Abstract: A reiterative delay line system utilizing an optical fiber, light transmitting (and modulating) means, light signal receiving means, and having signal multiplexing.The (n-1) first channels of the demultiplexer are linked to the like channels of the multiplexer to delay input signals supplied to the multiplexer first channel. The light signal passes n times through the optical fiber of delay T on independent channels to provide a total overall delay of nT.

Abstract: A slotted-waveguide linear array in which a pattern of slots in a narrow wall of a first waveguide forms the aperture of the array. A second waveguide runs parallel to the first guide, the other narrow wall of the first waveguide being a common wall with the second waveguide. The pattern of coupling holes through this common wall couples energy between the waveguides.A feed arrangement, preferably including a 180.degree. hybrid, has two of its ports connected one each to the first and second waveguides, the difference port, when driven, providing 180.degree. phase feed of the two waveguides so that the presence of the second waveguide is substantially nil. Thus, a single beam is formed as if the second waveguide were not present. The feed also provides for excitation of the waveguides through a mutual hybrid in-phase relationship when the sum port of the hybrid is driven, in which case the beam is angularly separated from the original beam.

Abstract: A fiber optic device for providing a visual indication when a subassembly, such as an electronic "ATR box", is in place in a rack mounting arrangement with its electrical connections firmly mated with the corresponding rack connections within a small predetermined tolerance. A special fiber optic connector has first and second parts, one of which is attached to the ATR box and the other mounting in the rack for mating concurrently with the mating of the electrical connections. A number of such devices may be provided in a rack of equipment, each fixed rack mounted connector being supplied with a light signal via a length of fiber optic conductor, preferably from a common light source. Within the ATR box unit itself, another length of fiber optic conductor connects the fiber optic connector to the front panel or some other location for convenient observation.

Abstract: The invention involves in-phase power splitting from an input into separate pairs of paralleled input variable circuits which may be linear amplifiers or linear controlled attenuators. The outputs of these circuits feed the input branches of a pair of 180.degree. hybrid circuits, the outputs of those hybrids providing the inputs of a 3 db quadrature coupler. An output of this coupler then provides the overall output which is shifted in phase with respect to the original input as a function of the gain control signal applied differentially between the variable circuits of the aforementioned pairs as the cosine of the desired phase angle in respect to the first pair of circuits and in accordance with the sine of the desired phase angle at the control terminals of the second pair of circuits.

Abstract: A correlation radar system utilizes a switching logic circuit for automatically switching a code word having a predetermined number of bits directly to a transmitter and through a delay to a receiver of the system and, alternately, directly to the receiver and through a delay to the transmitter. By utilizing the switching circuit, the delay need only produce up to one-half the number of bits in the code word.

Abstract: A device for suppressing autocorrelation sidelobes in a pseudo-random coded radar system employing a phase-coded CW signal in which the phase code is preselected to have a predetermined symmetry. Autocorrelation is affected in the standard manner and also in respect to the transmitted code shifted by one bit in time. Summation of the two autocorrelation functions provides a new autocorrelation function in which the sidelobes between main correlation peaks are suppressed.

Abstract: A device for precise vernier control of the net charge on the high-voltage filter capacitor in a high voltage, high energy power supply through control of the charge on a low-voltage capacitor in series with the grounded end of the main high-voltage filter/storage capacitor of a power supply. Current in this series capacitor arrangement is detected bidirectionally by a current transformer, the output of which is time-integrated. An error signal is detected by a reference amplifier through comparison of the instantaneous low-voltage (bootstrap) capacitor with the integrated value, the latter being a precise analog of the high voltage across the filter capacitor. The bootstrap signal in current amplified form is fed back (in the proper sense) from the output of this comparison to the low-voltage capacitor. Since the net high voltage is the algebraic sum of the voltages on the main filter capacitor and this bootstrap capacitor, the high voltage is thereby controlled or regulated on a pulse-to-pulse basis.

Abstract: A height finding arrangement for a range/azimuth surveillance radar using a mechanically rotated planar antenna array. The received outputs from the array are combined with suitable weighting functions to give two sectorial pattern signals whose effective phase centers are respectively above and below the center of the array aperture. The phase difference between these two signals is measured to provide the elevation angle of the target.

Abstract: A regulating charging circuit for the pulse-forming network in a line-type pulse modulator, such as commonly found in pulsed radar systems. A charging inductor is the primary of a transformer, the secondary of which is open-circuited until the resonant charge of the pulsed-forming network reaches a predetermined voltage. At that time, a sensor generates a trigger enabling a solid state device, of the thyristor genera, to connect the secondary of the charging inductor/transformer to a step-up network, including a second transformer. The output of the step-up network is fed through a diode into the filter/storage capacitor of the high voltage power supply from which the charging inductor draws current. The unused charging conductor energy is thereby recovered and used to help recharge the filter/storage capacitor. The combination including the step-up network relieves the thyristor and control circuits from the requirement of controlling high voltages.

Abstract: A coupling arrangement for mating electrical or optical connector subassemblies in which opposing coupling members are secured by a bayonet arrangement about their outer perimeters. Resilient (spring) fingers on at least one coupling member engage bayonet key-ways about the opposite member outer surface. The key-way and finger interface at the locked position is along at least one chamfered surface to permit the resilient fingers to deflect radially outwardly and "ride out" of the locked position to allow connector separation in response to excessive cable tension.

Abstract: An analog-to-digital converter characterized in that it includes a generator supplying a substantially linear voltage ramp, a source of at least two reference voltage levels precisely related one with respect to the other (one of which may be ground), an input for an analog signal whose voltage level is to be expressed in digital form, a comparator for comparing the increasing voltage of the ramp and the three voltage levels in order to identify the instants when the ramp reaches these levels, time/numerical conversion means for producing from these instants, a first number corresponding to the time for the ramp to go from the first reference voltage level to the second one, and a second number corresponding to the time for the ramp to go from one of the reference levels to the input analog signal level, and digital counting means arranged to carry out the quotient of these numbers, the quotient representing, in a digital form, the level of the input analog signal.

Abstract: A radio navigation system of the simulated Doppler type, including a ground beacon having a multi-element linear antenna array, the elements of which are energized discretely and, in turn, to provide digitized scanning. A remote receiver, in an aircraft on landing approach, for example, derives a beat signal relating to a navigational angle. The remote receiver has a bandpass filter covering the range of Doppler beat frequencies of directly received signals and also detects the start of each ground beacon commutation cycle. A unique combination of inhibiting circuits for eliminating filter transients during at least part of its transient response time and filter cut-off characteristics affords discrimination between direct and multi-path signals when the angular separation of the paths of those signals is at a minimum.

Abstract: This DME ground station permits the distance from the touchdown point (where no transponder can be installed) to be measured on the aircraft without any change in the airborne equipment. The time difference between the reception of an interrogating signal and the transmission of a reply signal is chosen so that the transmission of reply signals from the DME transponder located on one side of the runway corresponds to a transmission from the touchdown point with respect to the signal transit time.On the ground, a DME transponder is located on one side of the runway on a level with the touchdown point, and a receiver and a direction finder are provided on the other side.

Abstract: A scanning beam navigational beacon for transmission to a remote station (aircraft, for example) which measures a navigational angle therefrom. A thinned, two-dimensional main antenna array and linear reference array are provided. A single antenna element is provided at each vertical level of the array. Reference radiations are based on main array phase to allow coherent signal processing at the remote station. Azimuth frequency diversity is provided by grouping of the excited main elements and reference array elements at different frequencies, all features cooperating to minimize the effects of azimuthally displaced multipath signals which may fall inside the far-beam of elevation guidance. Thus, the effective array aperture exhibits a distributed frequency pattern in the azimuth plane.

Abstract: A torque-dependent, mechanical pressure-exerting device for friction gears with a planet wheel, particularly for steplessly adjustable gears, wherein for each direction of rotation, the torque between the drive shaft and the planet wheel is resolved into an approximately radially acting contact pressure and an approximately tangentially acting circumferential force via a pair of curves (cam and counterpart), with one element of the pair of curves disposed on the drive shaft, wherein the other element of the curve pair is disposed on the shaft of the planet wheel.

Abstract: A thermometer arrangement in which the active element is a block of birefringent material between two optical planar polarizers. Light energy from a source is conducted through a fiber optic light conductor through the input polarizer, the birefringent element, the output polarizer, and via a second fiber optic light conductor, into a light-to-electrical transducer. Polarization plane rotation effected by the birefringent element in combination with the fixed polarizers effectively modulates the light intensity from an arbitrary level (such as substantially zero at some selected temperature) so that the transducer output signal is a function of temperature. A reference accounting for light source variations, etc. is provided by a separate fiber optic conductor, a second transducer, and a differential detector. Linearizing means are also shown.

Abstract: A scanning beam radio guidance system in which a ground beacon equipment transmits a single frequency collimated beam which sweeps a space sector of interest, and also transmits a frequency offset reference signal. An airborne remote receiver is responsive to both transmissions and includes post-detection signal processing means in the form of a time gate for inhibiting those parts of the main beam signal corresponding to angles outside the sector. A filter is also included for reducing the total spectrum contribution of the residual side-lobes of any out-of-sector beam signal.

Abstract: A receiving system for a time-reference, scanning beam radio guidance system in which the scanning beam, an offset frequency reference signal and a time reference signal are provided from the ground beacon location. The receiving system includes a first detector responsive to the scanning beam and offset reference signals to provide a spectrum centered about the offset signal. A bandpass filter with sloping skirts on both sides of the center (offset) frequency provides tapering, with decreasing amplitude response on each side of the center frequency, the width of the spectrum being a function of the aperture of the beam transmitting antenna at the ground beacon. Angular information is determined by thresholding the beam signal to find two points on either side of beam center, averaging these times and comparing with the time-reference signal to air-derive angular navigational data, especially for aircraft landing approach systems.

Abstract: A radar system for transmitting pulsed circularly polarized wave, having two separate receiving channels corresponding to the two mutually orthogonal components of the received wave. Apparatus is included for detecting variations of phase between the two receiving channels and automatically adjusting amplitude and phase of at least one of the two channels in order to compensate for the depolarization effects of rain. For isolating rain return signals and bona fide target signals, the ordinary range gate of a tracking radar plus wide early and late gates are used, applicable to target and rain return signals, respectively.

Abstract: A hermetically sealed relay of the reed-type in which an elongated switching control rod is angularly displaced in operation. The extreme positions include internal stops, which may be contacts, in which case the switch is a single-pole-double-throw device. An attached actuator for the switch device provides tolerance-absorbing overtravel by means of uniquely arranged resilient means, such that switch-gap tolerances are effectively absorbed. The device may be of the magnetically latching type or may, in simplest form, include a single controlling electromagnet and only one fixed contact. Two embodiments are described.