JPH0531376U - High frequency signal switching device - Google Patents

Abstract

(57) [Abstract] [Purpose] Switching high frequency signals while maintaining good isolation even when high frequency signals are always supplied to the two input terminals. [Configuration] When the input terminals 16 and 20 are constantly supplied with high-frequency signals of different polarizations and the control terminals 22 and 64 are supplied with voltage, the energizing relay 24 and the high-frequency relay 2 operate, and the output terminals
A current flows from 12 through the energizing relay 24 to the PIN diode 60 and becomes conductive, and the signal of the input terminal 20 is supplied from the relay 2 to the output terminal 12. At this time, no current flows through the PIN diode 56 and the PIN diode 56 is non-conductive, and the signal at the input terminal 16 is attenuated by the PIN diode 56 and hardly flows through the relay 2. When no voltage is supplied to control terminals 22 or 64, the relay
24, the relay 2 does not operate, the signal at the input terminal 16 is supplied to the output terminal 12 in the opposite manner to the above, and the signal at the input terminal 20 is attenuated by the PIN diode 56.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a high-frequency signal switching device which supplies either one of high-frequency signals supplied to two input terminals to an output terminal according to selection, and in particular, a high-frequency signal supplied to two input terminals is different from each other. Regarding

[0002]

[Prior Art]

 Conventionally, such a high-frequency signal switching device as described above, for example, receives vertically polarized radio waves and horizontally polarized radio waves at the same frequency, which are transmitted from a communication satellite, after they are received by a satellite communication antenna and then vertically polarized respectively. A converter for waves and a converter for horizontal polarization, for example, converts it to a first intermediate frequency signal in the 1 GHz band, and supplies only one of these signals to a satellite communication tuner via a transmission line such as a coaxial cable. One input terminal is connected to the output side of the vertical polarization converter, the other input terminal is supplied to the output side of the horizontal polarization converter, and the output terminal is connected via a coaxial cable. Connected to the tuner.

An example of such a high frequency signal switching device is shown in FIG. This high-frequency signal switching device has a high-frequency relay 2, and this high-frequency relay 2 includes two contacts 4 and 6 connected in series and a drive coil 8. When the drive coil 8 is in a non-energized state, The contact 4 is closed and the contact 6 is opened. Conversely, when the drive coil 8 is energized, the contact 4 is opened and the contact 6 is closed. An interconnection point of these contacts 4 and 6 is connected to an output terminal 12 via a DC blocking capacitor 10, a contact 4 is connected to an input terminal 16 via a DC blocking capacitor 14, and a contact 6 is connected to a DC blocking capacitor 18. It is connected to the input terminal 20 via. The drive coil 8 is connected to a control terminal 22 to which a DC voltage of, for example, + 5V is applied or not applied. The input terminal 16 is connected to the output side of the converter for vertical polarization, the input terminal 20 is connected to the output side of the converter for horizontal polarization, and the output terminal 12 is connected to the satellite communication tuner. It is connected.

Therefore, in the state where the DC voltage of + 5V is not applied to the control terminal 22, no current flows in the drive coil 8, so that the contact 4 is closed and the contact 6 is opened as shown in FIG. A vertically polarized signal from the vertically polarized converter of the input terminal 16 is supplied to the output terminal 12 through the direct current blocking capacitor 14, the contact 4, and the DC blocking capacitor 10. On the other hand, in the state where the DC voltage of +5 V is applied to the control terminal 22, the current flows through the drive coil 8, the contact 4 is opened, the contact 6 is closed, and the horizontal polarization converter of the input terminal 20 is closed. The signal of the horizontal polarization signal from is supplied to the output terminal 12 via the DC blocking capacitor 18, the contact 6, and the DC blocking capacitor 10. In this way, the signal output from the output terminal 12 is switched to the vertically polarized or horizontally polarized satellite / communication signal depending on whether or not a DC voltage is applied to the control terminal 22.

By the way, this high-frequency signal switching device is of a so-called energizing type so that an operating voltage can be supplied to a converter for vertical and horizontal polarizations, and its operating voltage is supplied to an output terminal 12. Has been done. An energization relay 24 is provided to supply this to both converters via the input terminals 16 and 20. The energization relay 24 has two contacts 26 and 28 connected in series and a drive coil 30. When the drive coil 30 is not supplied with current, the contact 26 is closed and the contact 28 is open. When current is supplied to the drive coil 30, the contact 26 is opened and the contact 28 is closed. The interconnection point of these contacts 26, 28 is connected to the output terminal 12 via the high frequency blocking coil 32, the contact 26 is connected to the input terminal 16 via the high frequency blocking coil 34, and the contact 28 is blocked at the high frequency. It is connected to the input terminal 20 via the coil 36. Further, the drive coil 30 is connected to the control terminal 22.

Therefore, in a state where the DC voltage is not applied to the control terminal 22 and the vertically polarized satellite / communication signal from the input terminal 16 is supplied to the output terminal 12, no current flows through the operating coil 30. Therefore, the contact 26 is closed, and the operating voltage from the output terminal 12 is supplied to the input terminal 16 via the high frequency blocking coil 32, the contact 26, and the high frequency blocking coil 34. Is supplied with an operating voltage. In the state where a DC voltage is applied to the control terminal 22 and a horizontally polarized satellite / communication signal from the input terminal 20 is supplied to the output terminal 12, a current flows through the operating coil 30 and the contact 28 is closed. The operating voltage from the output terminal 12 is supplied to the input terminal 20 via the high-frequency blocking coil 32, the contact 28, and the high-frequency blocking coil 36, and thereby the operating voltage is supplied to the horizontal polarization converter. In FIG. 4, reference numerals 38, 40, 42, 44 and 46 denote bypass capacitors, reference numeral 48 denotes a negative voltage bypass diode, and reference numeral 50 denotes a ground terminal.

[0007]

[Problems to be solved by the device]

 When such a signal switching device is used in a general household, the operating voltage is supplied only to the converter for the polarized wave which the tuner is about to receive, and therefore, for example, a vertically polarized satellite / communication signal is transmitted. When receiving with a tuner, the operating voltage is not supplied to the input terminal 20 for horizontal polarization, so the satellite / communication signal of horizontal polarization is not supplied to this input terminal 20 and the isolation is good. .. However, when such a high-frequency signal switching device is used in a joint hearing facility, the operating voltage is supplied to each converter from a separate power supply rather than being sent from the tuner side. Is always on. Therefore, for example, even when the vertically polarized satellite / communication signal from the input terminal 16 is supplied to the output terminal 12, the horizontally polarized satellite / communication signal is supplied to the input terminal 20 and good isolation is obtained. There was a problem that I could not get it. FIG. 5 shows the isolation characteristic of this device, in which isolation of only about 25 dB is obtained in the vicinity of 1.1 GHz which is the frequency of the first intermediate frequency signal.

An object of the present invention is to provide a high frequency signal switching device which can obtain good isolation even when signals are supplied to both input terminals.

[0009]

The present invention comprises high frequency signal switching means having first and second input sides to which a high frequency signal is supplied and an output side connected to an output terminal. The switching means supplies a high-frequency signal on the first input side to the output side in response to the control signal in the first state, and a high-frequency signal on the second input side in response to the control signal in the second state. Is supplied to the output side. Further, a first input terminal to which the first high frequency signal is supplied and a second input terminal to which a high frequency signal different from the high frequency signal of the first input terminal is supplied are also provided. First switch means is provided between the first input terminal and the first input side of the high-frequency signal switching means, which is responsive to the control signal in the first state. The high frequency signal is supplied to the first input side, and in response to the control signal in the second state, the high frequency signal from the first input terminal is blocked from being supplied to the first input side. A second switch means is provided between the second input terminal and the second input side of the high frequency signal switching means, and this second switch means is responsive to the control signal in the first state to generate a high frequency signal at the second input terminal. Of the high frequency signal of the second input terminal is supplied to the second input side in response to the control signal in the second state. Further, a control signal generating means for generating a control signal for selectively taking the first or second state is provided.

The control signal generating means has a control terminal, and sets the control signal in the second state according to the DC voltage applied to the control terminal, and according to the non-application of the DC voltage to the control terminal. It can be the control signal in the first state. Further, the control signal generation means includes a first control terminal that receives the first DC voltage and a second control terminal that is connected to the control terminal through the step-down means and that receives the second DC voltage higher than the first DC voltage. It can also be equipped with a control terminal of.

Further, a DC voltage is supplied to the output terminal, and in response to the non-supply state of the DC voltage to the control terminal, the DC voltage of the output terminal is supplied to the first switch means to generate a high frequency signal. It is also possible to provide a switching means for setting the signal supply state and supplying the DC voltage of the output terminal to the second switch means in response to the supply state of the DC voltage to the control terminal to set the high frequency signal supply state. ..

[0012]

[Action]

 According to the present invention, when the control signal is in the first state, the second switch means prevents the signal at the second input terminal from being supplied to the second input side of the high frequency signal switching means. Ration is obtained. On the other hand, the signal at the first input terminal is supplied to the high frequency signal switching means via the first switching means which is not in the blocking state, and is supplied to the output terminal via this. Further, when the control signal is in the second state, the first switch means blocks the supply of the signal at the first input terminal to the high frequency signal switching means, so that isolation is obtained. On the other hand, the signal at the second input terminal is supplied to the high-frequency signal switching means because the second switch means is not in the blocking state, and is supplied to the output terminal via this. Therefore, even if a signal is always supplied to the first and second terminals, the isolation becomes good.

[0013]

【Example】

 As shown in FIG. 1, the high frequency signal switching device 53 of this embodiment is constructed in substantially the same manner as the conventional high frequency signal switching device shown in FIG. The same parts are designated by the same reference numerals and the description thereof is omitted. The first difference between this embodiment and the device of FIG. 4 is that switching means 52, 54 are provided between the input terminal 16 and the DC blocking capacitor 14 and between the input terminal 20 and the DC blocking capacitor 18. Is provided.

The switch means 52 has a PIN diode 56, the anode of which is connected to the input terminal 16 and the cathode of which is connected to the DC blocking capacitor 14. Then, the cathode is grounded via the resistor 58. Similarly, the switch means 54 also has a PIN diode 60, the anode of which is connected to the input terminal 20 and the cathode of which is connected to the DC blocking capacitor 18. Further, this cathode is grounded via a resistor 62.

Further, the second difference between this embodiment and the device of FIG. 4 is that, in addition to the control terminal 22 for + 5V, a control terminal 64 for + 12V is provided, and this control terminal 64 is a control terminal. It is connected to the terminal 22 via a resistor 66 for voltage drop.

The high frequency signal switching device 53 is used, for example, as shown in FIG. The input terminal 16 of the high frequency signal switching device 53 is connected to the output side of the vertical polarization converter 66, and the input terminal 20 is connected to the output side of the horizontal polarization converter 68. These converters 66 and 68 are supplied with an operating voltage from a DC power supply 70, and normally convert the vertically and horizontally polarized sanitary / communication signals received by the satellite communication antenna 72 into a 1 GHz intermediate frequency signal. Each of them is converted and the first intermediate frequency signal is supplied to the input terminals 16 and 20. The output terminal 12 of the high frequency signal switching device 53 is connected to the input side of the tuner 74 via a coaxial cable. The tuner 74 receives the first intermediate frequency signal from its input side and supplies a DC voltage to the output terminal 12 of the high frequency signal switching device 53. Further, either one of the control terminals 22 and 64 is connected to the DC control voltage terminal (not shown) of the tuner 74. This terminal is configured to generate a DC voltage when receiving a horizontally polarized satellite / communication signal, for example. When this DC voltage is + 5V, it is connected to the control terminal 22, and when this DC voltage is + 12V, it is connected to the control terminal 64.

When the high frequency signal switching device 53 is used as shown in FIG. 2, the first intermediate frequency signal is always supplied to the input terminals 16 and 20, but the control terminals 22 and 64 are connected to each other. When no DC voltage is supplied, a current flows from the output terminal 12 to the high frequency blocking coil 32, the contact 26 of the energizing relay 24, the high frequency blocking coil 34, the PIN diode 56, and the resistor 58, and the PIN diode 56 becomes conductive. .. As a result, the vertically polarized first intermediate frequency signal at the input terminal 16 is supplied to the output terminal 12 via the PIN diode 56, the DC blocking capacitor 14, the contact 4, and the DC blocking capacitor 10. At this time, no current flows through the PIN diode 60 of the switch means 54, and the PIN diode 60 exhibits a large high frequency resistance. As a result, the first intermediate frequency signal of horizontal polarization at the input terminal 20 is greatly attenuated by the PIN diode 60, is hardly transmitted to the contact 6 side, and large isolation is obtained.

When a DC voltage is supplied to any of the control terminals 22 and 64, a current flows through the drive coil 8 of the high frequency relay 2 and the drive coil 30 of the energization relay 24, and as a result, the contact 4 is opened. The contact 6 is closed, the contact 26 is opened, and the contact 28 is closed. As a result, a current flows from the output terminal 12 to the high frequency blocking coil 32, the contact 28, the high frequency blocking coil 36, the PIN diode 60, and the resistor 62. As a result, the PIN diode 60 becomes conductive, and the first intermediate frequency signal of horizontal polarization at the input terminal 20 is supplied to the output terminal 12 via the PIN diode 60, the DC blocking capacitor 18, the contact 6, and the DC blocking capacitor 10. It On the other hand, no current flows through the PIN diode 56, which shows a large high frequency resistance. As a result, the vertically polarized first intermediate frequency signal at the input terminal 16 is greatly attenuated by the PIN diode 56, is hardly transmitted to the contact 4 side, and a large isolation is obtained.

FIG. 3 shows the isolation characteristic of the high-frequency signal switching device 53. The isolation characteristic of about 40 dB is obtained at about 1.1 GHz, which is the same as the isolation characteristic of the conventional one shown in FIG. As is clear from the comparison, the isolation is improved by about 15 dB.

In the above-described embodiment, in order to make the PIN diodes 56 and 60 conductive, the currents flowing through them are obtained from the DC voltage supplied from the tuner 74 to the output terminal 12, but are connected to the output terminal 12. The high frequency blocking coil 32 may be connected to the control terminal 22 and a current for conducting the PIN diodes 56 and 60 may be obtained from the DC voltage supplied to the control terminal 22 or 64. Further, in the above embodiment, the high frequency relay 2 is used as the high frequency signal switching means, but instead of this, the high frequency signal switching means using a PIN diode, for example, may be used. In the above embodiment, the high frequency signals supplied to the input terminals 16 and 20 are vertically polarized and horizontally polarized satellite / communication signals, but they should be right circularly polarized waves and left circularly polarized waves. You can also

[0021]

[Effect of the device]

 As described above, according to the present invention, the first and second switch means are respectively provided between the first and second input terminals and the high frequency signal switching means, and the high frequency signal of the first input terminal is provided. Is supplied to the high-frequency signal switching means, the high-frequency signal at the second input terminal is supplied to the high-frequency signal switching means by the switch means provided between the second input terminal and the high-frequency signal switching means. While the high frequency signal at the second input terminal is being supplied to the high frequency signal switching means, it is blocked by the switching means provided between the first input terminal and the high frequency signal switching means. , Good isolation is obtained.

Furthermore, since two control terminals are provided and the control terminal to which a high voltage is applied is connected to another control terminal via the step-down means, the voltage supplied to the control terminal can be of two types: high and low. Even if it exists, it can be controlled to a state where good isolation can be obtained by any voltage.

In addition, in the case where the output terminal is configured to be supplied with the DC voltage, and the switching means for switching the DC voltage is supplied to any of the switching means according to the state of the control signal, The high-frequency signal switching device according to the present invention can be obtained by slightly modifying the conventional energizing high-frequency signal switching device.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of a high frequency signal switching device according to the present invention.

FIG. 2 is a block diagram showing a usage state of the embodiment.

FIG. 3 is a diagram showing isolation characteristics of the same example.

FIG. 4 is a circuit diagram of an example of a conventional high-frequency signal switching device.

5 is a diagram showing isolation characteristics of the high-frequency signal switching device of FIG.

[Explanation of symbols]

 2 high frequency relay (high frequency signal switching means) 12 output terminal 16 input terminal 20 input terminal 22 control terminal 24 energizing relay (switching means) 52 switch means 54 switch means 64 control terminal

Claims (4)

[Scope of utility model registration request] 1. A high frequency wave on the first input side in response to a control signal in a first state, having first and second input sides to which a high frequency signal is supplied and an output side connected to an output terminal. A high-frequency signal switching means for supplying a signal to the output side and a high-frequency signal on the second input side to the output side in response to the control signal in the second state, and a first high-frequency signal are supplied. First
Of the input terminal, a second input terminal to which a high-frequency signal different from the high-frequency signal of the input terminal is supplied, and a first input terminal provided between the first input terminal and the first input side of the high-frequency signal switching means. In response to the control signal in the first state, the high frequency signal of the first input terminal is supplied to the first input side, and in response to the control signal in the second state, the high frequency signal of the first input terminal is supplied. 1
Is provided between the second input terminal and the second input side of the high frequency signal switching means, and is responsive to the control signal in the first state. To prevent the high frequency signal from the second input terminal from being supplied to the second input side and supply the high frequency signal from the second input terminal to the second input side in response to the control signal in the second state. A high frequency signal switching device comprising a second switch means and a means for generating the control signal that selectively takes the first or second state. 2. The high-frequency signal switching device according to claim 1, wherein the control signal generating means has a control terminal, and the control signal is set to a first state in response to non-application of a DC voltage to the control terminal. The high frequency signal switching device, wherein the control signal is set to the second state in response to the application of the DC voltage to the control terminal. 3. The high-frequency signal switching device according to claim 2, wherein the control signal generating means is a first control terminal for receiving a first DC voltage and a first control terminal connected to the control terminal via a step-down means. A second control terminal for receiving a second DC voltage higher than the DC voltage of the high frequency signal switching device. 4. The high frequency signal switching device according to claim 2 or 3, wherein a DC voltage is supplied to the output terminal, and the output terminal responds to a non-supply state of the DC voltage to the control terminal. DC voltage of the output terminal is supplied to the second switch means in response to the supply state of the DC voltage to the control terminal. Then, a high-frequency signal switching device is provided, which is provided with a switching means for bringing this into a high-frequency signal supply state.