JPS5834641A - Signal transmitting and receiving device - Google Patents

Signal transmitting and receiving device

Info

Publication number
JPS5834641A
JPS5834641A JP13226081A JP13226081A JPS5834641A JP S5834641 A JPS5834641 A JP S5834641A JP 13226081 A JP13226081 A JP 13226081A JP 13226081 A JP13226081 A JP 13226081A JP S5834641 A JPS5834641 A JP S5834641A
Authority
JP
Japan
Prior art keywords
cable
signal transmission
signal
terminal
main device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP13226081A
Other languages
Japanese (ja)
Inventor
Cho Inagaki
稲垣　超
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP13226081A priority Critical patent/JPS5834641A/en
Publication of JPS5834641A publication Critical patent/JPS5834641A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/32—Reducing cross-talk, e.g. by compensating
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K3/00—Jamming of communication; Counter-measures
    • H04K3/80—Jamming or countermeasure characterized by its function
    • H04K3/82—Jamming or countermeasure characterized by its function related to preventing surveillance, interception or detection
    • H04K3/825—Jamming or countermeasure characterized by its function related to preventing surveillance, interception or detection by jamming

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Noise Elimination (AREA)

Abstract

PURPOSE:To restraint unnecessary radiation from a cable for signal transmission by wiring a cable for carrier wave that transmits a non-modulated signal having the same frequency with the carrier for signal transmission and greater power than signal transmitting power, near a cable for signal transmission. CONSTITUTION:A non-modulated signal of frequency f1 and power P2(P2>P1) is sent out from a carrier generator 13 to a cable 14 for carrier wave when a main unit 1 and a terminal 2 are transmitting and receiving at frequency f1, and power P1 using a cable 12 for signal transmission. The cable 14 shields the cable 12 and one end is grounded near the terminal and other end is released. Unnecessary radiation waves from the cable 12 is restrained by stronger radiation waves from the cable 14. Since radiation waves from the cable 14 is non- modulated, no influence is exerted by audible sound.

Description

【発明の詳細な説明】 本発明は信号送受信装置に関する。[Detailed description of the invention] The present invention relates to a signal transmitting/receiving device.

従来この稲の信号送受信装置は主装置と端末間の信号の
送受信は、搬送波に変調波を重畳したり、ある一定の周
波数での信号を送受信していた。Conventionally, this rice signal transmitting and receiving device transmitted and received signals between the main device and the terminal by superimposing a modulated wave on a carrier wave or by transmitting and receiving signals at a certain frequency.

このため、搬送波周波数や信号送受信周波数が高くなっ
友り、を友は、それらの高調波が発生したりして信号送
受信ケーブルより空中に放射され、ラジオ周波数帯域ま
で高くなった時、その変調波又は信号が可聴性のあるも
のである場合、ポータプルラジオ等で盗聴される可能性
があった。For this reason, as the carrier frequency and signal transmission/reception frequency increase, harmonics of these waves are generated and radiated into the air from the signal transmission/reception cable, and when the frequency reaches the radio frequency band, the modulated wave Or, if the signal was audible, there was a possibility that it could be eavesdropped using a portable radio or the like.

本発明の目的は、主装置と端末間の送受信用ケーブルか
ら漏れる電波を抑圧し、前記欠点を除去したものである
。An object of the present invention is to suppress radio waves leaking from a transmission/reception cable between a main device and a terminal, thereby eliminating the above-mentioned drawbacks.

本発明によると少なくとも一つの主装置と、該主装置に
接続される複数個の端末と、前記主装置と紛記端末間の
信号送受信用ケーブルと、前記信号送受信用ケーブルの
近くに配線され、前記主装置に１ｉＩ続され前記主装置
と前記端末間の信号送受信周波数に一致した無変調信号
を送出するケーブルとを含むことを特徴とする信号送受
信装置が得られる。According to the present invention, at least one main device, a plurality of terminals connected to the main device, a signal transmission/reception cable between the main device and the registration terminal, and wired near the signal transmission/reception cable, There is obtained a signal transmitting/receiving device characterized in that it includes a cable that is connected to the main device and transmits an unmodulated signal matching the signal transmission/reception frequency between the main device and the terminal.

次に本発明の実施例について図面を参照して説明する。Next, embodiments of the present invention will be described with reference to the drawings.

第１図は本発明の一実施例のプロ、り図で、第１図を参
照すると、本発明の実施例は主装置１の信号送受信部１
１と接続され、端末２間ＶＣ接続される信号送受信用ケ
ーブル１２と、主装置２の搬送波送信部１３に接続され
、信号送受信用ケーブル１２ｆｆｉシールドし、搬送波
を送出する一端を端末の近くて了−スし、他端を開校と
したケーブル１４とにより構成される。FIG. 1 is a professional diagram of one embodiment of the present invention. Referring to FIG.
A signal transmission/reception cable 12 is connected to 1 and connected to the terminal 2 by VC, and a signal transmission/reception cable 12ffi is connected to the carrier wave transmitter 13 of the main device 2, and one end that transmits the carrier wave is connected to the terminal near the terminal. - a cable 14 with one end open and the other end open.

図の構成で主装置１と端末２＃ｉ周波数ｆｌで、電力Ｐ
Ｉの変調した信号を送受信しているとき、主装置ｌの搬
送波送出Ｎ１３より周波数ｆｌで電力Ｐｇ（Ｐｇ＞Ｐｘ
）の無変調信号管送出する。このとき、ケーブル１２よ
り空中に放射される電波は当然ケーブル１４より空中に
放射される電波より弱い、一般にラジオ等の電波受信機
は、近接した搬送波による複数の電波を受信した場合、
強い電波を受信し、弱い方の電波管抑圧する回路を備え
ている。In the configuration shown in the figure, at main device 1 and terminal 2 #i frequency fl, power P
When transmitting/receiving a signal modulated by I, the power Pg (Pg>Px
) is sent out unmodulated signal tube. At this time, the radio waves radiated into the air from the cable 12 are naturally weaker than the radio waves radiated into the air from the cable 14.Generally, when a radio wave receiver such as a radio receives multiple radio waves with adjacent carrier waves,
It is equipped with a circuit that receives strong radio waves and suppresses weaker radio waves.

従って前記主装置１と端末間２間の送受信信号による弱
い電波は、ケーブル１４より放射される強い電波に抑圧
されて、ラジオ等には受信されない。Therefore, the weak radio waves caused by the transmitted and received signals between the main device 1 and the terminal 2 are suppressed by the strong radio waves radiated from the cable 14, and are not received by a radio or the like.

なお、この装置は、アナログ信号送受信装置、ディシイ
タル信号送受信装置のいずれにも適用され得る。Note that this device can be applied to either an analog signal transmitting/receiving device or a digital signal transmitting/receiving device.

以上説明したように、本発明によれば主装置。As explained above, according to the present invention, the main device.

端末間での送受信信号が空中に放射されるようなThe transmission and reception signals between terminals may be radiated into the air.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の一実施例管示すブｏ、り図である。 １・・・・・・主装量、２・・・・・・端末、１１・・
・・・・信号送受信部、１２＞・・・・・信号送受信ケ
ーブル、１３・・・・・・搬送波送信部、１４・・・・
・・搬送波送信ケーブル。FIG. 1 is a diagram showing an embodiment of the present invention. 1... Main loading amount, 2... Terminal, 11...
...Signal transmitting and receiving section, 12>...Signal transmitting and receiving cable, 13...Carrier wave transmitting section, 14...
...Carrier wave transmission cable.

Claims (1)

【特許請求の範囲】[Claims] 少なくとも一つの主装置と、該主装置に接続される複数
個の端末と、前記主装置と前記端末間の信号送受信用ケ
ーブルと、前記信号送受信用ケーブルの近くに配線され
、前記主装置に接続され前記主装置と前記端末間の信号
送受信周波数に一致した無変調信号を送出するケーブル
とを含むことｔ′特徴とする信号送受信装置。at least one main device; a plurality of terminals connected to the main device; a signal transmission/reception cable between the main device and the terminal; wired near the signal transmission/reception cable and connected to the main device. and a cable for transmitting an unmodulated signal matching a signal transmission/reception frequency between the main device and the terminal.
JP13226081A 1981-08-24 1981-08-24 Signal transmitting and receiving device Pending JPS5834641A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13226081A JPS5834641A (en) 1981-08-24 1981-08-24 Signal transmitting and receiving device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13226081A JPS5834641A (en) 1981-08-24 1981-08-24 Signal transmitting and receiving device

Publications (1)

Publication Number Publication Date
JPS5834641A true JPS5834641A (en) 1983-03-01

Family

ID=15077112

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13226081A Pending JPS5834641A (en) 1981-08-24 1981-08-24 Signal transmitting and receiving device

Country Status (1)

Country Link
JP (1) JPS5834641A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005114902A1 (en) * 2004-05-24 2005-12-01 Nippon Telegraph And Telephone Corporation Information leakage preventive device and information leakage preventive method

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005114902A1 (en) * 2004-05-24 2005-12-01 Nippon Telegraph And Telephone Corporation Information leakage preventive device and information leakage preventive method
JPWO2005114902A1 (en) * 2004-05-24 2008-03-27 日本電信電話株式会社 Information leakage prevention apparatus and information leakage prevention method
US7889866B2 (en) 2004-05-24 2011-02-15 Nippon Telegraph And Telephone Company Information leakage prevention apparatus and information leakage prevention method

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