Amplitude and frequency modulation using a wide dynamic range injected-beam crossed-field gun†

Abstract

ABSTRACT Methods for amplitude modulation and frequency modulation of injected beam crossed-field tubes using a wide dynamic range crossed-field gun (Sidhu and Wadhwa 1967) are described. This gun has the property that by properly adjusting the electric fields in the two regions of the transformer section, the electron beam can be injected into the interaction region at any desired level, with a fixed injection velocity or the velocity of injection can be varied over a wide range at a fixed injection level. The properties of injection level variations and injection velocity variation can be utilized to produce amplitude modulation and frequency modulation in injected beam crossed-field tubes. The beam is injected optimally into the interaction region as desired, without any cycloid formation under conditions of fixed magnetic field. The flexibility of the gun to give variable current and inject the beam optimally into the interaction region under the conditions of fixed magnetic field, can also be used for amplitude modulation purposes.