1. Field of the Invention
The invention relates to a quasi-optical gyrotron for generating electromagnetic radiation in the millimeter and submillimeter range, in which electrons passing along an electron beam axis are forced into gyration by a static magnetic field aligned parallel to the electron beam axis and excite in a quasi-optical resonator, which comprises two mirrors arranged opposite to one another on a resonator axis aligned perpendicular to the electron beam axis, an alternating electromagnetic field so that the electromagnetic radiation can be coupled out of the resonator.
2. Discussion of Background
A quasi-optical gyrotron of the type initially mentioned is known, for example, from the Patent CH-664045 or from the article "Das Gyrotron, Schlussel-komponente fur Hochleistungs-Mikrowellensender" (The gyrotron, key component for high-power microwave transmitters), H. G. Mathews, Minh Quang Tran, Brown Boveri Review 6-1987, pp. 303-307. Such a gyrotron can be used for generating electromagnetic radiation with high power in a frequency range of typically more than 100 GHz.
All previously known high-power sources for millimeter and submillimeter waves are distinguished by the fact that they operate at a fixed frequency and with an extremely narrow bandwidth. In the quasi-optical gyrotron, for example, this bandwidth is only a few MHz. In certain communications engineering applications (for example in the so-called "electronic countermeasures"), however, it is sometimes required for high-frequency radiation of wide bandwidths to be available.
If it is, for example, a matter of disturbing or preventing an electromagnetic communications link, it is not sufficient to interfere by means of an interference transmitter having a high power but a fixed frequency. This is because it is known that such "jamming" can be avoided by systematic frequency hopping.
If, however, it is possible to cover a wide frequency band by means of the interference transmitter, the frequency hopping must also fail.