JP2007172935A - High-frequency relay and television tuner using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve isolation in a high frequency relay. <P>SOLUTION: Not only arranging grounding terminals 51, 52 which are longer than fixed contacts 15, 16, 17, between the fixed contacts, but also the grounding terminals 51, 52 are arranged so that cross-sectional shapes on faces β1, β2 crossing at right angles to straight lines α1 connecting fixed contacts 15, 16, 17 are formed broader than the fixed contacts 15, 16, 17. Therefore, floating capacities between the fixed contacts 15, 16, 17 can be decreased more, and the isolation can be furthermore improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a high-frequency relay incorporated in a high-frequency switching device used for switching a received signal of a television broadcast and a television tuner using the same.

  Some of the television tuners are equipped with a high-frequency switching device incorporating the high-frequency relay. For example, in a product for North America, switching between a terrestrial television signal and a cable television signal is performed. In that case, the isolation between the contact terminals is determined by the standard. For example, 80 dB is required for a 216 MHz signal and 55 dB is required for a 864 MHz signal.

Therefore, in the prior art according to Patent Document 1, as shown in FIG. 8, the ground terminals E1 to E4 between the contact terminals T1 to T3 are formed longer than the contact terminals T1 to T3, so that each of the contact terminals T1 to T3 The stray capacitance through the tip is reduced, and leakage of high frequency signals is reduced.
Japanese Unexamined Patent Publication No. 7-240138

  However, there is a configuration that handles signals exceeding 2 GHz, such as an intermediate frequency signal of satellite broadcasting, and the terminal pitch is narrow due to the demand for miniaturization of parts. It has become difficult to ensure isolation.

  An object of the present invention is to provide a high-frequency relay capable of further improving isolation and a television tuner using the same.

  The high-frequency relay of the present invention is a high-frequency relay having a ground terminal formed between the contact terminals and having a length equal to or longer than the contact terminals, and a cross-sectional shape on a plane orthogonal to a straight line connecting the contact terminals is The ground terminal is formed wider than the contact terminal.

  According to the above configuration, in order to meet the demand for a narrow terminal pitch, by providing a ground terminal between the contact terminals that is longer than the contact terminal, the stray capacitance via the tip of the contact terminal can be reduced. In the high-frequency relay in which the leakage of the high-frequency signal is reduced, the cross-sectional shape in the plane orthogonal to the straight line connecting the contact terminals further forms the ground terminal wider than the contact terminal.

  Therefore, the stray capacitance between the contact terminals can be further reduced, and the isolation can be further improved.

  In the high frequency relay of the present invention, the wide ground terminal is divided into two forks.

  According to the above configuration, even if the ground terminal is formed wide as described above, it can be handled by being inserted into a sponge-like electrostatic mat as in the conventional case.

  Furthermore, the television tuner of the present invention is characterized by using the high frequency relay.

  According to the above configuration, in the television tuner that handles a high-frequency signal, it is preferable to use the high-frequency relay that can further improve the isolation as described above for high frequency and small size.

  As described above, the high frequency relay of the present invention provides a ground terminal formed between the contact terminals so as to have a length longer than that of the contact terminals in order to meet the requirement of narrowing the terminal pitch. In the high-frequency relay designed to reduce the stray capacitance through the terminal and reduce the leakage of high-frequency signals, the cross-sectional shape in the plane orthogonal to the straight line connecting the contact terminals forms a wider grounding terminal than the contact terminals To do.

  Therefore, the stray capacitance between the contact terminals can be further reduced and the isolation can be further improved.

  Furthermore, the television tuner of the present invention uses the high frequency relay as described above.

  Therefore, in a television tuner that handles a high-frequency signal, it is preferable to use the present high-frequency relay that can further improve the isolation as described above for high frequency and miniaturization.

  FIG. 1 is an exploded perspective view showing a structure of a high frequency relay 3 according to a first embodiment of the present invention. The high-frequency relay 3 is generally configured by arranging a drive mechanism 21 for driving the contact mechanism 11 in parallel with the contact mechanism 11.

  The contact mechanism 11 is provided with movable contacts 13 and 14 in a shield box 12, and the movable contacts 13 and 14 are driven to be displaced in the reference sign X direction by the drive mechanism 21, whereby fixed contacts 15 and 16; 16/17 contacts / separates and switches the high frequency signal. Therefore, the movable contacts 13 and 14 constitute a coaxial line having a central conductor and the shield box 12 being an external conductor. The movable contacts 13 and 14 are respectively held by drive members 18 and 19 that are displaced and driven by the drive mechanism 21. The fixed contacts 15, 16, and 17 are erected in an electrically insulated manner in the shield box 12 shown in an enlarged view in FIG. 2, and the side opposite to the movable contacts 13 and 14 protrudes from the back surface of the base 20. Thus, terminals P1, P2, and P3 are obtained.

  FIG. 3 schematically shows the contact mechanism 11. The intermediate fixed contact 16 (terminal P2) is a common contact that can be in contact with both the movable contacts 13 and 14. On the other hand, the fixed contacts 15 and 17 (terminals P1 and P3) at both ends are individual contacts that can contact only the movable contacts 13 and 14, respectively. In the example of FIG. 3, the fixed contact 15 is a normally-on contact that contacts the movable contact 13 when the drive mechanism 21 is not driven and is connected to the fixed contact 16, and the fixed contact 17 is movable when the drive mechanism 21 is not driven. The contact 14 is a normally-off contact that is separated from the fixed contact 16 by separating.

  As shown in FIG. 2, the shield box 12 has movable contacts 13 and 14 that are separated from the fixed contacts 15, 16, and 17 at the both ends and the center position in the longitudinal direction. Fixed contacts 12a, 12b, and 12c are provided for securing the connection, and ground terminals 51 and 52 are provided between the terminals P1, P2, and P3 of the fixed contacts 15, 16, and 17, respectively. In addition, the shield box 12 is preferably formed as large as possible with no gap in order to accommodate the movable contacts 13 and 14 as described above, but in order to avoid interference with the drive members 18 and 19. A notch 12e is formed.

  The drive mechanism 21 includes an electromagnet 22 and a displacement member 23. In the electromagnet 22, the iron core 26 is inserted into the bobbin 25 around which the coil 24 is wound, and a magnetic path is provided by the yoke 27 between one end portion 26 a and the other end portion 26 b of the iron core 26. Formed and configured. Each end of the coil 24 is connected to terminals 28 and 29 to which excitation current is applied from the outside.

  On the other hand, the displacement member 23 contacts the card 31 that supports the movable contacts 13 and 14 via the drive members 18 and 19, the magnet 32 provided at one end of the card 31, and both ends of the magnet 32. A pair of armatures 33 and 34 sandwiching the iron core 26, a pair of balance springs 35 and 36 extending from the other end of the card 31, and a balance spring holding for attaching the other end of the balance springs 35 and 36 to the base 20 And a plate 37. Therefore, when the electromagnet 22 is demagnetized / excited, the card 31 is displaced in the X direction by the deformation of the balanced springs 35 and 36 as shown in FIGS. 4 (a) and 4 (b). The movable contacts 13 and 14 can be displaced.

  The fixed contact 15, 16, 17, the shield box 12, and the electromagnet 22 are accommodated in the base 20, and the displacement member 23 is mounted on the electromagnet 22. 38 is put on.

  In the high-frequency relay 3 configured as described above, it should be noted that in the present embodiment, the ground terminals 51 and 52 of the shield box 12 are between the fixed contacts 15, 16 and 17 as shown in FIG. The cross-sectional shape on the orthogonal planes β1, β2 with respect to the straight line α1 connecting the two is formed wider than the fixed contacts 15, 16, 17. The ground terminals 51 and 52 are divided into two forks as indicated by reference numerals 51a and 51b; 52a and 52b.

  By configuring in this way, in FIG. 6, the ground terminals 51, 52 are simply compared with the case where the longer ground terminals 51, 52 are provided between the fixed contacts 15, 16, 17 indicated by the reference symbol γ 1. When the cross-sectional shape at the orthogonal planes β1, β2 with respect to the straight line α1 connecting between the fixed contacts 15, 16, 17 is formed wider than the fixed contacts 15, 16, 17, the fixed contacts 15, 16, 17 The stray capacitance between them can be further reduced, and the isolation can be further improved as indicated by reference numeral γ2. In addition, by dividing the ground terminals 51 and 52 into two forks, the ground terminals 51 and 52 can be inserted into a sponge-like electrostatic mat as before, even if the ground terminals 51 and 52 are formed wide. Can be handled.

  FIG. 7 is a perspective view showing the high-frequency switching device 1 configured using the high-frequency relay 3 configured as described above with the top cover removed. The high-frequency switching device 1 includes the high-frequency relay 3 and the printed circuit board 4 in a metal housing 2, and high-frequency connectors 5, 6, and 7 are attached to the metal housing 2, and is mounted on a television tuner. Thus, it is used for switching between a terrestrial television broadcast signal and a cable television signal. The printed circuit board 4 is provided with an amplifier, an element for impedance matching, and the like as necessary.

  In the example of FIG. 7, the high-frequency connectors 5 and 6 are F-type connectors, the high-frequency connector 7 is a pin-type connector, and the center conductors of the high-frequency connectors 5 and 6 are fixed contacts 15 and 17 (terminals) of the high-frequency relay 3. P1 and P3), and the center conductor of the high frequency connector 7 is connected to the fixed contact 16 (terminal P2) of the high frequency relay 3. Therefore, an input signal from either one of the high frequency connectors 5 and 6 is selected by the high frequency relay 3 and output to the high frequency connector 7, or an input signal from the high frequency connector 7 is output by the high frequency relay 3. 6 is output to either one.

  By using the high-frequency switching device 1 capable of improving the isolation configured as described above for a television tuner, it is suitable for high frequency and miniaturization.

  The above-described effect can be obtained only by forming one of the ground terminals 51 and 52 wide. Similarly, only one of the portions indicated by reference numerals 51a and 51b; 52a and 52b has a width. Even if it is formed widely, the above-mentioned effect can be obtained.

It is a disassembled perspective view which shows the structure of the high frequency relay which concerns on the 1st Embodiment of this invention. It is a perspective view which expands and shows the shield box in the high frequency relay shown in FIG. It is a figure which shows typically the contact mechanism in the high frequency relay shown in FIG. It is a top view which shows the mode of the displacement of the displacement member in the high frequency relay shown in FIG. It is a bottom view which shows the arrangement | sequence state of the stationary contact in the high frequency relay shown in FIG. It is a graph which shows the isolation characteristic by the experimental result of this inventor. It is a perspective view which removes the upper cover of the high frequency switching apparatus carrying the high frequency relay shown in FIG. It is a side view for demonstrating the structure of the relay of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High frequency switching apparatus 2 Metal housing 3 High frequency relay 4 Printed circuit board 5, 6, 7 High frequency connector 11 Contact mechanism 12 Shield box 12a, 12b, 12c Fixed contact 12e Notch 13, 14 Movable contact 15, 16, 17 Fixed contact 18 , 19 Drive member 20 Base 21 Drive mechanism 22 Electromagnet 23 Displacement member 24 Coil 25 Bobbin 26 Iron core 27 Relay 31 Card 32 Magnet 33, 34 Armature 35, 36 Balance spring 51, 52 Ground terminal P1, P2, P3 terminal

Claims (3)

In the high frequency relay having a ground terminal formed between the contact terminals and having a length longer than the contact terminal,
The high-frequency relay according to claim 1, wherein a cross-sectional shape in a plane orthogonal to a straight line connecting the contact terminals is formed so that a ground terminal is wider than the contact terminals.   2. The high frequency relay according to claim 1, wherein the wide ground terminal is divided into two forks.   A television tuner using the high-frequency relay according to claim 1 or 2.

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