Some requirements for new electron tube devices

Recent advances in active network theory and in the theory of voltage variable systems, have been based on and have resulted in several new concepts of "ideal" circuit elements. These concepts and the revolutionary circuit behavior for processing and generating signals, that they make possible are reviewed. A critical examination of the essential element-properties required for the realization of active filters and voltage variable transfer functions suggests two new classes of devices. The requirements are entirely different from those involved for amplification, oscillation and detection. The development of non-conventional space-charge control tube structures to meet these requirements is then discussed.