Патент USA US2408063код для вставки
Patented 8 Sept. 24,’ l 946 2,408,062 UNITED STATES PATENT OFFICE‘ 2,408,062 SIGNAL TRANSLATOR Donald D. Grieg, Forest Hills, N. Y., assignor to Federal Telephone and Radio Corporation, Newark, N. J ., a corporation of Delaware 1 Application May 24, 1943, Serial No. 488,178 9 Claims. (Cl. 250—20) This invention relates to radio receivers and particularly to pulse translating means in radio receivers and other electrical apparatus. It has been proposed heretofore to transmit pulses whose repetition rate or frequency varies according to F. M. (frequency modulation) prin ciple. That is,a train of pulses is modulated as to their repetition rate according to the in telligence to be conveyed thereby. One of the objects of my present invention is to provide a method and means for translating pulses of varying repetition rate into equivalent 2 by repetition modulated pulses by either wire or through space. Also it will be readily apparent that F. M. carrier energy may be transmitted and the intelligence conveyed thereby may be ?rst translated into pulses which vary in repe tition rate according to the frequency modula tion of, the carrier. ~ The output of the detector or other source of pulses Of varying repetition rate is applied to a local pulse generator M which preferably is ad ,justable to produce generated pulses having. a desired displacement. The generator l4 may‘ be time modulated pulses. ‘ of any known construction in which the opera Another object of my invention is to provide tion can be controlled by synchronizing pulses. a radio receiver adapted to detect and translate 15 By way of example, the generator may comprise pulses of varying repetition rate into equivalent a form of ‘relaxation oscillator such as a multi time modulated pulses for demodulation in a vibrator having a given mode of operation and T. M. (time modulation) demodulator. which is synchronizable by pulses occurring with; According to my invention provision is made in a given latitude of the operating frequency for generating locally a train of pulses the time 20 thereof- Such a multivibrator may be arranged displacement of vwhich is selected according to whereby the repetition’ modulated pulses detected the repetition modulation characteristics of the control the operation thereof so as to vary the pulses to be translated. This local generation of generation for alternate pulses in accordance with pulses may be performed by any one of several the instant repetition rate of ' the modulated methods whereby the generation may be synchro pulses received. nized' within a given latitude. The repetition modulated pulses are used to resynchronize the local pulse generator upon generation of alter As a further example of a local pulse generator the multivibrator may be associated with a re nate pulses. That is to say, alternate pulses locally generated are caused to coincide with the occurrence of succeeding pulses of the train of repetition modulated pulses, thereby translating the instant frequency characteristic thereof into a time displacement represented by the intervals between succeeding pairs of pulses. The adjust ment of the local pulse generator is such as to provide a normal time displacement between the generated pulses which is less than the minimum repetition interval but greater than one-half the ceiver of the triggering oscillator character sim ilarly as'disclosed in the copending application of E. Labin and myself, Serial No. 488,181, ?led May 24, 1943. As set forth in more detail in the afore said copending application, the triggering oscil lator, upon detection of a transmitted pulse, sets 7 up" an oscillation. ' The establishment of this os ' cillation, in accordance with the principles of the present invention, triggers the multivibrator - or synchronizes the multivibrator in accordance with the reception of the transmitted pulse, thereby initiating a new timing operation for the maximum repetition interval of the repetition 40 multivibrator. The output of the multivibrator modulated pulses. is applied to the triggering oscillator to ‘increase For a further understanding of the invention, the sensitivity thereof and consequently vary the reference may be had to the following detailed blocking potential for the‘ oscillator. ' , description to be read in connection with‘ the According to the present invention, the local 45 generator 14 is adjusted to repeat its operation accompanying drawing, in which: Fig. 1 is a block diagram of a radio receiver before the reception of the next succeeding pulse in accordance with my invention; and of the train of repetition modulated pulses. The Fig. 2 is a graphical illustration showing three pulse output of the generator is applied to any separate trains of signal pulses of di?erent repe suitable T. M. demodulator l6, which for exam tition rates. ' 50 ple, may be of the character disclosed in my afore Referring to Fig. 1, the radio receiver therein said application Serial No. 459,959. ' , shown is provided with a known detector l0 hav The region of synchronization for the generator ing an antenna l2 by which repetition modulated precedes the operation thereof a given interval pulses may be detected. It will be understood, of time during which the generator may be trigg of course, that intelligence may be transmitted 55 gered from one state of operation to another. 2,408,062 3 For repetition modulated pulses of a ?xed ampli tude, this region of synchronization is depend ent on the time constants of the pulse generator. In Fig. 2 there is shown for purposes of illus trating the principles of the invention, a series of curves having the same time base. Curve (2 represents a series of locally generated pulses L having a normal repetition rate T which may be varied within limits of synchronization accord 4 this region to cover the degree of repetition modu lation. As previously described in connection with pulse Bl the signal pulse DI synchronizes the generator to produce a pulse DLI (curve e). The generator operates normally thereafter to pro duce’ impulse L4 displaced an interval .T. from pulses DLI. The signal pulse D2 falling in syn chronizing region S3 resynchronizes the gen ing to the degree of frequency modulation of the 10 erator to produce pulse DL2 displaced from pulse L4 by a time interval 152. This continues for all train of pulses to be translated. The intervals signal pulses having the repetition rate f2. of time S preceding each of the pulses L repre Curve g shows still another series of signal sents the region of synchronization during which pulses G having a repetition rate is. Curve h the local pulse generator may be triggered by an input pulse. In other words, it is in this region 15 illustrates the translation of the repetition modu lated pulses G into equivalent time modulated that should a repetition modulated pulse be ap pulses in the manner previously described. It plied to the generator the generator will be caused will be noted that the interval of time is be to change its timing of the pulse generation. It tween pulses L1 and GL2 etc, corresponds to the will be understood, of course, that the pulses L of curve a will shift in occurrence in accordance 20 repetition rate is of the signal pulses G. Comparing the translation of the signal pulses with resynchronization thereof by an input of the rates f1, f2 and f3 (curves b, d and g) with pulse but that succeeding pulses L will occur the time modulated pulses indicated by curves thereafter at a time displacement of T until the 0, e and h, it will be clear that in accordance generator timing is changed by another input pulse. 25 with my invention a translation of the intelli Curve 1) represents one series of signal pulses B having a repetition rate of T1. The translation of the increment of intelligence represented by this repetition rate is indicated by the pulses of gence of the repetition modulated pulses into equivalent time modulated pulses is performed. Since ‘I have chosen‘, for purposes of illustration, increasing repetition rates (that is, decreasing periods) for the signal pulses B, D and G, it will be clear that the time displacement of the cor repetition pulse Bl falls within a synchronizing responding time modulated pulses decreases pro region S thereby synchronizing the generator for portionately as indicated by the time intervals operation to produce pulse BL! in timed relation i1, i2 and is. with pulse Bl. The mode of operation of the gen The T. M. pulses thus produced by the trans erator l4, however, is so chosen that it will pro 35 lation of the incoming signal pulses of varying duce thereafter at the time interval T. its next repetition rate are applied to the T. M. demodu pulse LI before reception of the next signal pulse lator 66. While the demodulator ‘l6 may be of B2. The displacement between the pulses BL! various constructions it preferably is of the char and LI, therefore, is T according to the mode of operation of the generator. The reception of 40 acter disclosed in my copending application Se rial No. 459,959. This demodulation,-for example, signal pulse B2 occurs within the synchronizing preferably is of the character involving the gen region SI preceding the next normal operation of erating or synchronizing of an energy wave hav the generator which is indicated by broken line ing recurring inclined portions, the period of 22. It will be noted that the interval between pulse B2 and the broken line 22 is less than the 45 which is comparable to the unmodulated time spacing of the pulses. The wave and the pulses region of synchronization SI of the generator. are combined, the pulses being superimposed on Therefore, the generator is resynchronized ac the wave at points along the inclined portions cording to the occurrence of the signal B2 to pro thereof according to the time displacement of duce pulse BL2 which is displaced from pulse the pulses. This produces by threshold clipping Ll an interval t1 different from interval T. output pulse energy which varies in amplitude Following the occurrence of signal E2 the gen according to the time modulation of the input erator operates normally to produce pulse L2. It pulses which may be detected in the usual man follows that the next succeeding pulse B3 which ner. falls within synchronizing region S2 will again curve 0. The local generator is adjusted so that resynchronize the generator to produce pulse 55 . BL3 which is displaced from pulse L2 by the same time interval t1 occurring between pulses LI and BL2. This control of the generator I4 continues for the signal pulses having the repetition rate f1. The increment of intelligence transferred by "the repetition rate ii of the signal pulses B is thus represented by the interval 221 between the pairs of pulses Ll, BL2; L2, BL3; etc. While I have shown and described the prin ciples of my invention in connection with speci?c apparatus, it is to be understood that the de scription and illustration are given by way of example only and not as limiting the scope of the invention as set forth in the objects and the ap pended claims. I claim: . 1. A method of translating repetition modu lated pulses into equivalent time modulated pulses Curve 11 shows another series of signal pulses D having a repetition rate f2 the occurrence of 65 comprising generating pulsesaccording to a given time displacement and using the successive pulses which is shown as falling Within the region of. of a train of repetition modulated pulses to be synchronization S of the generator according to translated for synchronizing the generation of the operating condition of the generator as in alternate ones of the generated pulses, dicated by curve a. Since curve d represents a 2. The method de?ned in claim 1 wherein the change in repetition rate, the ?rst signal pulse 70 given time displacement of the generated pulses DI is shown for purposes of illustration, shifted in absence of said synchronizing operation is se relative to pulse Bl . The region of synchroniza lected less than the minimum repetition interval tion S indicated by the line 2!! (curve a) of course, between the repetition modulated pulses. includes the pulse DI since the mode of opera 3. The method de?ned in claim 1 wherein the tion of the generator is so adjusted as to time 2,408,062 ‘, given time displacement of the pulses generated in absence of said synchronizing operation is se lected less than the minimum repetition interval’ but greater than one-half the maximum repeti tion interval of said repetition modulated pulses, 6 adjacent said alternate pulses being displaced therefrom according to the modulation of the corresponding repetition modulated pulses, and means for demodulating the time modulated pulses. _ '7. A radio receiver having means to: detect 4. A system for translating repetition modu~' repetition modulated pulses, means to translate lated pulses into equivalent time modulated the repetition modulated pulses into equivalent pulses comprising means to generate pulses at a time modulated pulses, the last named means in repetition rate the time displacement of which is less than the minimum repetition interval but 10 cluding means to generate pulses having a given time displacement, means for synchronizing the greater than one-half the maximum repetition generation of alternate pulses in time relation interval of the repetition modulated pulses, with successive modulated pulses, and means for means to apply to said generating means for demodulating the time modulated pulses. synchronizing control thereof the successive 8. In a‘ pulse system, a source of pulses, a pulse pulses of the train of repetition modulated pulses 15 generator for producing discrete pulses at a given to be translated, and said pulse generating means repetition rate which is higher than the average being adjustable to a mode of operation such pulse repetition rate of said source, and means ‘ that each of the successive repetition modulated to apply the pulses of said source to said genera pulses resynchronizes the pulse generating means. 5. The system de?ned in claim. 4 wherein the 20 tor to control the production of alternate ones of said discrete pulses. generating means is adjustable to produce the ‘9. A pulse system according to claim 8, wherein pulses at a repetition rate having the desired . the pulses of said source vary in repetition rate relation according to the limits of the modula between two given limits according to signal tion of said repetition, modulated pulses. 6. A radio receiver having 'means to detect 25 modulation thereof, the resulting spaces between successive discrete pulses produced by said gen repetition modulated pulses, means to translate erator corresponding substantially to the instan the repetition modulated pulses-into equivalent taneous repetition rate of the pulses of said source. time modulated pulses with alternate pulses equally spaced apart in time relation, the pulses > DONALD D. GRIEG.