Abstract: An improved system and technique for detecting and stabilizing long term thermal and mechanical drifts in a swept Fabry-Perot interferometer. Under the control of a timing circuit the distance between two interferometer optical surfaces is changed by periodically sweeping a first surface while the second surface is rocked in a positive and negative direction about two orthogonal axes. The light transmitted by the inerferometer is detected to provide a train of uniform pulses of random spacing having a maximum count when the surfaces are substantially parallel. A counter circuit senses the number of pulses during rocking in both the positive and negative direction about each axis and provides each count to a summing circuit for providing a difference output.

Abstract: An improved system and technique for reducing interference in signal receng systems, particularly in sidelobe canceller systems. Adaptive canceller loops receive inputs from an auxiliary channel signal and operate on a main channel signal to reduce interference in the main channel signal. The auxiliary channel signal is supplied through a quadrature hybrid circuit to provide I and Q components to the adaptive loops, which loops are connected in series and cascaded such as to form a plurality of serially connected I and Q loops.

Abstract: An improved technique for forming an electron emitting cathode of iridium d similar noble metals. A mixture of powders including a matrix material of one of the noble metals and a pore forming material of silver is shaped into a cathode configuration and sintered at a temperature sufficient to evaporate the silver, thereby producing a porous matrix. The matrix is impregnated with an active material and dried to produce a cathode having increased electron emission characteristics allowing operation at lower temperatures for longer time periods.