JPH08162995A - One frequency simplex communication system radio equipment - Google Patents

Abstract

PURPOSE: To make it possible to turn on the power source of a voltage control transmitter at all times by the use of a simple constitution, to eliminate the stabilization waiting time of the transmitter at the time of the input of the power source and to quickly stabilize communication by suppressing the sneak path of the output of the voltage control transmitter to a reception circuit. CONSTITUTION: By providing a transmission-reception changeover circuit 7 on the terminal of an antenna 1 and cutting off the antenna to a transmission side and a reception side at the time of transmission and reception, the output of the voltage control transmitter 4 on the transmission side is prevented from leaking to the reception side via the antenna. The phase of the output signal of the voltage control transmitter 4 is inverted by 180 degrees by a phase inversion amplifier 8, is radiated from a printing wiring and is made to cancel with spatial radiation leakage. Thus, by adding a simple circuit, the leakage between transmission and reception is suppressed, the turning on the power source of the voltage control oscillator on the transmission side becomes possible and stable transmission and reception become possible without waiting oscillation stabilizing time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 1-frequency simplex communication type radio device, and more particularly to a 1-frequency simplex communication type radio device requiring high-speed switching of transmission and reception.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional one-frequency simplex communication type radio apparatus includes a voltage-controlled oscillator 4 which outputs an FSK carrier wave as an input of a modulation signal as a transmission circuit, and an FSK.
It has a high frequency amplifier 2 for amplifying a carrier wave, a high frequency amplifier 3 as a receiving circuit for amplifying a received carrier wave input and outputting an amplified signal, and a mixer 6 for outputting a difference between the amplified signal and a local oscillator 5 as an intermediate frequency. High frequency amplifiers 2 and 3
The antenna 1 is connected between and.

The operation of the one-frequency simplex communication type wireless device configured as described above will be described below.

In FIG. 2, when an FSK carrier wave is to be transmitted by a modulation signal, a voltage controlled oscillator 4 constituting a transmitting circuit and a high frequency amplifier 3 constituting a receiving circuit are turned on and mixed with a high frequency amplifier 3 constituting a receiving circuit. The power source of the local oscillator 5 is turned on while the power source of the device 6 is turned off. On the contrary, when an FSK carrier wave from the outside is to be received, the power source of the voltage controlled oscillator 4 and the high frequency amplifier 2 that form the transmission circuit are turned off, and the high frequency amplifier 3 that forms the reception circuit and the mixer 6 are provided. The power of the local oscillator 5 is turned on.

By controlling the power supply as described above, the one-frequency simplex communication type radio device performs a switching operation between transmission and reception.

[0006]

In this conventional one-frequency simplex communication type radio device, when switching from the reception state to the transmission state, the time during which the voltage controlled oscillator 4 constituting the transmission circuit is stably in the oscillation state is provided. It was necessary to have a modulation signal for transmission.

Generally, the oscillation stabilization time of the voltage controlled oscillator 4 is as long as several ms, which causes deterioration of the communication speed in a communication mode in which switching between transmission and reception frequently occurs.

Further, in order to eliminate the stabilization time of the voltage controlled oscillator 4, when the power source of the voltage controlled oscillator 4 on the transmitting side is constantly turned on, the signal component of the voltage controlled oscillator 4 spills over to the receiving circuit and the receiving circuit Degrades performance.

Regarding the method for preventing this wraparound,
By monitoring the leakage power appearing at the intermediate frequency of the receiving circuit,
In order to cancel it, there is a method of branching from an oscillator on the transmitting side and controlling a leakage component and a component of opposite phase by a microcomputer and coupling them to an intermediate frequency to positively remove this sneak (for example, JP-A-1-174018). (Japanese Patent Laid-Open No. 1-311733).

However, such a method has a limit of a circuit scale and a problem of price, which is difficult to realize in practice. Further, the above method is premised on that the frequency component of leakage and the received carrier frequency are different, but both are the same frequency. For example, it does not work in a one-frequency simplex communication type radio that directly modulates the carrier frequency.

Similarly, as a technique for preventing this sneak, a voltage-controlled oscillator was skillfully shielded. However, in this method using a shield, the voltage-controlled oscillator and the receiving circuit are arranged on the printed wiring board. If it is near, it is very difficult to reduce the leakage of spatial radiation, which is an obstacle to making a small radio device.

Therefore, the object of the present invention is to prevent the voltage controlled oscillator from sneaking into the receiving circuit, so that the power source of the voltage controlled oscillator can be constantly turned on, and the transition from reception to transmission can be performed at high speed. It is to provide a simplex communication type radio.

[0013]

According to the one-frequency simplex communication system radio of the present invention, an antenna is provided in the one-frequency simplex communication system radio having a voltage controlled oscillator that directly outputs an FSK carrier by a modulation signal input. A transmission / reception switching circuit provided at an end and a phase inversion amplifier for separating and inverting and amplifying the output of the voltage controlled oscillator, and the output of the phase inversion amplifier is wired on a printed wiring board. A 1-frequency simplex communication type radio device that can be obtained is obtained.

Further, according to the present invention, in the one-frequency simplex communication type radio having a voltage controlled oscillator which directly outputs the FSK carrier by the input of the modulated signal, the FSK carrier is output to the input of the modulated signal as the transmission circuit. Voltage-controlled oscillator, a high-frequency amplifier that amplifies this carrier signal as a transmission carrier, a phase inverting amplifier that inverts the phase of the carrier signal and outputs it as an opposite phase signal, and radiates the opposite phase signal in space. Wiring on the printed wiring board for
As a receiving circuit, a high-frequency amplifier that amplifies the FSK carrier signal input from the antenna, a mixer that outputs the difference between the amplified signal and the local oscillator as an intermediate frequency, and a transmission and reception signal path provided at the antenna end are switched. A single-frequency simplex communication type wireless device including a transmission / reception switching circuit can be obtained.

[0015]

According to the one-frequency simplex communication type radio of the present invention,
Even if the power of the voltage controlled oscillator is turned on during reception, it is possible to suppress the output of this voltage controlled oscillator from sneaking into the receiving circuit, and to switch between transmission and reception at high speed by adding an inexpensive part with a small circuit scale. You can

Further, by providing the transmission / reception switching circuit at the antenna end, it is possible to suppress the leakage route passing through the antenna end to almost zero.

Further, regarding the spatial radiation leakage which remains as the leakage route, the phase of the output signal of the voltage controlled oscillator is set to 18
The phase inversion amplifier which inverts by 0 degree and amplifies, and the output can be offset by the wiring on the printed wiring board which radiates the space positively.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a one-frequency simplex communication type radio device of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a one-frequency simplex communication type wireless device according to one embodiment of the present invention.

Referring to FIG. 1, a single-frequency simplex communication type radio device includes a voltage control oscillator 4 which outputs a FSK carrier wave in response to a modulation signal input as a transmission circuit, and a high frequency wave which amplifies this carrier wave signal as a transmission carrier wave. An amplifier 2, a phase inverting amplifier 8 that inverts the phase of a carrier signal and outputs it as an opposite phase signal, and wiring (not shown) on a printed wiring board for radiating the opposite phase signal into space. , A high-frequency amplifier 3 that amplifies a FSK carrier signal input from the antenna as a receiving circuit, a mixer 6 that outputs the difference between the amplified signal and the local oscillator 5 as an intermediate frequency, and a transmitter and a receiver provided at the end of the antenna 1. Transmission / reception switching circuit 7 for switching the signal path
It has and.

The operation of transmission and reception in the embodiment having the above configuration will be described below.

When the FSK carrier wave is to be transmitted by the input signal, the power supplies of the voltage controlled oscillator 4 and the high frequency amplifier 2 forming the transmission circuit are turned on. The power of the phase inverting amplifier 8 is turned off. High-frequency amplifier 3 that constitutes the receiving circuit
The power supply to the mixer 6 is turned off. The power source of the local oscillator 5 is turned on. The transmission / reception switching circuit 7 is on the terminal a side.

On the contrary, when the carrier wave from the outside is to be received, the power supply of the high frequency amplifier 2 which constitutes the transmission circuit is turned off. The power supplies of the voltage controlled oscillator 4 and the phase inverting amplifier 8 are turned on. Further, the high-frequency amplifier 3, the local oscillator 5, and the mixer 6, which form the receiving circuit, are powered on.
The transmission / reception switching circuit 7 is on the terminal b side.

By controlling the power supply as described above, single-frequency simplex communication is enabled. Here, the feature of this one-frequency simplex communication radio is that the voltage-controlled oscillator 4 operates during reception.
Even if the power source of the above is turned on, it is possible to prevent the output of the voltage controlled oscillator 4 from sneaking into the receiving circuit. That is, as compared with the conventional technique, it is possible to realize a one-frequency simplex communication type wireless device capable of switching between transmission and reception at high speed by adding an inexpensive portion having a small circuit scale.

The mechanism for suppressing the frequency leakage of the transmission side voltage controlled oscillator to the receiving circuit will be described below.

In the reception state, when sneaking into the receiving circuit of the voltage control oscillator 4 on the transmission side due to the fact that the power supply of the voltage control oscillator 4 on the transmission side is turned on is viewed by route, the antenna 1 common to transmission and reception is selected. There are two types of leakage: one that leaks through the end of the antenna 1 when used, and one that leaks due to space radiation in which the oscillation frequency of the voltage controlled oscillator 4 is radiated into space and directly jumps into the receiving circuit.

By providing the transmission / reception switching circuit 7 according to the present invention at the end of the antenna 1, it is possible to suppress the leakage route passing through the end of the antenna 1 to almost zero. Regarding the spatial radiation leakage that remains as a leakage route, a phase inverting amplifier 8 that inverts the phase of the output signal of the voltage controlled oscillator 4 by 180 degrees and amplifies it, and a printed wiring board that radiates its output positively into the space. It can be offset by the wiring. Here, the phase inverting amplifier 8
Uses a polarity inversion type transistor amplifier, and manually adjusts the amplification factor of the amplifier with a variable resistor or the like. This does not mean that the adjustment needs to be made for each device, but it means that this operation is guaranteed without adjustment if the optimum circuit constant can be obtained once for the same device.

The length of the wiring on the printed wiring board that radiates the output of the phase inversion amplifier 8 into the space is appropriately determined according to the strength of the leaking signal. This is because the positional relationship between the phase inverting amplifier 8 and the receiving circuit is different for each device, and thus the magnitude of leakage cannot be grasped in advance.
Radiation to the space of the voltage-controlled oscillator 4 on the transmitting side is not originally designed for this purpose, and therefore the length of the wiring on the printed wiring board for sending out the anti-phase wave into the space is very small. It can be short. Further, when the transmission / reception switching circuit 7 added to the end of the antenna 1 is made into an IC and is small in size, the circuit scale does not become so large.

As described above, according to the one-frequency simplex communication type radio apparatus of the present invention, the voltage controlled oscillator 4 and the local oscillator 5 are always turned on by adding an inexpensive and small-scale circuit to the voltage controlled oscillator. It is possible to shift from reception to transmission at high speed without waiting for the oscillation frequency of 4 to stabilize.

In the above embodiment, the voltage controlled oscillator 4
The case where the frequency of the local oscillator 5 is constant has been described, but the present invention is also advantageous for a single-frequency simplex communication type wireless device in which the oscillation frequency can be freely changed by combining a PLL synthesizer and a voltage controlled oscillator. The invention is not limited to the above embodiment.

[0030]

As described above, according to the present invention, a circuit for switching between transmission and reception of an antenna, a phase inverting amplifier for separating and inverting and amplifying the output of a voltage controlled oscillator on the transmission side, and the phase inverting amplifier By adopting the 1-frequency simplex communication method wireless with the wiring on the printed wiring board that radiates the output spatially, the transmission / reception switching circuit can prevent leakage at the antenna end, which is a sneak into the receiving circuit of the voltage-controlled oscillator on the transmitting side. The leakage due to the spatial radiation from the voltage controlled oscillator is reduced by the phase inverting amplifier and the wiring on the printed wiring board that radiates the output to the space.

As a result, it is possible to always turn on the power supply of the voltage control oscillator on the transmission side, and as a result, the time for switching between transmission and reception, which has conventionally required a waiting time for oscillation stabilization of the voltage control oscillator on the transmission side, is shortened. Has the result that

Further, the circuit newly added according to the present invention has a circuit size much smaller than that of the conventional method aiming at the same effect, so that it is possible to realize miniaturization and low power consumption of the radio device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a one-frequency simplex communication type wireless device of the present invention.

FIG. 2 is a block diagram showing a conventional one-frequency simplex communication type wireless device.

[Explanation of symbols]

 1 Antenna 2, 3 High Frequency Amplifier 4 Voltage Controlled Oscillator 5 Local Oscillator 6 Mixer 7 Transmission / Reception Switching Circuit 8 Phase Inversion Amplifier

Claims (3)

[Claims] 1. In a 1-frequency simplex communication type radio device that outputs an FSK carrier wave when a modulation signal is input, a transmission / reception switching circuit provided at an antenna end and a voltage that outputs an FSK carrier wave as a transmission circuit when a modulation signal is input. A single-frequency simplex comprising a control oscillator and a phase-inverting amplifier that separates the output of the voltage-controlled oscillator and inverts and amplifies the phase, and outputs the output of the phase-inverting amplifier on a printed wiring board. Communication system radio. 2. A one-frequency simplex communication type radio device which outputs an FSK carrier wave by a modulation signal input, and a voltage controlled oscillator which outputs an FSK carrier wave in response to a modulation signal input as a transmission circuit, and a carrier wave of this carrier wave signal. , A phase inversion amplifier that inverts the phase of the carrier signal and outputs it as an opposite phase signal, wiring on a printed wiring board for radiating the opposite phase signal into space, and As a circuit, a high frequency amplifier that amplifies the FSK carrier signal input from the antenna, a mixer that outputs the difference between the amplified signal and the local oscillator as an intermediate frequency, and a transmission / reception that switches the transmission and reception signal paths provided at the antenna end A single-frequency simplex communication type wireless device comprising a switching circuit. 3. The one-frequency simplex communication type wireless device according to claim 1, wherein the phase inverting amplifier is a polarity inverting type transistor amplifier.