Abstract: The present invention relates to a method and system for determining target elevation angle, altitude and range and the like in a monopulse radar system with reduced multipath errors. A transmitter/receiver unit receives monopulse sum and difference signals caused by echoes from targets. The sum and difference signals are then logarithmically-amplified in a logarithmic amplifier unit. A selector selects one of the sum and difference signals having the largest amplitude, and generates a selection signal indicating which of the sum and difference signals has the largest amplitude. The selection signal is provided to a search radar target tracking unit which determines whether a target at a given range interval and azimuth interval, for example, has been selected for tracking by an operator.

Abstract: The invention relates to an apparatus and method for generating target range, azimuth angle, or elevation angle output signals corresponding to an apparent beam in a multiple-feed monopulse radar system. The multiple-feed monopulse radar system according to the present invention includes a transmitter/receiver unit, an adder/subtracter unit and a video comparator/adder unit. The transmitter/receiver unit is used to generate first and second actual antenna beams. Echoes caused by such actual beams are received and processed to provide first sum and first difference signals and second sum and second difference signals corresponding to the first and second actual beams, respectively. These signals are then supplied to the adder/subtracter unit which adds the first sum and first difference signals to provide a result .SIGMA..sub.1 +K.DELTA..sub.1, subtracts the first sum and first difference signals to provide a result .SIGMA..sub.1 -K.DELTA.

Abstract: A mirror antenna employing a continuous mirror without a hole. A feed horn nd an electromagnetic lens, located behind a rotatable twist reflector (the mirror), collimates a beam toward a polarized reflector located near the twist reflector and tilted to aim energy toward the twist reflector. Energy reflected back toward the polarized reflector from the twist reflector passes through the polarized reflector to free space.

Abstract: A dual band mirror antenna employing a continuous mirror without a hole. e-by-side feeds for each band and an electromagnetic lens, located behind a rotatable twist reflector (the mirror), collimate beams toward a pair of polarized reflectors located near the twist reflector and tilted to aim the reflected energy toward the twist reflector. One polarized reflector is reflective at the higher radiofrequency band and transparent at the lower radiofrequency band. The other polarized reflector is reflective at both bands. Energy directed back toward the polarized reflectors from the twist reflector passes through the polarized reflectors to free space.

Abstract: A target indicating system includes a high-range-resolution monopulse radar hich produces four dimensions of data: a range trigger signal, elevation angle error data, azimuth angle error data, and range video data. Additionally included is a display system having an x-y display for presenting the four dimensions of data. The display is improved by the addition of a sweep generator, elevation summary amplifier, and azimuth summing amplifier which cause the trace on the display to be driven diagonally and generate an isometric presentation of the four dimensions of data.

Abstract: 1. In a signal jamming device, first and second transducers physically displaced relative to each other said transducers having substantially identical signal coupling characteristics on the basis of direction to a selected distant object, means for coupling said transducers whereby signals received by one transducer are emitted by the other and vice versa, and differential impedance means connected to said means for coupling for producing phase shift of signals emitted by one transducer relative to signals emitted by the other transducer.

Abstract: The disclosed invention provides an accurate, simple and flexible method processing the receiver output of a high range resolution monopulse tracking radar to generate range and angle tracking error voltages based on the location of only the leading edge of the target echo replacing the conventional analog range error detectors and angle error processors in closed tracking loop systems. The invention also processes the radar return signal to avoid interference from repeater jammers or multipath returns at low angle tracking.