Патент USA US3092801код для вставки
J1me 4, 1963 R. L. HUBBELL ET AL 3,092,791 MICROWAVE swncnms DEVICE HAVING MOVEABLE JUMPER FOR INTERNALLY SHORTING ELECTRODES OF T-R TUBE F'iled March 8. 1961 '3: 25 2_f 2 6 28 FIGZ INVENTORS RICHARD L. HUBBELL FRANK A. RECORD ATTO R N EY United States Patent 0 we 3,d92,791 . ICC Patented June 4, 1963 1 Z 3,092,791 invention with a portion of the tube envelope broken away to reveal internal structure; FIG. 2 is ‘an enlarged detailed view of the embodiment shown in FIG. 1 along the line 2—-2. Referring now to the drawing, the illustrative embodi MICROWAVE SWITCHING DEVICE HAVING MOVEABLE JUNIPER FOR INTERNALLY SHORTING ELECTRODES 0F T-R TUBE Richard L. Hubbell, Arlington, and Frank A. Record, Danvers, Mass., assignors, by mesne assignments, to Varian Associates, Palo Alto, Calif., a corporation of California ment is 1a broad band TR switching tube comprising a sec_ tion of rectangular waveguide 1 de?ning parallel broad walls 2 and narrow walls 3. Secured adjacent the ends Filed Mar. 8, 1961, Ser. No. 94,297 are conventional mating ?anges 4 and 5. A resonant win 5 Claims. (Cl. 333—13) dow assembly 6 encloses each end of the waveguide sec 10 tion to thereby provide a hermetically sealed envelope. The present invention relates vgenerally to microwave Each window assembly includes a dielectric member per frequency gaseous discharge switching devices with inte gral protective mechanisms and, more speci?cally, to a novel and improved mechanism for attenuation of unde sirable microwave frequency signals. Prior art switching devices incorporated in radio direc vious to microwave energy signals. The envelope con tains a ‘gaseous ionizable atmosphere under reduced pres sure to provide a highly intense gaseous discharge when high power microwave frequency energy is transmitted to the window assembly positioned within ?ange 4. tion and ranging systems are coupled between the com Disposed transversely within the waveguide envelope at mon antenna and the sensitive receiver. A speci?c group intervals of a quarter of a wavelength are a’ plurality of vof such devices is commonly referred to as transmit resonant elements. Included are a plurality of paired receive 01' TR tubes. An internal highly ionized gaseous metallic plate members 7 de?ning irises 8. Disposed discharge within a metallic or dielectric envelope is initi within each iris are spaced oppositely disposed conical ated upon exposure to high power pulses transmitted to electrodes 9, 10, 11, 12 de?ning ‘discharge gaps 13 and 14, the common ‘antenna. The re?ected returning pulses at having axes taken in the direction of a discharge across a lower power level pass through the TR tube without *a discharge to the receiver. It is necessary to protect the 25 the gaps. An ignitor electrode 15 having a metallic probe 16 and dielectric bead 17 is supported by a ‘collar 18 with sensitive elements within the receiver during nonvopera the inner end 19 of the probe exposed to the inside of the tion of the TR tube when a ‘discharge cannot be initiated. An attenuating protective mechanism has ‘been incorpo envelope adjacent one ‘of the plate members 7. An ioniz a'ble gaseous atmosphere of a suitable gas such as helium, rated in the TR tube. This mechanism is referred to as a “shutter” in accordance with US. Patent 2,734,171, 30 argon or hydrogen with a small percentage of water vapor is provided within the envelope at a reduced pressure of issued February 7, 1956 to Harold Heins and assigned to a few millimeters of mercury. the iassignee of the present invention. The mechanism Pursuant to the teachings of the present invention, the disclosed provides a metallic shorting member within a novel attenuating mechanism is introduced into the tube resonant element of the TR tube ‘and is electromechani cally controlled. When the TR tube is inoperative, the 35 envelope through one of the narrow walls 3. The mecha nism comprises an elongated shorting ‘bar member 20 sup shorting member extends across the Waveguide path to ported by a drive rod 21. A desirable material may be contact another resonant element and thereby attenuate 'berrylium copper or other metals having a resiliency for any undesired signals. good contact and a slight ?ex-ing or bowing is preferred. In accordance with advancements in the art, generators FIG. 1 illustrates the mechanism in the open position with of very high frequency signals have become available. At the discharge gaps 13 and 14 uninhibited for normal TR these frequencies waveguide dimensions are extremely switch operation. The member 20 is touching the face small and the aforementioned attenuating mechanisms of the plate iris members 7 and is the end limit of travel cannot be employed. An example may be the 15 to 17 toward the adjacent narrow waveguide wall 3. kilomegacycle frequency range where the broad Wave FIG. 2 illustrates the ‘closed position when the TR guide wall is .702 inch and the narrow wall is .391 inch. 45 switch tube is inoperative. The shorting bar member 29 Since ‘generators have now been developed up to 75 kilo contacts both pairs of conical electrodes to thereby effec megacycles, a need exists for a protective attenuating mechanism for TR switching devices at such high fre quencies of transmission. Accordingly, it is an object of the present invention to provide a gaseous discharge switching device having a new and novel protective ‘attenuating mechanism. In accordance with the present invention, a gas switch tively short circuit the electrodes and attenuate any unde sired signals entering the tube envelope. The bar 29 moves into the gaps 13 ‘and 14 from a direction transverse to the axes of the gaps. To facilitate seating of the bar member against the ‘convergent end of all the conical elec trodes, a notch 22, visible in FIG. 1, may be desirable. ing TR tube having conventional internal resonant ele The attenuating mechanism is activated by electrome ments is provided with metallic means extending parallel 55 chanical means 23 secured to the narrow waveguide wall to the envelope broad walls. Movement of the metallic 3 by a collar member 24. A metallic core 25 of soft iron means by conventional electromechanical means results having an axial bore 26 houses an end of the rod 21. An electrical coil 27 surrounds core 25 and is connected to elements to attenuate by a value ‘of 40 db or better any an appropriate voltage supply, such as 14 or 28 volts DC. 60 signals entering the tube. A feature of the invention re by means of terminals 23 mounted ‘on an insulator 29 sides in the provision of ‘a new and novel means for pro in simultaneous short circuiting of a plurality of resonant with wires 30 extending from the ‘coil. The housing 31 encloses the aforementioned components. Armature 32 of a suitable material secured to rod 21 is urged forward shorting of multiple resonant discharge gaps with single electromechanical means at a saving in cost, as well as, :a 65 by spring 33 and upon energizing of the electromechanical means the tension of the spring is overcome to move the reduction in number of ‘external structures disclosed in shorting member 29 to the open position. To avert dis the aforementioned patent. location of the armature 32 in moving between the open Further objects, features and advantages will become apparent after consideration of the following detailed 70 or closed positions, an anchor pin 34 may be provided extending through an aperture in the armature. speci?cation and appended drawing, in which: In an experimental embodiment for use at a frequency FIG. 1 is a perspective view of the embodiment of the tecting a sensitive receiver in TR switching tubes having small internal dimensions. An additional feature is the 3,092,791 4 3 wherein the dimensions necessitate conical electrodes hav broad walls to de?ne plural discharge gaps, attenuating ing a tip-of .015 inch or less, attenuations of 40 db or bet ter were achieved. In the open position, the shorting bar means including an elongatedmmetallic shorting .bar mem ber adapted to simultaneously contact all the electrode member appears to have a negligible effect on insertion ends and being movable in a-plane approximately parallel loss since the overall tube measured only .5 db insertion loss. to the bro-ad side walla-and» electromechanical means mounted on one of saidnarrow'walls to control~move ment of said shorting bar member. 3. A microwave switching-device according to claim 2 Hence, ‘while prior art protective mechanisms require separate short circuiting means for each discharge gap, there is disclosed a single means for‘achieving this pur pose for a plurality of gaps. Further, a single electrome chanical means will now activate an ‘attenuating mecha wherein said shorting, bar member-is fabricated with a ' 10 nism for protection of switching tubes from undesired microwave frequency signals. bowed con?guration. 4. A microwave switching deviceia'ccording-to claim 2 wherein said electrode ends are provided ' with means adapted to ifa‘cilitate seating of the‘shorting bar member While a specific illustrative embodiment has been de upon contact therewith. 5. A microwave switching device comprising, an en velope ?lled with an i-onizable atmosphere-under reduced pressure, a resonant element disposed within said envelope sense consonant with the spirit and scope of the invention to de?ne a discharge gap, said discharge gap having van vas de?ned in the appended claims. ' axis taken in the direction of the discharge across the‘ gap, What is claimed is: 1. A microwave switching device comprising a metallic 20 attenuating means for short ‘circuiting said discharge gap by moving into the gap, from a direction approximately envelope ?lled with-an ionizable atmosphere under re transverse to the axis of said discharge gap, and an electro .duced pressure, resonant elements including plural op mechanical means cooperating with and controlling the posed conical electrode structures spaced within said en movement of said attenuating means. velope to de?ne plural discharge gaps having axes in the direction of the discharge across :the gaps, attenuating 25 References Cited inthe ?le of this patent means including a metallic shorting bar member adapted to simultaneously contact a plurality of said electrode UNITED STATES PATENTS structures. by moving into the gap from a‘ direction trans Heins ________________ __ Feb. 7, 1956 scribed above, it is intended that all matter appearing herein and shown in the drawing be interpreted in a broad verse to the axes of said gaps, and electromechanical means to control movement of said shorting 1bar member. 30 2. A microwave switching device ‘comprising a rectan gular waveguide envelope having parallel brood and nar row walls and containing an ionizable atmosphere under reduced pressure, plural spaced. resonant conical electrodes having opposed ‘convergent ends extending ?rom opposite 2,734,174 2,816,272 Braden ______________ __ Dec. 10, 1957 OTHER REFERENCES “Design and Development of- Shutter and TR-Shutter Tubes,” Bom-ac Laboratories pamphlet,’ FIGS; 4 and- 5 re Received US. Patent Oi?ce March 18,1955. 35 ferred to.