Electron gun with a control electrode for millimeter wave devices

Elaboration of electron optical systems (EOS) with low voltage electron beam grid control for millimeter wave devices of type-O is a difficult task because of the increase of technological demands, which are conditioned by the cathode-grid link miniaturisation. EOS using an ordinary focusing electrode (with zero potential in the nominal regime) for low voltage beam control are much simpler in design and are easily manufactured, but they are less effective than the systems with grid beam control.