JPH05129970A - Transmitter - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a transmission device capable of preventing any unwanted waves generated by, for example, oscillation of an amplifier from being emitted to the outside world. According to the present invention, a phase synthesizer 6 is a signal obtained by returning a high frequency signal output from a transmitter 2 via a folding tester 3, a variable attenuator 4 and a phase shifter 5 to an intermediate frequency signal. , A control circuit for synthesizing the intermediate frequency signal input from the directional coupler 1 and, as a result, when any signal is output from the phase synthesizer 6, that is, when both intermediate frequency signals are different. Reference numeral 8 has a configuration in which it is determined that an unnecessary wave is output from the transmitter 2 by the detection voltage of the detector 7, and the transmission operation of the transmitter 2 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-sized transmitter, and more particularly to a circuit for preventing unnecessary oscillation from being emitted.

[0002]

2. Description of the Related Art Conventionally, in a large transmission device, when the local oscillation is out of lock, the transmission is stopped so that unnecessary waves are not emitted to the outside world. However, when an unnecessary wave is generated due to the oscillation of the amplifier in the transmitter, the above function does not work, and the unnecessary wave is emitted to the outside world, which causes various troubles.

[0003]

Conventionally, in a large-sized transmitter, when an unnecessary wave is oscillated by the oscillation of an amplifier,
Since no measures were taken to prevent this from being emitted to the outside world, there was a drawback in that the unwanted waves were emitted to the outside world, causing various obstacles.

Therefore, the present invention eliminates the above-mentioned drawbacks, and an object of the present invention is to provide a transmitter capable of preventing the emission of all unnecessary waves generated by, for example, oscillation of an amplifier to the outside.

[0005]

According to the present invention, an intermediate frequency signal is input to a transmitter, the transmitter converts the intermediate frequency signal into a high frequency signal and outputs the high frequency signal to an antenna, which is output from the transmitter. Converting means for converting the high frequency signal to the original intermediate frequency signal, comparing means for comparing the intermediate frequency signal converted by the converting means with the intermediate frequency signal input to the transmitter, and the comparing means. When it is determined by the determination means that determines whether or not the two intermediate frequency signals are different by the result of comparison, and the both intermediate frequency signals are different by this determination means,
And a control means for stopping the operation of the transmitter.

[0006]

In the transmitting apparatus of the present invention, the converting means converts the high frequency signal output from the transmitter into the original intermediate frequency signal. The comparing means compares the intermediate frequency signal converted by the converting means with the intermediate frequency signal input to the transmitter. The determining means determines whether or not the intermediate frequency signals are different from each other, based on the comparison result of the comparing means. The control means stops the operation of the transmitter when the determination means determines that the two intermediate frequency signals are different.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the transmitting apparatus of the present invention. 1 is a directional coupler that inputs the intermediate frequency signal input from the input terminal 9 to the transmitter 2 and the phase synthesizer 6, and 2 is a transmission that converts the input intermediate frequency signal into a high frequency signal and outputs it to the antenna 10. 3 is a folding tester for inputting a part of the output signal of the transmitter 2 and converting it to the original intermediate frequency signal. 4 is a variable attenuator for adjusting the level of the intermediate frequency signal output from the folding tester 3. Reference numeral 5 is a phase shifter for adjusting the phase of the intermediate frequency signal output from the variable attenuator 4, and 6 is an intermediate frequency signal input from the directional coupler 1 and an intermediate frequency signal input from the phase shifter 5. A phase combiner for combining, 7 is a detector for detecting the combined signal output from the phase combiner 5, 8 is a control circuit for controlling the transmission operation stop of the transmitter 2 based on the detection result of the detector 7, and 9 is Input terminal to which the intermediate frequency signal is input, 10 is high An antenna for radiating a wave signal to the outside world.

Next, the operation of this embodiment will be described. The intermediate frequency signal input from the input terminal 9 is a directional coupler 1
Is input to the transmitter 2 and the phase combiner 6. Transmitter 2
After performing various processes such as converting the input intermediate frequency signal into a high frequency signal, the obtained high frequency signal is transmitted to the antenna 10
Output to. From the antenna 10, the high-frequency signal becomes a radio wave and is radiated to the outside world. On the other hand, a part of the high frequency signal output from the transmitter 2 is input to the folding tester 3 and converted into the original intermediate frequency signal, and then input to the variable attenuator 4. The variable attenuator 4 is adjusted so that the level of the input intermediate frequency signal is the same as the level of the intermediate frequency signal input from the directional coupler 1 to the phase synthesizer 6, and then the obtained intermediate frequency signal is obtained. To the phase shifter 5. The phase shifter 5 adjusts the phase of the input intermediate frequency signal so that the phase is opposite to the phase of the intermediate frequency signal input from the directional coupler 1 to the phase combiner 6, and then obtains it. The intermediate frequency signal thus obtained is output to the phase synthesizer 6. Phase synthesizer 6
Is to combine the intermediate frequency signal input from the directional coupler 1 and the intermediate frequency signal input from the phase shifter 5, and output the combined wave to the detector 7.

When the frequency of the high frequency signal output from the transmitter 2 is a predetermined value, the directional coupler 1
Since the level of the intermediate frequency signal output from the phase shifter 5 and the level of the intermediate frequency signal output from the phase shifter 5 are the same and the phases of these intermediate frequency signals are different by 180 degrees, the phase synthesizer 6 outputs the two , The combined wave becomes zero. Therefore, at this time, the detection voltage output from the detector 7 is 0
Becomes However, due to the lock deviation of the local oscillation frequency in the transmitter 2 or the abnormal oscillation of the amplifier in the transmitter 2, a high frequency (unwanted wave) having a different frequency from the transmitter 2 is generated.
Is output, the level of the intermediate frequency signal output from the directional coupler 1 differs from the level of the intermediate frequency signal output from the phase shifter 5, or the phase difference between these two signals deviates from 180 degrees. Therefore, the composite wave of the phase combiner 6 does not become 0, and some signal is input to the detector 7.
As a result, the detection voltage output from the detector 7 does not become 0, so the control circuit 8 monitors this detection voltage, and when it does not become 0, determines that the unnecessary wave is being output from the transmitter 2 and transmits it. The transmission operation of the machine 2 is stopped.

According to this embodiment, the intermediate frequency signal input from the input terminal 9 and the high frequency signal output from the transmitter 2 are controlled by the folding tester 3 to the original intermediate frequency signal. The control circuit 8 judges that the unnecessary wave is emitted from the transmitter 2 and stops the operation of the transmitter 2 when the two signals are different from each other, so that the cause of the unnecessary wave is generated. Even if there is, it is possible to prevent the unnecessary wave from being output from the transmitter 2, and of course the antenna 1
It is possible to reliably prevent the unnecessary wave from being emitted to the outside from 0.

In addition to the above-described embodiment, the same effect can be obtained with the same configuration when the unnecessary wave is emitted from the large receiver. That is, a part of the high frequency signal input to the receiver that selects the high frequency signal input from the antenna and converts the high frequency signal into the intermediate frequency signal is converted into an intermediate frequency signal by a folding tester, and the intermediate frequency signal is received by the receiver. The intermediate frequency signal output from the variable attenuator 4 of FIG.
The same circuit as the phase shifter 5 and the phase combiner 6 is used for comparison, and when the detection voltage of the comparison result is not 0, the operation of the receiver is stopped so that the receiver emits the signal. Radiation of unnecessary waves to the outside can be prevented by the same configuration as the above embodiment.

[0012]

As described above, according to the transmitter of the present invention, it is possible to prevent the emission of all unnecessary waves generated by, for example, the oscillation of the amplifier to the outside world.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a transmission device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Directional coupler 2 ... Transmitter 3 ... Folding tester 4 ... Variable attenuator 5 ... Phase shifter 6 ... Phase synthesizer 7 ... Wave detector 8 ... Control circuit

Claims (1)

[Claims] 1. A transmission device for inputting an intermediate frequency signal to a transmitter, which converts the intermediate frequency signal into a high frequency signal and outputs the high frequency signal to an antenna, wherein the high frequency signal output from the transmitter is the original signal. Converting means for converting into an intermediate frequency signal, comparing means for comparing the intermediate frequency signal converted by the converting means with the intermediate frequency signal input to the transmitter, and the both intermediates according to the comparison result of the comparing means. A determination means for determining whether or not the frequency signals are different; and a control means for stopping the operation of the transmitter when the determination means determines that the intermediate frequency signals are different. A transmitting device characterized by the above.