JPH0521501U - Circuit device having a dielectric filter - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the cost of a plurality of types of high-frequency circuit devices including a dielectric filter. A pair of conductor films 9a and 9b for obtaining a coupling capacitance is provided on a printed circuit board 1 for mounting a dielectric filter 1 and other electronic parts. The pair of lead terminals 22 and 24 of the dielectric filter are connected to the pair of conductor films 9a and 9b. Changing the coupling capacitance changes the filter characteristics. The filter characteristics are changed on the circuit board 1 side without depending on the dielectric filter 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a circuit device having a dielectric filter such as a mobile phone.

[0002]

[Problems to be solved by conventional techniques and devices]

 Dielectric filters are used in mobile communication devices such as mobile phones. By the way, in order to construct high frequency circuit devices having various characteristics, dielectric filters having various characteristics are required. If many types of dielectric filters are prepared to meet this demand, the cost of the circuit device will inevitably increase.

Therefore, an object of the present invention is to reduce the cost of a circuit device having a dielectric filter.

[0004]

[Means for Solving the Problems]

 The present invention to achieve the above object is to provide a circuit board having a wiring conductor film and a grounding conductor film for forming a predetermined circuit, and electrically connecting to the wiring conductor film and the grounding conductor film of the circuit board. In the circuit device including the dielectric filter, the input terminal, the output terminal, and the ground terminal of the dielectric filter are provided on the circuit board, and the pair of connection portions of the wiring conductor film and the ground conductor film are provided. The present invention relates to a circuit device, which is characterized in that a conductor film for connecting to each other and for obtaining a coupling capacitance is provided between a pair of connecting portions.

[0005]

[Action]

 In the present invention, the conductor film for obtaining the coupling capacitance provided on the circuit board is used for adjusting the characteristics of the dielectric filter by the coupling capacitance. That is, the filter characteristics can be changed by changing the coupling capacitance of the conductor film. This makes it possible to use dielectric filters having the same characteristics when creating a plurality of types of circuit devices. The conductor film for obtaining the coupling capacitance in the circuit board must be changed according to multiple types of circuit devices, but this is necessary because the wiring conductor pattern of the circuit board must be changed when different circuit devices are formed. At the same time, if the conductor film of the coupling capacitance is changed, the cost will not increase.

[0006]

【Example】

 Next, a high frequency circuit device according to an embodiment of the present invention will be described with reference to FIGS. This high frequency circuit device is configured by mounting a dielectric filter 2 on a circuit board 1. Electronic components other than the dielectric filter 2 are mounted on the circuit board 1 to form a target high-frequency electric circuit, but other electronic components are not shown.

The circuit board 1 is an insulating substrate made of glass epoxy, and on one surface 3 thereof, wiring conductor films 4a and 4b for connecting the dielectric filter 2 and through holes 5a, as shown in FIG. The lead terminal connecting portions 6a and 6b, which are formed so as to surround 5b and are continuous with the wiring conductor films 4a and 4b, the grounding conductor film 7, and the wiring conductor film 8 for other electronic parts are provided. . Further, according to the present invention, a pair of conductor films 9a and 9b for obtaining a coupling capacitance are continuously provided on the lead terminal connecting portions 6a and 6b. Reference numeral 10 is a ground terminal through hole, and 11 is an electronic component lead through hole. The conductor films 4a, 4b, 7, 8, 9a, 9b and the connecting portions 6a, 6b are printed wiring conductors and are simultaneously formed.

As shown in FIGS. 1 and 3, the dielectric filter 2 has a prismatic dielectric block 12 made of a dielectric ceramic. Two resonance holes 13 and 14 are provided so as to penetrate from one end surface of the dielectric block 12 to the other end surface, and inner conductor films 15 and 16 are provided on the wall surfaces of these two resonance holes 13 and 14, respectively. An outer conductor film 17 is provided on the four side surfaces of the dielectric block 12. An end face conductor film 18 for short-circuiting the inner conductor film 15 and the outer conductor film 17 is provided on the upper end face of the dielectric block 12 in FIG. Reference numeral 19 denotes a coupling hole, which is provided between the two resonance holes 13 and 14.

An input coupling capacitor 20 is inserted in one resonance hole 13, and an output coupling capacitor 21 is inserted in the other resonance hole 14. Each of the coupling capacitors 20 and 21 has lead terminals 22, 23, 24 and 25, and the lead terminals 23 and 25 inserted into the resonance holes 13 and 14 are coupled to the inner conductor films 15 and 16 with solders 26 and 27. ing. The lead terminals 22 and 24 project from the dielectric block 12.

Reference numerals 28 and 29 denote metal plates each having a ground terminal 30, which are half-bonded to the outer conductor film 17. The four ground terminals 30, like the lead terminals 22 and 24, project from the end surface of the dielectric block 12.

The dielectric filter 2 is mounted on the circuit board 1 by inserting a pair of lead terminals 22, 24 and a ground terminal 30 into the through holes 5a, 5b, 10 and connecting the wiring conductor films 4a, 4b with solder 31. The parts 6a and 6b and the ground conductor film 7 are coupled. Also, another electronic component is connected to another conductor film 8. As a result, a high frequency circuit device is obtained in which the conductor films 9a and 9b for obtaining the coupling capacitance (capacitor) are connected between the pair of lead terminals 22 and 24 of the dielectric filter 2.

FIG. 4 shows a change in the filter characteristic when the facing distance between the conductor films 9a and 9b is changed and the value of the capacitance based on the change is changed. When the capacitance is 0.069 pF, the spread of both sides of the center frequency (815 MHz) of the pass band is large as shown by the solid line, but when the capacitance is set to 0.126 pF, the spread of both sides is shown as the dotted line. Is suppressed. The two characteristics shown by the solid line and the dotted line in FIG. 4 are obtained by making the dielectric filter 2 the same and changing the pattern (spacing and / or width) of the conductor films 9a and 9b for coupling capacitance of the circuit board 1. . Therefore, it becomes possible to mass-produce the dielectric filter 2 having the same characteristics and use it in various high-frequency circuit devices, and the cost can be reduced. It is necessary to change the pattern of the conductor films 9a and 9b for coupling capacitance of the circuit board 1. However, if the target high-frequency circuit device is different, various conductor patterns on the circuit board 1 are also changed. At the same time, the patterns of the coupling capacitance conductor films 9a and 9b may be changed. Therefore, this does not increase the cost. That is, as disclosed in, for example, Japanese Patent Application Laid-Open No. 61-230403, it is possible to integrally provide a coupling capacitance to a dielectric filter to obtain a plurality of dielectric filters having different characteristics. In that case, a dedicated coupling capacitance must be formed independently, which increases the cost. On the other hand, in this embodiment, the coupling capacitor conductor films 9a and 9b are formed simultaneously with the conductor film for other electronic parts on the side of the circuit board on which the dielectric filter is mounted, so that the cost does not increase.

[0013]

[Modification]

 The present invention is not limited to the above-mentioned embodiment, and the following modifications are possible, for example. (1) As shown in FIG. 5, the circuit board 1 may be a laminate of the first layer 1a and the second layer 1b. (2) The coupling capacitance conductor films 9a and 9b may be provided on the other surface side of the circuit board 1 or between the two layers 1a and 1b of FIG. (3) Although the open end surface of the dielectric block 12 is in contact with the circuit board 1 in FIG. 1, it may be mounted so as to be separated. (4) The lead terminals 22 and 24 can be directly connected to the inner conductor films 15 and 16 without providing the coupling capacitors 20 and 21. (5) The dielectric filter 2 is not limited to those shown in FIGS. 1 and 2, but a multi-stage dielectric filter having three or more resonance holes or a 1/2 wavelength type dielectric without the end face conductor film 18 is provided. It can be various types of dielectric filters such as body filters. Further, two dielectric resonators can be combined to form a dielectric filter. (6) Instead of inserting the lead terminals 22 and 24 of the dielectric filter into the through holes 5a and 5b of the circuit board 1, the dielectric filter can be mounted on the circuit board in a surface mounting form.

[0014]

[Effect of the device]

 As is apparent from the above, according to the present invention, it is possible to reduce the cost of a plurality of types of circuit devices having different characteristics.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view of a high frequency circuit device according to an embodiment of the present invention.

FIG. 2 is a bottom view of the circuit board shown in FIG.

FIG. 3 is a bottom view of the dielectric filter of FIG.

FIG. 4 is a filter characteristic diagram of a combination circuit of the dielectric filter of FIG. 1 and a coupling capacitance conductor film.

FIG. 5 is a side view showing a modified circuit board.

[Explanation of symbols]

 1 Circuit Board 2 Dielectric Filter 9a, 9b Coupling Capacitance Conductor Film 22, 24 Lead Terminal

Claims (1)

[Scope of utility model registration request] 1. A circuit board having a wiring conductor film and a ground conductor film for forming a predetermined circuit, and a dielectric filter electrically connected to the wiring conductor film and the ground conductor film of the circuit board. In a circuit device provided with the dielectric filter, an input terminal, an output terminal, and a ground terminal are respectively connected to the pair of connecting portions of the wiring conductor film provided on the circuit board and the ground conductor film, and 2. A circuit device, wherein a conductor film for obtaining a coupling capacitance is provided between the connection portions of the circuit device.