Патент USA US2110278код для вставки
March 8, 1938. 2,110,278 R. c. SHAW TRANSLATING CIRCUIT Filed April 14, 1932 ‘ |¢E \ I‘ ' \ J2‘ c ' 2. 2 ' L \ N V ’ 1q 5 l, T. T Z____ lu f, ' ‘ ‘ l 2" vfd ( ..._ > uuucsa ' CIRCUIT [- . 6’ - 9 lNl/L'NTOR ’ R. c. SHAW. "W A TTORNEV Patented Mar. 8, 1938 ‘ 2,110,27 STATES PATENT orrlcs 2,110,278 TRANSLATING CIRCUIT Robert 0. Shaw, Red Bank, N. J., assignor to Bell a ‘ 7 Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application April 14, 1932, Serial No. 605,243 ‘20 Claims. (Cl. 178—44) This invention relates to systems for the trans point. The balanced circuit‘Lz may be coupled lation of electrical energy and more particularly to another balanced circuit associated with wind to signaling systems operating at radio fre ing 9 of transformer T,. such as the input of a quencies. push-pull ampli?er; or circuit L2 may, for ex To maintain the two sides of an electrical cir ample, comprise an open wire transmission line cuit in balanced relation with respect to ground connected to the members of a horizontal is a problem frequently encountered in the de double-V, or diamond-shaped, antenna or of a sign of high frequency signaling systems. It is a similar balanced radiating structure. The un particularly difficult problem to meet where the balanced circuit L1, likewise, may comprise a 10 frequencies are of the order of those employed transmission line of open wire, or other type, or in short wave radio transmission. The slightest‘ merely a connection to adjacent apparatus. unbalance in the output circuit of a push-pull Between the terminals 0, d, of the balanced cir ampli?er, for example, may be su?icient to create cuit is connected a linear conductor 3, the a “singing” condition that will render the am terminals of which are represented as a and b. 15 pli?er useless. Where, also, an antenna of Shielding the conductor 3 is a tubular conductor balanced type is to be connected to a remote 4, which is grounded preferably at a plurality of transmitter or receiver through a transmission points. The connections between the terminals line, one side of which is grounded, it is desirable, of conductor 3 and the terminals of circuit L2 are though for a different reason, that the balanced made of the, same length l and preferably are 2O condition remain undisturbed. One of the chief balanced physically with respect to ground, so sources of unbalance in such systems is in the that the electrical balance at terminalsc, d is device used to couple the balanced circuit to a not affected. . circuit that is not electrically balanced with re The length of conductor 3 is critically related spect to ground. to the frequency of the waves which are to be An object of the present invention is to couple transmitted, or more accurately, to the length 25 25 an unbalanced or grounded circuit to a balanced of the waves as they are transmitted through I circuit without disturbing the balance of. the latter. In accordance with the invention, the trans the conductor. As an approximation, the length of conductor 3 may be one-half wave length or any odd multiple thereof, or symbolically, 30 formation from a balanced circuit to .an un (Lei balanced. circuit is eiiected by taking advantage of the changes in phase that a wave transmitted along a conductor undergoes. The nature of the present invention will more fully appear in the following description of several speci?c embodi ments which are illustrated in the three ?gures of the accompanying drawing. In the accompanying drawing, Figure 1 shows where n is an integral number and A is the wave length. Where conductor 3 is thus proportioned it is apparent that the phase of a wave transmitted from terminal 0 of. the balanced circuit and through conductor 3 to terminal b of the latter, a device for coupling an unbalanced circuit to a will be altered exactly one-half cycle with respect balanced circuit. Figure 2 shows a different embodiment of the to a similar wave transmitted directly from terminal d of the balanced circuit to terminal b. Since, then, the phases of the voltage waves ap invention. Figure 3 shows still another embodiment of the invention. Referring to Fig. 1, there is shown a device providing for the bilateral translation of elec trical waves between an unbalanced circuit L1 and a balanced circuit L2. The unbalanced cir cuit is represented as a coaxial conductor pair comprising a central conductor l and a grounded, tubular return conductor 2 surrounding the cen tral conductor and effectively shielding it. The balanced circuit shown comprises a pair of ordi nary conductors connected to winding 8 of trans 55 former T, winding 8 being grounded at its center 30 pearing at the respective terminals 0, d, of the balanced circuit are exactly opposite, it, follows that the waves transmitted through the two sides 45 of the circuit to point b will be in phase with respect to any external load connected between point b and ground. Because of the phase re versal in conductor 3, point b is effectively at the same potential withreference to both terminals of the balanced circuit. Any circuit connected , to point b, therefore, will have the same effect on the two sides of. the balanced circuit and the balance of the latter will notbe affected. Cir cuit L1, being connected between point b and 55 2 " 2,110,278 I V ‘ ground accordingly has no unbalancing eftfect'on ' V'Thislmay be seen from Fig. 1, where E repre- sents the voltage across' the unbalanced circuit circuit L2 with which it is coupled. 1 The bilateral character of’ the coupling circuit ' and I, the current therein. Going into the bal- ' is believed to require but j little discussion. ' anced.‘ circuit the current I divides and produces in that circuit a circulating current. of 1/2. Voltage variations‘createdr between point b'and ‘ The voltages E producedacross both halves of ground by waves in line Lnar'e' transferred to the balanced circuit are added in phase, resulting points c 'andd and the'terminalsof winding _8. ~ in a total of 2E. ' The’ impedance of the balanced The reversalrrinrphase occurring. in conductor.’ 3 circuit therefore appears as results in thephasefopposi't'ioh of the 'waves at 10 - v10 the respective terminals of’ winding'8 which is necessary for the translationiof waves through: ,_ V the transformer. > .orfour times the-impedance (E/I) of‘the an; ». _ Fig-'2‘ illustrates an embodiment of the inven balanced-circuit. The tuned: circuits» are also ' tion‘as utilized ior coupling the output circuit of . useful, in correcting small phase .di?erences that 15' ;a balanced‘ or ‘ push-pull. ampli?er; :to Ian may exist at'the terminals of the balanced cir . balanced circuit such a'sz'a coaxial ciomiuct‘orv : cui't. 'By slight yariations'in the length of the transmission line L1. In thisgcaser'the separate .conductor l3, likewise, impedance and phase -' conductor 3 of critical length? shown in Fig.- -1 .dissymfmetries of the system maybe compensated . is omitted and the terminals. c and d of. the bale‘v 20 anced circuit areconnected directly-to the point > for. ' ' ' ' ' ' ' The combinationof coaxial conductor line and 20f b and ‘the unbalanced circuit connectedfthereto. ~ ' Therequired phase changeis obtainedby'making, balanced openfwire line‘illustratedin Fig. 3 may be’us'edg-forexample, where a'balanced or sym-' "the-conductor bc electricallyv longer than 'con- . metricaliantenna array is to be. connected to‘ a 'ductor 1 bd by an amQunt'equivaIent ‘to one-half a wave length or an odd‘multiple ‘thereof. Thus, v ' if the length‘ bd be represented by ‘l, the length ‘he must be, ' _ ,, ‘ _ _ _ , remoteiradio' station; _ The v open wire line i pro : vides animpedance match for theantenna, while ' ‘ the coaxial conductor line provides an e?lciently ' shielde‘d transmission path, to the‘ station. . ' Although‘ the invention has been described with. reference to "specific embodiments and applica 7 i The embodiment:- of "thei‘invention- shown "in 'tions of it, it is to be understood that the in ' .Fig. ._3-.has certain advantages “over the; systems.‘ vention is limited only by the scope and- spirit ; hereinbetore described, jparticularlye with regard ‘ of the appended claims. to compactness, ?exibility and’ accurate matching 1 "What is claimed is: 'Y 1. In a high frequency transmission system, ‘a _of the impedances of the: connected circuits.‘ J It is ‘similar; to . the system shown fin Fig. ._,1'- with the. ' circuit balancedto ground, a circuit one side of‘ . substitution" of e l a UQ-shaped conductor. l3 for" ‘which is grounded," and leads from the terminals‘ ' the linear conductor 3 of the-‘latter ?gure and r of said balanced circuit'tothe ungrounded side of said second mentioned circuit, the electrical nections, ac‘and 'bd'... Arrangingconductor l3 . lengths of said ‘leads di?eringfrom each other 40 in the-form of a U or long, 'narrowiloop does f by an odd number of-half-wave lengths of, the -, not materially alter its effectiveness ‘as a‘ phase 7 waves transmitted therethrough. ' " r 2. In a high'frequency transmission system, a shifting device and‘ it hasthe advantage'that the ’ terminals needi‘not. be widely separated. from circuit balanced to ground,’a circuit one side of with‘ the insertion of tuned'circuits in the com Moreo'ver‘the over-all ‘dimensions ' which is. grounded, and connections from the are reduced, :With fa. straight conductor as‘ in , terminals of said balanced circuit to the un-. . each other, Fig. 1, ‘a length‘ of, the order OfthlI‘tYfGBt would ' be required» in a system operating at ?fteen meg acycles per second, whereas therlength" ‘ofthe' grounded side of’said second mentioned circuit, ~ ‘ and means in said connections for reversing the relative phases’ of 'vwavestransmittedr, theree‘ to I space required may be reduced to approximately . In ‘a 'high frequency transmissionsystem, a half the amount by using the _ U construction. ' circuit balanced to ground, a‘ conductor ‘having 1 ‘ ‘ In any, of these cases an unshielded conductor through. V . . _ van electrical lengthequivalent to .an- odd num ber of‘ half-wave lengths of‘ the waves transmit sible by providing short-circuiting- connections ted, symmetrical connections from the termi- ; nals of said balanced circuit to .the terminals of across. the loop at di?erent"points',i'these con may alternatively beemployed. ‘1 ~ , V . _ Operation at different frequencies is made pos nections being selectivelycompleted by 'means of said conductor, andra circuit connected between remotely controlled switches l5, l6. Thegéxact; location of the'short-circuiting connections may be adjusted from" time to time to accommodate, . 4. vIn a'high frequency transmission system, a ' balanced circuit, an unbalanced. circuit, means one terminal'of said conductor and ground. GO changing load conditions; 'for couplingisaid lation comprising _Terminals ,a and b of conductor l3 are con nected to intermediate‘ points of inductance coils 7 of. said balanced ‘ ‘2| a-ndlll, respectively, the adjacent terminals balanced circuit, circuits‘in energy transfer re connections from the terminals circuit to one side of said un the ‘relative electrical lengths of'rwhicharev grounded. CondensersIC1 and C2 of said connections being such that the balance ‘ of said'?rst mentioned circuit is maintained. 7 23; respectively,rof the. respective coils ‘20 and - '5.‘ In a high frequency transmission system, a are connected’ between ground and‘taps 22 and 2|. The terminals c, ‘d of the balanced line In. balanced circuit, an unbalanced circuit, and/ means‘for coupling said circuits in energy trans . are symmetrically connected to taps on the two coils; .The tuned circuits comprising condensers vferrelatlon comprising connections from the ' C1 and C2‘ and coils Y20 and ‘2I’perm'it an ad- - terminals of said balanced circuit to onefside of said unbalanced circuit, one- of saidconnec- _ justm'ent‘of, the» impedance ratio or the trans forming system. "Without such" adjustment‘ an tions including a phase reversing device ‘compris impedance-ratio or 1:4 is obtained; looking ‘from ' , ing a conductor greater in length than the short thev unbalanced circuitto the balanced circuit.‘ est distance between its terminals. ' 2,110,278 6. A combination in accordance with claim 4, comprising means for adjusting the relative ef ul 3 respect to ground potential, means for providing di?erent frequencies. a circuit coupling arrangement between said un symmetrical and symmetrical circuits, said means comprising conductor leads from the terminals of said symmetrical circuit to the ungrounded 7. In a high frequency transmission system, a balanced circuit, an unbalanced circuit, and side of said unsymmetrical circuit, the electrical lengths of said conductor leads differing from means for coupling said circuits comprising con nections from said balanced circuit to said un each other by an odd number of half wave lengths of the waves transmitted therethrough. balanced circuit, the electrical lengths of said connections being substantial and different by 16. In a high frequency coupling arrangement 10 comprising a circuit which is normally unsym metrical with respect to ground potential, a sec ond circuit which is normally symmetrical with respect to ground potential, means forv providing a symmetrical circuit coupling arrangement be 15 tween said unsymmetrical and symmetrical cir cuits, said means comprising concentric conduc tors, at least one of said conductors being ground ed and branched, the difference in the geometric length of said branch lines being differently fective geometrical lengths of said connections to adapt said coupling means for operation at in ‘ an amount such that the balance of said ?rst mentioned circuit is preserved. 8. A combination in accordance with claim 7, in which said connections consist of conductors. 9. In a high frequency transmission system, a circuit substantially balanced with respect to ground, a circuit unbalanced with respect to ground, and means coupling said circuits in en ergy transfer relation, said coupling means com prising a ?rst connection from a point on one side of said balanced circuit to a point in said unbalanced circuit, a second connection from a point on the other side of said balanced circuit 25 to a point in said unbalanced circuit, said con nections differing in electrical lengths by an amount corresponding to the di?erence in phase between said respective points on said balanced circuit and ground. 30 10. In a‘ high frequency transmission system, a balanced circuit and an unbalanced circuit and means for coupling said circuitsv together com prising connections from said balanced circuit vto a common point on said unbalanced circuit, CO 921 the electrical lengths of said connections differ ing by an amount su?icient to introduce the phase change required to maintain the electrical balance of said balanced circuit. 11. A combination in accordance with claim 10 40 in which said coupling includes means effective to match the impedances of said balanced and un balanced circuits. 12. A combination in accordance with claim 10 comprising means for suppressing radiation from said coupling connections. 13. A combination in accordance with claim 10 in which each of said connections comprises the inner conductor of a coaxial pair, the outer con ductor of each pair being grounded at a plurality of points. 14. In combination, a circuit balanced with respect to ground, a circuit unbalanced with re spect to ground and means for coupling said circuits in energy transfer relation comprising a conductor connected across said balanced cir cuit, said conductor being electrically and physi cally symmetrical with respect to ground and said balanced circuit, and a connection from said unbalanced circuit to a point on said conductor 60 that is an odd number of half wave-lengths farther from one end of said conductor than from the other end. 15. In a high frequency coupling arrangement comprising a circuit which is normally unsym 65 metrical with respect to ground potential, a second circuit which is normally symmetrical with chosen so as to compensate for the unsymmetrical circuit. arrangement. 17. In a high frequency coupling arrangement comprising a circuit which is normally unsym metrical with respect to ground potential, a sec ond circuit which is normally symmetrical with respect to ground potential, means for providing a symmetrical circuit coupling arrangement be tween said unsymmetrical and symmetrical cir cuits, said means comprising concentric conduc tors, at least one of said conductors being ground ed and branched, the difference in length of said branches being such as to compensate for the unsymmetrical circuit arrangement. 18. In a high frequency coupling arrangement comprising a circuit which is normally unsym metrical with respect to ground potential, a sec ond circuit which is normally symmetrical ‘with respect to ground potential, means for providing a symmetrical circuit coupling arrangement be tween said unsymmetrical and symmetrical cir cuits, said means comprising concentric conduc tors, at least one of said conductors being ground ed and branched, the di?erence in length of said branches being an uneven number of half waves so as to compensate for the unsymmetrical cir cuit arrangement. 19. In a high frequency transmission system, a circuit substantially balanced with respect to ground, a circuit unbalanced with respect to 50 ground, and means coupling said circuits in en ergy transfer relation comprising a connection from a point in said balanced circuit to a point in said unbalanced circuit and a connection from a point of different phase in said balanced cir cuit to a point in said unbalanced circuit, the electrical lengths of said connections differing by an amount sufficient to introduce the phase change required to maintain the electrical bal ance of said balanced circuit at the frequency of 60 transmission. 20. A combination, in accordance with claim 19, in which at least the electrically longer of said connections comprises the inner conductor of a coaxial pair. ROBERT C. SHAW.