Sperry Corporation

Sperry Rand Corporation

Harry M Cronson

Gerald F Ross

Basrur R Rao

Richard M Mara

David Lamensdorf

Prentis B Drew

Werner Lerchenmueller

A method and apparatus for detecting a short pulse signal in the presence of an interfering jamming signal wherein the jamming signal is utilized as the local oscillator in a diode mixer when it is received at a sufficiently high level for efficiently mixing with a short pulse signal. When the received jamming level is insufficient to act as a local oscillator, an internal local oscillator signal is coupled to the diode to maintain an efficient mixing operation.

Baseband detector with anti-jam capability

A short pulse radar receiver having a detector with a threshold automatically adjustable with the level of noise and interfering signals. Interfering signals at signal levels which exceed the maximum for which a threshold may be achieved to prevent a false alarm are attenuated prior to coupling to the variable threshold detector by an attenuator variable automatically in accordance with the received signal level.

Short pulse receiver with anti-jam capability

A surface wave transmission line enclosed in a dielectric shield and supported within the enclosure at a predetermined distance from the base of the enclosure. The enclosure being constructed such that the surface wave transmission line may be in close proximity to reflecting objects positioned along the enclosure and at a predetermined distance from a mounting structure.

Shielded surface wave transmission line

A collision avoidance system for rapid transit vehicles employing baseband radar principles in which signals with duration in the order of nanoseconds are transmitted down track along a surface wave transmission line. Reflections from a passive target located on the preceding vehicle are processed to establish the distance between the vehicles to within an accuracy previously unachievable.

Collision avoidance system using short pulse signal reflectometry

A 360 degree fan beam scanning antenna which includes a transreflector created by a plurality of reflecting elements arranged on a surface of revolution formed about a generating axis and a feed antenna rotatable about the internal focal circle of the transreflector that provides an illumination beam for the transreflector which minimizes spillover and antenna pattern skewing.

Transreflector scanning antenna

A continuous, self-supporting microwave transmission line along which ultra short pulses of microwave signals may propagate over distances of several hundred feet with minimum pulse distortion and signal attenuation. Propagation along the line is accomplished by an electromagnetic field thereabout that is sensitive to objects positioned in the proximity of the transmission line, a characteristic that may be utilized in short pulse reflectometer systems for monitoring and control of vehicles on a prescribed course.

A sequence of short pulses are produced from a single input pulse of longer duration by use of a plurality of step recovery diodes connected in shunt across a transmission line. The number of individual pulses produced in response to each applied longer pulse is determined by the number of step recovery diodes shunting the transmission line and the distance between adjacent pulses in the sequence is determined by the spacing between the diodes producing the adjacent pulses.

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Lexington, MA, United States of America

Harry M Cronson