Патент USA US2405217код для вставки
Patented Aug. 6, 1946 2,405,217 UNITED STATES PATENT OFFICE' 2,405,217 _ IMPULSE OSCILLATOR ' Emile Labin, New York, N. Y., assignor to Inter national Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application March 13, 1941, Serial No. 383,116 7 Claims. 1 This invention relates to impulse generating and transmitting systems and more particularly to systems in which properly timed impulses are obtained from damped oscillations. It is often desirable, particularly in distance measuring systems, to transmit energy impulses (Cl. 250-17) 2 spark gap I2 and a transmission line I3, pref erably a coaxial line having an outer conductor Ill and an inner conductor I5. At the remote end of transmission line I3 is provided a resistance element It which is made to be equal to the surge impedance or characteristic impedance of the having a relatively short period of duration com line. As shown in Fig. 1, this resistance is illus pared to the period of oscillation or repetition of _ trated as a plate coated with a high resistance the impulse. For such generators a spark gap material. This resistance, however, may take any oscillator would appear to be well suited. It is 10 desired form and may be arti?cially cooled by found, however, that in ordinary spark gap oscil a water jacket or the like in order to dissipate lators the duration of the impulse at a particular heat generated by the energy traversing the re frequency is not suf?ciently controllable and is sistance. The resistance can also be part of a generally not su?lciently long to make such ar more complicated dipole taking into account the rangements practicable. change in the characteristic impedance of the It is a principal object of my invention to pro transmission line due to the coupling with the vide a system utilizing spark gap discharge cir cuits in which the length of impulse at a par~ ticular frequency may be readily controlled. This object may be accomplished according to a feature of my invention by producing a spark gap discharge across a point coupled to one end of a transmission line, the other end of which is terminated in the characteristic impedance of the resonant cavity. . . The outer conductor I 4 of the transmission line is provided with a plurality of apertures I'I ar ranged in spaced longitudinal relationship along the transmission line. Over each opening I1 is provided a resonant cavity shown in Fig. 1 as being substantially spherical in shape. These This arrangement will then produce an 25 cavities l 8 serve to extract energy at the resonant frequency thereof from the discharge energy as impulse traveling from the spark gap down the it traverses transmission line I3. To each of the length of the line to the terminating impedance. ' resonant cavities I8 is coupled an antenna unit Along the transmission line at one or more points I9 forming a dipole radiator. is coupled a resonant circuit, preferably a hol low resonant cavity for extracting energy at the 30 In operation a voltage is built up by energy supplied from source Ill across condenser II until resonant frequency of the cavity from the dis this voltage is sufficiently high to cause a spark charge current or voltage as it traverses the line. discharge across gap I2. These discharges will Due to the high Q value of the resonant cavity be produced periodically depending upon the na the duration of the pulse can be made long enough for practical purposes. 35 ture of source Ill. The discharge across gap I2 will produce an impulse which will traverse line While I have broadly set forth the principal 113 to its remote end where it will be absorbed in object and feature of my invention, a better line. understanding of my invention and the objects terminating resistance I6. The discharge im and features thereof may be had from the par pulse traversing line I3 will have a steep wave front and will be highly damped as in most spark ticular description thereof made in conjunction with the accompanying drawing, in which discharge systems. Accordingly, because of the form of the discharge it is clear that energy com ponents of various high frequencies will be pres ent in the wave. As the wave caused by the dis 45 rupted discharge travels past apertures I7 a por invention; and Fig. 3 represents a different form of impulse tion of the energy will be extracted by resonant generator according to my invention. cavities I8 and will be radiated from antenna In Fig. l, at I0, is shown a source of potential elements I9. By properly choosing the spacing connected across a condenser II. Source II] is between the apertures and the antenna units the preferably an alternating or impulse potential proper phase relationship for obtaining a desired source having a period equal to the desired spac directive effect may be produced directly in the ing between the impulses to be produced and a system. For example, if antennae I9 are suc potential sufficiently high to cause a spark dis cessively spaced a wavelength apart and it is charge over the spark gap terminals I2. Across assumed that the discharge traverses transmis Fig. 1 illustrates partially in cross-section a circuit in accordance with my invention; Fig. 2 illustrates a modi?ed embodiment of my condenser II is provided a circuit comprising 55 sion line I3 at the speed of light, then each suc 2,405,217 3 4 cessive antenna unit will be energized in phase tended as limitations of the scope of my inven tion. Many changes and alterations in the struc tural details of the system may be made within and a so-called broadside array will be produced. In traversing line l3 the impulse waves may be slightly attenuated as to the frequencies absorbed in resonant circuits I8. However, if this absorp the spirit of my invention. For example, resonant cavities such as shown at 18, in Fig. 1, may be made in the form of ?gures of revolution instead tion is sufficiently great so as to tend to produce of the spherical arrangements shown. Also, many other changes in the type of transmission line used and in the various circuits applied there large di?erences in theenergization of antennae 19, the losses in resonant chambers [8 may be adjusted to care for this decrease. This may be accomplished by choosing materials or providing 10 to may be provided within the terms of my in vention. For example, instead of using a spark a coating on the inner surface of chambers ill, gap to produce the impulses traveling from the or, preferably, by controlling the coupling be fed end down to the terminating impedance of tween the chambers and the loading so as to have the line, it is possible to use any kind of pulse a higher Q in the chamber ?rst traversed by the generator, such as an electronic tube generator. energy than in the succeeding chamber. In Fig. 2 a slightly modi?ed arrangement is What is claimed is: 1. An electrical impulse generator comprising illustrated. The source [0, condenser I l, and a two-conductor line, means for terminating one spark gap 12 may be substantially the same as end of said line in its characteristic impedance, those shown in Fig. 1. Likewise, a similar co axial transmission line i3 having an inner con 20 means for producing a damped electrical dis charge periodically at the unterminated end of’ ductor l5 and outer conductor M is provided. As said line, whereby electrical impulses will shown in this ?gure, the terminating impedance periodically traverse said line to said character I6 is illustrated as a generalized resistance, al istic impedance means, and a substantially closed though it should be clearly understood that any resonant chamber coupled to said line to extract form of resistance unit may be used. Along the a portion of the energy at the resonant frequency length of outer conductor M are provided a plu of said chamber from said impulses traversing rality of coupling openings 20. rI'he ?rst open ings are shown as rectangular in form while those at the center are shown as circular openings. It said line. ' ' 2. An impulse generating system according to should be understood that any types of openings 30 claim 1, wherein said two-conductor line com prises a coaxial line provided with an opening, may be used, it merely being necessary to provide and said resonant chamber is coupled to said line some apertures for coupling an external circuit to by ?tting over said opening. the transmission line. Instead of a plurality of 3. An impulse generator according to claim 1, separate chambers, a single resonant cavity 2| wherein said two-conductor line comprises a is provided. This cavity is coupled with the line length of coaxial line provided with a plurality at a plurality of places corresponding to open of openings spaced apart along said line, and ings 20. To cavity 21 is coupled a line 22 so that said substantially closed resonant chamber com energy may be furnished to a load circuit. If prises a single cavity coupled with said line desired, a plurality of lines 22 may be coupled at spaced points along the surface of cavity 2| 40 through said spaced openings. 4. A radiating arrangement comprising a two to provide differences of phase in the energized conductor line, means for terminating one end of circuits. generator to be used in place of the simple spark said line in its characteristic impedance, means for producing a damped electrical discharge gap of Figs. 1 and 2. ‘ I In this ?gure an end of the cable cut at line periodically at the unterminated end of said line, whereby electrical impulses will periodically , In Fig. 3 is shown a preferred type of impulse traverse said line to said characteristic impedance means, a substantially closed resonant chamber coupled to said line to extract a portion of the energy at the resonant frequency of said chamber from said impulses traversing said line, and a radiating unit coupled with said resonant cham her. 5. A radiating arrangement compising a two conductor coaxial transmission line terminated at one end in its characteristic impedance, means for providing a damped electrical discharge periodically at the unterminated end of said transmission line, a plurality of openings in the GO outer conductor of said transmission line, said A—A is shown, comprising inner and outer con ductors l3, M, respectively. A source of energy 30 is provided connected at one side to outer con ductor M, which conductor is made to extend past 1 the inner conductor [3 and is preferably reduced in ‘diameter beyond the inner conductor. The other terminal of source 30 is connected to a rod 32 provided in spaced relation with central con ductor H3. The potential of source 30 is sum ciently high to maintain an arc discharge 34 between l3 and 32. This is preferably accom plished by arranging the arc equipment in an atmosphere of inert gas. A source of energy 3| which is preferably periodic in nature is connected to a pair of de ?ecting coils 33. When coils 33 are energized are 34 is forced to one side and into contact with the reduced portion of outer conductor 34. Each time the arc contacts 33 and again breaks away from contact a short damped impulse is produced which traverses the transmission line in a manner similar to that described in connection with Figs. 1 and 2. The period of the impulse generation may be controlled by the frequency of pulsation " or interruption of energy from source 3!. While I have described above for the purpose of illustration some structural embodiments of my invention, it should be distinctly understood that these embodiments do not serve and are not in openings being spaced longitudinally of said line a predetermined fraction of a wavelength, a plu rality of substantially closed resonant cavities ?tted over respective ones of said openings to extract energy therefrom during passage of an impulse along said line, and individual radiators coupled to said resonant chambers. 6. An electric impulse generator according to claim 1, wherein said means for producing a damped electrical discharge comprises an are dis charge gap provided in one of the conductors of said line, a source of electrical energy connected to said transmission line conductors to maintain an arc discharge across said gap, and periodically operating means for distorting said are periodi 5 2,405,217 cally into contact with the other conductor of said line whereby damped impulse waves are pro duced in said line. '7. An electric impulse generator for use in a two-conductor transmission line comprising an arc discharge gap provided in one of the con ductors of said line, a source of electrical energy connected to said transmission line conductors to maintain an arc discharge across said gap, and periodically operating means for distorting said are discharge periodically into contact with the other conductor of said line whereby damped im pulse waves are produced in said line. EMILE LABIN.