JPH0375102B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a duplexer, and particularly to a duplexer capable of simultaneously transmitting DC power and AC power via a high frequency transmission line such as a coaxial cable. It is composed of

<Prior art> Conventionally, for example, as shown in FIG. for satellite broadcast reception
When a BS-IF converter) 4 is provided to transmit each high frequency signal to the first and second receiving devices 21 and 41, separate transmission paths 22 and 42 are provided to transmit the high frequency signals, respectively. Ta. Generally, the first receiving device 21 has a built-in AC power source for operating the high-frequency device 2, and the AC power is supplied to the transmission line 2.
2 to the first high frequency equipment 2,
Similarly, a DC power supply for operating the second high-frequency device 4 is built in the second receiving device 41, and the DC power is transmitted to the second high-frequency device 4 via the transmission path 42. A rectifier circuit is provided in the high-frequency device 2 to convert the sent alternating current into direct current and use it as operating power.

<Problems to be solved by the invention> As mentioned above, conventionally, two high frequency devices 2,
4, two signal transmission lines 22, 4 are installed.
It was necessary to provide 2. This means that when AC power and DC power are mixed and transmitted to the high frequency equipment 2 and 4 sides through one high frequency transmission line, the AC power and DC power are separated on the high frequency equipment 2 and 4 sides. This is because it is not possible. High frequency equipment 2, 4
There is also a system in which the outputs of the signals are mixed in a mixer and sent through a single high-frequency transmission line, and then separated into each high-frequency signal by a demultiplexer on the receiving side and supplied to the corresponding receiving devices 21 and 41. In this case as well, for the same reason as above, operating power for the high-frequency devices had to be selectively supplied to only one of the high-frequency devices via the high-frequency transmission line. Therefore, in order to supply power for each operation in order to operate both high-frequency devices simultaneously, it was necessary to provide one separate power supply path for operation.

<Means for Solving the Problems> The present invention transmits AC power for operation of the high-frequency device 2 and DC power for operation of the high-frequency device 4 from the receiving devices 21 and 22 to a high-frequency signal through a single high-frequency transmission path. This invention relates to a duplexer that has the function of being able to time-divisionally transmit multiplexed signals. The duplexer according to the present invention can be used to mix and transmit signals such as VHF and
A first high frequency signal consisting of a UHF television broadcast reception signal and, for example, a BS-IF during satellite broadcast reception.
a duplexer main body that separates a second high-frequency signal consisting of a signal, supplies the first high-frequency signal to a first receiving device, and supplies the second high-frequency signal to a second receiving device; a time division circuit having a first input terminal coupled to the first receiving device, a second input terminal coupled to the second receiving device, and an output terminal coupled to the signal transmission path. are doing. The first receiving device supplies AC operating power with a first voltage, and the second receiving device supplies DC operating power with a second voltage. Further, the time division circuit couples only the second input terminal to the output terminal during a half cycle in which the AC voltage has the same polarity as the DC voltage, so that the DC power having the second voltage is output. AC power transmitted through the signal transmission path and having the first voltage is coupled to the first input terminal to the output terminal during a half cycle in which the AC voltage has a polarity opposite to the DC voltage. It has a switching circuit that allows the signal to be transmitted through the signal transmission path.

<Function/Effect> In the above-described time-divisional transmission device for DC and AC, when both the first receiving device and the second receiving device are operated, the AC power supply provided in the first receiving device, for example, AC power for operation of VHF/UHF television signal amplification booster (e.g. voltage
24V) is supplied to the time division circuit, and DC power (e.g. 15V) for operating a BS-IF converter for satellite broadcast reception is supplied to the time division circuit from a DC power supply provided in the second receiving device. Supplied.
The time division circuit transmits DC power at a voltage of 15V through the signal transmission path during the half cycle period when the polarity of the AC voltage is the same as the polarity of the DC voltage, and the polarity of the AC voltage is opposite to the polarity of the DC voltage. During the half cycle period, AC power with a voltage of 24V can be transmitted through the signal transmission path. Generally, on the high frequency signal input side of the signal transmission path, there is a mixer that mixes each signal sent from the booster and BS-IF converter and sends it to the signal transmission path, and only the DC power transmitted in the time division manner. Take it out, smooth it and make the above BS
−Supplies power to the IF converter for its operation,
Further, a power separation circuit is provided that extracts only the AC power transmitted in a time-division manner and supplies it to the booster.

According to this invention, operating power is supplied to the booster for VHF/UHF television signal amplification and the BS-IF converter for satellite broadcasting reception to operate them simultaneously without providing a dedicated operating power transmission path. Since the first receiving device can
It is possible to simultaneously receive VHF/UHF television broadcasts and satellite broadcasts with a second receiving device.

<Example> The structure and operation of the apparatus of the present invention will be described with reference to FIGS. 1 to 3.

Figure 1 is a block diagram explaining this principle.
4 is a first high frequency device consisting of, for example, a VHF/UHF television signal amplification booster, and 4 is a second high frequency device consisting of, for example, a BS-IF converter for satellite broadcasting signals, and the high frequency signals supplied from each high frequency device are mixed. The signals are mixed in the filter 6 and transmitted to the duplexer 10 via one transmission line 8. The duplexer 10 is the first
The amplified television signal transmitted from the high frequency device 2 is supplied to the first receiving device 21, and the BS-IF converted signal of the satellite broadcast is supplied to the second receiving device 41. AC operating power of high frequency equipment 2,
The DC operating power of the high frequency device 4 is transmitted from the receiving devices 21 and 41 via the signal transmission path 8 and the mixer 6, respectively.

FIG. 2 is a circuit diagram of the main part showing an embodiment of the duplexer 10, in which the signal transmission path 8 is coupled to the input 14 of the duplexer main body 10a via a coupling capacitor 12, and The first output 16 of 10a is connected to the first output via a coupling capacitor 18 and a signal transmission line 20.
The second output 24 is coupled to a second receiving device 41 via a coupling capacitor 26 and a signal transmission path 28 .

The first receiving device 21 includes a power source that steps down a 100 V commercial voltage to generate, for example, 24 V AC operating power as shown in FIG. 3A, and the second receiving device 41 similarly includes a 3rd from 100V commercial voltage
A DC power supply that generates a DC operating power of, for example, 15V as shown in Figure B is included.

30 is a part constituting a switching circuit of a time division circuit which is the main part of this invention, and the receiving device 21
The AC power supplied from the first input terminal 31,
The signal is then supplied to the connection point 32 through a high frequency blocking low-pass filter consisting of an inductor L1 and a capacitor C1. Therefore, the high frequency signal from the first output 16 does not go around to the connection point 32 . The DC power supplied from the receiving device 41 is supplied to the line 34 via the second input terminal 33 and the same high-frequency blocking low-pass filter consisting of inductors L2, L3 and capacitors C2, C3. Therefore, there is no looping of the high frequency signal from the second output 24 to the line 34 either. Here, when the AC voltage at the connection point 32 shown in FIG.
1 and R2, turning on transistor T1 at _t1 in FIG. The voltage drop across bias resistors R3 and R4 also turns on transistor T2. Note that D3 is a protection diode for the transistor T2. At this time, the trigger diode D2, whose anode is grounded through the resistor R5, is in the off state, so the thyristor
Sr is not triggered and remains off. As the AC voltage passes through the positive peak and decreases, at t ₂ in FIG. ,T2
turn off together. Therefore, during the period t ₁ to _{t 2} when the polarity of the AC voltage in FIG. 3A is the same as the polarity of the DC voltage in FIG. For example, a direct current of 15 V appears, and the direct current power is transmitted to the mixer 6 through a high frequency blocking low-pass filter consisting of inductors L4, L5 and capacitor C4, an output terminal 35 and a signal transmission line 8. From t ₂ to t ₃ when the AC voltage A becomes 0, both the thyristor Sr and the transistor T2 are off, and the connection point 36 is in a no-voltage state.

At t ₃ when the AC voltage A reverses polarity, the trigger diode D2 conducts and turns on the thyristor Sr. At this time, the diode D1 is in a reverse bias state, so it is off, and therefore the transistor T
1, T2 also remains off. During the period t ₃ to t ₄ when the AC voltage A is of opposite polarity to the DC voltage B at the connection point 36, for example, as shown by Q1 in FIG.
A negative alternating current of 24V appears. This alternating current power is similarly transmitted to the mixer 6 via a low-pass filter consisting of inductors L4 and L5, a capacitor C4, an output terminal 35, and a signal transmission path. Thus, during each half cycle in which the polarity of the AC voltage is the same as the polarity of the DC voltage, DC power such as P1, P2, ... in FIG. During the half cycle in which the polarity of A is opposite to the polarity of the DC voltage, AC power such as Q1, Q2, . . . in FIG. In this way, the time division circuit 30 can transmit AC power and DC power having different voltages in a time division manner. For example, the mixer 6 on the high frequency equipment side has DC P1, P2... and AC Q1,
Q2... are separated into second high frequency equipment 4,
A separation circuit for supplying operating power to the first high-frequency device 2 is provided.

[Brief explanation of drawings]

Fig. 1 is a block diagram explaining the principle of the time-divisional transmission device for alternating current and direct current according to the present invention, and Fig. 2 explains the structure and operation of the main parts of the time-divisional transmission device for alternating current and direct current according to the present invention. FIG. 3 is a diagram showing voltage waveforms at various parts to explain the operation of the circuit shown in FIG. 2, and FIG. 4 is a block diagram showing a conventional device. 8... Signal transmission line, 10... Branching filter, 10a...
...Dunplexer main body, 21...First receiving device, 31...
...First input terminal, 33...Second input terminal, 3
5... Output terminal, 41... Second receiving device, {D
1, D2...Diode, R1, R5...Resistor,
Sr...Thyristor, T1, T2...Transistor} Switching circuit.

Claims (1)

[Claims] 1. A first signal that is mixed and transmitted via a signal transmission path.
and a second high-frequency signal, and supply the first high-frequency signal to a first receiving device and the second high-frequency signal to a second receiving device. A time division circuit having a main body, a first input terminal connected to the first receiving device, a second input terminal connected to the second receiving device, and an output terminal connected to the signal transmission path. The time division circuit further comprises: an AC operating voltage having a first voltage supplied from the first receiving device to the first input terminal; The second input terminal is coupled to the output terminal during a half cycle of the same polarity as a DC operating voltage having a second voltage applied thereto to transmit the signal. the first input terminal is coupled to the output terminal during a half cycle in which the alternating current voltage is of opposite polarity to the direct current voltage, and the alternating current voltage having the first voltage is transmitted to the signal. A duplexer with a DC/AC power superimposition function, characterized by having a switching circuit that allows the power to be transmitted through a transmission path.