US2834884A - Wave guide with crystal diode socket having captive clamping means - Google Patents

Description

y 3 1958 c. P. DOME'NICHINI ETAL 2,834,884

WAVE GUIDE WITH CRYSTAL mom: SOCKET HAVING CAPTIVE CLAMPING MEANS Filed April 8. 1954 /NVENTO/25 CARLO R DOMEN/CH/N/ JOSEPH BA/(U o lvsv United States Patent WAVE GUIDE WITH CRYSTAL DIODE SOCKET HAVING CAPTIVE CLAMPING MEANS Carlo P. Domenichini, Lexington, and Joseph Bakura,

Watertown, Mass., assignors to Raytheon Manufacturing Company, Waltham, Mass, a corporation of Delaware Application April 8, 1954, Serial No. 421,721

1 Claim. (Cl. 250-31) This invention relates to microwave radiation, and particularly to the construction of those components which perform the modulating or mixing function in a high frequency wave guide assembly. For such purpose, it is customary to employ a crystal composed of a material which lends itself to the accomplishment of the heterodyning function entering into the process of extracting a lower frequency band of signal energy from a carrier wave of much higher frequency.

The invention is characterized by the provision of quickly attachable and readily removable means for firmly holding such a crystalline element in good electrical contact with the terminal ,of a conductor leading from the wave guide to an I. F. amplifier or other point of utilization of the heterodyned output. A feature of the construction is the use of parts which do not require threading or screwing operations for insertion or removal, and which are self-captivating without reliance upon chains or similar appendages awkward to manipulate.

These and other characteristics of the invention will be better understood upon reference to the following description of the embodiment of, the invention illustrated in the accompanying drawings wherein:

Fig. 1 is an elevation view of a radiant energy transmitting wave guide structure of a type to which the invention is applicable; 7

Fig. 2 is a longitudinal sectional view of one end of the wave guide structure of Fig. 1 showing an embodiment of the invention; and

Fig. 3 is a top plan view of the assembly of Fig. 2.

In these drawings, reference character 11 designates a microwave guiding conduit having at its outer end a coupling flange 12 for engagement with an antenna feed conduit (not shown) adapted to cooperate with a conventional reflector element (also not shown) for the radiation of high frequency radiant energy. Intermediate the ends of the wave guide 11 there is disposed a transmitting oscillator assembly including a klystron 13, a surrounding heat controlling oven 14, and a coaxial transducer 15 connecting the klystron generating cavity with the longitudinal wave guide 11. Also intermediate the ends of the wave guide 11 there is disposed a second resonant cavity structure 17 constituting a second frequency control cooperating with the principal wave guide section 11 and cooperating with the crystal mixer or modulation assembly located near the inner end of the wave guide 11 and constituting the subject matter of the present invention.

As shown best in Figs. 2 and'3, the mixer assembly includes a crystal element 21 of cylindrical contour and terminating in a smaller cylindrical portion 22 adapted to enter within and to be frictionally and resiliently grasped by a plurality of resilient metallic fingers 23 extending upwardly from a metallic conducting element 24 having at its lower end a terminal formation 25 adapted to receive the end of a current-conducting wire or cable by which signal-carrying energy is supplied from the crystal 2,834,884 Patented May 13, 1958 ice 21 and the wave guide 11. This conductor 24 is in alignment with the longitudinal axis of the crystal 21 and is retained in such alignment by the surrounding assembly including an inner guide bushing 27 fitting within an orifice formed in the cylindrical wall of the wave guide 11 in alignment with a second orifice adapted to receive the crystal 21. The bushing 27 is retained in its orifice by interengagement with a shoulder formed internally of the outer cylindrical casing 29, which casing is thermally united to the wall of the wave guide 11 along the outer circular shoulder 31. The casing 29 has a transversely extending partition 33 spaced from bushing 27 by an insulating element 30, the part 33 serving as an abutment for flange 34 on conductor 24. A dielectric spacer 36 is retained in position by a circular retaining spring 37 fitting within a circular groove 38 formed on the inner cylindrical surface of the casing 29. Other insulation 38a surrounds flange 34.

The means for retaining the crystal 21 in operative engagement with the fingers 23 of the conducting element 24 includes a bifurcated metallic cap having its longitudinally extending portions 41 and 42 in registry with diametrically opposite portions of a circular groove 43 extending about the periphery of a metallic bushing 44 whose central bore receives the crystal 21 and whose inner reduced end 45 fits within and is thermally united to the upper orifice previously referred to. The cap has an additional portion of circular contour uniting the previously described portion with a crystal engaging upper portion resting on the end surface of the crystal and, by reason of the resiliency of the metal, causing a retaining pressure to be exerted along the axis of the crystal, thus insuring its continuing conductive relationship with the fingers 23. The outer ends of the fingers 41 and 42 have inwardly turning portions 47 and 48 of suflicient extent to serve as limiting elements when the cap is withdrawn laterally of the bushing 44 a sufiicient distance to free the upper end of the cap from engagement with the upper end of the crystal. When this has been done, the crystal 21 is free to be withdrawn from the assembly for inspection or replacement by a counterpart. During such an operation, the cap, while Withdrawn, cannot actually escape from the assembly in view of the retaining action of the toe elements 47 and 48. Thus, the assembly is maintained intact during a crystal withdrawing and replacing operation and without the necessity of resorting to retention chains or other cumbersome and obstiucting devices.

The wave guide assembly of Fig. 1 may be supported upon a panel or bracket (not shown) by inserting the cylinder 29 into an opening in such panel or bracket, and clamping the cylinder thereto by means of clamping nuts 51 and 52. These nuts may then be secured by tightening lock washers 53 and 54. All these parts are threaded upon the threaded exterior of cylinder 29.

This invention may be applied to either a transmitting or receiving wave guide, or to any equivalent structure to which energy pickup by crystal means is desirable. The invention, in any of its applications, is not limited to the particular details of construction, materials and processes described, as many equivalents will suggest themselves to those skilled in the art. It is, accordingly, desired that the appended claims be given a broad interpretation commensurate with the scope of the invention within the art.

What is claimed is:

In an electromagnetic wave energy guiding structure, the improvement comprising first and second spaced bushings secured to said wave guiding structure, said bushings having aligned central apertures therein communicating with the interior of said wave guiding structure, a con- 3; q ounted. i h nh eamr u e f. id s nd bu ing, said conductor terminating in resilient gripping elements, a crystal element positioned in the aperture of said first .bushing and projecting within said wave guiding structure, said crystal elementhaving a portion thereof engagedby-said gripping element's establishing an electrical juncture, said firstbushing having a peripheral groove therein, a slidable member having a pair of spaced parallel fingers carrying a resilient element, said fingers cooperating with saidperipheral groove whereby said resilient element may be slidably positioned over the aperture in said first bushing to bear upon the exposed end of said crystal element, said parallel fingers being of suflicient length to permit said resilient element to be displaced entirely clear of said aperture, and means 4 ecur o. firifiasem. t l ads. hereqi. o. pr v t separation of said slidable mernber from said first bushing.

References Cited in the file of this patent UNITED STATES, PATENTS 483,221 um et al. Sept. 27, 1 92 1,334,212 Becker et a1. Mar. 16, 1920 2,291,674 Alden Aug. 4, 1942 2,469,222 Atwood etal. May 3, 1949 2,544,842 Lawson Mar. 13, 1951 2,636,120 Brod et al; Apr. 21, 1953 2,642,494 Zaslavsky et a1. June 16, 1953 FOREIGN PATENTS 979,826 France Dec. 13, 1950

Images