US3287668A

US3287668A - Delay line for traveling wave tubes, especially for millimeter-waves, constructed from a plurality of laddershaped structures, bent to form a spiral line

Info

Publication number: US3287668A
Application number: US403667A
Authority: US
Inventors: Veith Werner; Poebl Konrad
Original assignee: Siemens AG
Current assignee: Siemens and Halske AG; Siemens AG
Priority date: 1961-11-10
Filing date: 1964-10-13
Publication date: 1966-11-22
Anticipated expiration: 1983-11-22
Also published as: GB1013090A; NL6411934A; NL285205A; US3366897A; CH406450A; DE1296274B; DE1281586B; DE1295706B; GB958923A

Description

w. VEITH ETAL 3,287,668

ESPECIALLY FOR CONSTRUCTED FROM A PLURALITY Nov. 22, 1966 DELAY LINE FOR TRAVELING WAVE TUBES,

MILLIMETER-WAVES,

OF LADDERSHAPED STRUCTURES,BENT TO FORM A SPIRAL LINE 2 Sheets-Sheet 1 Filed Oct. 13, 1964 Fig.2

ETAL DELAY LINE FOR TRAVELING WAVE TUBES, ESPECIALLY FOR MILLIMETER- VES, CONSTRUCTED FROM A PLURALITY OF DDERSHAPED STRUCTURES,BENT

TO FORM A SPIRAL LINE Nov. 22, 1966 w m 3,287,668

Filed Oct. 15, 1964 2 Sheets-Sheet 2 Fig.4

INVEpTC Z IZS Werner e/ A on/"ac/ 0b/ ATTYS.

United States Patent Claims. 61. 333-41 The invention relates to a delay :line for moving field tubes, especially for the amplification of millimeter waves, which consists of a spiral arranged in the interior of an electrically conductive hollow body and in which the individual windings are rigidly mounted on metal supports, which extend inwardly from the wall of the hollow body toward the spiral and are progressively olfset against one another in the longitudinal direction of the spiral. In such a line it has already been proposed that the spiral be composed of arcuate-shaped sections which are disposed in planes perpendicular to the iongitudinal axis of the delay line between two adjacent metal supports, and straight sections which extend in the longitudinal direction of the delay line.

According to the present invention it is proposed, in a delay line of the type described, that the spiral and the metal supports be produced from several stamped sheet metal strips which, as a development of the arcuate-shaped sections of the spiral and of the contiguous metal supports, have the form of a ladder whose rungs are stepped, forming alternately towards the stringers of the ladder-shaped structure a half support member, and are so assembled, in star form, continuously in the circumferential direction of the spiral that the central portion of the rungs form the arcuate-shaped sections of the spiral, while the longitudinally extending sections of the delay line are formed by the side portions of the step-like offsets of the rungs extending parallel to the stringers.

A delay line proposed aclciording to the invention has, in the first place, the advantage that there results an extremely low capacitance loading of the delay line from winding to winding of the spiral. This corresponds to a high line impedance and, therefore, to a high coupling resistance of the delay line. On the other hand, a delay line according to the invention is simple from the viewpoint of manufacturing technology and can be produced very accurately as to its dimensions, in view of which it is especially suitable as 'a delay line for millimeter wave operation which, as is well known, requires very small geometric dimensions. In the production of such a delay line the sheet metal strips are simply bent about a mandrel assembled thereon and soldered together, prior to their insertion in the hollow conductor.

In the drawings, wherein like reference numerals indicate like or corresponding parts:

FIG. 1 is a perspective view of a portion of a spiral line embodying the invention, with portions broken away to show the details thereof;

FIG. 2 is a development of one of the strips forming the structure illustrated in FIG. 1;

FIG. 3 is an end view of a hollow body in which the spiral line assembly of FIG. 1 is to be received;

FIG. 4 schematically illustrates the spiral current path of the structure illustrated in FIG. 1; and

FIG. 5 is a transverse sectional view through a delay line embodying the invention, utilizing a hollow con- 'ductor formed from a plurality of longitudinally extending members of arcuate cross-section.

The spiral line illustrated in FIG. 1, with the supports therefor, is composed of six stamped sheet metal strips 1, individually illustrated in FIG. 2. Such sheet metal strips 1 are suitably formed, as by stamping in the shape of a ladder, whose rungs, indicated generally by the reference numeral 2, are alternately stepped toward the stringers 3. As is apparent from FIGS. 1 and 2, the central portion of rungs 2 having a uniform width or height as viewed in FIG. 2, represents the development of the arcuate-formed sections 4 of the spiral, which are disposed in planes perpendicular to the longitudinal axis of the delay line. The stepwise enlarged ends of the rungs 2 form in each case a half support member 5. The portions 5 extending parallel to the stringer-s 3, of the step-like offsets of rungs 2, define sections of the spiral line which extend in longitudinal direction of the delay line.

FIG. 4 schematically illustrates the spiral current path through the delay line.

In a delay line according to the invention, the spiral with metal supports as illustrated in FIG. 1 is to be so arranged on an electrically conductive hollow body that the metal supports 5 support the spiral line within the hollow body. As illustrated in FIG. 3, for this purpose there are provided in the hollow cylindrical metal body 6 longitudinally extending grooves 7 whose depth b corresponds to the width of the stringers 3 and whose width a corresponds to twice the stringer thickness. The sheet metal strips of FIG. 2 following arcuate formations of the rungs '2, and assembly according to FIG. 1, can then be inserted in the hollow body 6 in such a way that the stringers 3 of the sheet metal strips are disposed within the wall of the hollow body 6, the stringers 3 expediently being soldered in the 1onlgitudinal grooves 7 thereof.

In the embodiment of the invention illustrated, the angle which two metal supports of a strip enclose with respect to one another amounts to 60. The invention is obviously not limited to such a supporting angle. On the contrary, the metal supports may enclose any angle with respect to one another, which in the assembled structure total 360.

In a delay line according to the invention, as illustrated in FIG. 5, the hollow conductor may also be composed of several parts. Such a delay line can be manufactured in a particularly simple manner if, in the arrangement shown in FIG. 1, longitudinally extending strips 8, of arcuate cross section, as assembled between the respective spaced pairs of stringers 3 disposed in a star pattern, which upon soldering of the assembly produces a hollow body, having a cross-section as illustrated in FIG. 5.

Changes may be made within the scope and spirit of the appended claims which define what is believed to be new and desired to have protected by Letters Patent.

We claim:

1. A delay line for moving field tubes, especially for the amplification of millimeter waves, which consist of a spiral arranged in the interior of an electrically conductive hollow body, with individual windings rigidly attached to met-a1 supports which extend inwardly from the Wall of the hollow body toward the spiral and are angularly offset with respect to one another progressively in the hollow body in the longitudinal direction of the spiral, the spiral comprising arcuate-shaped sections which are disposed between two adjacent metal supports in respective planes extending perpendicular to the longitudinal axis of the delay line, and straight sections which extend in the longitudinal direction of the delay line, characterized in that the spiral and the metal supports are made of a plurality of stamped sheet metal strips which, as a development of the arcuate-shaped sections and of the adjoining metal supports, have the form of a ladder whose rungs are stepped alternately toward the stringers thereof forming in each case a. half support member, the formed strips being interassembled progressively in a star pattern in circumferential direction of the spiral whereby the central portion of the rungs form the arouate-shaped sections of the spiral, while the longitudinally extending sections of the delay line are formed by the step-like portions of the rungs extending parallel to the stringers. I

2. A delay line according to claim 1, wherein the stningers of the ladder-shaped sheet metal strips are disposed within the wall of the hollow body.

3. A delay line according to claim 2, wherein the hollow body has a circular cross-section.

4. A delay line according to claim 3, wherein there is provided in the interior wall of the hollow body a plurality of longitudinal grooves corresponding to the number of metal supports distributed about the circumference of the hollow body, the depth of such grooves corresponding to the width of the ladder stringers and the width of such grooves corresponding to twice the thickness of the ladder stringers, the ladder being dis posed in corresponding grooves and secured to the hollow body.

5. A delay line according to claim 3, wherein the hollow body is constructed of longitudinally extending segments which are arranged between separated pairs of stringers resulting from a star pattern of the laddershaped sheet metal strips, and secured thereto.

No references cited.

HERMAN KARL SAALBACH, Primary Examiner.

R. D. COHN, Assistant Examiner.

Claims

1. A DELAY LINE FOR MOVING FIELD TUBES, ESPECIALLY FOR THE AMPLIFICATION OF MILLIMETER WAVES, WHICH CONSIST OF A SPIRAL ARRANGED IN THE INTERIOR OF AN ELECTRICALLY CONDUCTIVE HOLLOW BODY, WITH INDIVIDUAL WINGINGS RIGIDLY ATTACHED TO METAL SUPPORTS WHICH EXTEND INWARDLY FROM THE WALL OF THE HOLLOW BODY TOWARD THE SPIRAL AND ARE ANGULARLY OFFSET WITH RESPECT TO ONE ANOTHER PROGRESSIVELY IN THE HOLLOW BODY IN THE LONGITUDINAL DIRECTION OF THE SPIRAL, THE SPIRAL COMPRISING ARCUATE-SHAPED SECTIONS WHICH ARE DISPOSED BETWEEN TWO ADJACENT METAL SUPPORTS IN RESPECTIVE PLANES EXTENDING PERPENDICULAR TO THE LONGITUDINAL AXIS OF THE DELAY LINE, AND STRAIGHT SECTIONS WHICH EXTEND IN THE LONGITUDINAL DIRECTION OF THE DELAY LINE, CHARACTERIZED IN THAT THE SPIRAL AND THE METAL SUPPORTS ARE MADE OF A PLURALITY OF STAMPED SHEET METAL STRIPS WHICH, AS A DEVELOPMENT OF THE ARCUATE-SHAPED SECTIONS AND OF THE ADJOINING METAL SUPPORTS, HAVE THE FORM OF A LADDER WHOSE RUNGS ARE STEPPED ALTERNATELY TOWARD THE STRINGERS THEREOF FORMING IN EACH CASE A HALF SUPPORT MEMBER, THE FORMED STRIPS BEING INTERASSEMBLED PROGRESSIVELY IN A STAR PATTERN IN CIRCUMFERENTIAL DIRECTOIN OF THE SPIRAL WHEREBY THE CENTRAL PORTION OF THE RUNGS FROM THE ARCUATE-SHAPED SECTIONS OF THE SPIRAL, WHILE THE LONGITUDINALLY EXTENDING SECTIONS OF THE DELAY LINE ARE FORMED BY THE STEP-LIKE PORTIONS OF THE RUNGS EXTENDING PARALLEL TO THE STINGERS.