DE1541979B2

DE1541979B2 - WANDERFELD AMPLIFIER TUBE WITH A PERIODIC STRUCTURE HAVING A DELAY LINE

Info

Publication number: DE1541979B2
Application number: DE19671541979
Authority: DE
Inventors: Franz Dr 8000 München Groß
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1967-07-04
Filing date: 1967-07-04
Publication date: 1972-02-10
Also published as: DE1541979A1

Description

3 43 4

kurve der Grundwelle und mit 2 die Dispersions- zelnen Blechschnitten aufgebaut. Die Dicke und der kurve der ersten vorwärtslaufenden Teilwelle be- gegenseitige Abstand der einzelnen Querwände 5 zeichnet. Man erkennt, daß bei einer bestimmten ändert sich jeweils in drei Abschnitten I bis III, so mittleren Elektronenstrahlgeschwindigkeit, die dem daß jeder Abschnitt bei ansonsten gleicher Form der Verzögerungsmaß clv_e entspricht und für eine Wech- 5 Leitungszellen gegenüber dem nächsten Abschnitt selwirkung mit der ersten vorwärtslaufenden Teil- eine andere Periodenlänge der periodischen Struktur welle für eine mittlere Betriebswellenlänge l_m vor- hat, welche von dem Hohlleiter 4 mit den Quergesehen ist, auch eine Kopplung des Elektronen- wänden 5 gebildet ist. Auf diese Weise kann ein Strahls mit der rückwärtslaufenden Grundwelle Anschwingen der Grundwelle vermieden werden, (Kurve 1) bei der Wellenlänge A₁ vorliegt. Es ist des- io während ein breitbandiger Verstärkerbetrieb mit der halb ab einer bestimmten Leitungslänge die Anre- ersten vorwärtslaufenden Teilwelle möglich ist. Zur gung einer Störschwingung mit der Wellenlänge X₁ Erhöhung des Wirkungsgrades der Verstärkung empneben der gewünschten Verstärkung zu befürchten. fiehlt es sich, die Periodenlänge der einzelnen AbWenn man nun, wie erfindungsgemäß vorgeschlagen, schnitte in Elektronenstrahlrichtung abnehmen zu das Verzögerungsmaß der Verzögerungsleitung ab- 15 lassen. Um einen reflexionsfreien Übergang von schnittsweise unterschiedlich bemißt, nimmt die einem Abschnitt der Verzögerungsleitung zum näch-Kurve 1 für jeden Leitungsabschnitt eine etwas sten Abschnitt zu erzielen, hat jeweils jene Querwand andere Form und Lage ein. Man erhält also unter- 5 a und Sb, die zwei benachbarte Abschnitte I und II schiedliche Schnittpunkte der gestrichelten Linie 3 bzw. II und III voneinander trennt, eine solche mitt-(Elektronenstrahlgeschwindigkeit) mit den jeweiligen 20 lere Dicke, daß eine breitbandige Hochfrequenz-Dispersionskurven der Grundwelle. Dies bedeutet, anpassung der einzelnen Leitungsabschnitte aneindaß in jedem Leitungsabschnitt der Elektronenstrahl ander erreicht ist.curve of the fundamental wave and built up with 2 individual sheet metal cuts. The thickness and the curve of the first forward-running partial wave, the mutual spacing of the individual transverse walls 5, are drawn. It can be seen that in a particular one changes in three sections I to III, the mean electron beam speed, which _{corresponds to the delay measure clv e} for each section with otherwise the same shape and interacts with the first for an alternating line cell compared to the next section Forward part has a different period length of the periodic structure wave for a mean operating wavelength l _m , which is seen from the waveguide 4 with the transverse, a coupling of the electron walls 5 is formed. In this way, a beam with the fundamental wave running backwards can be prevented from starting to oscillate (curve 1) at the wavelength A ₁ . It is therefore possible during broadband amplifier operation with which half of the first forward-running partial wave is possible from a certain line length. In order to cause an interfering oscillation with the wavelength X _{1 to} increase the efficiency of the amplification, the desired amplification is to be feared. If one now, as proposed according to the invention, decrease cuts in the electron beam direction, it is not possible to reduce the period length of the delay line. In order to achieve a reflection-free transition from differently dimensioned in sections, the one section of the delay line to the next curve 1 for each line section to achieve a somewhat most section, each transverse wall has a different shape and position. Thus, under 5 a and Sb, which separates two adjacent sections I and II different intersections of the dashed line 3 or II and III from each other, such a mean (electron beam speed) with the respective 20 ler thickness that a broadband high frequency Dispersion curves of the fundamental wave. This means adapting the individual line sections so that the electron beam is reached differently in each line section.

mit der Grundwelle bei einer anderen Wellenlänge Die Erfindung beschränkt sich nicht auf das dargekopplt ist. Die Anschwingbedingung für die Grund- gestellte Ausführungsbeispiel. Insbesondere kann das welle hängt für eine bestimmte Intensität des Elek- 25 Verzögerungsmaß der einzelnen Leitungsabschnitte tronenstrahls von der wirksamen Leitungslänge ab. der dargestellten Struktur auch dadurch unterschied-Durch eine entsprechend kurze Baulänge der einzel- lieh bemessen sein, daß die Kopplungsöffnungen in nen Leitungsabschnitte läßt sich deshalb ohne weite- den Querwänden des Hohlleiters in jedem Abschnitt res erreichen, daß die Grundwelle bei keiner der eine andere Ausdehnung haben. Diese Maßnahme möglichen Wellenlängen anschwingt. 30 kann entweder für sich allein oder zusätzlich zu der Die F i g. 2 zeigt im Längsschnitt ein praktisches dargestellten Änderung der Dicke und Abstände der Ausführungsbeispiel einer erfindungsgemäßen Ver- Querwände vorgesehen sein. Eine Variation der zögerungsleitung. Diese Leitung besteht in an sich Dicke der Querwände als auch der Größe der Koppbekannter Weise aus einem Hohlleiter 4 von bei- lungsöffnungen ist besonders vorteilhaft, wenn das spielsweise kreisrundem Querschnitt, in dem Quer- 35 Verzögerungsmaß der einzelnen Leitungsabschnitte wände 5 angeordnet sind, die jeweils mit einer zen- bei der unteren Grenzfrequenz im wesentlichen auf tralen Elektronendurchtrittsöffnung 6 und zusatz- der gleichen Geraden ψ = π (F i g. 1) liegen soll, liehen Kopplungsöffnungen 7 versehen sind. Die Weiterhin sei bemerkt, daß man eine reflexionsfreie Kopplungsöffnungen 7 befinden sich dabei abwech- Anpassung der unterschiedlich bemessenen Leitungsselnd an einander diametral gegenüberliegenden 40 abschnitte auch durch eine geeignete Wahl der Größe Seiten des Hohlleiters 4. Die gesamte Verzögerungs- der Kopplungsöffnungen in einer benachbarte Ableitung ist, wie ebenfalls bekannt, mit Vorteil aus ein- schnitte trennenden Querwand vornehmen kann.with the fundamental wave at a different wavelength. The invention is not limited to what is shown. The oscillation condition for the basic exemplary embodiment. In particular, the wave depends on the effective line length for a certain intensity of the electron beam delay of the individual line sections. The structure shown also differed by a correspondingly short overall length of the individual borrowed that the coupling openings in NEN line sections can therefore be achieved without further transverse walls of the waveguide in each section res that the fundamental wave at none of the other expansion to have. This measure increases possible wavelengths. 30 can either by itself or in addition to the Die F i g. 2 shows, in longitudinal section, a practical change in the thickness and spacing of the exemplary embodiment of a transverse walls according to the invention. A variation on the delay line. This line consists in the thickness of the transverse walls as well as the size of the Kopp-known manner of a waveguide 4 of filling openings is particularly advantageous if the, for example, circular cross-section, in the transverse 35 delay dimension of the individual line sections walls 5 are arranged, each of which coupling openings 7 are provided with a central electron passage opening 6 and, in addition, the same straight line ψ = π (FIG. 1) at the lower limit frequency. It should also be noted that a reflection-free coupling openings 7 are located alternately As is also known, can advantageously make incisions separating transverse wall.

Hierzu 1 Blatt Zeichnungen1 sheet of drawings

Claims

1 2 largest share of the patent claims existing on the line: high-frequency energy provides. It did, however, for various reasons, for example with regard to

1. Traveling-field amplifier tube with a peri- to high thermal load capacity, increasingly odical structure having delay 5 also delay lines with backward running line, whose fundamental wave is running backwards, fundamental wave for traveling-field amplifier tubes characterized that the clarification gained / In the case of using the delay line from several similar, each delay lines for amplifier purposes but for a different amount of delay in each case one usually brings the electron beam along dimensioned sections (I, II, III), which in io of the first forward partial wave in alternating longitudinal direction the delay line in effect.

connected to each other without reflection In traveling wave tubes with a delay

and in detail such a short overall length of the line, the fundamental wave of which is running backwards,

would have that an oscillation of the backwards is, however, the risk of an undesirable

running fundamental wave in the operation of the tube from 15 self-excitation, if the fundamental wave for discrete

closed is. Frequencies the same phase velocity as

2. Traveling-field amplifier tube after An has the first forward partial wave and therefore Claim 1, characterized in that each of the electron beams precut not only with the first the delay line another downward partial wave, but also with the Has the period length of the periodic structure. 20 fundamental wave interacts. This danger

3. Traveling-field amplifier tubes are subject to delay lines in particular, at Claim 2, characterized in that the periods are the degree of delay of the first forward ode length the delay line of the section of the current partial wave decreases with increasing frequency, To section, in the electron beam direction, such delay lines had to be see steadily decreasing. 25 for traveling-wave amplifier tubes, whether

4. Traveling-field amplifier tube, according to Anwohl, straight lines of this type are often a large one Claim 2 or 3, characterized in that bandwidth and a high coupling resistance have the delay line in each of the low frequency dependence sections.

In addition to another period length, a sub- The invention is based on the object of a

having different sizes of the line cells. 30 delay line with backward running basic

5. Traveling-field amplifier tube after one of the waves and one that decreases with increasing frequency Claims 1 to 4, characterized in that the amount of delay of the forward moving first part is the Parts of the delay line, with which wave to design so that the line for Wanderzwei adjacent sections of each other field amplifier tubes is usable. To the solution limit, a mean measure between the prostitutes- 35 this task becomes with a traveling field amplifications of the two sections have. tube of the type mentioned at the beginning according to the

6. Traveling-field amplifier tube proposed according to the invention that the delay line Claim 5, characterized in that the comparison consists of several similar, but each for one delay line consists of a waveguide, different delay measure-sized sections are arranged in the transverse walls, which consists of 40, in the longitudinal direction of the delay coupling openings are provided. line are connected to one another essentially without reflections and in particular such a short overall length have that an oscillation of the backward

running fundamental wave during operation of the tube

45 is closed.

In a traveling field amplifier according to the invention

The invention relates to a traveling-wave amplifier tube which has the measure of the delay tube with a periodic structure exhibiting tion in sections, each for a different one Delay line, whose fundamental wave backward delay measure to measure, the consequence that a is ongoing. 50 agreements responsible for an interaction

The physical principle of traveling wave tubes tuning the electron beam speed with is known to be based on the interaction between. the phase velocity of the backward running an electron beam and a delayed fundamental wave in each line section electromagnetic wave. A significant part of it occurs at a different frequency. The singular ones A component of traveling wave tubes is therefore the 55 nen sections of the delay line can now Delay line, which is generally a peri- without affecting the overall gain of the has odic structure. The periodic structure tube can be short enough to accommodate another Delay line causes a certain oscillation of the fundamental wave at the operating current strength persion behavior, with the wave propagation along the electron beam for each possible disturbance Exclude delay line from so-called spatial frequencies 60.

Partial waves is described. The fastest of these Using the figures in the drawing, the

Partial waves are called the fundamental wave; it can be explained in more detail below,
Depending on the type of periodic structure, forward or Die F i g. 1 shows in a dispersion diagram

going backwards with respect to the electron beam with the wavelength λ as the abscissa and the delay. 65 gerungs Maß clv as the ordinate the dispersion behavior

For traveling-wave amplifier tubes, a typical broadband delay-delay line is per se with a forward-running basic line of a periodic structure whose fundamental wave is particularly suitable because the fundamental wave is the backward-running. With 1 is the dispersion