US2416567A - Space resonant system - Google Patents

Description

Feb. 25, 1947. Q QT U 2,416,567

- SPACE RESONANT SYSTEM Filed Oct. 25, 1942 fig.

ANOEflggR/D \LOLTAGE RE D IN HASE CURRENT VOLTAGE I A d w' ANODE-GRID a VOLTAGE POSITION 0F COUPLING SLOT Inventor; Elmer D. Mo Arthuw;

His Attorney.

Patented Feb. 25, 1947 SPACE RESONANT SYSTEM Elmer D. McArthur, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application October 23, 1942, Serial No. 463,087

My invention relates to space resonant systems and more particularly to ultra high frequency systems for the utilization and production of ultra high frequency energy.

- It is an object of my invention to provide a new and improved ultra high frequeny space resonant system.

It is another object of my invention to provide a new and improved ultra high frequency space resonant system comprising improved coupling means for interconnecting a plurality of space resonant regions.

It is a further object of my invention to provide a new and improved space resonant system comprising coupling means for interconnecting a plurality of space resonant regions and which is suitable for utilization in a system intended to operate over a wide range of frequency without entailing adjustment of the coupling means.

Briefly stated, in the illustrated embodiment of my invention I provide a new and improved ultra high frequency space resonant system which constitutes, as an energizing or control element of the system, an electric discharge device includa plurality of enclosed electrodes including an anode, a cathode and a grid andin which anode-grid and grid-cathode space resonant regions are defined by a, plurality of conductive members which may be concentric. The intermediate member forming the common boundary between the two regions, or the member connected to the grid of the discharge device is provided with an opening positioned within the vicinity of the maximum of the anode-grid standing potential wave, thereby constituting a coupling or communicating path between the respective regions. This opening may have a configuration such that it has an appreciable axial or longitudinal dimension to permit adjustment of th operating frequency of the space resonant system as a whole, whereby the desired degree of coupling is obtained throughout the range of operating frequencies without necessitating adjustment of the coupling means. For example,

the opening may have a helical configuration and is of such width that its presence will not materially disturb the desired wave transmitting and propagating characteristics of the respective regions, and at the same time affords the desired coupling.

For a better understanding of my invention, reference may be had to the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims. Fig. 1 diagrammatically illus- Claims. (01. 2504s) 2 trates an embodiment of my invention as applied to a space resonant system including an electric discharge device and three concentric conductive or metallic cylinders connected to the electrodes of the discharge device, and wherein the coupling means constitutes a helical opening, or a pair of such openings, in the cylinder constituting the common boundary between the anode-grid and the grid-cathode regions. Fig. 2 is a detailed view of the discharge device employed in the arrangement of Fig. 1. Fig. 3 represents certain features of the space resonant system and the coupling opening or slot.

Referring to Fig. 1 of the accompanying drawing, my invention is there illustrated as applied to an ultra high frequency space resonant system which may include, as a control element thereof, an electric discharge device I which is associated with apluraiity of metallic or conductive membars which define a plurality of space resonant regions. Prior to the description of the space resonant system as an entirety, it is believed that reference may initially be had to Fig. 2 wherein the discharge device I is shown in more detail. The discharge device I includes a plurality of enclosed electrodes, such as a metallic cylindrical anode 2, a cylindrical cathode 3 having its emissive surface 4 facing the end of anode 2, and a grid 5 spaced between the anode 2 and cathode 3 and preferabiy lying in a plane spaced a small distance from the cathode emissive surface. The discharge device I is constructed preferably to have a generally stepwise configuration and constitutes a plurality of metallic members or discs r 5, l and 8 which support anode 2, grid 5 and cathode 3, respectively. It will be observed that the diameters of discs 68 progressively increase to afford the above mentioned stepwise configuration. Disc 8 may be formed integral with a cylindrical skirt 9 which serves as a supporting or securing means between the elements of the discharge device and base ill. Discs 6, 1 and 8 are maintained in spaced relation with respect to each otherby means of a pair of cylindrical insulating cylinders H and I2 which are sealed to the discs and constitute in part an enclosure for the electrodes of the discharge device.

Cathode 3 is provided with a. flanged part l3 which parallels the under-surface of disc 8 and is spaced therefrom by means of an insulating member or washer M. In this manner, the oathode 3 is electrostatically coupled to disc 8 but electrically insulated therefrom so far as direct currents are concerned. Unidirectional current or potential may be applied to cathode 3 bymeans of conductors I and I6 which are terminated in contact pins I1 and I8 secured to base ill. Cathode heating element or coil I9 is provided with a pair of conductors 2i! and 2| which are likewise terminated in contact pins 22 and 23 also secured to base I9. It will be appreciated, of course, that conductors I5, I6, and ill are sealed to a metallicheader (not shown) located Within the base Ill, this header also being, of course, welded or soldered to the skirt 9 thereby completing the evacuated enclosur for the electrodes of the discharge device.

In order to afford a high frequency connection mean for the discharge device, anode 2 may be provided with an enlarged section or part 24. It will be appreciated that the anode 2 and disc 6 are closely fitted in order to maintain the desired low pressure within the discharge device. The discharge device described above is the prior invention of James E. Beggs and is described and claimed in his copending application, Serial No. 436,633, filed March 28, 1942, and assigned to the assignee of this invention.

Referring again to Fig. 1, I employ means in conjunction with the discharge device I for defining a plurality of space resonant regions More particularly, in one form of my invention the space resonant regions may be defined in part by a plurality of substantially concentric metallic or conductive cylinders 25, 26 and 21. Cylinders 25 and 26 define the anode-grid space resonant region, and cylinders 26 and 21 define the gridcathode space resonant region. Cylinder 26 may be connected to disc I of the discharge device I through adapting means, such as a resilient annular member 28 of conductive character, to afford a suitable high frequency connection thereto, and a disc 8 may be connected to cylinder 21 through an annular member 29 of metallic construction which may be secured rigidly to cylinder 21 by being attached to a metallic ring 38 closely fitting to the inner surface of cylinder 21. The combination of an electric discharge device having transverse disk-like terminals and concentric resonators, is described and claimed in the copending Jensen and Keister application 448,206, filed June 24, 1942, and assigned to the assignee of this invention.

The discharge device I may be held rigidly in the position illustrated by using a onstruction which comprises a cylinder 3| which telescopes cylinder 21 at one end thereof. Cylinder 3| is provided with a threaded collar 32 to engage threads upon a portion of the outer surface of cylinder 21. A metallic ring 33 is closely fitted to, or may be formed integral with, cylinder 3| and constitute a means for supporting socket 34 for discharge device I in position, and hence serves as a means for rigidly supporting the discharge device I in firm engagement with members 28 and 29.

In order to connect cylinder 25 to anode 2, and more particularly to the part 24 thereof, I may employ a metallic adapter 35 which is, of course, conductively connected to cylinder 25. This adapter may be constructed of a solid metal such as brass or copper and be provided with a recess to receive the enlarged section 24 of the anode construction.

I provide means for tuning the space resonant regions. One of these tuning means may be associatedwith the anode-grid region and may comprise a piston 36 which i in engagement with and slideable along the outer surface of cylinder 25 and the inner surface of cylinder 26 and may To apply unidirectional potential to the anode-.

grid circuit of the discharge device I, the anode 2 and more particularly the part 24 thereof may be connected to a source of unidirectional potennected to adapter 35.

tial. by means of a cylindrical conductor lil which is positioned within cylinder 25 and which is con- Of course, the negative terminal of the unidirectional source is connected to contact pins II or I8 of the discharge device through either terminal 40 or 4| of socket 34.

Energy may be derived from the anode-grid region of the system by employing output electrode means which may comprise a loop 42 constituting an extension of an inner conductor 43 of a concentric transmission line 44. Of course, it is to be appreciated that other forms of electrode means may be employed for extracting energy from the space resonant system.

I provide within the cylinder 26 which defines the common boundary between the anode-grid and grid-cathode space resonant regions, an opening 45 having an appreciable axial or longitudinal dimension to afford sufiicient coupling between these regions throughout a substantial range of the operating frequency of the system. This opening, which may have a configuration generally described as a narrow spiral or helical slot, is preferably positioned within the vicinity of the maximum of the standing potential wave,

in the anode-grid region.

I have found that in space resonant systems which may be operated as coaxial wave propagating systems having Wave lengths which are odd multiples of quarter wave lengths, such as threenuarters or five quarters wave lengths, there are certain phase reversals which occur inside the lines or the region defined by the conductive members in such a way that the cathode and anode potentials of the discharge device are brought geometrically close to each other on opposite sides of the member which defines the common boundary between the two regions. The existence of this phenomenon is, of course, due to the self -shielding characteristics of the respective coaxial lines. More particularly, it is due to the thin penetration depth of the current which permits the existence of two individual and relativel independent currents on opposite sides of the same piece of metal defining the common boundary between the two regions. Consequently, the above described coupling slot 45 is employed to supply the feed back connection required. The slot 45 when placed at the proper position permits the flow of energy from one side of cylinder 26 to the other side, thereby exciting the grid-cathode region at the proper'position to obtain the desired phase relationship between the respective electrode voltages of the discharge device. It will be appreciated that there are a number of places or points at which such a coupling slot may be located, the number of course depending upon the electrical length of the space resonant regions under consideration. 7

In accordance with another feature of my invention, cylinder 26 may be provided with another opening 45, diametrically opposed .to opening 45. The two openings may operate in conjunction, or

discharge device I, the system will oscillate.

Energy may be derived from the anode-grid region through the concentric .transmission line 44 and supplied to an external or utilization circuit. The grid-cathode region is maintained in oscillation through the energy supplied thereto from the anode-grid cavity through opening or 85", or both, which constitute the coupling means. By virtue of the fact that the opening 45 or 45' has an appreciable axial length, it should be appreciated that this feature permits substantial adjustment of the operating frequency of the system without materially changing the coupling between the anode-grid and the grid-cathode regions, thereby dispensing with the necessity of adjustable coupling means or devices. By positioning openings 45 and 45 within the vicinity of the voltage maximum of the standing electromagnetic wave within the anode-grid region, suflicient coupling is provided throughout a range determined by the efiective axial dimension of the openings.

The relation of the position of openings 45 and 45' with respect to the voltage and current standing waves within the anode-grid regionmay be mor fully appreciated by referring to Fig. 3 which represents in simplified form the anodegrid region defined, by cylinders 26 and 21 and plunger 36 and which may be considered as constituting, for the purposes of analysis, a tuned three-quarter wave length coaxial line having a physical length compensated for end-effects, and establishing standing voltage and current waves A and B, respectively. Upon adjustment of the op erating frequency of the system, it will be appreciated that the voltage maximum of the standing wave within the anode-grid region will change in position. However, due to the helical shap of the openings 45 and 45 the efiect of such a change in 6 defined bya pair 01'- outer conductive members and an intermediate conductive member, said'inter mediate conductive member being provided with an opening located within the vicinity of the potential maximum of the standing electromagnetic wave within one of said regions, said opening having both longitudinal and lateral progression along the surface of said intermediate member,

. and means for exciting said one of said regions.

position'of the voltage maximum does not change.

the coupling between the anode-grid and gridcathode regions and consequently permits adjustment of the operating frequency without entailing a loss of output power.

While in the above description of my invention I have chosen to describe its operation with particular reference to an oscillator, it will be understood by those skilled in the art that itmay be applied to space resonant systemsgenerally where it is desired .to couple a pair or plurality of space resonant regions.

While I have shown and described my invention as applied to a particular system and as embodying various devices diagrammatically shown, it will be obvious to those skilled'in the art that changes and modifications may be made without departing from myinvention, and I, therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A high frequency space resonant system comprising a plurality of space resonant regions 2. A high frequency space resonant system comprising a plurality of space resonant regionsdefined by a plurality of cylindrical conductive members, the intermediate member defining the common boundary between the space resonant regions being provided with a slot located within the vicinity of the potential maximum of the standing electromagnetic wave within one of said regions and constituting coupling means between the regions, said slot having both longitudinal and tangential progression along the axis of said intermediate member, and means for establishing an electromagnetic wave within one of said regions.

3. A high frequency space resonant system comprising a pair of space resonant regions defined by a plurality of concentric conductive cylinders, means for establishing an electromagnetic wave within one of said regions, the intermediate cylinder defining the common boundary between said regions being provided with a pair of oppositely disposed slots located within the. vicinity of the potential maximum of the standing electromagnetic wave within said one region said slotshaving both longitudinal and tangential pro gression along the axis of said intermediate cylinder.

4. A high frequency spac resonant system comprising a plurality of space resonant regions defined by a pair of outer conductive members and an intermediate conductive member, means for establishing an electromagnetic Wave within one of said regions, and means for controlling the operating frequency of said space resonant system, said intermediate conductive member being provided with a helical opening located within the vicinity of the potential maximum of the standing electromagnetic wave within one of said regions thereby constituting a coupling path between said regions effective throughout a predetermined range of operating frequencies. v

5. A high frequency space resonant system comprising a plurality of space resonant regions defined'by a pair of outer conductive members and an intermediate conductive member, means for establishing an electromagnetic wave within one of said regions, meansfor controlling the operating frequency of said system, said intermediate member being provided with a helical opening located within the vicinity of the potential maximum of the standing electromagnetic wave within said one region and having an appreciable axial dimension thereby constituting coupling means substantially independent of the operating frequency.

6. A high frequency space resonant system comprising an electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid, a plurality of conductive members connected to said electrodes to form anode-grid and grid-cathode space resonant regions, one of said members being provided with an opening having an appreciable axial length and tangential progression to form a communicating path between said anode-grid and said grid-cathode regions located within the vlcinity of the maximum of the anode-grid region standing potential wave to afford substantial couplingbetween said regions throughout an ape preciable range of operating frequencies of said system. I I

7. --A high frequency space resonant system comprising an electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid, and a plurality of. substantially concentric members connected respectively to said electrodes anddefining-anodegrid and grid-cathode space resonant regions, the intermediate member connected to said grid-being provided with an openinglocated within the vicinity of the potential maximum of the standing electromagnetic waveof said anode-grid region and having appreciable axial length to afford substantial coupling between said regions throughout the range of operating frequencies of said system.

. 8 A high frequency space resonant system comprising an electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid, and a plurality of substantially concentric members connected respectively to said electrodes and defining anodegrid and grid-cathode space resonant regions, th -intermediate member being provided with a helical opening constituting a communicating path between said regions.

--9. A high frequency space resonant system comprising an electric discharge device having aplurality of enclosed electrodes including an anode, a cathode and a grid and high frequency terminals therefor, three concentric conductive cylinders connected respectively to the terminals for said electrodes for defining anode-grid and grid-cathode space resonant regions, means for tuning at least one of said regions, the intermediate cylinder connected to said grid being provided with an opening constituting a communicating path between said regions and having-a substantial axial dimension to afford sufficient coupling throughout a range of operating frequencies of said system.

I 10. A high frequency space resonant system comprisingan electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid, a plurality of substantially concentric conductive members con:

nected respectively to said electrodes and defining anode-grid and grid-cathode space resonant regions, the intermediate member being provided with a helical opening constituting a communicating path between regions, and means for tuning at least one of said regions. 11. A high frequency space resonant system comprising an electric discharge device including aplurality f enclosed electrodes including an anode, a cathode and a grid, a plurality ofconductive members connected .to said electrodes to form anode-grid and grid-cathode space resonant regions, the member connected to said grid being provided with a narrow helical slot located within the vicinity of the maximum of the anodegrid region standing potential wave, and means for tuning at least one of said regions.

12. A high frequency space resonant system comprising an electric discharge device includ-, ing a plurality of enclosed electrodes including an anode, acathode and a grid, a plurality of substantially concentric conductive members con-, nected respectively to said electrodes anddeflning anode-grid and grid-cathode space resonant regions, the intermediate member connected to said grid being provided with a pair of opposed openings located within the vicinity of the poten-. tial maximum of .the standing electromagnetic wave of said anode-grid region and constitute ing coupling means between the anode-grid and the grid-cathode space resonant regions.

13. A high frequency space resonant system comprising an electric discharge devic includ ing; a. plurality of enclosed electrodes including an anode, a cathode and a grid, a plurality of cylindrical conductive members connected to said electrodes to form anode-grid and grid-cathode space resonant regions, and a pair of diametrically opposed coupling paths in the cylinder defining the common boundary between the anode: grid and the grid-cathode space resonant re gions, said cylinder being provided with helical slots to form said paths.

14. A high frequency space resonant system comprising an electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid, a plurality of substantially concentric conductive cylinders connected respectively to said electrodes .and defining anode-grid and grid-cathode space resonant regions, the intermediate cylinder connected to said grid being provided with a pair of diametrically opposed and longitudinally and tangential,- ly progressive slots located within the vicinity of the potential maximum of the standing electromagnetic wave of said anode-grid region thereby constituting coupling means between the anode-grid and the grid-cathode space resonant regions. r

15. A high frequency space resonant system comprising an electric discharge device includ ing a plurality of enclosed electrodes including an anode, a cathode and agrid, a plurality of sub stantially concentric conductive members con nected respectively to said electrodes and define ing anode-grid and grid-cathode space resonant regions, the intermediate member connected to said grid being provided with a. pair of. slots having reverse curvatures relative to the'longi-v tudinal axis of said regions thereby'constituting coupling means between the anode-grid and the grid-cathode space resonant regions.

ELMER D.McARTI-1UR. I

' REFERENCES CITED The following references are of record in the file of this patent:

Trevor Apr. 29, 1941

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