Патент USA US2409608код для вставки
Oct. 22,1946. A. E. ANDERSON ’ ULTRA HIGH FREQUENCY DETECTOR Filed Sept. 24_, 1941 ' ‘2,409,603 I , 3 Sheets-Sheet l Fm " . _ lllllzllllll I + F162 (4/ A TTORNE Y Oct. 22, 1946. 2,409,608 A. |-:. ANDERSON ULTRA HIGH FREQUENCY DETECTOR Filed Sept. 24, 1941 3 Sheets-Sheet 2 _ FIG. 3 a 9% 18/ 58 80 50 5659 8/ 57 60 62 INVENTOR By A. EANDERSON WM Oct. 22, 1946. - " u ‘ I A, E_ ANDERSON Y 2,409,608 ULTRA HIGH FREQUENCY DETECTOR Filed Sept. 24, 1941 ‘ 3 Sheets-Sheet 3w ‘ F104, A TTORNEV Patented Oct. 22, 1946 2,4 ES ATNT QFFHCE 2,409,608 ULTRA HIGH FREQUENCY DETECTOR Alva Eugene Anderson, New York, N. Y., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application September 24, 1941, Serial No. 412,065 1 Claim. (Cl. 250—20) 1 2 This invention relates to electron beam devices, particularly for operation at ultra-high frequen closures or chambers 4 and 5 are associated with c1es. An object of the invention is to intermodulate wave energies by virtue of non-linear actions in electron beams associated with a plurality of elec certain electrodes within the envelope l. The resonating chamber 4 is designated as the input resonator and is provided with any suitable means 6 for the introduction thereinto of an incoming electromagnetic wave. A source ‘I of electromo trodes, particularly for use in frequency shifting arrangements for radio repeaters, first and sec ond detectors in superheterodyne receiving sys tive force of relatively low frequency is asso ciated with one of the elements of the electron gun 2. The resonator 5 is provided with means tems, and the like. 10 8 for leading away therefrom developed or am Another object is to improve and stabilize the pli?ed energy in theform of an electromagnetic operation of electron beam devices. wave. The electron gun 2 is provided with an A feature of the invention is a method of freelectron emitting cathode 9 which is associated quency conversion employing combinations of with any suitable heating means energized, for velocity variation and density variation effects in 15 example, through leads I0 and II by a source l2 an electron stream with the aid of resonating of electromotive force. Associated with the oath chambers. ode 9 is an electrode l3 for use in regulating A further feature is a detector making use of and varying current of the electron beam and a varying electron current intercepted by an commonly known as an accelerating electrode. apertured electrode, the amount of current inter- 20 It may be adjacent to and coaxial with the oath cepted being varied as the result of the shifting ode. A pair of suitably-shaped electrodes l4 and of a focal point of a focussed electron beam. Another feature of the invention is an auto- [5 which may be fused into the walls of the enve lope I, de?ne an input gap l5 and serve to close matic volume control employing variable electron the resonator 4 except for suitable apertures left velocities. 25 in the electrodes for the passage of an electron Still another feature is the coupling of two beam or stream from the gun 2. The walls of resonators through a common wall thereof, both the envelope I serve to separate the resonators 4 resonators being also coupled to a common elecand 5 by a desired distance and to determine a tron beam. suitable drift space H. A pair of electrodes l8 Further objects and features of the invention 30 and I9 de?ne an output gap 20 associated with will be apparent from the following detailed dethe resonator 5. The resonators 4 and 5 may be scription and the accompanying drawings, while the scope of the invention is de?ned in the appended claim. In the drawings, Fig. 1 shows an arrangement for shifting from conductively connected together and to the col lector 3, making a system which is maintained at a substantially constant potential difference 35 from the cathode 9 by a source 2| of electro motive force, the negative terminal of which is one ultra-high frequency to another, as for examconnected to the cathode. A supplemental out ple in a radio repeater; put means 22 is associated with the resonator 5, Fig. 2 shows a superheterodyne receiving syspreferably in the form of a coaxial line, the inner tern employing features of the invention in con- 40 conductor of which is connected to an interme nection with the ?rst detector stage; diate point 24 of the source 2! through a recti Fig. 3 shows another form of superheterodyne ?er 23. The recti?er is shunted by a parallel receiving system employing features of the invencombination of a resistor 25 and a condenser 26, tion in the first and second detector stages; the unit formed by the elements 23, 25 and 26 Fig. 4- shows an alternative form of ?rst de- 45 being serially inserted in circuit with the source tector; and l and the accelerating electrode IS. A stabilizing Fig. 5 shows a detector employing a focussed resistor 21 may be provided in the cathode lead. electron beam with variably displaceable focal The arrangement of Fig. l is adapted to effect point. a transfer of modulated energy from one high In the arrangement of Fig. 1 an envelope l 50 frequency wave to another, both of which may of insulating material is shown enclosing a plube in the ultra-high frequency range. In the rality of elements including an electron gun operation of the system an incoming wave of the shown generally at 2 and an electron interceptfrequency to which the resonator 4 is tuned, is ing or collecting electrode 3 referred to- hereinintroduced through the input means 6 with the after as the collector. A pair of resonating en- 55 consequent setting up of a high frequency alter 2,409,608 E5 in the input gap H6. The source ‘I is arranged to operate at a frequency equal to the di?erence which it is desired to introduce between the fre quency of the incoming wave and the frequency with the steady biasing potential impressed upon the accelerating electrode H3. The circuit is so arranged that the potential difference across the resistor 25 opposes the potential of the source 2i in determining the resultant potential of the electrode l3. In the well-known manner of automatic control systems of this type, changes in the amplitude of the output wave of the outgoing wave. The resonator 5 is tuned to the frequency of the outgoing wave. The function of the source ‘I’ is to superpose variations of the above-mentioned difference frequency upon the potential of the electron accelerating due to variations of the input wave are mini electrode :3 to regulate the space charge effect in the tube and consequently to produce corre sponding variations in the current or electron density of the beam. The beam, in traversing the input gap i5, has superimposed upon the above-mentioned current variations from source ‘I, a succession of electron velocity variations impressed by the incoming wave. It is further contemplated that the incoming wave will carry amplitude modulations corresponding to a signal mized. If it is desired, instead, to emphasize amplitude changes to secure a volume expansion effect, the polarity of the recti?er 23 may be made the reverse of that shown. Stabilization of the system against power sup; which is to be repeated. . The electron beam, thus modulated in density in accordance with the oscillations of the local source ‘I and in ‘velocity in accordance with the variations of the incoming wave, is allowed to traverse the sub 4 ing slow changes of current to produce a varying potential difference across the elements in series nating potential between the electrodes M and 25 ply fluctuations associated with the source 21 is provided by means of the resistor 27 in the cathode return lead. Changes in the cathode return current affect the potential difference across theresistor 2T inherently in the proper sense to minimize such current changes by con trolling the effective voltage between the cathode on the one hand and the system comprising the resonators 4 and 5, collector 3, and associated electrodes on the other hand. stantially ?eld-free drift space H to permit Arrangements for maintaining an electron further grouping of the electrons to take place. beam in any other suitable manner may be In the absence of the density variations im substituted for the electron gun 2. Any suitable pressed upon the electron beam by the source l but in the presence of velocity varying poten 30 resonators and electrodes may be substituted for the corresponding elements illustrated provided tials across the gap N5, the velocity variations tend to produce approm'mately proportional elec tron density variations at the output gap 26. ‘The effect of the superposed density variation in the beam current is to produce a variation in the number of electrons per unit time which are subjected to the velocity variation at the input gap. As a result, the electron density variation at the output gap 26 tends to be pro 'portional to the product of the two superposed variations, thereby introducing components cor responding tointermodulation products, such as combination frequencies according to well-known principles. Any desired modulation product may be accentuated by dimensioning or tuning the resonator 5 to resonate at the frequency of the selected modulation product. For example, the component of frequency equal to the incoming only that means are present for superposing an amplitude or current density variation and an electron velocity variation upon an electron beam which beam is thereafter subjected to suitable conditions or manipulation which results in a regrouping of the electrical charges in the beam in some manner adapted to produce intermodu lation of the original variations. The automatic control features and stabilizing elements may, of course, be either omitted or included, as desired. Fig. 2 illustrates certain features of the inven tion embodied in a superheterodyne radio re ceiver. The facilities for producing the electron beam, the envelope l, the collector 3, and the input and output resonators and associated ar rangements are substantially the same as in the frequency minus the frequency of source ‘I may system of Fig. 1, except that the output resonator be selected ‘by making the critical dimensions of the resonator 5 somewhat greater than those of the, resonator 6 in such proportion as to tune the resonator 5 to the desired output frequency. resonator 4. Intermediate between the input and output resonators are two auxiliary chambers 28 With proper tuning, an electromagnetic wave 5' is tuned to the same frequency as the input and 29 having a common wall 39. The interiors of the chambers are shown coupled by means of of the selected frequency will be sustained in 55 a coupling loop 3| passing through an aperture the resonator 5 and delivered to the ouput means 3. By making the resonator 5 somewhat smaller than the resonator ll, on the other hand, the fre quency component equal to the incoming fre in the Wall 3!}. Alternatively, the loop 3| may be omitted and the aperture itself may be suitably repeater. provided between the resonators 6i and 28 and the resonators 29 and 5’. Electromagnetic focussing coils 38 and 39, respectively, may conveniently be, placed. adjacent to the drift spaces 36 and 31 and energized by sources 45) and iii of electromo dimensioned to provide the coupling. If desired, an iris or other suitable arrangement may be used quency plus the frequency of source ‘I may be 60 to secure a variable coupling. Conductively con nected with‘ the wall 30 is an electrode 32 com selected. Of particular interest in the use of the prising adisc with an axial aperture surrounded arrangement of Fig. 1 as a radio repeater, the by a short tube 33. The resonators 28 and 29 are diiference between the input and output fre provided with electrodes 34 and 35 respectively quencies is utilized to avoid undesirable reaction of the output upon the input which would other 65 having apertures aligned with the aperture in the disc 32. Drift spaces 36 and 31 respectively are wise cause self-oscillations or f‘singing” in the Automatic stabilization of the intensity of the output wave is provided by taking a sample of the output wave from the resonator 5 through the coupling means 22 and applying the sample wave to the rectifier 23. The time constant of the resistor-condenser combination 25, 26 is preferably adjusted to a suitable value to smooth out rapid variations of the recti?ed current, leav tiverforce. Alternatively, suitably designed per ‘manent magnets may be substituted for the elec ‘tromagnets. The collector 3 is connected by way 75 of a tuned circuit 42 to the cathode 9. An inter 2,409,608 6 5 The system of Fig. 2‘ may be employed simply mediate frequency ampli?er 43, a detector 44 and as a high frequency ampli?er if desired, in which case, the high frequency output may be taken from the resonator 5' by any suitable output means such as the coupling 8 illustrated in Fig. 1 and the collector may be connected to the posi tive terminal of the source of biasing potential. Elements 42, 43, M and 45 and source ‘5 may then a translating device 155, such as a telephone re ceiver, are coupled in tandem arrangement with respect to the tuned circuit 132 in the conventional manner of a superheterodyne receiving system. The control elements 23, 25 and 26 may be coupled to the output device 22 in a manner similar to that shown in Fig. 1. In this case, however, the control is shown applied to the potential of the resonating system instead of the electron accel erating electrode. The operation of the system of Fig. 2 in its \be omitted. - ' The automatic control arrangement‘of Fig, 2 is shown as operating to control the average electron velocity at the electrode i4 thereby con trolling the electron transit time through the drift spaces 35 and 3‘! and consequently controlling broad aspect is similar to that of any super heterodyne receiver. An input wave is impressed upon the resonator it through the input coupling 15 the gain of the device as a high frequency am pli?er. With the recti?er 28 polarized in the di 6 to impress velocity variations upon the electron rection indicated by the arrow the control is such stream which has also been given an electron as to minimize volume changes. If instead, it is density variation through the action of the local desired to emphasize the volume changes to give source ‘i. The operation of the system differs a volume expansion effect, the polarity of the from that of Fig. 1 among other particulars, in recti?er should be reversed. that the essential interrnodulation of the local Fig. 3 shows a superheterodyne receiving sys and incoming waves is effected in a somewhat tem employing two electron beam devices in a different manner. Intermodulation according to tandem arrangement. In the ?rst tube, shown the scheme described in connection with Fig. 1 at the top of the ?gure, the incoming wave is may also occur in the drift space 36 of Fig. 2, but impressed upon the resonator G by means of the by tuning the resonator 28 to the frequency of coupling 5 to produce a velocity variation in the the incoming wave the intermodulation at this electron beam at the gap :6. Conversion of the point may be subordinated to ampli?cation of velocity variations into current density variations the incoming wave, the latter process being is provided for in the drift space ll. The local brought about by electron density variations serv oscillations are generated in a resonant chamber ing to set up forced oscillations in the resonator of concentric structure having an outer wall 50, 28. A portion of the energy of these oscillations and inner walls 5!, 52, 53 and M, of which 52 and is transmitted to the resonator 29 by means of a 53 are conductively connected with the outer wall coupling loop 3! to produce a second and rela tively intense velocity variation of the electron I by wires 88 and 38, respectively. The wires are preferably of su?iciently small dimensions not to beam in the gap between electrodes 33 and 35. interfere materially with the transmission or os By electron drift action in the drift space 3? a cillation of electromagnetic waves within the en further ampli?ed electron density variation is closure. The wires preferably extend radially or produced in the gap 28, causing forced oscilla tions in the resonator 5’. The ampli?ed oscilla 40 substantially perpendicular to the electrical lines of force normally existing therein. Three gaps tions in the resonator 5’ will impress a new and 55, '56 and 57 are provided along the course of still further ampli?ed velocity variation upon the the electron beam separated by additional drift electron beam before the beam enters the space spaces 58 and 59. The electrode I851 together with between the electrode Iii and collector 3. To obtain the desired intermediate frequency 4 an electrode I8! de?nes the gap 55 and the gaps '55 and 57 are de?ned by similar pairs of elec component which may be at the frequency of the trodes. The ends of the resonating chamber are difference between the incoming wave and the closed by means of annular pistons 6t and SI, source if, velocity sorting of the electrons is ef which are slidable for purposes of tuning the resonant chamber. The collector 3 is conduc tively connected to the inner conductor 6!! of a concentric transmission line of which a tube '65 fected by subjecting the beam to a retarding or re?ecting ?eld. The ?eld is conveniently pro duced by connecting the collector 3 to the cathode 9 as illustrated, thereby placing the collector 3 at a potential considerably negative with respect to the potential of the electrode l9. Due to the reflecting ?eld, the slower electrons passing elec of conductive material connected conductiv'ely with the walls of the resonanting chamber is the outer conductor. The conductor 6!! is connected to the tuning chamber and to ground through a high frequency choke coil 86. The concentric line 64, 65 is connected to another concentric line trode it are unable to reach the collector 3 and are turned back, but the faster electrons are able to enter the collector 3 and induce a pulsating current in the return circuit. The intermediate 68 of smaller diameter through a tapering sec tion 67. frequency component of the pulsating current is resonated by the tuned circuit 42, thereby supply ing an input to the intermediate frequency ampli ?er @3. Intermediate frequency ampli?cation and a A second electron beam tube serving as an am ?nal detection as well as translation of the signal ‘ are accomplished in the usual manner as in any superheterodyne receiving system. It is contemplated that the frequency of source v pli?er and second detector is shown in the lower portion of the ?gure and has an input resonator 82 coupled to the transmission line 68 by means of a coupling loop 69 inside the resonator. The wave impressed upon the resonator 62 produces a velocity variation of the electron beam at an input gap ll]. Velocity sorting is effected in the ‘I will be relatively low compared to the frequency output gap ‘ll due to the steady difference of of the wave incoming at the coupling 6, in which potential maintained between insulated portions 70 case the difference frequency will lie within the 82 and '83 of an output resonator by the electro transmission band of the resonators ll, 23, 29 and mctive force of a biasing‘source 84. The slower 5’. If desired the transmission band may be electrons of the beam are turned back and only widened by detuning slightly one or more of the the faster electrons continue, ?nally striking a resonators or by increasing the degree of cou 75 collector 12. A coupling transformer 13 is pro pling between resonators 28 and 29. 2,409,608 7 8 vided for repeating the alternating portion of the used instead of the connected electrodes I03 and pulsating current in the collector lead and a translating device such as a telephone receiver 14 is connected to the secondary of the‘ trans former ‘I3. In the operation of the system of Fig. 3 the in coming oscillations and local oscillations are com bined in the ?rst or upper tube to produce a wave I04. Focusslng means such as an eleotromagnet I01 energized in any suitable way as for ex ample by a battery I08 is provided to bring the electron beam to a focus near the electrodes I03 and I04. 7 In the operation of the system of Fig. 5 the incoming wave is resonated in the chamber I00 of somewhat lower frequency corresponding to and by means of the gap IOI impresses a velocity the usual “intermediate frequency” wave. The 10 variation upon the electron beam. The electron wave so produced is ampli?ed by the second or gun 2 is preferably of a type which focusses or lower tube and the signals are detected by the concentrates the electron beam, and arranged to velocity sorting process above described. The establish a focal point in the gap I M. The local oscillator is substantially a, two-stage am focussing coil I01 normally produces a point of pli?er with coupling between the output and in 15 concentration of the beam in the neighborhood put. The relative voltages impressed upon the of the electrodes I03 and I04. The electron input gap 55 and the output gap 51 may be ad velocity variation impressed upon the beam is justed by proper setting of the tuning pistons 60 arranged'to be su?icient to cause a shifting of and BI, a movement of both pistons in thesame the point of concentration axially with respect to direction an equal amount having substantially 20 the electrodes I03 and I04 in accordance with no effect on the resonant frequency. I If it is de amplitude modulations of the incoming wave. sired to operate the lower tube at a much lower The electrodes I03 and I04 are thus caused to frequency, e. g. in the ordinary intermediate fre intercept a variable portion of the electrons of quency range, the second tube may be replaced the beam, thereby producing a pulsating current by a conventional intermediate frequency am through the resistor I 005 and receiver I06. If pli?er. desired, the resistor I 05 may be replaced by a Fig. 4 shows another arrangement for the ?rst tuned circuit resonant to a desired intermediate detector of a superheterodyne receiving system. frequency and the voltage variations in this A resonant chamber 90 is tuned to the incoming tuned circuit may be employed to excite an in frequency. Another resonant chamber SI having : termediate frequency ampli?er. a wall in common with the resonator 90 is tuned What is claimed is: to the frequency desired for the local or beating A modulating system comprising an electron oscillator. A gap 92 is provided within the reso beam-type tube, a plurality of resonating cham nator 90 and gaps 93 and 04 within the resonator bers arranged in succession along the path of 0|. The collector 3 is connected to the biasing the electron beam, one of said resonating cham potential source through a tuned circuit 05 which bers having two electron permeable electrode may be tuned to the difference frequency. portions in opposite walls, in alignment with the In the operation of the arrangement of Fig. electron beam to permit the beam to traverse 4 the electron beam receives a velocity variation said resonating chamber, another of said reso in accordance with the incoming waves at the 40 nating chambers being located beyond said ?rst gap 92. The beam receives a second electron mentioned resonating chamber and enclosing a velocity variation at the gap 93 in accordance drift tube and having two electron permeable with the local oscillations. The electron path electrode portions in opposite walls, said elec between the gap 93 and the collector 3 is essen trode portions and the axis of said drift tube tially a drift space and due to the non-linear being in alignment with the electron beam, said character of the drift space action, difference fre > second-mentioned resonating chamber being quency components are set up in the electron resonant at a frequency di?erent from the density variations e?ected by the drifting of resonant frequency of the ?rst-mentioned reso the electrons. The gap 94 is provided for the nating chamber, a source of electroenagnetic purpose of extracting enough energy from the waves coupled to said ?rst-mentioned resonat electron stream to support continuous oscilla ing chamber to excite forced oscillations there tions in the resonator 0%. The intermediate fre in and to impress an electron velocity variation quency wave may be of sufficiently low frequency upon the electron beam at the frequency of said to be handled with ordinary tuned circuits, and forced oscillations as the beam traverses the any desired utilization device, such as an inter resonating chamber, a substantially ?eld-free mediate frequency. ampli?er, may be coupled to drift space between said ?rst and second-men the tuned circuit '95 in well-known manner. tioned resonating chambers for converting the Fig. 5 shows an alternative form of detector said velocity variation of the electron beam into which may be used either as a ?rst or second a corresponding electron density variation, means detector in a superheterodyne receiving, system including the said electron permeable electrode or as a simple detector for the direct conversion portions of said second-mentioned resonating of an ultra-high frequency wave to recover the chamber and the said drift tube enclosed within original signals in a single step of detection. A said resonating chamber for generating self resonator I00 is provided for the input wave oscillations in said second mentioned resonating and is associated with a gap IOI. Separated chamber and for impressing upon the said density from the ?rst gap by a space I02 are a pair of varied electron beam at a point ahead of said connected electrodes I03 and ‘ E04, which may be enclosed drift tube, a second velocity variation at like the electrodes shown herein for the accom the frequency of said self-oscillations and means modation of a resonating chamber, but with the including the said enclosed drift tube for con chamber omitted. The electrodes I03 and I04 70 verting the compound variation of the electron are connected to the positive terminal of the beam so produced into a second electron density biasing potential source through a resistor I05 variation comprising an intermodulation of said which is shunted by a translating device such forced oscillations and said self-oscillations. as a telephone receiver I06. A single electron permeable electrode of any suitable type may be 75 ALVA EUGENE ANDERSON.