JPS58116807A - Frequency multiplier - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a frequency multiplier operated by the interaction of an electron beam and electromagnetic waves to generate sub-millimeter and millimeter radio electrical waves.

Such generators may be used, for example, on December 6-1, 1976.
Y, A, F1yag1n%A3/, Gapo presented at the 2nd National S Golden Conference and Winter Training on 9-nap millimeter waves and their applications held in Puerto Rico on the 1st.
noma, M, I, P@t@lln and V, Jul
@gyrateron(g)rratr by patov
In these generators, the electron beam, exposed for a certain period of time to a uniform magnetic field, traces a spiral around an axis along which the magnetic field is induced.
,*K to produce a rotational motion, an electron beam is generated by a cathode system capable of imparting a tangential velocity component to the electrons.

% rounding to generate high power in mm and sub-V wave range
This type of tube is used. These high powers operate at the cyclotron frequency f of the electrons in the spectral magnetic field B. This frequency company, as is well known, has one set [in the formula, the town is the pulsation corresponding to the cyclotron frequency (・
, = 2ffc) and #) is the electron charge, Toll, and m is the relativistic mass]. This equation expresses that the pulsation is proportional to the magnetic field.

To obtain a sub-meter field, the magnetic field must be increased (assuming, of course, that all other conditions remain unchanged). The difficulties encountered in this field are well known. This difficulty is associated with using superconducting electromagnets operating under cryogenic conditions once B exceeds a certain level.

In particular, if a high operating frequency is required without such a high magnetic field to avoid such cryogenic conditions, the system should be designed to operate at the already defined single-wave frequency fc. It can constitute the whole. Such a condition is only possible through the nonlinearities that exist in the beam. These nonlinearities are slight and therefore require high beam currents to reach appreciable levels. Furthermore, the efficiency with respect to these harmonics is very low, and this efficiency decreases very rapidly with harmonic order.

The present invention relates to a frequency multiplication device that overcomes these difficulties. It consists of two circuit parts that provide electromagnetic waves that interact with the electron beam.

The first part is in resonance at a frequency approximating the cyclotron frequency f, and the second part is in resonance with frequencies that are integer multiples of this frequency under conditions to be described below.

Other features and advantages of the invention will become apparent from the following embodiment, one of possible embodiments, with reference to the accompanying drawing in which: FIG.

a cathode 3 and an accelerating electrode or anode 4 to which a DC voltage is supplied.
An electron beam 6 emitted by a cathode system or electron gun passes through a resonant cavity 1 resonating with a pulsation approximating a city. The cavity has a length and impedance such that vibrations do not occur at this frequency. Under operating conditions, the amplitude of this oscillation is small, so that in this part of the multiplier only a small part of the beam energy is dissipated via interaction with the electromagnetic field of the cavity.

However, given the high 1 overvoltage that can reach such a cavity, it is generally accepted in the field of interaction tubes, and more particularly in the field of velocity modulation tubes, that It is quite possible to obtain beams exhibiting large depth modulations.

The beam generated by the tapered cathode emitting from the side is shown in the figure by two straight dotted bands parallel to the axis xx. This figure shows the complete line in cross-section. The part F in front of the first cavity 1 is arranged in such a way that high frequencies do not affect the electron gun and contains 91 or more traps, as is known in the prior art. includes any particularly fragile system in such a tube. This section 5 is also configured to perform the same function and meet the high frequency attenuation band, again as known in the prior art.

The part 5 consists of a potential slipping or drifting space for the accelerated beam, which space is practically at the same DC potential as the anode 4.

The electron beam then enters the second cavity 2. This cavity is in a resonant state at a frequency that is an integral multiple of the self-excited vibration frequency that corresponds to the aforementioned pulsation #. Upon passing through this cavity 2, the beam emits most of its energy in the form of electromagnetic energy at a harmonic frequency nf, where n is an integer. This energy is removed by the output guy y7 while being captured by the electron rector (not shown).

In another example, as in the Klystron, the ends of two cavities ( 8 and 9) may be increased beyond that shown in the figure. This tunnel is preferably at the same potential as the anode 4 and the cavities l and 2.

Furthermore, the first cavity can be modified such that it no longer self-oscillates by reducing its length and overvoltage to the self-oscillating range 9. A voltage is applied to this by a moving external high frequency source (not shown) K. This requires additions to the first cavity (e.g. a coaxial loop, a guiding aperture) for connection to an external high frequency source.

Suitable exemplary dimensions for the tube proposed in the invention, ie for KL=2, are shown below.

The length is in angular form, i.e. x/'vo or 2 for l.
πCL/λ), where Vo is the velocity imparted to the electron by the DC accelerating potential, or anode potential, and is very close to the velocity of light for relativistic electrons. in this case,
- is pulsation), A is the frequency f regarding the cavity (2)
P at the wavelength that is practiced by monks.

and nf is the wavelength that corresponds to the frequency associated with the second cavity. A cavity with a cylindrical shape along the axis XX is rw2K (
r/λ)-3,9.

and has a length t parallel to the axis such that 2π(j/λ)=2g.

A beam accelerated to 80 kilovolts at 5 a/pair is 1
Draw a spiral with a radius smaller than P defined by 2g(p/J)K with respect to the wavelength of the harmonic to be generated.

The opening in the center of the first cavity can be the same size or larger than the opening in the second cavity, as shown. First, in this example, the very short slipping tube or drifting tube is a small section with the smallest radius r mentioned above.

This multiplier makes it possible to generate high levels of energy at the top of the VHF range H. This O multiplier is
It has the same applications as t IJ wave generators and subori wave generators in the prior art, namely measurements in plasmas, radar transmission, and telecommunications.

[Brief explanation of drawings]

The figure shows a schematic cross-sectional view of a frequency multiplier. 1......First cavity, 2......
...Second cavity, 3...Cathode, 6...
・・・・・・Electron beam, xX・・・・・・axis. Daikakejinben sit Imamura Hajime

Claims (1)

[Claims] (1) Applying a DC voltage between the cathode system from which the beam is emitted and the collector where the beam is captured.
Thus, a multiplier involving an interaction of an electron beam propagating along an axis with an electromagnetic field of a resonant cavity along the path of the beam, the beam spiraling around the axis in which it induces a magnetic field. a resonant cavity is formed of two chambers surrounding an axis, the first wrinkle cavity being in resonance at a frequency approximating the cyclotron frequency of the electrons in the magnetic field;
A frequency multiplier characterized in that the second cavity is in a resonant state at a harmonic of this number jI#L. (The multiplier according to claim 1, characterized in that the two cavities are separated by an equipotential tritching space. (3) The first cavity with a high overvoltage is The multiplier according to claim 1, characterized in that the multiplier is self-oscillating at a cyclotron frequency. (4) The first cavity with a low overvoltage is oscillating at a frequency close to the cyclotron frequency. Multiplier according to claim 1, characterized in that it is energized by a generator.