US3688152A

US3688152A - High power klystron

Info

Publication number: US3688152A
Application number: US120394A
Authority: US
Inventors: Hinrich Heynisch; Hannjoerg Bittorf
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1970-03-05
Filing date: 1971-03-03
Publication date: 1972-08-29
Anticipated expiration: 1989-08-29
Also published as: DE2010480B2; FR2084165A5; DE2010480C3; GB1327679A; DE2010480A1

Abstract

A high power klystron including means for forming an electron beam, preferably a hollow electron beam, with a perveance which is greater than 3 and means for defining interaction paths including delay line type structures in resonator chambers as sections with extended interaction.

Description

United States Patent Heynisch et al.

[ 1 Aug. 29, 1972 [54] HIGH POWER KLYSTRON [72] Inventors: Hinrich Heynisch, Graefelfing; Hannioerg Bittorf, Munich, both of Germany [73] Assignee: Siemens Aktiengesellschaft, Berlin and Munich, Germany [22] Filed: March 3, 1971 [21] Appl. No.: 120,394

[30] Foreign Application Priority Data March 5, 1970 Germany ..P 20 10 480.7

[52] U.S. Cl ..3l5/5.31, 315/539, 333/83 R [51] Int. Cl ..H01j 25/14 [58] Field of Search ..3l5/5.31, 5.39, 5.29

[56] References Cited UNITED STATES PATENTS 3,270,240 8/1966 Lavoo ..315/539 X 7 2,659,024 11/1953 Bernier et a1. ..315/531 X 3,130,340 4/1964 Koziak ..315/5.31 X 2,316,264 4/1943 Litton ..315/5'.3l 2,945,155 7/1960 Chodorow ..315/539 3,375,397 3/1968 Leidigh et a1 ..315/5.5l X 3,453,483 7/1969 Leidigh ..315/5.39 2,466,064 4/ 1949 Wathen et a1. ..315/5.31

Primary Examiner-Herman Karl Saalbach Assistant Examiner-Saxfield Chatmon, Jr. Attorney-Hill, Sherman, Meroni, Gross & Simpson ABSTRACT A high power klystron including means for forming an electron beam, preferably a hollow electron beam, with a perveance which is greater than 3 and means for defining interaction paths including delay line type structures in resonator chambers as sections with extended interaction.

ICIaiImIDraWingFigure 1 HIGH POWER KLYSTRON BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to high power klystron particularly for television transmission, with an electron beam producing system, in which a number of resonator chambers are permeated by an electron beam which is extended therethrough in a reduced beam bundle, and an electron beam collector device.

2. Description of the Prior Art High power klystrons are preferably utilized in the ultra high frequency (UHF) range for the transmission of television programs, whereby high transmission qualities are of primary importance in the UHF range. In order to comply with the high demands placed on the transmission and in particular to the requirement for linearity in amplification, klystrons for television applications must be operated with a beam perveance of the electron beam which is smaller than 2 (reference here being taken to Rundfunkteschnische Mitteilungen, volume 12, 1968, issue 6, pages 262-268, as well as NTZ, 1966, issue 6, beginning at page 365). The reason for this is that the high, merely positive, electron stress on the resonators due to the electron beam. It is furthermore stated that, in order to obtain the television qualities required, the qualities of the resonators should essentially be determined by the externally applied stress.

SUMMARY OF THE INVENTION In contrast to these prior art klystrons for television applications, it is proposed according to the present invention that a high power klystron of the above-mentioned kind have a perveance which is greater than 3 for the electron beam, which beam is preferably formed as a hollow beam, and that the interaction paths are designed as sections with extensive interaction by providing delay line like structures, which structures are known per se, in the resonator chambers of the klystron.

Klystrons with extended interaction, generally called Extended Interaction Klystrons are known in the art, they have heretofore been driven with electron beams having a perveance that is less than 2. Here, compare IRE TRANSACTIONS ON ELECTRON DEVICES, January 1961, pages 44-55, in particular at page 49, left-hand column near the bottom.

The present invention therefore proceeds from the recognition that the electron stress depends strongly on the beam speed in a resonator cavity with distributed or strongly extended interaction. With a suitable selection of the beam speed, the electronic stress can be made almost zero. This is alsovalid for perveance values which are greater than 2 (i.e. 2- A/V It has been shown that the perveance of the electron beam is only limited by the fact that the average center geometric distance of two successive resonators must be a fourth of the plasma wave length, and thereby the resonator chambers are still sufficiently decoupled with respect to high frequency.

BRIEF DESCRIPTION OF THE DRAWING Other objects, features and advantages of the invention will be best understood from the following detailed description taken in conjunction with the accompanying drawing which carries a single FIGURE showing an elevational cross-sectional view of a high power klystron constructed in accordance with the principles of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, a highly perrneant hollow electron beam 18 is produced by an electron beam producing system 1 which comprises a wing-shaped cathode 2, which has an end thereof surrounded by Wehnelt electrode 3. A pulling anode 4 is preferably defined as a modulation anode and is disposed adjacent to the electrode 3 and generally aligned therewith axially of the klystron. The electron beam 18 traverses the klystron generally about the longitudinal axis thereof to reach an electron beam collector 8 which is provided with cooling plates 7, after first having permeated a series of

resonator chambers

5 and 6. Suitablyv arranged and dimensioned electromagnets 9 are provided to effect guidance of the electron beam through the tube without permitting radial dispersion of the beam, the entire magnet arrangement being preferably arranged between a pair of pole plates 10.

The sample embodiment set forth in the figure illustrates a klystron having a plurality of chambers, say a five-chamber klystron, and for the sake of simplicity, the second and third chambers have. not been illustrated, which chambers are however constructed'to correspond to the resonator chambers 5. The fifth resonator chamber 6 differs somewhat from the construction of the preceding resonator chambers 5 in order to provide an optimum adaptation of the reduced electron beam speed. Spiral-shaped delay structures 11 and 12 are provided in the resonator chambers in order to form a broad-band extended interaction zone corresponding to the aforementioned and so-called extended interaction, in place of the usually narrowband interaction between the beam and interaction gaps.

In order to prevent interfering backward-facing waves on the delay sections 11 and 12, measures have been provided which are in themselves known in the art and which are not illustrated here for the sake of simplicity and clarity. The delay structures 11 and 12 are connected with

internal conductors

13, 14 and 15 of coaxial decoupling members which are respectively sealed with respect to the vacuum within the resonator chambers by means of ceramic windows, the

windows

16 and 17 being illustrated in the drawing.

Although we have described our invention by reference to a specific illustrative embodiment, many changes and modifications may be effected by those skilled in the art without departing from the spirit and scope of our invention, and it is to be understood that we intend to include within the patent warranted hereon all such changes and modifications as may reasonably and properly be included within the scope of our contribution to the art.

WHAT WE CLAIM IS:

1. In a high power extended. interaction klystron of the type which includes an electron beam producing system, a number of resonator chambers which are permeated with an electron beam which is extended in a reduced bundle, and an electron beam collector for receiving the electron beam, the improvement therein comprising means for producing the electron beam as a hollow beam with a perveance which is greater than 3, and means defining interaction paths including delay 5 line structures in the resonator chambers which are operable as sections with extended interaction.

Claims

1. In a high power extended interaction klystron of the type which includes an electron beam producing system, a number of resonator chambers which are permeated with an electron beam which is extended in a reduced bundle, and an electron beam collector for receiving the electron beam, the improvement therein comprising means for producing the electron beam as a hollow beam with a perveance which is greater than 3, and means defining interaction paths including delay line structures in the resonator chambers which are operable as sections with extended interaction.