A new theory of ultrahigh-frequency electronic generators is proposed, based on the following ideas of the author. 1) The nature of electronic processes and the mechanism of oscillation maintenance are identical in all ultrahigh-frequency generators (klystron, generator with braking field, magnetron). The role of the primary mechanism is played by a continuous electron flux, in which, due to special conditions of its use, the process of phase focusing takes place; due to this, the necessary interaction of the flux with the elements of the oscillating system is established. 2) From the kinematic point of view, the physics of ultrahigh frequencies can be considered as a development and practical application of electron optics.

A sufficiently general method of investigating the state of electron flow by introducing the concept of a moving focus and studying the movement of focuses in the flow has been developed.

The possibility, based on the adopted picture of the internal mechanism, to explain from the electron-optical point of view all characteristic features of ultrahigh-frequency generators of various types, namely:
The case of electron flux drift has been studied; the conclusions have been applied to the study of an electron-beam generator of the "klystron" type; an analogy between the behaviour of the latter and the Barkhausen generator has been established.

The case of electron flux focusing in constant and alternating braking fields is studied; the results are applied to the study of generators with braking field by linear and radial fluxes (Barkhausen scheme). The possibility of explaining all specific features of the Barkhausen scheme - discreteness of oscillation regions, location of the centres of the regions (Barkhausen's relation), and occurrence of "dwarf" waves - by means of the electron-optical theory is shown. It is shown that for the case of self-excitation of a phase lens the behaviour of the oscillator in the presence of an alternating braking field can be described by the same relations as in the case of a constant braking field. For oscillators with "two-sided" excitation is found the law of distribution of centres of oscillation regions in the plane - U_A, U_G.

The stadies focusing in electric and magnetic fields has been studied; the results have been applied to the study of the behaviour of the generator with a braking field in weak magnetic fields; the regularity for the shift of the centres of oscillation regions has been established and confirmed by experiment. The electron-optical theory of a magnetron with a solid anode is constructed. The regularities to which its behaviour obeys are explained.

© JETP Lett., 1944, vol. 14, v.7-8, p. 289-306.