US2415485A - Ultra high frequency oscillator and amplifier - Google Patents

Description

Feb. 11, 1947.. c. E. HALLER.

ULTRIPHIGH FREQUENCY OSCILLATOR AND AMPLIFIER Filed Oct. 17, 1942 3 Sheets-Sheet 1 Fz'gal.

INVENTO Feb. 11, 1947. c. E. HALL'ER ULTRA-HIGH FREQUENCY OSCILLATOR AND AMPLIFIER Filed Oct. 17, 1942 3 Sheets-Sheet 2 M. 1 5 W MW 4 v a 4 M 4 u a 8 5 v 4 M W4 /0- INVENTOR v WW ATTORNEY Feb. 11, 1947. c. E. HALLER ,4

ULTRA -HIGH FREQUENCY OSCILLATQR AND AMPLIFIER Filed on. 17, 1942 s Sheets-Sheet s INVENTOR CeelZEmr 4mm;

ATTORNEY Patented Feb. 11, 1947 UNITED STATES PTENT OFFICE nicer rnnoocncr oscittsron AND AMPLKFIER Cecil E. Heller, Bloomfield, N. 3., assigncr to Radio @orporation of America, a corporation of Delaware 21 Claims.

. High Q Sufficient mechanical dimensions Low radiation Low surge impedance lines in order to (a) Prevent excessive line shortening, if

possible, due to tube capacity.

(b) Aid getting a balanced circuit (c) Minimize the eiiect of stray capacities so that they do not become a troublesome item.

power and grid return at points in the circult Where no F, voltage exists.

in conventional tubes employed in conventional circuits, it is to obtain these desirable characteristics.

. Convenient means of introducing the D. C.

diflicult if not sometimes impossible I It is, thcreiore, an object of my invention to provide an electron discharge device and associate-cl circuit particularly suitable for use at ultra high frequencies.

Another object of my invention is to provide a circuit particularly suitable for use with electron discharge devices designed for ultra high frequency use and provided with a plurality of leads for each of electrodes.

Another object of my invention is to provide a stable high frequency oscillator for use at frequencies up to 1200 inegacycles and more.

A further object of my invention is to provide such an oscillator in which undesired radiation is reduced to a minimum.

A still further object of my invention is to provide a combined oscillator and power amplifier utilizing electron discharge device of the type described which compact and fully shielded.

Another object of my circuit for use at ultra high frequencies but of ample mechanical dimensions,- having high Q, and provided with convenient means for introducing electrode voltages at points in the circuit where no R.-F. voltages exist.

The novel features which I believe to be characteristic of my invention are set forth with particularity the appended claims, but the invention itself will best be understood b reference to the following description taken in connection with the accompanying drawings in which Figure l is a top View with cover removed of an electron discharge device and associated circuit made 2. cording to my invention and used as an ultra high invention is to provide a eniency oscillator, Figure 2 is a longitudinal 3' along the line 2-2 of Figure 1, lELlTBS-J 3 and a are schematic diagrams illusiie according to invention, and Figure 7 is schematic circuit diagram of the apparatus 51 own in Figure 6 and its associated voltage sources.

In accordance with my invention I utilize an electron discharge device particularly designed for ul ra high frequencies and provided with pairs of oppositely extending electrode leads and supports which reduce tube inductance and capacity when used at ultra high frequencies. These leads psi t utilization of novel circuit apparatus made according to my invention.

l et'erring to Figures 1 and 2, the electron dis ce device utilized in accordance with my inon comprises an envelope it and contains a cathode ll, grid l2 and anode the grid l2 and 1 mole being provided with oppositely extendleads and supports l t--54 and ll5. The device is provided with cathode heater leads it and cathode lead ll connected and disposed in a manner to be described.

The oscillator circuit comprises concentric consive collars or ring-1ilre members l8l llCh supporta pair of electron discharge devices betwcen them as illustrated, the collars being provided with clip-like engaging elements M and ill for engaging the leads M and i5. Surrounding the electron. discharge device and the oscillator circuit proper and acting as a shielding member is a drum-lilre member Eli provided with a closed bottom 23 and removable top 2d, The ring members are supported from the member i b means of the insulatin supports 2! and Extending from the bottom of the shielding member is a tubular extension 25 through which the cathode leads 2t and 2'5 extend, a conducting member contacting these tubular members for tuning the same in a manner and for a purpose to be described. As illustrated the cathode heater extend through and are shielded by the elements 25 and 2?, the cathode lead proper ll being electrically connected to the outside of these tub or members.

To tune the circut I provide a plurality of rotatable condenser elements so, 35, 82 and 33, which extend between. but are out of conta ct with the collar elements it and i9. Oppositely disposed elements ti and 33 are supported on an arm 35 while elements 3!) and 32 are su ported on an arm 38. These arms are in turn supported by coaxial concentric shafts 3i and 38 connected to an electrical gear box 39 provided with a corn ventional arrangement of gears whereby the turning of a knob 40 connected to the gear mechanism will cause condenser elements 38, 31, and 32, 33 to move away or toward each other as desired.

The member 20 is provided with aperture 45 through which the coupling loop 46 extends for taking energy from within the shielding member 20 to a load or a radiator.

The schematic circuit diagram shown in Figure 5 shows the electrical relationship between the various elements and the voltage sources. The anode collar I 9 is connected through a choke 41 to a source of positive potential whereas the grid collar I8 is connected through a biasing resistor 48 to ground. The shielding structure comprising the elements 20, 23, 24, 25 and 2B are also grounded. The cathode heater voltage is supplied by means of transformer 49.

The collar members I8 and [9, which are closed loops, serve as inductances for the oscillator, Whereas the natural capacity between these elements plus the capacity of the tuning condensers provide the capacity for a resonant circuit driven by the electron discharge devices If]. Proper positioning of the shorting disc 23 will adjust the impedance of the cathode lines so that they offer feedback impedance to R.-F. currents attempting to travel along the conductors 26 and 27, such that proper grid excitation is obtained.

In Figure 3 is illustrated somewhat schematically the collar-like elements l8 and I9 which have been developed into parallel strips with the grids and anodes connected to opposite strips. As there indicated the distance between the anode and grid connections, and between the ends of the line and between the anode elements is equal to a'half and a quarter wavelength. In other words, the electron discharge devices are spaced a half wavelength from each other. With this arrangement the voltage loop appears at the point of anode connection and the node midway between the same. Thus the effect is that of closed loops each a half wavelength long, the equivalent circuit of two such loops being shown in Figure 4. The capacity 43 is that capacity represented by the electrode elements and the loops 4| and 42 represent the inductance of that part of the collars l8 and I9 between the electrode elements and the nodal point on the collars. It will be observed that the result is a resonant circuit which will oscillate if properly driven, that is if an alternating voltage is applied across the plates of the condenser 43 which is the function of the electron discharge devices. Energy from the plate circuit to the grid circuit to support oscillation is chiefly through the capacity coupling between the collar elements, the electron discharge devices acting in push-pull.

While normally the device is operated with the cover 24 in place, the cover may be removed and the screening member 20, 23 used as a reflector for focusing the radio beam in any desired direction.

In connection with the tuning elements 30, 3|, 32 and 33, as these elements are moved closer to the electron discharge devices It! the resonant frequency of oscillation of the oscillator is reduced and as the elements are moved farther away from the electron discharge devices the resonant frequency of oscillation is increased. Moving the element away from the device I0 is the equivalent of tapping a condenser across fewer and fewer turns of an inductor in an oscillator tank circuit, whereas in moving the elements toward the electron discharge device is equivalent to including more and more turns of the inductor between the terminals of a condenser bridged across the inductor so that at the tube, it is the equivalent of placing the condenser across all of the turns of the inductor, thereby decreasing the resonant frequency of the circuit.

With an apparatus made according to my invention and utilizing tubes of the type described, and using a 5 inch diameter outer copper cylinder and a l inch diameter inner copper cylinder, both 2 inche wide and 20 mils thick, I have obtained a frequency of operation of about 830 megacycles. Under certain conditions of operation the apparatus has also been made to operate at 1224 megacycles. Oscillations will start at about 300 volts on the plate with a power output from 8 to 10 watts.

In the modification shown in Figures 6 and '7 my invention is applied to a combined oscillator and grounded grid power amplifier. In this arrangement the oscillator comprises the lower section in which tubes ID are mounted between the concentric collar cylinders l8 and 19', The grid leads are connected to member I 8' and the anode leads to member IS. The tubes and the cylinders are mounted within a shielding arrangement comprising cylinder 50 closed at the top and bottom by covers 52 and 5|. oppositely extending tubular members 53 and 54 surround the coaxial cathode lines 55 and 56 shorted by the elements 51 and 58 and closed by means of the insulating discs 59 and B0. The member 50 is divided into two compartments by means of transverse partition 6|.

The upper compartment encloses the amplifier. It includes the tubes ID mounted between the cylinders 62 and 63. The member 63 is electrically connected to the shielding casing 50. The cylinder 62 is connected to the anode leads and the cylinder 63 to the grid leads. Thus the grid in the amplifier is grounded on the shielding apparatus. The upper compartment is provided with the cathode lead tuning extensions 64 and 65 coaxial with and surrounding cathode leads 66 and 61, the tuning being accomplished by the shorting discs 68 and 69. The members 64 and 23 are closed by the insulating closure members To couple the oscillator to the amplifier I provide a pair of coupling members 14 and I5 shielded against radiation by means of tubular elements 1-6 and 11, thus forming coaxial lines. The cathode lines are so turned as to present a variable capacitive reactance which may be adjusted so that proper excitation is obtained. The R.-F. field within the members 53 and 5d furnishes the necessary energy for the coupling loops M and 15 which in turn excite the space within the tubular members 64 and 65 for feeding energy to the cathode of the tubes in the amplifier. The circuit relationships and voltage sources are best shown in Fig. '7.

As shown a high positive voltage is supplied to the inner cylinder l9 through choke 8| in the oscillator and to the inner cylinders 62 through choke in the amplifier. The cathodes are heated by means of the heating transformer 18, i9, 83 and 84. Energy may be taken from the amplifier by means of the coupling loop 13 extending through aperture 12 in the outer cylinder 50.

In operation the oscillator portion of the apparatus is made to function in the same manner as the apparatus shown in Figure 1. Energy from the cathode circuits 55, 53 and 54, 56 which are tuned for proper grid excitation of the oscillator, is transferred by means of the coaxial lines and loops id--l and l5'l'i, which feed energy into the cathode circuit of the amplifier tube and the amplifier portion of the apparatus. Thus an R.F. voltage is applied between the cathode and grid of the amplifiers within the upper portion of the member 58, controlling the flow of current to the anodes of the electron discharge devices and exciting the space between the collar member 92 and collar member 53, energy being taken from this space by means of coupling loop l3 extending through aperture 72 in member 50.

While I have indicated the preferred embodiment or my invention of which I am now aware and have also indicated only one specific application ior which my invention may be employed, it will be apparent that my invention is by no means limited to the exact forms illustrated or the use indicated, but that many variations may be made in the particular structure used and the purpose for which it is employed without departing from the scope of my invention as set forth in the appended claims.

What I claim as new is:

1. An oscillator including a plurality of electron discharge devices, each of which has grid and an anode, and a pair of concentric collar-like elements, one of said elements being connected to the grids of said electron discharge devices and the other of said collar-like elements being connected to the anodes of said electron discharge devices, said electron discharge devices being spaced around said collar-like elements.

2. An oscillator including a plurality of electron discharge devices, each of which has a grid and an anode, each grid and each anode being pro vided with a plurality of leads, and a pair of concentric collar-like elements, said electron discharge devices being oppositely disposed and spaced around said collar-like elements, all of the grid leads being connected to one of said collar-like elements and all of the anode leads being connected to the other of said collar-like elements.

3. An oscillator including a plurality of electron discharge devices, each of which has a cathode and an anode, each cathode and each anode being provided with a plurality of leads, and a pair of concentric collar-like elements, said electron discharge devices being oppositely disposed, all of the grid leads being connected to one of said collar-like elements and all of the anode leads being connected to the other of said collar-like elements, and means capacitively coupled between said collar-like elements and movable between said electron discharge devices.

An oscillator circuit for an electron discharge device having an elongated envelope and having grid and anode electrodes, said grid and anode electrodes each being provided with a plurality of terminal leads, said circuit including a pair of concentric collar-like elements of conducting material, said concentric collar-like elements being provided with registering apertures through which said electron discharge device extends between said collar-like elements with the elongated dimension of the envelope perpendicular to the axis of said collar-like elements, one of said collar-like elements being connected to said grid leads nd the other collar-like element being connected to said anode leads for exciting said oscillator circuit.

5. An oscillator circuit for an electron discharge device having an elongated envelope and having grid and anode electrodes, said grid and anode electrodes each being provided with a plurality of terminal leads, said circuit including a pair of concentric collar-like elements of conducting material, said concentric collar-lik elements being provided with registering apertures through which said electron discharge device extends between said collar-like elements with the elongated dimension of said envelope perpendicular to the axis of said collar-like elements, one of said collar-like members being connected to the grid leads and the other collar-like element being connected to the anode leads for exciting said oscillator circuit, and hollow conducting means surrounding the concentric collar-like elements of conducting material.

6. An oscillator circuit for an electron discharge device having a cathode, grid and anode electrodes, said cathode, grid and anode electrodes each being provided with a, plurality of terminal leads, said circuit including a pair of concentric collar-like elements of conducting material having equal lengths parallel to their axis, said collar-like elements being coextensive in a direction parallel to their axis, one of said collarlike members being connected to the grid leads and the other collar-like element being connected to the anode leads for exciting said oscillator circult, and a hollow shielding conducting member surrounding the concentric collar-like elements of conducting material, and a tubular extension mounted on said shielding member, the interior of which opens into the interior of said shielding member, said cathode leads extending through said tubular extension and means in said extension for tuning said cathode leads.

7. An oscillator including a plurality of electron discharge devices, each of which has a cathode, grid and anode, the grid and anode of each of said devices each being provided with a plurality of terminal leads, a pair of concentric collar-like elements between which and through which said electron discharge devices extend, said electron discharge devices being oppositely disposed and spaced around said collar-like elements, the grid leads of said electron discharge devices being connected to one of said collar-like elements and the anode leads of the electron discharge devices being connected to the other of said collar-like elements.

8. An oscillator including a plurality of electron discharge devices, each of which has a cathode, grid and anode, the grid and anode of each of said devices each being provided with a plurality of terminal leads, a pair of concentric collarlike elements between which and through which said electron discharge devices extend and around which said electron discharge devices are spaced, the grid leads of said electron discharge devices being connected to one of said collar-like elements and the anode leads of the electron discharge devices being connected to the other of said collar-like elements, and a cathode lead for the cathodes of each of said electron discharge devices, and means for tuning said cathode leads.

9. An oscillator including a pair of electron discharge devices, each of which has a cathode, grid and anode, the grid, anode and cathode being provided with terminal leads, a pair of concentric collar-like elements between which and through which said electron discharge devices extend, said electron discharge devices being oppositely disposed, the grid terminal leads of said electron discharge devices being connected to one of said collar-like elements and the anode terminal leads of the electron discharge devices being connected to the other of said collar-like elements, and shielding means surrounding said electron discharge device and said collar-like elements, and means extending from one side of said shielding means through which the cathode leads extend, and means within said extension for varying the effective length of said cathode leads for tuning the same.

10. An oscillator including a plurality of electron discharge devices, each of which has a cathode, grid and an anode, the grid, anode and cathode of each device being provided with terminal leads, a pair of concentric collar-like elements between which and through which said electron discharge devices extend, said electron discharge devices being spaced around said concentric collar-like elements, the grid terminal leads of said electron discharge devices being connected to one of said collar-like elements, and the anode terminal leads of the electron discharge devices being connected to the other of said collar-like elements, and shielding means surrounding said electron discharge devices and said collar-like elements.

11. An oscillator including a plurality of electron discharge devices, each of which has a cathode, grid and an anode, the grid, anode and cathode of each device being provided with terminal leads, a pair of concentric collar-like elements around which said electron discharge devices are positioned, the grid terminal leads of said electron discharge devices being connected to one of said collar-like elements, and the anode terminal leads of the electron discharge devices being connected to the other of said collar-like elements, said collar-like elements having a circumference equal to a multiple of half wavelengths of the operating frequency, the terminal leads of said electron discharge devices being connected at half wavelength intervals.

12. An oscillator including a pair of electron discharge devices, each of which has a cathode, grid and anode, each grid and anode being provided with a plurality of terminal leads, a pair of collar-like conducting members concentric with each other and provided with oppositely disposed apertures for receiving said electron discharge devices and supporting the same Within said apertures, contacts on said collar-like conducting members adjacent said apertures for receiving said terminal leads, the terminal leads of said grids being connected to contacts in one of said collar-like conducting members, and the terminal leads of the anodes being connected to the contacts of another of said collar-like conducting members.

13. An oscillator including a plurality of electron discharge devices, each of which has a cathode, grid and anode, each grid and anode being provided with a plurality of terminal leads, a pair of collar-like conducting elements concentric with each other, the terminal leads on said grids being connected to one of said collar-like elements, and the terminal leads on the anodes bein connected to another of said collar-like elements, a, shielding means surrounding said electron discharge devices and said collar-like conducting elements, conducting means extending between but out of contact with said collar-like elements and movable between said electron discharge devices, and means supported by said shielding means for supporting and moving said conducting means between said electron dis- 8 charged devices for varying the resonant frequency of said oscillator.

14. An oscillator including a plurality of electron discharge devices, each of which has a cathode, grid and anode, said grids, anodes and cathodes being provided with terminal leads, a pair of collar-like conducting members concentric with each other, the terminal leads on said grids being connected to one of said collar-like members and the terminal leads on said anodes being connected to another of said collar-like members, a shielding casing surrounding said electron discharge devices and said collar-like conducting members, a first tubular member extending from said shielding casing, a plurality of smaller tubular members within and coextensive with the first tubular member, the cathodes of said electron discharge devices being of the filament type and provided with a center tap lead, the center tap lead of said cathodes being connected to the smaller tubular members, the other terminal leads of said cathodes extending through said smaller tubular members, and movable conducting means within said first tubular member slidably supported on said smaller tubular members for tuning the cathode leads.

15. An oscillator including a plurality of electron discharge devices, each of which has a cathode, grid and anode, said grids, anodes and cathodes being provided with terminal leads, a pair of collar-like conducting members concentric with each other, the terminal leads on said grids being connected to one of said collar-like members and the terminal leads on said anodes being connected r to the other of said collar-like members, a shielding casing surrounding said electron discharge devices and said collar-like conducting members, a first tubular member extending from said shielding casing, a plurality of smaller tubular members Within and coextensive with said first tubular member, the cathodes of said electron discharge devices each being provided with three leads, one of which is electrically connected to one of said smaller tubular members and the others of which extend through the smaller tubular member, and means for closing the end of the first tubular member.

16. An oscillator circuit apparatus for use with a plurality of electron discharge devices, each of which has a cathode, grid and anode, said circuit apparatus including a pair of collar-like conducting members concentric with each other, the anodes of said electron discharge devices being connected to one of said collar-like conducting members and the grids of said electron discharge devices being connected to the other of said collar-like conducting members, and a drum-like shielding member surrounding said collar-like conducting members, a tubular member extending from one side of said drum-like Shielding member, the interior of said tubular member communicating with the interior of the drum-like shielding member, and a plurality of parallel elongated elements supported within said tubular member and extending within the drum-like shielding member, the cathodes of said electron discharge devices being connected to said parallel elongated members, oppositely disposed conducting means extending between but out of contact with said collar-like conducting members, means for rotatably supporting said conducting means from one wall of said drum-like shielding member, and means for rotating said supporting means to vary the position of said conducting means between said collar-like members.

17. An oscillator circuit apparatus for use with a plurality of electron discharge devices, each of which has a cathode, grid and anode, said circuit apparatus including a pair of collar-like conducting members concentric with each other, the anodes of said electron discharge devices being connected to one of said collar-like conduct members and the grids of said electron discharge devices being connected to the other of said collar-like conducting members, and a drum lilee shielding member surrounding said collar-like conducting members, a tubular member extending from one side of said drum-like shielding member, the interior of said tubular member communicating with the interior of the drum-like shielding member, a plurality of parallel elongated elements supported Within tubular member and extendin within the drum-like shielding member, the cathodes of said electron discharge devices being connected to said par allel elongated members.

18. A combined oscillator and amplifier including a first group of electron discharge devices, each of which has a cathode, grid and an anode, the grids, anodes cathodes being provided with terminal leads, a first pair of concentric collar-lilre members, the terminal leads of said grids being connected to one of said colla -like bers and the anode leads on said electron discharge device being connected to the other of said collar-like members, hollow shielding means surrounding said electron discharge devices said collar-like members, cathode terminal leads extending externally of said hollow shielding and conducting means surrounding said cathode terminal leads and extending from said hollow shielding means, a second group of electron discharge devices each of which has a cathode, grid and anode, said last grids, anodes and cathodes being provided with terminal leads, a second pair of concentric collar-like members, the grid terminal leads of said second group of electron discharge devices being connected to one of said second pair of collar-like members and the anode terminal leads of said second group of electron discharge devices being connected to the other of said second pair of concentric collar-like members and a hollow conducting member surrounding said second group of electron discharge devices and said second pair of collar-like elements, the cathode terminal leads of said second group of electron discharge devices extending externally of said hollow conducting member, and cnducting means surrounding the cathode terminal leads of said second group of electron discharge devices, and extending from said hollow conducting memher, and means for coupling the cathode leads of the two groups of electron discharge devices.

19. A combined oscillator and amplifier including a plurality of groups of electron discharge devices, each of which electron discharge devices has a cathode, grid and an anode, a plurality of pairs of concentric collar-like members one of said groups of electron discharge devices having its anodes connected to one of the collarlike members of one pair and its grids connected to the other of said collar-like members of said one pair, and another group of said electron discharge devices having its anodes connected to one of the collar-like members of another pair of concentric collar-like members and the grids connected to the other of the collar-like members of said other pair, and a hollow conducting means surrounding said concentric collar-like members and their associated electron discharge devices a d having a partition for electrically shielding of collar-like members and their associated electron discharge devices from each other.

A comb ned oscillator amplifier includ ing a plural .y of groups of electron discharge devices, each. vhic'n electron discharge devices has a cathode, grid and an anode, plurality of pairs of concentric collar-like members, one of said groups of electron discharge devices havin its anodes connected to one of he collar-like members of one pair and its :ids connected to the other of said collar-like members oi. the same pair, and another of said groups of electron discharge devices having the ano es connected to a collar-like member of another pair and the grids connected to the other collar-like member of the last mentioned pair of collar-lile members, hollow conducting means surrounding said pairs of concentric collar-like members and their associated electron discharge devices and a partition extending across said hollow conducting means for separately enclosing each of said collar-like members and their associated electron discharge devices and means for coupling one pair of concentric collar-like members and their associated electron discharge devices with another pair of collar-like members and their associated electron discharge devices.

21. A combined amplifier and oscillator comprising a hollow drum-like conducting member and conducting means dividing said drum-like conducting member into two compartments, a pair of concentric collar-like members within one or said compartments, and electron discharge devices, each of which has a cathode, grid and anode, the grids being connected to one of said collar-like members and the anodes being connected to the other of said collar-like members, and a second pair of concentric collar-like members in the other compartment, and electron discharge devices, each of which has a cathode, grid and anode, the anodes being connected to one of REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,979,668 Boddie Nov. 6, 1934 2,068,991 Kolster Jan. 26, 1937 2,190,712 Hansen e Feb. 20, 1940 2,207,346 lNolff July 16, 1940 2,216,176 I-lollmann Oct. 1, 1940 2,284,405 McArthur May 26, 1942 2,074,253 Mar. 16, 1937 2,034,433 Heintz Mar. 17, 1936

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