JPS5844658Y2 - SoukiyoushinAtsudenrohaki - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an assembly structure of a small filter using a classical vibrating piezoelectric vibrator.

A dual-resonant oscillator is one oscillator that has two resonances in close proximity, and has characteristics equivalent to two conventional single-resonant oscillators. It has the feature that it can be configured as a polar or non-polar filter.

By introducing a bi-resonant oscillator, the number of oscillators can be reduced compared to, for example, a ladder configuration to realize a filter with the same guaranteed attenuation, and there are expectations for a filter that is that much smaller.

In order to polarize the transducer, one polarized capacitor is required for each biresonant resonator, and when cascading multiple stages, a coupling capacitor is required between each stage, and these polarized capacitors, Unless the structure and arrangement of the coupling capacitor are appropriate, the desired compact filter cannot be realized.

The present invention uses a rectangular ceramic capacitor as the polarized capacitor in a polarized filter using one twin-resonant oscillator, and in the case of a non-polar filter, the electrodes are arranged so that the capacitor does not have a capacitor effect. For filters that utilize bi-resonant oscillators that require multiple capacitors, these capacitors can be realized as a single composite rectangular ceramic capacitor, and twin capacitors can be placed on predetermined electrode surfaces of the rectangular ceramic capacitor. Connect the mount wire that mounts the resonant resonator at its predetermined position, and also pull out the required number of input/output external terminal wires from the electrode surfaces of these capacitors in the opposite direction to the mount wires to connect the bi-resonant resonator and the capacitor. The assembly is constructed by inserting this assembly into an insulating case, positioning the capacitor in the opening of the case, gluing both together with an insulating adhesive, and sealing the vibrator inside the case. The purpose is to realize the desired small filter without using any mechanical pieces.

This will be explained in detail below using examples.

Figure 1 is a circuit diagram of a 455 KHz intermediate frequency filter in an embodiment, in which two 1.1' condensed pendulums with almost identical characteristics are used.
It is composed of a coupling capacitor 2 between stages and a polarized capacitor 3, 3' at each stage.

2a, 1) show the structure of an embodiment for the filter circuit of FIG. 1. FIG.

In Figure 2 a, 1 and 1' are H-shaped standard pendulums, and 4 is 3
The two capacitors are formed on the same ceramic substrate.

The pendulums 1 and 1' are connected to the capacitor 4 by the mounting wire 7.
is mounted with solder.

In addition, the classical pendulums 1 and 1' have a capacitor 4 connected to the lead wire 8.
is connected to.

From capacitor 4, there are three external lead terminals 5.5', 6.
is being taken out.

The above-mentioned classical pendulum and capacitor are inserted into a case 9, and the bottom of the case is sealed with an encapsulating resin 10.

Here, the classical pendulums 1 and 1' have an H-shaped structure in which the central parts of two transverse effect vertical oscillators that vibrate in the longitudinal direction are connected.
A piezoelectric ceramic plate with a length of 4 mm, a width of 3.2 mm, and a thickness of Q of 5 mm has a width of 1.2 mm and a depth of 1.7 m in the center of the width direction.
Electrodes are provided on the front and back surfaces of each resonator in the form of m grooves formed on both sides.

FIG. 2 is a cross-sectional bottom view taken along line AA', showing how three capacitors are provided on the same substrate.

Electrodes are provided at three locations on the top surface of the ceramic dielectric, and electrodes are provided at one location on the bottom surface.

As a result, the upper and lower electrodes face each other at three locations 30, 30' and 20, and these portions act as a capacitor.

The structure shown in FIG. 2 is electrically connected as shown in FIG.

The structure of the example had a small size of 11 mm in width, 2 mm in thickness, and 9 mm in height.

The above embodiment is an example of a cascade configuration of two stages with polarity, but the same filter configuration as in the embodiment is possible with two stages of non-polarization or a combination of polarity and non-polarity by partially changing the electrode arrangement of the capacitor 4. It is.

Also, when using three or more bi-resonant oscillators, 1
Realize the required number of capacitors with multiple composite capacitors,
The assembly and mounting structure of the present invention in which the capacitor is disposed in the case opening can be adopted, and there is no particular restriction on the number of vibrators used.

In the case of a non-polar type using one bi-resonant vibrator, a structure similar to that of the embodiment can be achieved by arranging the electrodes so that the capacitor does not substantially have a capacitor action.

Even in the case of a polarized case, move the common ground terminal wire to one end and use the terminal wire between the other end and the terminal wire for human power and output. If the wire is drawn from the middle, some modifications to the electrode arrangement are required.

In any case, this is a modification of the present invention in which a capacitor is disposed in the case opening, similar to the embodiment, and utilized for drawing out external terminal wires and supporting mount wires to realize a compact filter.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a filter with polar characteristics that uses bi-resonant oscillators and has two stages connected in series. 1 and 1' are bi-resonant oscillators, 2 is a coupling capacitor between stages, and 3 and 3' are It is a polarized capacitor. FIG. 2 shows the structure of the embodiment of the present invention for the circuit of FIG. A new generation ceramic oscillator,
Reference numeral 4 denotes a rectangular capacitor made of a ceramic material. Depending on the arrangement of electrodes on both the front and back surfaces, regions 30 and 30' perform a circuit operation as a polarized capacitor, and 20 performs a circuit operation as an inter-stage coupling capacitor. 5.5', 6 is external input/output terminal wire and ground terminal wire, 7
8 is a mount wire for supporting the vibrator, and 8 is a thin wire for grounding the vibrator, and these are all connected to the corresponding electrodes of the capacitor. Reference numeral 9 denotes an insulating case in which a capacitor is placed in the opening, and the opening and the gap between the case side wall and the capacitor are sealed with an insulating adhesive 10.

Claims (1)

[Scope of utility model registration request] A mount wire with a bi-resonant vibrator mounted at a predetermined position is connected to a predetermined electrode surface of a rectangular ceramic capacitor, and a required number of input/output external terminal wires are drawn out from these electrode surfaces in the opposite direction to the mount wire. The assembly of the bi-resonant vibrator and the condenser is inserted into an insulating case, the condenser is positioned in the opening of the case, and both are glued together with an insulating adhesive, and the bi-resonant vibrator is sealed in the case. The ultimate oscillating piezoelectric filter.