JPH0531338U - High frequency filter - Google Patents

Abstract

(57) [Abstract] [Purpose] In a high-frequency filter, downsize a high-frequency coil and easily adjust the values of its self-inductance and mutual inductance. [Structure] Two printed circuit boards, each having a spiral print coil formed thereon, are slidably arranged with their backs back to each other, and a bypass or short circuit is formed in each coil conductor. The coil conductor length is adjusted, and one of the printed circuit boards is slid to change the distance between the coils.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a high-frequency filter used as a built-in filter for mobile phones, cordless phones, satellite broadcast receivers, and the like.

[0002]

[Prior Art]

 Conventionally, this type of high-frequency filter has mainly used a molded coil as a high-frequency coil in order to prevent variations in high-frequency characteristics, and has used this by incorporating it into a printed circuit board. The input and output ends of this forming coil used intermediate taps that were drawn out according to their respective impedances. (JP-A-6-65811)

[0003]

[Problems to be solved by the device]

 However, since the above-mentioned conventional high-frequency filter mainly uses a molded coil, it requires a certain three-dimensional space, and there is a limit to miniaturization, and at the time of manufacture, assembly, impedance adjustment, etc. There was a problem that it took time.

The present invention has been made in view of the above points, and an object thereof is to provide a high-frequency filter which can solve the above problems and can be miniaturized, and which can be easily assembled and impedance adjusted during manufacturing. .

[0005]

[Means for Solving the Problems]

 The structure of the present invention for achieving the above object is as follows. (1) Two high-frequency coils, each having a spiral wound print coil formed on a printed circuit board, are slidably arranged with their backs facing each other, and one end of each coil is an input end. , Output terminals, and the other end thereof as a common ground terminal, and a detour or short circuit is formed at one or more places of each of the print coils to obtain a required self-inductance value for each coil. It is a high-frequency filter that is configured as described above.

(2) Two high-frequency coils each having a spiral-wound printed coil formed on a printed circuit board are slidably arranged with their backs facing each other, and one end of each coil is placed. Input terminals and output terminals, and the other ends thereof as a common ground terminal, and one of the printed circuit boards is slid with respect to the other to change the distance between the print coils. It is a high-frequency filter that can obtain the required mutual inductance value.

[0007]

[Work]

 Since the present invention is configured as described above, it has the following effects. (1) Since the high-frequency coil is formed on the printed circuit board, the overall size can be reduced. (2) Since the coil length can be adjusted by the short circuit or the bypass formed in the coil conductor of each of the print coils, the required self-inductance value can be obtained. (3) The printed circuit boards, which are slidably arranged so that their back surfaces are slidable with respect to each other, can be slid to change the distance between the respective print coils so that a desired mutual inductance value can be obtained between the two coils. .

[0008]

【Example】

 Hereinafter, a preferred embodiment of the present invention will be exemplarily described in detail with reference to the drawings. 1 to 3 show an embodiment of the high-frequency filter of the present invention. FIG. 1 shows two printed circuit boards on which components are mounted on the wiring pattern surface, and the back surfaces of the two printed circuit boards are slidably arranged on the back. 2 is a side view of FIG. 1, and FIG. 3 is a circuit diagram of the high frequency filter.

In the figure, a high frequency filter 1 has rectangular spiral print coils 4 and 5 with the same winding direction (or reverse) on the copper foil surfaces of two single-sided printed boards 2 and 3. Are formed at the same distance from the reference plane R of the printed circuit boards 2 and 3.

One end of each of the print coils 4 and 5 serves as an input end 4a and an output end 5a, passes through the respective connecting conductors 6 and 7, and passes through the chip capacitors 8 and 9 and the input terminal P _{i of the} high frequency filter 1. And an output terminal _Po , and the other end is connected to a common ground terminal GND. In addition, from the input end 4a and the output end 5a of each of the coils 4 and 5, through the connection conductors 6 and 7, respectively, and through the chip capacitors 10 and 11, the ground terminal GND (ground of the printed circuit boards 2 and 3). Terminals are commonly connected).

Detours 12 and 13 are formed at two locations on the outer periphery 4b, 5b of each of the coils 4, 5 and a short circuit 14 is formed at two locations on the inner periphery 4c, 5c (the same portion as 4c). , 15 (same part as 14) are formed.

In this way, the two printed circuit boards 2 and 3 on which the components are mounted on the wiring pattern surface are arranged so as to be slidable on the basis of the reference plane R while the back surfaces of the two printed circuit boards 2 and 3 are closely attached to each other. The high frequency filter 1 is configured.

In order to adjust the self-inductance of each of the print coils 4 and 5 of the high frequency filter 1 to a required value, they are arranged in parallel with the detours 12 and 13 formed on the outer peripheries 4b and 5b of the coils. The conductors of the outer peripheral portions 4b and 5b are cut by a suitable cutter and opened to allow the coil conductors to pass through the detours 12 and 13. Further, the short-circuit paths 14 and 15 formed in the coil inner peripheries 4c and 5c are similarly cut and opened to adjust the conductor lengths of the coils 4 and 5.

In order to adjust the mutual inductance M between the printed coils 4 and 5 to a required value, the printed boards 2 and 3 are adhered to each other on their back surfaces and the printed board is referenced with the reference plane R 1 as a reference. 2 is slid in the direction of the arrow with respect to another printed circuit board 3, and the distance between the printed coils 4 and 5 is changed to adjust the required mutual inductance M value. Then, the two printed boards 2 and 3 are fixed to each other.

As the printed circuit board, for example, a copper-clad laminate that does not change over time, such as an epoxy resin material, is used, so that the high-frequency characteristics of each coil are dependent on the ambient environmental conditions, particularly temperature and humidity. The variation due to is extremely small.

The technique of the present invention is not limited to the technique in the above-described embodiment, and means of another aspect having a similar function may be used. The technique of the present invention is within the scope of the above configuration. Various changes and additions are possible.

[0017]

[Effect of the device]

 As is clear from the above description, the high frequency filter of the present invention can be miniaturized because the high frequency coil is formed on the printed circuit board.

Two spiral printed coils formed on a printed circuit board are slidably arranged so that their backs are opposite to each other, and detours or short-circuit paths are provided at one or more positions of each printed coil. Is formed, or one of the printed circuit boards is slid against the other to change the distance between the printed coils, so that the self-inductance of each coil and the mutual inductance between both coils can be reduced. It can be easily set to the required value, and it takes less time to assemble and adjust impedance during manufacturing.

[Brief description of drawings]

FIG. 1 is a layout view of one embodiment of a high frequency filter of the present invention, in which components are mounted on respective wiring pattern surfaces of two single-sided printed circuit boards.

FIG. 2 is a side view of FIG.

3 is a circuit diagram of a high frequency filter in FIG.

[Explanation of symbols]

 1 High frequency filter 2,3 Printed circuit board 4,5 Printed coil 4a Input terminal 5a Output terminal 12,13 Detour circuit 14,15 Short circuit GND terminal

Claims (2)

[Scope of utility model registration request] 1. Two high-frequency coils each having a spiral wound print coil formed on a printed circuit board are slidably arranged so that their backs are opposite to each other, and one end of each coil is an input end and an output, respectively. And the other end thereof as a common ground end, and a detour or a short circuit is formed at one or more places of each of the print coils so that each coil can obtain a required self-inductance value. A high-frequency filter characterized in that 2. Two high-frequency coils, each having a spiral-wound printed coil formed on a printed circuit board, are slidably arranged with their backs facing each other, and one end of each coil is an input end and an output, respectively. An end, and the other end thereof as a common ground end, and one of the printed boards is slid with respect to the other to change the distance between the printed coils.
A high frequency filter characterized in that a required mutual inductance value is obtained between the coils.