Operational-amplifier circuits with variable phase shift and their application to high-Q active RC-filters and RC-oscillators

In high-frequency applications using operational amplifiers, I~~~~~~~~ the undesirable phase shift produced by the amplifiers often degrades -1 circuit performance. In this paper, simple operational-amplifier circuit units are described, which can give leading or lagging phase as desired. These units can be used for cancellation of undesired phase in a variety of 1 V2 circuits, thereby improving their high-frequency performance vastly. Ex- R (m-1)R amples are given, of the applications of these variable-phase units in -oscillators and high- active -filters.