Abstract: The present invention is a rectangular waveguide providing amplification of an electromagnetic wave via interaction with an electron beam in a linear interaction channel where the electron beam enters the waveguide at a first curved part of the waveguide, traverses the linear interaction channel and exits the waveguide at a second curved part of the waveguide.

Abstract: The present invention is a rectangular waveguide providing amplification of an electromagnetic wave via interaction with an electron beam in a linear interaction channel where the electron beam enters the waveguide at a first curved part of the waveguide, traverses the linear interaction channel and exits the waveguide at a second curved part of the waveguide.

Abstract: The present invention is a rectangular waveguide (100) providing amplification of an electromagnetic wave via interaction with an electron beam (107) in a channel defined by two parallel rows of alternately provided substantially identical pillars ((109), (111)). The pillars are attached to the base (113) of the waveguide, with a void between the top of each pillar and the roof (103) of the waveguide.

Abstract: Disclosed herein is a triode-type field emission device, in particular for high frequency applications, having a cathode electrode, an anode electrode spaced from the cathode electrode, a control gate electrode arranged between the anode electrode and the cathode electrode, and at least a field-emitting tip; the cathode, control gate and anode electrodes overlapping in a triode area at the field-emitting tip and being operable to cooperate with the field-emitting tip for generation of an electron beam in the triode area. The cathode, control gate and anode electrodes do not overlap outside the triode area, and have a main direction of extension along a respective line; each of these respective lines being inclined at a non-zero angle with respect to each one of the others.