JPH0645803A - Strip line filter and filter device - Google Patents

Abstract

PURPOSE:To improve compactness, productivity and reliability by laminating a circuit part, which is formed by covering a coupling circuit pattern with any conductive material while holding it between an input/output part and a resonator part. CONSTITUTION:On the surface of a dielectric substrate, this device is provided with a resonator 11 covering a resonator pattern 11a with the conductive material, a circuit part 12 covering a coupling circuit pattern 12a with the conductive material, and an input part 13 covering an input/output electrode pattern 13a with the conductive material. The circuit part 12 is laminated while being held between the input/output part 13 and the resonance part 11. Since a single filter part can be formed while containing a coupling circuit part and a synthesis circuit part. Further, since a three-terminal filter can be constituted only by connecting the strip line filter and the other filter on the substrate, man-hour in a production process can be considerably reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stripline filter and a filter device, and more particularly to a stripline filter and a filter device used in a small and lightweight portable device.

In recent years, a personal electronic device having a transmitting / receiving function, which is premised to be carried indoors or outdoors,
For example, cordless phones are rapidly becoming popular. For this reason, there is an increasing demand for miniaturization of devices from the viewpoint of convenience of carrying.

However, the component parts of the filter required to realize the transmitting / receiving function have not been sufficiently reduced in size and weight compared to other parts.

Therefore, it has been desired to provide a filter and a filter device which can effectively reduce the size and weight of a personal electronic device having a transmitting / receiving function to be carried and used.

[0005]

2. Description of the Related Art FIG. 4 shows an example of a conventional dielectric filter. FIG. 4A is a perspective view and FIG. 4B is an equivalent circuit diagram.

In FIG. 4A, three sets of dielectric blocks 20 are provided with resonator holes in the longitudinal direction, and one of the open faces is an open face 20a. Open surface 20a
The outer surface and the inner surface of the resonator hole are all metallized. Three sets of dielectric blocks 20 are short-circuited surfaces
In 20b, the metallized portions are joined and integrated. A coupling circuit 30 is externally connected to the three sets of dielectric blocks 20, and thereby capacitive coupling is performed.

In FIGS. 4A and 4B, the coupling circuit 30 includes an input terminal 25a and an output terminal 25b on a dielectric substrate 23 placed on a metal case 24 serving as a ground.
Three coils 21 connected in series (inductance = L
1, L2, L3) and seven capacitors 22 connected in parallel
(Capacitance = C1, C2, C3, C4, C5, C6, C7). The dielectric filter 1b for band elimination is constructed as described above.

FIG. 5 shows an example of a conventional filter device,
The same figure (A) shows a plan view and the same figure (B) shows an equivalent circuit diagram. In the figure, parts that are the same as the parts shown in FIG. 4 are given the same reference numerals, and descriptions thereof will be omitted.

The filter device shown in FIG. 5 represents a three-terminal filter device 2b such as a transmitter / receiver distributor, and includes a transmission band pass filter 33 including a dielectric block 20 and a coupling circuit 30, and a surface acoustic wave filter 32. The dielectric substrate 23 in which the reception bandpass filter 34 consisting of and the synthesis circuit 31 for synthesizing the signals passing through the transmission bandpass filter 33 and the reception bandpass filter 34 are connected and mounted is housed in the metal case 24. It is composed by.

Since there is a limit to miniaturization of the above-mentioned conventional dielectric filter 1b, a laminated distributed constant type stripline filter capable of miniaturization has been recently developed.

FIG. 6 shows an example of a general stripline filter. FIG. 6A is an exploded perspective view and FIG.
Shows side sectional views taken along line A ₁ -A ₂ of FIG.

In FIG. 6 (A), a plain surface shows an exposed surface of a dielectric material having a large dielectric constant, and a hatched surface shows a surface covered with a conductive material such as copper or silver. The stripline filter 1c is configured by bonding and laminating a dielectric material coated with the input / output electrode pattern 13a and a dielectric material coated with the resonator pattern 11a as shown in the figure. .

In FIG. 6 (B), the portion of the dielectric material is shown in satin and the portion of the conductive material is shown in bold. As shown in the figure, a stripline filter formed by bonding
The conductive material coating the outer surface of 1c is the input / output electrode 13a.
₁ and the ground electrode 13a ₂ , and the conductive material sealed between the two dielectric materials constitutes the resonator 11a ₁ by the interaction with the dielectric material.

[0014]

In the above-mentioned conventional dielectric filter 1b, there is a limit to miniaturization of the dielectric block 20 constituting the filter, and in order to construct the filter device 2b, the coupling circuit 30 or Since the synthesizing circuit 31 needs to be attached externally, there is a problem that the number of assembling steps of the filter and the filter device increases, which causes a decrease in the productivity and reliability of the electronic device to be produced.

Further, a general strip line filter
Even when 1c is used, since it is still necessary to attach a coupling circuit and a synthesizing circuit externally, the number of man-hours for assembling the filter and the filter device is increased, which causes a decrease in the productivity and reliability of the produced electronic device. There was a problem that

The present invention has been made in view of the above points, and an object of the present invention is to provide a stripline filter and a filter device which can be made smaller than conventional ones and have high productivity and reliability.

[0017]

In order to solve the above-mentioned problems, according to the invention of claim 1, a resonator portion is formed by coating a resonator pattern on the surface of a dielectric substrate with a conductive material, and The dielectric substrate includes a circuit portion formed by coating a coupling circuit pattern with a conductive material on a surface of the dielectric substrate, and an input / output portion formed by coating a surface of the dielectric substrate with an input / output electrode pattern by a conductive material. Then, the circuit portion was sandwiched between the input / output portion and the resonator portion and laminated.

According to the second aspect of the present invention, there is provided the above-mentioned circuit portion in which the surface of the dielectric substrate is coated with a synthetic circuit pattern together with the coupling circuit pattern by a conductive material.

According to the third aspect of the present invention, a resonator portion is formed by coating a resonator pattern on the surface of the dielectric substrate with a conductive material, and the surface of the dielectric substrate is input / output by the conductive material. Laminating a circuit section formed by coating a coupling circuit pattern and a synthesis circuit pattern on the surface of the dielectric substrate with an input / output section formed by coating an electrode pattern, and stacking the circuit section. The stripline filter constituted by the above was connected to another filter mounted on the same substrate to constitute a three-terminal filter.

In the invention according to claim 4, the three-terminal filter is enclosed in a metal case.

[0021]

According to the structures of the above-mentioned claims 1 and 2, the circuit portion in which the coupling circuit pattern is covered with the conductive material is laminated by sandwiching the circuit portion between the input / output portion and the resonator portion. The circuit part and the combined circuit part may be included in a single filter component. Therefore, the filter device can be downsized.

Further, according to the constitutions of claims 3 and 4, a three-terminal filter can be constructed only by connecting the stripline filter of claims 1 and 2 to another filter on the substrate. Therefore, the number of work steps in the production process of the three-terminal filter can be significantly reduced.

[0023]

1 and 2 show the construction of an embodiment of a stripline filter according to the present invention, showing a perspective plan view and an exploded perspective view, respectively. In both figures, the same components as those in FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted.

Further, 12 is a circuit portion incorporating a predetermined distributed constant circuit pattern, 12a is a coupling circuit pattern incorporated in the circuit portion 12, and 12a ₁ is a capacitor portion which functions as a capacitor in the coupling circuit pattern 12a. , 12a ₂ denote inductor portions which function as coils in the coupling circuit pattern 12a.

The stripline filter 1a shown in FIG.
A circuit section in which a coupling circuit pattern 12a having the same function as that of the coupling circuit 30 shown in FIG. 4B is incorporated between the resonator section 11 and the input / output section 13 in the stripline filter 1c shown in FIG. It is configured by stacking 12 in between.

In FIG. 1, the hatched portion is the resonator portion.
Resonator pattern 11a formed by coating on 11 dielectric substrates
The portions indicated by satin indicate the coupling circuit pattern 12a formed by coating on the dielectric substrate of the circuit portion 12, respectively. And the rectangular part of satin (capacitor part 12a ₁ )
Serves as a capacitor, and the thin rectangular portion (inductor portion 12a ₂ ) having a satin finish serves as a coil.

Therefore, it becomes possible to form the coupling circuit shown in FIG. 4 which has been externally provided separately from the filter on the surface of the dielectric substrate in the same process as the process of producing the filter.

As a result, the coupling circuit, which has been externally attached to a single filter, is integrated with the filter, and the filter device including the filter and the coupling circuit can be downsized. Further, by integrating the production work steps, productivity and reliability can be greatly improved.

Further, although not shown, the synthesizing circuit 31 shown in FIG. 5 can also be incorporated into the circuit section 12 to produce a filter device. This makes it possible to further reduce the size of the filter device and improve productivity and reliability.

FIG. 3 shows an embodiment of the filter device according to the present invention. 5, those parts that are the same as those corresponding parts in FIG. 5 are designated by the same reference numerals, and a description thereof will be omitted. Further, 1a is a stripline filter incorporating the coupling circuit 30 and the synthesis circuit 31 shown in FIG. 5 together with the original filter, and 26 is a printed circuit board.

In the figure, a stripline filter 1a and a surface acoustic wave filter are provided on a printed circuit board 26.
32 is placed, these are connected by wiring, and the antenna terminal,
After the TX terminal (transmission side connection terminal) and the RX terminal (reception side connection terminal) are provided, the entire printed board 26 is covered with the metal case 24, whereby a filter device having a function of a three-terminal filter is manufactured.

As a result, it becomes possible to reduce the size of the filter device which has conventionally been complicated as shown in FIG. Moreover, since the number of parts and the number of assembling steps are significantly reduced, the productivity and reliability of the filter device can be significantly improved.

[0033]

As described above, according to the first and second aspects of the present invention, the filter device can be downsized, so that the electronic equipment using the filter device can be downsized. There is.

According to the third and fourth aspects of the invention, the number of man-hours in the production process of the three-terminal filter can be significantly reduced, so that the three-terminal filter and the three-terminal filter are provided.
It has the feature that the productivity and reliability of electronic devices that use terminal filters can be greatly improved.

[Brief description of drawings]

FIG. 1 is a perspective plan view showing a configuration of an embodiment of a stripline filter according to the present invention.

FIG. 2 is an exploded perspective view showing the configuration of an embodiment of the stripline filter according to the present invention.

FIG. 3 is a diagram showing an embodiment of a filter device according to the present invention.

FIG. 4 is a diagram showing an example of a conventional dielectric filter.

FIG. 5 is a diagram showing an example of a conventional filter device.

FIG. 6 is a diagram showing an example of a general stripline filter.

[Explanation of symbols]

1a Stripline filter according to the present invention 2a Filter device according to the present invention 11 Resonator portion 11a Resonator pattern 11a ₁ Resonator 12 Circuit portion 12a Coupling circuit pattern 13 Input / output portion 13a Input / output electrode pattern 13a ₁ Input / output electrode 13a ₂ Ground electrode 20 Dielectric block 20a Open surface 20b Short circuit surface 21 Coil 22 Capacitor 23 Dielectric substrate 24 Metal case 25a Input terminal 25b Output terminal 26 Printed circuit board 30 Coupling circuit 31 Synthesis circuit 32 Surface acoustic wave filter 33 Transmission band pass filter 34 Receive band pass filter C1 to C7 Capacitor L1 to L3 Inductor

Claims (4)

[Claims] 1. A resonator part (11) comprising a surface of a dielectric substrate (23) formed by coating a resonator pattern (11a) with a conductive material, and the surface of the dielectric substrate (23) having conductivity. Circuit part (12) formed by coating the combined circuit pattern (12a) with a material
And an input / output unit (13) formed by coating an input / output electrode pattern (13a) on the surface of the dielectric substrate (23) with a conductive material. A stripline filter characterized in that the stripline filter is sandwiched between a portion (13) and the resonator portion (11) and laminated. 2. The circuit part (12) comprising the dielectric circuit board (23) formed on the surface of the dielectric circuit board (23) with a conductive circuit material together with the coupling circuit pattern (12a) and a synthetic circuit pattern. The stripline filter according to claim 1. 3. A resonator part (11) formed by coating a resonator pattern (11a) with a conductive material on the surface of a dielectric substrate (23), and a conductive material on the surface of the dielectric substrate (23). A coupling circuit pattern (12a) and a synthesizing circuit made of a conductive material on the surface of the dielectric substrate (23) between the input / output part (13) formed by coating the input / output electrode pattern (13a) with the material. Circuit part formed by coating the pattern (1
A filter device comprising a three-terminal filter in which a stripline filter formed by sandwiching 2) is sandwiched and connected to another filter mounted on the same substrate. 4. A metal case (24) for the three-terminal filter.
The filter device according to claim 3, wherein the filter device is enclosed inside.