JPH0725639U - Obstacle suppression device - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] The purpose is to suppress interference radio waves that adversely affect communication equipment and electronic equipment from a relatively short distance. [Structure] The output of the amplitude modulation type obstacle radio wave receiving unit 1 is 180 degrees phase-inverted by a phase inverter 8 and the output is again converted into a fixed intermediate frequency different from the reception frequency by an amplitude modulator 9, amplified and transmitted. Intrude into the partner obstacle source circuit to cancel, neutralize, and suppress the partner obstacle wave.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is intended to suppress unnecessary radio waves that enter the communication devices and electronic devices directly and intrude irrespective of whether they like it or not in the radio waves that constantly fly. Many of these radio waves that cause obstacles are illegal, and mobile radio, amateur radio, wiretapping radio, etc. are many, and most transmitters / receivers cannot be specified. Therefore, in the present invention, it is intended to provide a measure against these, which has not been dealt with in the past.

[0002]

[Problems to be solved by the device]

 As mentioned in the previous section, it is almost impossible to find the source of radio waves that cause interference, and of course the source of reception is also the same. Therefore, in the present invention, communication is suppressed by using wireless guidance for a relatively short distance.

[0003]

[Methods for solving problems]

 That is, the method according to the present invention positively tunes and receives these obstacle radio waves, phase-inverts the output waveform by 180 degrees, transmits this on the intermediate frequency that is easily induced and mixed in the other device, and cancels it with the original waveform. This will suppress communication.

[0004]

[Constitution of the product]

 FIG. 1 is a block diagram of an example of the product of the present invention. The receiving unit 1 is a general amplitude modulation type super heterodyne system, and an input signal is input from a receiving antenna 2, is converted to an intermediate frequency by a frequency converter 4 and a local oscillator 5 via a high frequency amplifier 3. The frequency of this intermediate frequency is usually 455 kHz, 10.7 MHz, etc., but in the present invention, these frequencies are used for the transmission output of the latter stage, so this frequency is set avoiding this. The signal converted to the intermediate frequency is amplified by the intermediate frequency amplifier circuit 6 and detected by the next detector 7.

Up to this point, there is no change from the circuit used in a general receiver, and only the selection of the intermediate frequency is different. Next, the detected signal is phase-inverted by 180 degrees through the phase inverter 8 which is a feature of the present invention. FIG. 2 shows an example of a typical circuit of the phase inverter. That is, the operational amplifier 15 uses, for example, one element such as μA741 and is composed of resistors R ₁ , R ₂ , R ₃ , R ₄ and capacitors C ₁ , C ₂ , C ₃ as peripheral components.

The signal passes through the operational amplifier 15 from the input terminal 13, the phase of the signal is inverted by 180 degrees, and the signal is output to the output terminal 14. This output waveform is the opposite of the input waveform, and if they overlap, they will cancel each other out.

This output is converted into a frequency set by the following amplitude modulator 9 and local oscillator 10, amplified by the power amplification unit 11, and transmitted and output by the transmission antenna 12. For this frequency, the frequency used for the intermediate frequency of the so-called super-heterodyne system such as 455 kHz, which is estimated to be widely used in electronic device circuits, or 10.7 MHz is used. In electronic equipment circuits, high-frequency circuits shield the necessary parts, but they are not always 100% perfect. Therefore, in the device of the present invention, this frequency is selected because it is often used in the other party's circuit and it is easy to enter and approach.

[0008]

[Effects of this product]

 When a radio wave causing an obstacle is found, first, the reception frequency of the device of the present invention is tuned to the obstacle radio wave. Then increase the transmission output of this unit. An output with a waveform opposite in phase to the received waveform is transmitted from this unit. This output frequency uses the same frequency as the intermediate frequency used by most of the transmitters and receivers that emit radio waves for interference, so the intermediate frequency is tuned to the amplifying circuit. The waveform of this incoming wave has a phase opposite to that of the wave of the disturbing radio wave, and neutralizes and suppresses the disturbing radio wave.

[Brief description of drawings]

FIG. 1 is a block diagram of the product of the present invention.

FIG. 2 is a circuit diagram of an example of a phase inverter used in the device of the present invention.

[Explanation of symbols]

1 Receiving Section 2 Receiving Antenna 3 High Frequency Amplifier 4 Frequency Converter 5 Local Oscillator 6 Intermediate Frequency Amplifier 7 Detector 8 Phase Inverter 9 Amplitude Modulator 10 Local Oscillator 11 Power Amplifier 12 Transmitting Antenna 13 Input Terminal 14 Output Terminal 15 Op Amp 16 Transmission Part R ₁ , R ₂ , R ₃ , R ₄ resistors C ₁ , C ₂ , C ₃ capacitors

Claims (1)

[Scope of utility model registration request] 1. An amplitude modulation type radio receiving circuit detects a received signal, phase-inverts its output by 180 degrees by a phase inversion circuit, amplitude-modulates it again, and converts it into a fixed frequency different from the reception frequency, power amplification. Obstacle radio wave suppression device