Abstract: Ring-and-bar slow wave electronic interaction circuits of the singly and/or doubly connected variety are supported from a surrounding conductive barrel structure via the intermediary of ceramic comb structures which extend along the slow wave circuit. The ceramic "teeth" of the comb structure are brazed at their ends to the connecting bars of the slow wave circuit to enhance thermal conduction from the circuit. The free space between the teeth avoids excessive dielectric loading of the circuit. The "spines" of the ceramic combs are brazed to the barrel to provide good thermally conductive paths from the combs to the barrel for cooling of the slow wave circuit. A microwave tube employing a doubly connected ring-and-bar circuit, supported as aforedescribed, provides a high power structure having a small signal gain bandwidth between 3.7 db points of 6 GHz at Ku band.

Abstract: In a transponder having first and second antennas an inverse gain modulator is provided. The inverse gain modulator comprises a power-responsive balance circuit coupled to the two antennas. The power level of the output signal returned by the second antenna is inversely related to the power level of the signal received by the first antenna.

Abstract: 1. An underwater acoustic reflector for use at elevated hydrostatic press comprising:(A) a plurality of thin paper laminae assembled in an integrated stack wherein all the paper laminae run in essentially the same direction,(B) a thin-walled gas confining wrapping intimately surrounding and enclosing said stack of paper, and(C) a waterproof jacket enclosing said wrapped stack of paper and being of a material having characteristic acoustic impedance approximately the same as that of seawater enclosing said wrapped paper.

Abstract: 1. A reflectance modulator exhibiting an omni-azimuttal reflectance pattern comprising a microwave lens for focusing electromagnetic energy, a plurality of reflector means positioned on a focal surface of said lens and including a gaseous plasma, means for sequentially controlling the ionization level of said plasma to modulate the reflectance of said energy.

Abstract: Detection of slowly moving and stationary targets that are normally obscured by ground clutter is accomplished by an AMTI synthetic aperture radar system that utilizes multiple receiving antennas mounted along the flight velocity vector of the radar bearing aircraft. Each antenna is separated by a distance d from each other. Synthetic arrays are formed by processing the radar returns from each antenna terminal. The radar PRF is controlled so that the aircraft flies a distance d during the interpulse period. The synthetic array outputs of adjacent pairs of antennas are subtracted to provide clutter cancellation. The resulting outputs from adjacent terminals can be used in a monopulse mode for angular discrimination.

Abstract: A training cockpit on a hydraulic motion system is responsive to the cockpit controls to simulate an aircraft in flight. A simulated radar display of the aircraft vicinity is provided from a data base memory of the topographic and cultural data of the gaming area.As the antenna scans, particular blocks of data are transferred from the district memory to smaller sector core memories at high speed access and transfer rates. The sector memory provides a line of data for each sweep of the simulated radar. Reflectance and elevational data is retrieved from the sector memories and processed, one sweep at a time, through digital radar equation computation equipment which calculates the brightness of each spot in the simulated radar display. This digital brightness data is processed through an earth curvature subsystem which modifies the brightness in accordance with the horizon effect. The modified brightness is applied to a digital to analog converter and then to the radar display.

Abstract: A device for reducing the backlobe radiation from small aperture antennas is shown to comprise a thin hemispherical radome having both radio frequency energy absorbing and reflecting materials attached thereto. The absoring material dissipates a portion of the edge currents existing on the antenna aperture, while the reflecting material intercepts a portion of the energy radiated from the antenna and reflects that portion back to the edge of the antenna to produce destructive interference with the edge currents.

Abstract: An antenna tracking system in which attenuation of gain in the azimuth tracking circuit as a function of the angle of elevation of the antenna is compensated. A correction circuit is provided in the servo loop for amplifying the azimuth error signal and rate gyro signal by an amount equal to the secant of the elevation angle.

Abstract: A foamed ceramic slab is bonded to a three-layer polyimide RAM substrate to roduce a radar absorber capable of at least 10db absorptivity of the range 3 to at least 10 GHZ and of withstanding very high temperatures, for example, 3,000.degree. F for 80 seconds or 900.degree. F for 10 minutes, while weighing only about 5.0 lbs/sq. ft.

Abstract: A homodyne type radar for detecting intrusions into its field of radiation using the Doppler effect, working by pulses connected to an alarm device triggered in case of an intrusion. The output circuit of the pulse generator of the radar apparatus comprises a capacitor connected at the pulse frequency to a pulse generating and receiving circuit, the load variation of this capacitor controlling the alarm.The resistor is series connected to the emitter-collector circuit of a hyperfrequency transistor which is common to the pulse generating and receiving circuit.The cicuit connecting the capacitor to the alarm device comprises a low-pass filter and a step-apparatus.An oscillator controlling the pulse generating apparatus is also used to control a direct voltage to direct voltage converter when the power is supplied by a battery.

Abstract: An FM-CW vehicular distance and relative speed measuring device which compares instantaneous reflection signal frequency to the instantaneous FM-CW transmitted frequency to derive distance (range) and speed information. Searching means including a mixer, frequency programmer, and logic circuits evaluates a plurality of fractional range increments for signal presence and Doppler spectrum evaluation to determine relative velocity with sense. The FM-CW waveform is a sawtooth and means are included for blanking the sawtooth flyback.

Abstract: In a medium PRF pulse doppler type radar receiver, target detection is achieved in both search and track modes. In the search mode, the video signal from the receiver section is notch filtered to cancel the main beam clutter. The remainder of the signal is threshold detected, followed by ranging each of the thresholded signals to resolve the range ambiguity of the signals. The unambiguous signals are gated through a range sensitive threshold which operates along a power curve of R.sup.4, resulting in true target returns being thresholded by the range sensitive threshold circuit and blocking out discrete sidelobe returns. In the track mode, the video signal from the receiver is clutter cancelled to remove main beam clutter, as in the search mode, and the remaining signals pass through a velocity track filter with a narrow band window.

Abstract: An obstacle detecting system comprising an oscillating device for generating and directing to an obstacle a first oscillating signal in a first time period and a second oscillating signal having a different frequency than that of the first oscillating signal in a second time period; an antenna for receiving the signals reflected from the obstacle; a detector for mixing the signals received by the antenna and the output of the oscillating device to generate a detected signal which comprises a first signal component derived by mixing the first oscillating signal reflected by the obstacle and received by the antenna with the second oscillating signal generated by the oscillating device and a second signal component derived by mixing the second oscillating signal reflected by the obstacle and received by the antenna with the second oscillating signal generated by the oscillating device; and an information signal circuit for receiving the detected signal and generating information relating to the distance between

Abstract: A variable range marker device for use with a PPI radar with digitized video displayed in non-real time. The position of the range marker is initially operator determined by rotation of a knob mechanically linked to an optically encoded disc. Optical sensors produce a digital output indicative of the disc rotation angle and range mark position as a distance from the center of the radar display screen. A counter is preset with the digital output at the start of each sweep and decremented once each range cell until a count of zero is reached at which time an unblanking pulse is produced. A numeric display of range is produced by dividing the number of range cells to the range mark by the range setting and displaying the result with a three digit LED display.

Abstract: The specification relates to a telemetering apparatus comprising a generator which generates at least a single frequency rf signal, a transponder for receiving that signal and for amplitude modulating it in accordance with information selected for transmission, an antenna on the transponder for reflecting the amplitude modulated signal, and a receiver which is preferably located at the generator. The receiver processes the signal to determine the information carried thereby.

Abstract: A signal processor for use in a small, lightweight radar-guided missile to provide a discrete Fast Fourier Transform (FFT) on received radar return signals. The radar return signals are converted into a sequence of binary digits enabling a simple decoder to perform complex addition and subtraction processing, thereby minimizing the space and complexity of the signal processor.

Abstract: The circuit includes means for regenerating and removing noise from a reced pseudo-random IFF interrogation signal modulated onto a radar signal. The regenerated code is decoded by correlating it with a locally generated replica thereof which is run at a different bit rate, thus achieving asynchronous correlation.

Abstract: Apparatus is herein disclosed for imminent collision detection equipment for acknowledging proximity between a first object carrying the equipment and a second object. The imminent collision detection apparatus is a radio distance measuring device and includes a transmitter and a receiver. The transmitter has a pulsed energy output which is reflected back by a target and mixed with a reference source of pulsed energy generated a predetermined time after the transmitted output and coherent thereto. The coherent feature of the equipment lies in the fact that the transmitter pulsed output and the pulsed reference signals are both generated with the same starting phase each generated pulse. Furthermore, the transmitted and reference signals are jittered to provide a resistance to countermeasures capability.

Abstract: A method and system for determining the distance between two stations interconnected through a carrier wave connection for data transmission by frequency modulation (FM) or phase modulation (PM) and, if necessary, transferring the data concerning the distance determined. At least one of the two stations is movable and each station comprises a transmitter, a receiver and a transceiver antenna for said FM or PM data transmission. During operation the antennas are interlocked. The carrier wave transmitted by the first station and being normally FM or PM modulated by data signals is interrupted a number of times in this station. Upon detection of each one of these interruptions, the second station introduces a similar, corresponding interruption into the carrier wave transmitted by this second station. The carrier wave is normally also FM or PM modulated by data signals.

Abstract: The invention involves an electronic countermeasure technique which is used gainst a pulse compression, random PRF, frequency diverse radar by stretching a pulse received from the radar before returning it. By progressively delaying the pulse until its delay is greater than the range gate of the radar, the return pulse to the radar is either blocked entirely or else it is received as a spurious, misleading echo.