Abstract: An adaptive clutter canceller for adaptively cancelling clutter with non-zero mean Doppler frequencies. Received clutter signals averaged over a predetermined number of range cells and over an azimuth extent. The resulting averaged signal is used to shift the clutter spectrum to a zero mean Doppler and subsequently cancelled.

Abstract: First and second gate-controlled switches are connected analogously to a Darlington transistor pair with a slow-response diode connected to delay application of a turn-off signal to the second gate-controlled switch until the first gate-controlled switch is fully turned OFF. The Darlington-type connection reduces a drive current required from a driving source to maintain the second gate-controlled switch fully ON for passing a load current therethrough.

Abstract: A method and apparatus for eliminating the sidelobe ambiguity in the range esponse of an FM-CW radar. An FM-CW signal with a periodic modulation frequency is transmitted and reflected from a target, received and combined with a sample of the transmitted signal to provide a combination signal. A portion of this combination signal including a selected harmonic and next adjacent harmonic is amplified and mixed with reference signals comprising the selected harmonic and next adjacent harmonic to provide two separate difference signals. These signals are in turn low pass filtered and further mixed to provide a range response with a mainlobe of one polarity and all side lobes of an opposite polarity. The energy under the mainlobe is detected and integrated to provide a voltage signal. When this voltage signal reaches a preset threshold level a further signal is generated.

Abstract: A line end stage for a television receiver which comprises a transformer, a first high voltage rectifier and a second high voltage rectifier. The transformer has a primary winding coupled to the line sweep coils of the receiver, and a secondary winding. The secondary winding has one end coupled through the first high voltage rectifier to ground and through the second high voltage rectifier to the anode of the television receiver picture tube. The transformer comprises a core having a longitudinal axis. The primary winding is mounted on the core coaxial with the longitudinal axis and an insulating winding form surrounds the primary winding. The winding form is provided with spaced longitudinally-distributed radially-extending chambers and the secondary winding is located within these chambers. The thicknesses of the winding form between the bottoms of the chambers and the primary winding are greatest at the ends of the winding form and become progressively smaller toward the center of the form.

Abstract: An apparatus for providing precise convergence compensation in a shadow mask type color CRT display. Coarse compensation is provided by the coefficients of primary terms x.sup.2, y.sup.2 of the beam's longitudinal and vertical position polynomial in an analog format, and fine compensation is provided by digital programmable read-only-memories. The fine compensation is representative of the precise values of the coefficients of the remaining terms in these polynomials, and a digital-to-analog converter converts the fine compensation to an analog format. The coarse and fine data are summed together and applied to the convergence correction coils of the CRT.

Abstract: A primary winding of a power transformer is coupled to a source of DC voltage. First and second controllable switches are coupled to the primary winding in a push-pull arrangement. A control circuit responsive to a deflection rate input signal that is synchronized with deflection circuit scanning applies a turn-off switching signal alternately to the two controllable switches during each deflection cycle. In response to the turnoff of each one of the two controllable switches, a turn-on switching signal is applied to the other switch to develop a deflection rate alternating polarity output voltage across an output winding of the power transformer. The output voltage is rectified and applied to a deflection generator to thereby energize the generator into developing scanning current in a deflection winding.

Abstract: The system according to the invention utilizes a transmission--reception radar antenna protected by a radome and an interrogation antenna having at least one set of two networks engaged laterally on the outer wall of the radome. The networks are arranged symmetrically to an axis of revolution of the radome. Supply means supply the interrogation antenna with an ultra-high frequency interrogation signal and the switching and phase-displacement means and the networks constitute an electronic scanning antenna.

Abstract: An image pickup apparatus designed to improve the amplitude modulation degree particularly at edge portions of an image comprises an image pickup tube and a yoke assembly. The image pickup tube includes a target, a focusing electrode and an electron beam limiting aperture for limiting the diameter of an electron beam. The yoke assembly comprises means for generating a focusing magnetic field and means for generating a deflection magnetic field. The distance between the electron beam limiting aperture and the target is at least 5.5 times the maximum diameter of the focusing electrode. The half width of the focusing magnetic field intensity distribution along the axis of the image pickup tube is at least 85% of the distance between the electron beam limiting aperture and the target.

Abstract: A communications system including main and auxiliary antennas for reducing sidelobe interference with circuitry included in the feedback loop for estimating clutter by determining the difference between repetitious signals and subtracting a portion of the difference in the proper time sequence, relatively rapid changes between repetitous signals being composed generally of clutter.

Abstract: A multi-channel amplifier apparatus for oscillation or pulse packets wherein there is provided an amplifier having an input connected by a number of input time-delay lines with a respective input channel, each of which is correlated to an oscillation or pulse packet. The output of the amplifier is connected by means of respective series circuits of an output time-delay line and an output switch connected thereafter with a respective output channel correlated to the corresponding oscillation packet.

Abstract: A novel Direction Finding system is described, using a small aperture circular array of vertical dipoles, the outputs of which are rotated in phase by angles corresponding to their angular location on the array circle. A phased ring combiner is used to add the dipole pair outputs, giving two resultant waveforms, one advanced in phase and the other retarded by the same angle .theta., where .theta. is the relative bearing angle of the incoming signal. The phasing elements are made independent of the signal frequency either by the use of all-pass networks or by prior conversion to a fixed intermediate frequency. DF processing can be performed by a digital meter which computes the phase difference between the two resultant waveforms. In addition, an orthogonal DF display is available through a .SIGMA./.DELTA. conversion.

Abstract: In a single channel medium PRF pulse doppler radar receiver, the return signal data is processed to prevent sidelobe return signals from being displayed and rejects ground moving targets up to approximately 80 knots while having no high velocity blind speeds. After the returns are filtered by a doppler filter notch for rejecting returns having a velocity substantially less than the 80 knot example, the return data undergoes three stages of correlations to reject sidelobe returns, and undergoes processing including a fourth correlation which enables the third stage of correlation to output a signal only for unambiguous ranges that contain target data in excess of the 80 knot range.

Abstract: A common antenna system for a primary and a secondary radar transceiver, designed for monitoring air traffic, has a primary feeder or source connected to a primary-radar transceiver and terminating in a horn confronting a reflector, this source including two transverse probes connected to a secondary-radar transceiver which also communicates with a pair of ancillary feeders flanking the horn in an azimuthal plane. The horn is also flanked by two dipoles, closer than the ancillary feeders, delivering a difference signal of a monopulse channel to an angular-deviation-measuring receiver to which an incoming sum signal of the same channel is fed from the probes by way of the secondary-radar transceiver.

Abstract: A radar system comprising a filter with a variable pass band to which radar video signals are fed, data storage means including a main store having a plurality of storage addresses into which data appertaining to the velocity of targets in a plurality of range bearing cells is fed one cell to each address and control signal producing means operative to set the frequency of the filter in dependence upon stored data so that for reception of video signals appertaining to any specified range/bearing cell the frequency of the filter is set in dependence upon the data stored in the address of the main store corresponding to that specified range/bearing cell which appertains to the velocity of any target detected in that range/bearing cell in immediately preceding scans.

Abstract: An arrangement for displacing a marker on the picture screen of a display device, in which, to shift the marker rapidly as well as exactly, the marker is displaced by means of a rotary pulse generator, the direction of rotation determining the direction of displacement and the speed of rotation the speed of displacement. The output pulses of the rotary pulse generator are supplied to a progressive frequency transformer which generates more output pulses per input pulse the higher the frequency of the input pulses.

Abstract: A synthetic aperture radar correlation system including a moving diffuser located at the image plane of a radar processor. The output of the moving diffuser is supplied to a lens whose impulse response is at least as wide as that of the overall processing system. A significant reduction in clutter results.

Abstract: A radar system having means for effectively eliminating or cancelling intering signals characterized by the side lobes of the radar antenna received signals. An adaptive side lobe canceller system is combined with a frequency selective limiter such that the adaptive side lobe canceller is sampled by the output of the frequency selective limiter to derive a weighting signal from the adaptive control circuit. The weighting signals effectively provide simultaneous cancellation of both broad and narrow band interfering side lobe signals.

Abstract: The present invention is an apparatus for producing a frequency change of wave propagating energy including microwave radar beams, electro-optical signals, other electro-magnetic signals, acoustic signals, and other wave propagating energy. In the first embodiment the apparatus includes a self-directive reflecting device which may be a plurality of trihedral corner reflectors, Luneberg lenses, etc., and a motion imparting device for imparting motion to the reflecting device. The motion imparting device includes a supporting member and an axial member which is rotatably coupled to the supporting member. The motion imparting device also includes a mounting member which is rigidly coupled to the axial member and on which the plurality of corner reflectors are mounted.

Abstract: A system, which interfaces with a radar indicator, for improving signal-toise ratio (SNR) and enhancing the detection of moving targets includes an analog-to-digital (A/D) converter, an integrator, a digital memory, a digital-to-analog (D/A) converter, and a synchro-to-digital converter. Radar video is converted to digital signals which are integrated and stored in memory. The angle signal from the antenna pedestal synchro is fed to the synchro-to-digital converter and stored in memory. The contents of the memory is processed, converted to analog form, and fed to the indicator. The radar provides a number M of sweeps within each beamwidth, or angular sector, of the antenna during each antenna scan. Contiguous sets of M sweeps are added to form batches. The signal content for each batch is displayed on the indicator in the angular sector which is identified with the M sweeps. The width of each sector is approximately a beamwidth.

Abstract: A transponder-responder system is provided which comprises a home station and at least one remote station. A transmitter at the home station periodically generates interrogation pulses by means of a directional sweep antenna across a search area. Each remote station includes a receiver and transmitter. Upon receipt of an interrogation pulse by the remote station receiver and while enabled, the remote station transmitter transmits a digitally encoded response signal which is received by a receiver at the home station. Upon receipt of the response signal by the home station receiver, timing circuitry at the home station determines the distance between the home and remote station by measuring the elapsed time between the transmission of the last interrogation pulse and the receipt of the response signal. Additionally, the home station includes circuitry which determines the rotational position of the sweep antenna and circuitry which decodes the response signal.