JPH0346572Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an antenna switching device that selects a desired antenna from two antennas installed facing different directions.

Conventionally, when receiving radio waves arriving from multiple directions and transmitting radio waves in each direction, there have been methods of rotating a single antenna or methods of pre-mixing using a mixer/distributor.

However, the former method of rotating the antenna requires wiring an expensive rotating device and the electric wire that controls this device separately from the antenna's power supply line, and the latter method of mixing and distributing the antenna requires wiring separately from the antenna's power supply line. However, in order to distinguish the output of each antenna according to the frequency of the target direction, a filter-type mixer or distributor with a large insertion loss is required.

Furthermore, if an amplifier is provided to amplify the radio waves received by the antenna or to amplify the signal to be transmitted and supply it to the antenna, this amplifier will be used to Considering the loss, it is necessary to arrange the antenna as close as possible to the antenna, but in the former method of rotating the antenna, the power supply line for driving the amplifier should be connected to the control line of the rotating device and the antenna. In addition, in the latter method of mixing and distributing, the circuit between this amplifier and the filter-type mixer or distributor is extremely complicated. It had the disadvantage of becoming a nuisance.

This idea was made in view of the above circumstances,
The purpose of this is to install an amplifier near the antenna, without the need for separate control wires, and without using filter-type mixers or distributors with high insertion loss, so that the power supply for the amplifier can be made independent. An object of the present invention is to provide an antenna switching device that can reliably transmit and receive radio waves in a target direction without having to install an antenna.

In other words, this invention connects the switching amplifier installed near the antenna and the switching operation unit installed near the television receiver with a single feeder line, and connects the switching amplifier installed near the antenna to the switching operation unit installed near the television receiver, and connects the positive and negative DC current from the switching operation unit. By switching either one of the signals or the AC signal by operating one knob, you can receive the signal from the desired antenna from the antenna installed in each of the two directions, or receive the signal from the desired antenna. At the same time as the transmission, the switching signal is used to supply power to the amplifier in the switching amplifier. Therefore, there is no need for conventional expensive antenna rotation devices, filter type mixers that degrade performance, distributors, or distribution switching devices that require multiple feed lines, etc., and the antenna can be easily operated while maintaining a simple configuration. It is possible to realize an antenna switching device in which an amplifier is installed nearby and there is no need to separately provide a power source for the amplifier.

An embodiment of this invention will be described below with reference to the drawings. FIG. 1 shows a circuit configuration in which antennas installed in two directions are switched by an operating device installed near a television receiver. In the figure, 1 is an antenna installed toward broadcasting station A, and 2 is an antenna installed toward another broadcasting station B, which is in a different direction from broadcasting station A. A switching amplifier 3 is provided near these antennas 1 and 2. On the other hand, a switching operation section 4 is provided near a television receiver (not shown). The switching operation section 4 and the switching amplifier 3 are connected by a power supply line, for example, a coaxial cable 5. The outer conductor 5a of this coaxial cable 5 is grounded at each of the switching amplifier section 3 and the switching operation section 4.

Antenna connection terminals 6 and 7 are provided outside the switching amplification section 3, and antennas 1 and 2 are connected to these terminals 6 and 7, respectively. The antenna connection terminals 6 and 7 are connected to fixed contacts 8a and 8b of a changeover switch 8, respectively, inside the changeover amplifier 3. A movable contact 8c of the changeover switch 8 is connected to an input end of an amplifier 9. The changeover switch 8 switches the signal received by the antenna 1 or the antenna 2 and guides it to the amplifier 9. The output end of the amplifier 9 is connected to the center conductor 5b of the coaxial cable 5 via a capacitor 10 for high frequency signal coupling. Moreover, the negative DC power supply terminal 9a of the amplifier 9 is
It is connected to the center conductor 5b of the coaxial cable 5 via a rectifier diode 11 and a high frequency blocking coil 12. The connection point between the coil 12 and the center conductor 5b is connected to one end of a solenoid 15 via a high frequency blocking coil 13 and a rectifying diode 14, and the other end of the solenoid 15 is grounded. The solenoid 15 is for controlling the changeover switch 8, and when no current flows through the solenoid 15, the movable contact 8c is connected to the fixed contact 8a. Note that 16 and 17 are decoupling capacitors, respectively.

In addition, in the switching operation section 4, the coaxial cable 5
The center conductor 5b is connected to an external television receiver connection terminal 19 via a high frequency signal blocking capacitor 18, and is also connected to a movable contact 21c of a changeover switch 21 via a high frequency blocking coil 20.
It is connected to the. A fixed contact 21a of the changeover switch 21 is connected to one end of a secondary winding 23a of a power transformer 23 via a rectifying diode 22. On the other hand, the fixed contact 21b directly connects the secondary winding 23
connected to one end of a. This secondary winding 23a
The other end is grounded. Both ends of the primary winding 23b of the power transformer 23 are provided externally.
It is connected to input terminals 24 and 25 for AC100V. That is, the changeover switch 21 switches the signal for switching the antenna 1 or the antenna 2, and is input from the input terminals 24 and 25 and outputs an AC voltage regulated by the power transformer 23 or a DC voltage obtained by rectifying this AC voltage. It outputs either voltage.

Next, the operation of the antenna switching device configured as described above will be explained.

First, in the switching operation section 4, operate a knob (not shown) to close the movable contact 21c of the switching switch 21.
is connected to the fixed contact 21b, the secondary voltage of the power transformer 23, that is, the appropriately regulated AC voltage, is connected to the changeover switch 21 and the coil 20.
The signal is sent to the switching amplification section 3 via the coaxial cable 5. The AC voltage sent to the switching amplifier 3 is rectified by the diode 11 and capacitor 16 via the coil 12, and then applied as a negative DC voltage to the power supply terminal 9a of the amplifier 9, thereby operating the amplifier 9. . At the same time, this AC voltage is rectified by the diode 14 and the capacitor 17 via the coil 13, and then applied to the solenoid 15 as a positive DC voltage, which causes the movable contact 8c of the changeover switch 8 to move to the fixed contact 8b side. connected to. Therefore, the received signal of the antenna 1 connected to the fixed contact 8b of the changeover switch 8 is guided to the amplifier 9 and amplified, and then passes through the coaxial cable 5 via the high frequency signal coupling capacitor 10 to the changeover operation section. Sent to 4. The signal sent to the switching operation unit 4 is guided to a connection terminal 19 via a high-frequency signal coupling capacitor 18, and is supplied to a television receiver connected to this connection terminal 19. Thus, in this state, the signal from the antenna 1, that is, the television broadcast from the broadcast station A can be received.

Next, operate a knob (not shown) provided on the switching operation section 4 to switch the movable contact 21 of the changeover switch 21.
When c is switched to the fixed contact 21a side, the regulated AC voltage on the secondary side of the power transformer 23 is rectified by the diode 22, and is applied to the coaxial cable 5 via the changeover switch 21 and the coil 20 as a negative DC voltage. The signal is then sent to the switching amplification section 3. The negative DC voltage sent to the switching amplifier 3 is applied to the power supply terminal 9 of the amplifier 9 via the coil 12 and the diode 11.
a, and the amplifier 9 operates.
At the same time, this DC voltage is also applied to the diode 14 via the coil 13, but the direction of the diode 14 is connected in a direction that allows a positive current to flow through the solenoid 15, and in this case, the applied voltage is negative. Therefore, no current flows through the solenoid 15. Therefore, the movable contact 8c of the changeover switch 8 is switched to the fixed contact 8a side. The received signal of the antenna 2 is then guided to the amplifier 9 and supplied to the television receiver in the same manner as described above. That is, broadcast station B
It is possible to receive television broadcasts from.

In the above embodiment, the case where radio waves are received from a broadcasting station has been described, but it goes without saying that the present invention can also be applied to the case where radio waves are transmitted conversely.

As described above, according to this invention, the switching amplifier installed near the antenna and the switching operation section installed near the television receiver are connected by a single power supply line, and the switching operation section is connected to the switching amplifier installed near the antenna. By switching either the negative DC signal or the AC signal by operating one knob, you can receive the signal from the desired antenna from the antennas installed in each of the two directions, or At the same time as transmitting from the desired antenna, the switching signal is used to automatically supply power to the amplifier in the switching amplifier, which eliminates the need for expensive antenna rotation equipment and performance deterioration as in the past. Filter-type mixers, distributors, or distribution switches that require multiple feed lines are no longer required, and while the configuration is simple, it is necessary to install an amplifier near the antenna and provide an independent power supply for the amplifier. It is possible to realize an antenna switching device without

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an antenna switching device according to an embodiment of this invention. 1, 2...Antenna, 3...Switching amplifier section, 4...
Switching operation unit, 5... Coaxial cable, 8, 21...
Changeover switch, 9...Amplifier, 12, 13, 20
... High frequency blocking coil, 15 ... Solenoid,
11, 14, 22... rectifier diode, 10,
18...Capacitor for high frequency signal coupling, 16,1
7... Decoupling capacitor, 23... Power transformer, 24, 25... AC input terminal.

Claims (1)

[Scope of utility model registration request] In an antenna switching device that selects a desired antenna from two antennas installed facing different directions, a first antenna that switches and outputs either a positive or negative DC signal or an AC signal for selection control is used. a switching mechanism, which is provided near the antenna and connected to the first switching mechanism via a power supply line, and receives an output signal transmitted from the first switching mechanism from within the antenna. a second switching mechanism for selecting a desired antenna; an amplifier connected to the second switching mechanism for amplifying the output signal of the selected desired antenna; An antenna switching device characterized by comprising means for supplying power to the amplifier using one of the positive and negative DC signals or the AC signal for selection control.