead wire or a conductor plate is connected to the plane of the dielectric resonator to form the plane. By connecting to the ground, the Q is improved, and even when the dielectric resonator is miniaturized, deterioration of the characteristics of the dielectric resonator is prevented.

(Principle of the present invention)

The principle of the dielectric resonator according to the present invention will be described with reference to FIG. A ground mounting pattern 7 and an output conductor pattern 8 are formed on the insulating substrate 15 by a conductor such as copper. A rectangular dielectric resonator 9 is fixed on the ground mounting pattern 7 by soldering the bottom surface 16 with solder paste. As is well known, the dielectric resonator 9 is formed by covering a rectangular dielectric sintered body with a flat, bottom, and side surfaces covered with a good conductive metal 17, such as gold, silver, or copper, and penetrating from the front to the back. A hole 18 is provided.
10 is inserted and fixed. This resonator 9 has a wavelength λ
When resonating in the / 4 mode, the above-described good conductive metal layer is also provided on the back surface, and when resonating in the λ / 2 mode, the good conductive metal layer is not provided.

In the resonance device of the present invention, one end of the auxiliary electrode 19 is soldered to the plane 14 of the dielectric resonator 9 in the above-described configuration, and the other end of the auxiliary electrode 19 is soldered to the ground mounting pattern 7. The output electrode 10 is soldered to the output conductor pattern 8.

In the above-described configuration, assuming that the resonator has a frequency of about 1 to 3 GHz, the plane 14 of the dielectric resonator 9 does not have the same potential as the ground mounting pattern 7 which is the reference potential.

This is because the dielectric constant of the dielectric substance alone is extremely high with respect to the dielectric constant of air at 70 to 90, and since the sintered surface of the dielectric substance has irregularities, an impedance circuit for high-frequency current is formed. Conceivable.

In the present invention, by providing the auxiliary electrode 19, a short-circuit path is formed with respect to the pattern 7, which is the ground potential surface, and by bringing the potential of the plane 14 of the resonator 9 closer to the ground potential, the impedance is reduced, resulting in resonance. The Q of the vessel has been improved.

To develop this idea, the bottom electrode 16 of the resonator 9 is in contact with the ground potential with a certain length from the front to the back of the resonator, so that the auxiliary electrode 19 on the plane 14 is not a point connection but from the above-described front to back. It can be considered that the Q of the resonator 9 is further increased by connecting a plate having a width not less than the length to the plane 14 of the resonator 9 and using the plate as an auxiliary electrode.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 and 2 show a first example of the dielectric resonator according to the present invention.
Is shown. In these figures, a ground mounting surface 7 and an output conductor pattern 8 are formed on the upper surface side of a printed circuit board 6 functioning as a circuit board in a state of being separated and insulated from each other by a conductor such as copper foil. An appropriate number of ground lead patterns 12 for connecting the same surface 7 to the ground are formed on the ground mounting surface 7 in a branched manner. A ceramic resonator 9 as a dielectric resonator is mounted on the ground mounting surface 7 and fixed by soldering. At the time of this soldering, for example, a solder paste is provided in advance on the bottom surface side of the ceramic resonator 9, and
The bottom surface of the ceramic resonator 9 is placed on the ground mounting surface 7 and heated by a soldering iron or blown with hot air to achieve the solder connection. In the mounted state of the ceramic resonator 9, the electrode 10 of the output terminal of the ceramic resonator 9 is connected to the output conductor pattern 8 using solder or the like.

As shown in FIG. 1, around the ceramic resonator 9, there is provided a conductor case 11 having upstanding conductor surfaces facing both side surfaces of the ceramic resonator 9.
The printed circuit board 6 on which is mounted is fixed to a conductor case 11 made of a metal plate such as copper. In this fixed state, the ground mounting surface 7 and the conductor case 11 are These points are connected by soldering. The connection point (the number of ground lead patterns) between the ground mounting surface 7 and the conductor case 11 is appropriately determined by the resonance frequency of the ceramic resonator 9, and when the resonance frequency is high, the connection points are increased. Preferably, in this embodiment, the resonance frequency is 1 GHz to 3 GHz.
G Hz is set, and in this case, it is desirable that the connection be made at least at three or more points.

The conductor case 11 is connected to a chassis ground and serves as a ground as a reference potential.On the side surface of the conductor case 11, a base end side of an auxiliary electrode 13 formed by a conductor metal plate is fixed by soldering. , This auxiliary electrode
The tip side of 13 extends to the plane 14 of the ceramic resonator 9 and is connected to the plane 14 by soldering. That is, the plane 14 of the ceramic resonator 9 is connected to the ground via the auxiliary electrode 13.

According to the present embodiment configured as described above, the ceramic resonator 9 has its bottom surface connected and fixed on the ground mounting surface 7 and its flat surface 14 is electrically connected to the ground by the auxiliary electrode 13. The Q of the ceramic resonator 9 can be greatly improved. In this embodiment, despite the size reduction of the ceramic resonator 9 far beyond the conventionally limited size of 3 mm square, the conventional mounting method, that is, the plane of the ceramic resonator 9 is grounded. Compared with the mounting method without conducting connection, Q is improved by 30% or more, and overall characteristics are improved by 50% or more. As a result, it was possible to obtain the same characteristics as when a 5 mm square ceramic resonator was mounted by the conventional mounting method, and to achieve ultra-miniaturization of the ceramic resonator without causing deterioration in characteristics. .

Note that the present invention is not limited to the above embodiment,
Various embodiments may be employed. For example, in the above embodiment, a printed board is used as a circuit board, but a multilayer board may be used instead of the printed board.

〔The invention's effect〕

The present invention mounts a dielectric resonator on a ground mounting surface,
Since the plane of the dielectric resonator is electrically connected to the ground, the Q of the dielectric resonator can be greatly improved. Conventionally, when a dielectric resonator is miniaturized, the resonance frequency becomes extremely high, and adverse effects such as impedance with a peripheral circuit such as a transistor connected to the dielectric resonator and a floating distribution capacitance become large. When an object moves near the dielectric resonator, the floating distribution capacitance between the dielectric resonator and the moving object fluctuates according to the distance between the dielectric resonator and the moving object (unstable and unstable). Become),
There have been problems such as deterioration of frequency characteristics. On the other hand, in the present invention, a conductor case having a standing conductor surface facing both side surfaces of the dielectric resonator is provided around the dielectric resonator, and the conductor case is connected to a chassis ground. Therefore, even if the dielectric resonator is downsized and the resonance frequency becomes very high, the generation of the floating distribution capacitance between the dielectric resonator and the peripheral circuit can be blocked by the conductor case, and the connection with the peripheral circuit can be prevented. The adverse effect of the floating distribution capacitance can be removed, and the deterioration of the frequency characteristics can be prevented. In addition, as described above, since the conductor case is connected to the chassis ground, the stray distributed capacitance between the dielectric resonator and the conductor case can be stabilized, and the dielectric resonator and the moving object are separated from each other as in the related art. It is possible to reliably prevent the floating distribution capacitance from being interposed, and the floating distribution capacitance from becoming unstable and deteriorating the frequency characteristics. As described above, even if the dielectric resonator is made ultra-small, which has never been considered before, no significant deterioration in characteristics will occur. This makes it possible to provide an ultra-small dielectric resonator device with high sensitivity, and furthermore, as described above, prevents the occurrence of stray distributed capacitance between the dielectric resonator and the peripheral circuit by the conductor case. Therefore, even if the distance between the dielectric resonator and the peripheral circuit is reduced, there is no floating distribution capacitance between the dielectric resonator and the peripheral circuit. Deterioration of the characteristics of the dielectric resonator can be avoided, thereby increasing the circuit packaging density of various devices using the dielectric resonator without deteriorating the characteristics of the dielectric resonator. It is possible to miniaturize various devices using the body resonance device.

Further, the weight of the device can be reduced by miniaturizing the device, and the handling of the device becomes very easy.

Furthermore, since the Q can be improved by a simple configuration in which the plane of the dielectric resonator is connected to the ground, the dielectric resonator of the present invention having excellent performance can be easily manufactured, and it can be manufactured at low cost. Can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a dielectric resonator according to the present invention, FIG. 2 is a perspective view showing a main part of the embodiment, and FIG. 3 is a dielectric resonator according to the present invention. It is explanatory drawing which shows the principle of an apparatus. 6 printed circuit board, 7 ground mounting surface (ground mounting pattern), 8 output conductor pattern, 9 dielectric resonator, 10 electrode, 11 conductor case, 12 ground lead pattern, 13 auxiliary electrode, 14 ... flat, 15 ... insulating substrate, 16 ...
Bottom, 17: good conductive metal, 18: through hole, 19: auxiliary electrode.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tetsuo Osawa 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd. (56) References JP-A-62-120703 (JP, A) JP-A Sho 63-190405 (JP, A)

Claims (1)

(57) [Claims] 1. A dielectric resonator in which a dielectric resonator is mounted on a ground mounting surface of a conductor patterned on a surface of a circuit board by soldering a bottom surface of the dielectric resonator. Around the periphery there is provided a conductor case having a standing conductor surface facing both side surfaces of the dielectric resonator, and a ground mounting surface on which the dielectric resonator is mounted is a ground lead pattern formed on a circuit board. Are connected to the conductor case at one or more points, and the plane of the dielectric resonator facing the mounting bottom surface on the ground mounting surface is via an auxiliary electrode soldered to the plane. The dielectric resonator device is electrically connected to the conductor case by soldering, and the conductor case is connected to a chassis ground.