Abstract: A monopole antenna is mounted on a ground plane and incorporates a radiating structure in the form of a blade perpendicular to the ground plane, for loading the antenna. An elevated feed is formed by a biconical central post between the blade and the ground plane. Tuning is also accomplished by a capacitive strips spanning the biconical central post and by outboard inductive posts which connect between the ground plane and the blade to provide shunt inductance. Alternatively, additional tuning may be accomplished by a circuit between upper and lower portions of the central post.

Abstract: A CDMA format is used within a network to permit communication between members of a network. Network members are synchronized to each other and are each aware of a predetermined set of code words which has been established. A member desiring to transmit data selects a code word from the predetermined set. If there are unused code words, one of the unused words is randomly selected. If all words are being used, the code word of the farthest user is selected. Since all members are synchronized in time to stable clocks, the range of each user is known. All members of the network are always listening and keeping track of detections of other users and code words. Transmitted signals are a series of pulses with a jitter or sync pulse inserted within each series. The number and location of sync pulses is unique for each code and defines the CDMA code of the signal.

Abstract: Disclosed is an AM stereo receiver capable of receiving signals representing at least two different types of AM stereo systems, but using an integrated circuit (IC) decoder designed to properly decode received signals representing only one of the two types of systems. The receiver includes circuitry coupled to the IC which adapts the IC for also properly decoding received signals representing the second type of AM stereo system as well. Circuitry is also disclosed for automatically detecting which type of AM stereo system is being received and for configuring the receiver's decoding circuits to properly decode the received stereo signals.

Abstract: An angular filter for electromagnetic radiation is formed of a set of elements supported on a dielectric substrate. The elements are electrically conducting and include resistance for dissipating energy of the radiation. Each element is formed as a closed loop in a plane normal to an axis of propagation of the radiation so as to minimize interaction with a transverse magnetic field of the radiation at zero angle of incidence to the filter, the interaction and consequent attenuation increasing with increasing angle of incidence. Thereby, spurious sidelobes of a radiation pattern associated with a radar or other antenna can be reduced by the filter in favor of the main lobe along the antenna axis. The elements may be formed by a set of members spaced apart to introduce capacitance for resonating with inherent inductance of the members, thereby to enhance the filter attenuation.

Abstract: A monopole antenna is mounted on a ground plane and incorporates a radiating structure such as a disc or hollow cap parallel to the ground plane, for loading the antenna. An elevated feed is formed by a biconical central post between the radiating structure and the ground plane. Tuning is also accomplished by a partial or total circumferential dielectric (which may also function as a support) having an outer electrically conducting sheet spaced apart from the central post to provide shunt capacitance, and by outboard inductive posts which connect between the ground plane and the radiating structure to provide shunt inductance. Alternatively, additional tuning may be accomplished by a circuit between the upper and lower portions of the central post.

Abstract: Two or mutually nonparallel dipoles for operation over a common frequency band. Each of the dipoles has a central feed port and an inner end connected to a junction box with conductive walls. Each feed port is connected through a junction in the box to a receiver for the common frequency band. For diversity, two receivers for the common frequency band are connected to the two feed ports. For pseudodiversity, the dipoles are connected to a common receiver and are positioned to have noncoincident phase centers separated by more than one-quarter wavelength over some part of the common frequency band.

Abstract: A system for the correction of nonuniformities in both color and brightness as provided for the correction of such nonuniformities in a color CRT display. The system employs correction signals which are obtained by photographing a white screen of the display at maximum brilliance. These correction signals are then added to video signals during normal operation of the display for presenting image data provided by the video signals. In the absence of any video signal, the full value of the correction signals is applied to the display. For increased amounts of video signal which cut back varying amounts of the primary colors of red, green, and blue, the correction signals are reduced in magnitude so as to provide a smaller contribution at the input video terminals of the display. Thereby, correction can be obtained over a range of varying values of intensity.

Abstract: The oil detecting switch includes a light oil float switch, a water float switch and a heavy oil float switch. When the light oil float switch is closed, a relay is activated energizing a light oil indicator light and its associated coil. The coil is part of a relay which inhibits pumping action. When the water float switch is activated, the inhibiting relay is bypassed so that pumping action can continue. When the heavy oil float switch is activated and closed, a relay is activated which energizes a heavy oil indicator light and its associated coil. The coil is part of a relay which inhibits pumping action. The light oil indicator light, its associated coil and the water indicator light are bypassed when the heavy oil float switch is activated. The status of the float switches is monitored by an analog-to-digital converter associated with a Remote Monitoring System Transmitter.

Abstract: Received scanning signals radiated by a MLS ground system are used to determine and evaluate the approach angle of the aircraft. The difference between the angle for a particular scanning signal and the angle for a previous scanning signal is compared to a predetermined difference. A flag or alarm is indicated when the difference is greater than the predetermined difference for one second.

Abstract: A delay line circuit provides variable delay and phase shift to electric signals propagating along the delay circuit. The circuit is formed of a set of varactors constructed either as varactor chips or as a set of mesas upstanding from a gallium arsenide substrate. A ground plane interconnects bottom terminals of the varactor chips while a strip line conductor interconnects top terminals of the varactor chips. In the case of the mesa configuration, a metallized layer covers the regions between the mesas without contacting the base portions of the mesas. The strip line conductor makes contact with the respective mesas via a set of metallic posts upstanding from respective ones of the mesas. Dielectric material may be inserted between the strip line conductor and the metallic layer to position the strip line conductor relative to the metallic layer, which layer serves as a ground plane in a transmission line comprising the strip line conductor.

Abstract: An array of axially oriented thin resistive elements having a certain value of conductance or resistance in the axial direction is supported in dielectric material. For a wave at normal incidence, the apparatus is essentially invisible. For a wave incident at oblique angles in the E plane, current is induced in the resistive elements and dissipative attenuation occurs. The attenuation does not rely on resonance so that the apparatus operates over a wide frequency band and does not require tight dimensional tolerances.

Abstract: An improved transmitter for a compatible independent sideband (ISB) AM stereo system develops a phase modulated carrier where the modulation represents the stereo difference signal inverse modulated by the stereo sum signal in accordance with a selected modulation function. The phase modulated carrier then is amplitude modulated by the stereo sum signal. This simplified modulation scheme provides the second-harmonic sideband correction required to develop a true single sideband type signal wherein left and right stereo information are transmitted in separate lower and upper sidebands, which can be demodulated without distortion in ISB AM stereo receivers. Simplified receivers which use inverse modulation are also disclosed.

Abstract: An LMS adaptive control loop module for reducing the effects of received interference includes a single antenna coupled to a first hybrid for generating a reference channel and an auxiliary channel. The auxiliary channel provides I/Q signals from a second hybrid and I/Q drive signals from I/Q correlation multipliers which are used to weight the I/Q signals from said second hybrid. The weighted signals and the reference channel signals are combined and provide an output.

Abstract: A solid state remote monitoring transmitter which transmits a 40 bit word that contains status information about a transformer via the secondary of a power distribution network to a central receiver associated with the primary (feeder) cable supplying the transformer. A program card specifies the carrier signal frequency and the identification of the transmitter. Multiple analog inputs are switched through a multiplexer to an A/D converter, the output of which is stored in a shift register to form the 40-bit word. The word is DPSK-coded by clock pulses in synchronism to the 60 Hz zero crossings of the AC power source and amplified by an unregulated power supply which is also powered by the AC power source. The phase transitions of th DPSK-coded word occur at the zero crossings diminishing any transients in the transmitter circuitry which would be caused by the phase transitions.

Abstract: An apparatus for use in a fluid medium which activates at a deeper depth and then releases at a lesser depth. A rod depresses a spring in a housing. The rod is prevented from being ejected from the housing by a ball bearing which engages between openings in the rod and the housing. When in use, the pressure exerted by the fluid medium forces the rod deeper into the housing. When the first depth is reached the ball bearing disengages from the rod and the device is activated. As the activated apparatus rises, the pressure on the rod decreases and the rod moves out of the housing. When the deployment depth is attained the housing floods and the rod is ejected.

Abstract: A waveguide manifold for monitoring the operation of an array antenna. The waveguide is centerfed and has reflecting termination at either end. The waveguide output is matched to the waveguide as if non-reflecting terminations were at either end of the waveguide. The waveguide input is a plurality of slots wherein adjacent slots have alternating polarity. A standing wave created in the waveguide have a plurality of cells of alternating phase. Each slot is located within one of the resonating standing wave cells. The resulting manifold beam forming characteristics will be temperature and frequency independent over a practical range.

Abstract: A waveguide manifold for monitoring the operation of an array antenna. The waveguide is centerfed and has reflecting terminations at either end. The waveguide output is matched to the waveguide as if non-reflecting terminations were at either end of the waveguide. The waveguide input is a plurality of groups of slots wherein adjacent groups have alternating phase. Adjacent slots in each group have alternating polarity. A standing wave created in the waveguide has a plurality of cells of alternating phase. Each slot is located within one of the resonating standing wave cells. The resulting manifold beam forming characteristic will be temperature and frequency independent over a practical range.

Abstract: A solid state remote monitoring transmitter which transmits a 40 bit word that contains status information about a transformer via the secondary of a power distribution network to a central receiver associated with the primary (feeder) cable supplying the transformer. A program card specifies the carrier signal frequency and the identification of the transmitter. Multiple analog inputs are switched through a multiplexer to an A/D converter, the output of which is stored in a shift register to form the 40-bit word. The work is DPSK - coded by clock pulses in sychronism to the 60 Hz zero crossings of the AC power source and amplified by an unregulated power supply which is also powered by the AD power source. The phase transistion of the DPSK - coded word occur at the zero crossings diminishing any transients in the transmitter circuitry which would be caused by the phase transitions.

Abstract: A external feedback network for decreasing variations in a beam pointing angle of a scanning antenna array. A dedicated aperture manifold is intergral with the aperture of the scanning antenna and provides a signal which represents the beam pointing angle. The signal is detected, decoded, and converted into digital data for averaging and processing by a CPU. The processed data is then compared with a value stored in memory and any difference forms the basis of a correction signal. For application to a microwave landing system, the correction signal is used to adjust the start/stop time of the scanning commands of the antenna to remove the error without modifying the beam steering algorithm. A space-coupled monitor may also be used independent of the feedback network to provide an alarm in response to any failure of the dedicated aperture manifold, the automatic stabilization circuitry or the array system.

Abstract: In a receiver for composite amplitude and angle modulated signals and having a non-flat automatic gain control characteristic, there is provided apparatus for providing distortion correction to the quadrature component produced by the angular modulation in accordance with the amplitude modulation component. In accordance with the invention, the output of an amplitude demodulator is modified to remove the carrier signal level dependent magnitude multiplier and develop a modification signal which is used to inversely amplitude modulate the quadrature signal component to provide distortion correction over a range of carrier signal levels. Such inverse modulation can be provided before or after quadrature demodulation of the received signal.