US1722789A - Antiinterference radio signaling system - Google Patents

Description

y 30, 1929- H. J. J. M. DE R. DE BELLESCIZE v1,722,739

ANTIINTERFERENCE RADIO SIGNALING SYSTEM Filed March 19, 1924 DETECTED our [FREQUf/VCX L -uu- -"mavwmtoz [Mi/H.011 R. 0: 862A [Sp/z:

Patented July 30, 1929.

warren stares mazes earner caries.

HENRI JEAN JOSEPH MARIE DE BEGNAULD DE BELLESOIZE, 0F PARIS, FRANCE.

ANTIIN'IERFERENGE RADIO SIGNALING SYSTEM.

Application filed March 19, 1924, Serial No. 760,246, and in France April 20, 1923;

The present invention relates to a new and improved anti-interference system for radio signalling.

More specifically my invention relates to asystem which utilizes the fact that oscillations caused by disturbances in the receiving apparatus present, as compared with the os cillation of the signal, a difference in phase that changes from one disturbance to another.

By combining conveniently with a local oscillation or wave of a phase that is constant with relation to the wave of the sig nal, a complex oscillation is set up by virtue of the combined effect of the signal wave and the wave due to atmospherics, and it is found that, by choosing a convenient phase for the local or auxiliary oscillations, the eiiect of the atmospheric waves upon the in dicating device can be diminished in a given proportion with reference to the energy of" the signal.

Let us consider the case of a receiving apparatus simultaneously passed by:

A signal: S sin (Mi-Q) A stray oscillation: Pe' sin (wt+) An auxiliary oscillation: A sin (n+5) of the same frequency as the signal and constantly adjustedwith reference to it.

Various objects and advantages of my invention will appear from the following description taken in connection with the accompanying drawing in which,

The figure is a schematic diagram of a preferred embodiment of my invention.

The signals of a form S sin (wttgb), the frequency of which is preferably lowered by the aid of any convenient means (heterodyne, for instance) act upon the circuit 1 which is connected with tubes 2 and 3. The circuit 1 is a low frequency receiving circuit placed beyond the ordinary detector which is not shown. The local source of oscillations acts I at some point of the high frequency circuits in front of the detector. Tube 2 transmits the incoming oscillations to resonance circuit 7 possessing a high time constant through the intermediary of tube 4 and a coupling 5-6, comprising a variable mutual inductance and a potentiometer device, so that allowance is made for adjusting the phase 5 of the local oscillation of the form A sin (wt+) induced in 7 By convenient adjustment, equality between qi and E is possible. The signal is integrally recorded, whereas a given stray will be diminished to an extent measured by cos The resonator 7 tuned to pulsation of the signal, has a very high timec0nstant, or in other words, low damping. As a consequence, the signal periodically interrupted by keying is changed in 7 into an unbroken oscillation, consecutive trains corresponding to 7 si nal impulses becoming superposed upon one another on account of the high time constant. 7 therefore is the seat of an auxiliary oscillation being more or less continuous and of the same periodas the signal. After this result is attained, it becomes necessary to insure phase coincidence by the means 5-6. In other. words, the operator is able to impart to the phase 5 of the auxiliary oscillation at 7 any desired value. In doing this, he is guided by the intensity of the signal received at 8, the intensity being of a maximum value for since cos s-) =1.

The arrangement of 5-6 consists of two coupling d-evices,the one inductive (trans-- such a way that after having passed the resonator 7 they will'reinforce the signal oscillations coming directly from circuit 1 to valve 3. Since all parasitic oscillations whether damped or not will have some phase (which is moreover variable if the oscillations are damped) and this phase will in almost every case be'different from that of the signal, the beats due to the heterodyne and the parasite will not be'reinforced by the current derived from circuits 2, 5, 6, 1,7, The oscillation of the form A sin (wt+) is the local oscillation produced by the passage of part of the current coming from the resonator 1 through the assemblage 2, 5, 6, 4, 7, and not by a separate source. This oscillation has naturally the same oscillation as thesignal. The local oscillation is therefore, as has just been shown, different from that of the heterodyne employed to lower the frequency. The high frequency current is first combined with the heterodyne and rectified shown in the drawing. On issuing therefrom it is divided into two parts of which the one is fed directly to the valve 3 Without change while the other is by the assemblage 2, 5, 6, 4, 7, adjusted inphase and transformed into a quasi stationary oscillation. The phase of the oscillation fed directly from 1-3 is qiv while the phase adjusted in 56 of the oscillations transmitted'by the shunt circuit is The resultant phase acting on the valve 3 is rf. I Therefore the continuous current inthe plate circuit of valve 3 and in the indicator 8' is proportional to. S cos ;5$). By

suitable adjustmentof the elements 5 and 6 the current becomes proportional to the signal on the signalling oscillation, which comprises diverting a portion of the signaling oscillations forproducing an auxiliary oscillation of the same frequency as the signalling oscillations and adjusting the phase of said auxiliary oscillation with respect to that of the signalling oscillations whereby the disturbing oscillations are-weakened with reference to the signal oscillations.

2. In radio signalling, the method of minimining the effects of disturbing oscillations on the signalling oscillations, which comprises diverting a portion of the signaling oscillations for producing an auxiliary oscillation of the same frequency as the signalling oscillations, adjusting the phase of said auxiliary oscillation with respect'to that of the signalling oscillations, and recombining the diverted portion with'the signaling oscillations, whereby the disturbing oscillations are weakened with reference to the signal oscillations.

I In radio signaling, the method of minimining the effects of disturbing oscillations on the signaling oscillations which comprises combining the incoming energy with oscillations derived therefrom of the same frequeir cy as the signaling oscillations and adjusting the phase thereof to strengthen the signaling oscillations relative to the disturbing oscillations.

4. A device for receiving signaling oscillations and reducing the effects of disturbing waves comprising means responsive to the received energy and means for applying oscillations of the same'frequency as the sig naling oscillations to said first named means, said last named means comprising means for adjusting the phase of theapplied oscillations for reinforcing the signaling oscillations.

5. A device for receiving signaling oscillations and reducing the effects of disturbing oscillations comprising a main circuit including'signal responsive means and an auxiliary circuit connected to said signal responsive means and to saidmain circuitadapted to ship of the oscillations therein with respect to the signalling oscillations to obtain maxi mum intensity, said auxiliary circuit including a portion having a high time constant.

j 7. A device for receiving signalingv oscillations and reducing the effects of disturbing oscillations including a resonant circuit, a vacuum tube connectedto said circuit and signal responsive means connected to said vaccuin tube, an auxiliary circuit connected to said signal responsive means including two vacuum tubes connected in cascade to said resonant circuit adapted to derive energy from the incoming signaloscillations'and said v circuit comprising means for adjusting the phase relationship of the oscillationsin saidvacuum tubes whereby they will reinforce the signaling oscillations, said circuit also comprising a portion having a high time.

constant. j V

8. A circuit arrangement for receiving signalling oscillations and reducing the effects of disturbing oscillations, comprising a main circuit for receiving a major portion of the incoming energy, a shunt circuit comprising means for diverting a portion of the incoming energy, phase adjusting means connected with said shunt circuit for insuring phase coincidence between the diverted portion of the incoming energy and the main portion,

and means for recombining both of said portions, whereby the signalling oscillations are reinforced and the disturbing oscillations weakened. I I a 9. In radio signalling, the method of'minimizing the effects of disturbing oscillations on the signalling Wave which comprises di verting a portion of the signalling wave for producing an auxiliary oscillation of the same frequency as the signalling wave, rejecting the disturbing oscillations within a circuit having a high time constant, adjusting the phase of said auxiliary oscillation with respect to that of the signallingwave, and re combining the diverted portion withthe signalling wave wherebythe disturbing oscillations are weakened relative to the signal wave.

HENRI JEAN JOSEPH MARIE de REGNAULD de strrrsclzli.

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