Abstract: A millimeter wave microstrip, high reverse loss isolator is provided comprising a monolithic ferrite element disposed on one surface of a section of microstrip dielectric substrate having a ground plane on the opposite substrate surface. The ferrite element has a pair of right prism-shaped central portions each having three prism faces and two downwardly sloping transition arm portions extending radially outwardly from two of the prism faces. A bar shaped connecting arm portion interconnects the remaining prism faces of the pair of central portions. All of the top surfces of the ferrite element are covered with microstrip conductor and four sections of microstrip conductor are disposed on the surface of the substrate in alignment with the downwardly-sloping transition arm portions of the element. Permanent magnet biasing means mounted on the ground plane beneath the ferrite element central portions cause these portions to act as microstrip Y-junction circulators.

Abstract: Amplitude error compensation is provided for a surface acoustic wave (SAW) reflective array correlator (RAC) device having a first reflective array grating fed by an input interdigital transducer and a second reflective array grating which feeds the reflected SAW signal output from the first array grating to an output interdigital transducer. A third or auxiliary reflective array grating is disposed between the first and second array gratings to reflect a portion of the SAW signals reflected from the first array grating to the second array grating to an acoustic absorber. The portion of the SAW signals reflected to the acoustic absorber are those SAW signals which when present in the output of the second array grating which is fed to the output transducer produce the unwanted amplitude errors. The third reflective array grating is fabricated of a photosensitive polymer material so that the frequency and amplitude selective configuration of the grating may be obtained by using photolithographic techniques.

Abstract: The framing bit errors of a received digital communications signal are monitored and recorded. The framing bit error rate is determined and an audible alarm is sounded when the error rate exceeds a predetermined threshold value in a plurality of calculation modes. The framing bit error rate and the total framing bit errors detected over a predetermined fixed time period is also displayed. A link to a remote network monitor can be implemented for monitoring and displaying framing bit error rate at a remote location.

Abstract: An amplitude error compensated surface acoustic wave reflective array corator is provided having an input interdigital transducer feeding a first slanted reflective array grating, a second slanted reflective array grating feeding an output transducer and a third, amplitude error compensation slanted reflective array grating feeding the output transducer. The third array grating receives only the leakage surface acoustic waves leaking past the second array grating from the first array grating and has a frequency and amplitude selective configuration which enables it to select those leakage surface acoustic wave signals which when added to the output of the second array grating by means of a multistrip coupler and fed to the output transducer provide an amplitude error compensated output RF signal.

Abstract: Amplitude error compensation is provided for a surface acoustic wave (SAW) lanted array correlator (SAC) device having an input interdigital dispersive slanted array transducer feeding a plurality of frequency dispersed SAW signals to an output interdigital dispersive slanted array transducer over a plurality of parallel, frequency dispersed first paths. A reflective array grating having a frequency and amplitude selective configuration is disposed between the input and the output transducers to reflect along a second path to an acoustic absorber a portion of the SAW signals sent from the input transducer to the output transducer. The second path is perpendicular to and traverses the plurality or first paths. The portion of the SAW signals reflected to the acoustic absorber are those SAW signals which when present in the output of the output transducer produce the unwanted amplitude errors.

Abstract: An optical controlled switch circuit for controlling a two-way voltage drn microwave switch. The optical controlled switch circuit includes, a light source, a control connected to the light source, an optic fiber having an end coupled to the light source, a field effect transistor coupled to a second end of the optic fiber, an inverting dc amplifier means coupled to the field effect transistor, a non-inverting dc amplifier means coupled to the field effect transistor, and a two-way voltage driven microwave switch having signal inputs respectively coupled to the inverting dc amplifier means and to the non-inverting dc amplifier means and having a microwave input and having first and second microwave outputs.

Abstract: An optical switch control circuit for controlling a microwave switch using single optical control link. The optical switch control circuit includes, a light source, a control connected to the light source, an optic fiber cable having an end coupled to the light source, a field effect transistor coupled to a second end of the optic fiber cable, an amplifier coupled to the field effect transistor, an analog to digital converter coupled to the amplifier, and a multi-bit microwave switch coupled to the analog to digital converter.

Abstract: A low-cost SAW device package comprises a ceramic or glass carrier chip, a SAW device substrate mounted on the carrier chip via a conventional adhesive and a package cover mounted over the SAW device by a glass frit. The glass frit provides a tight vacuum seal for the SAW device so that outside contamination is prevented. The package cover is fabricated of a low-cost nonmetallic, non-single crystalline material (i.e. glass) having thermal characteristics similar to or the same as those of the SAW device substrate. The packaged SAW device is mounted into a circuit or subsystem using conventional bonding techniques.

Abstract: An acoustic charge transport (ACT) device is easily constructed to provide for variable carrier frequency operation or, alternatively, for variable time delays. Variable carrier frequency operation in an ACT device is achieved by incorporating a two dimensional dispersive transducer array which has an interdigitated finger arrangement. This array has a graded periodicity or finger spacing that varies along the length of the array and also has the fingers placed at a 45 degree angle with respect to the length of the array. Because of the varying spacing of the electrode fingers, different spatial regions in the piezoelectric substrate are preferentially excited reflecting the presence of specific frequency components in an applied input signal. A variable time delay is similarly achieved in an ACT device by incorporating a two dimensional interdigital transducer array having fingers with a graded periodicity.

Abstract: Lightning protection apparatus for antenna-coupled RF equipment is provided. A one quarter wavelength shorting stub bandpass filter shunts the RF equipment and a distributed capacitance, high voltage coaxial capacitor is serially coupled between the equipment and antenna. The shorting stub is tuned to one quarter wavelength of the RF equipment operating frequency. The series capacitor passes frequencies at or above the operating frequency of the RF equipment.

Abstract: A dipole feed for a paraboloidal reflector antenna uses a conical reflector to direct the radiation of the dipole towards the concave reflecting surface of the parabola. The size and apex angle of the conical reflector are optimized to yield the desired feed pattern, the optimization parameters depending on the reflector size and focal length and being obtained numerically or experimentally to maximize reflector gain.

Abstract: A high signal reception efficiency, multi-channel Bragg cell is provided for an interferometric acoustooptic signal processor. The Bragg cell comprises a block of acoustooptic material which is illuminated on one block surface by a laser beam. A plurality of sets of electroacoustic transducers are mounted on another surface of the block which is normal to the first block surface and each transducer set is responsive to the output of a different one of a plurality of antennae so that the laser beam is acoustooptically modulated by the signal outputs from the antennae as it passes through the block. The transducers are arranged in a phased array comprising the plurality of transducer sets. A Fourier transform lens receives and focusses the modulated beam from the block to produce a two dimensional display which represents the power spectrum of the antennae outputs as a function of the angles of incidence of the antennae with respect to an incoming electromagnetic wavefront.

Abstract: A latching type of microstrip reciprocal phase shifter is provided having a oroidal-shaped ferrite core with a length of microstrip conductor wound about the outer cylindrical surface of the core and a ground plane mounted on the inner cylindrical surface of the core surrounding the aperture in the core. A single control wire is passed through the aperture in the core and creates a circular magnetic field in the core surrounding the aperture when the core is pulsed with a unidirectional current pulse.

Abstract: A microstrip nonreciprocal latching phase shifter has a ferrite rod with ramp-shaped dielectric waveguide members at the ends thereof mounted on one surface of a microstrip dielectric substrate having a ground plane on the opposite surface thereof. The dielectric constants of the ramp members and the rod are substantially the same and the substrate dielectric constant is substantially less than the dielectric constant of the ramp members. A dielectric plate is on top of the rod. A microstrip conductor mounted on the substrate, the ramp members and the plate in axial alignment with the rod extends between the ends of the substrate. The rod has a rectangular longitudinally-extending passageway therein filled by a dielectric core insert having a dielectric constant greater than the dielectric constant of the rod. A single control wire is disposed in and aligned with the core insert.

Abstract: A millimeter wave microstrip Y-junction circulator is provided comprising a ection of microstrip dielectric substrate having a cone-shaped ferrite element mounted on one side thereof together with three, Y-junction oriented sections of microstrip conductor extending from the base of the ferrite element and an electrically conductive ground plane mounted on the other side thereof. The ferrite element is covered with a cone-shaped microstrip conductor which electrically interconnects the three Y-oriented sections of microstrip conductor. When the ferrite element is fabricated of a spinel type of ferrite, a small permanent magnet is mounted on the ground plane beneath the ferrite element to provide a unidirectional magnetic field which produces a circulator action with respect to RF energy applied to the three sections of microstrip conductor.

Abstract: An optical gain control circuit for controlling the gain of a GaAs MMIC dributed amplifier having a dc gain control is provided. Variable intensity light from a controlled LED is directed to the surface of a GaAs multi-finger FET by means of an optical fiber. The FET is gate biased to a point near pinch-off to maximize its light sensitivity and the drain and source of the FET are serially connected with a fixed resistance in a dc voltage divider circuit so that the output of the voltage divider circuit changes as a function of the change in light intensity of the LED. A MMIC operational amplifier connected in an inverter mode is coupled between the output of the voltage divider circuit and the dc gain control of the distributed amplifier to control the gain of that amplifier.

Abstract: A single transistor dual mode crystal oscillator circuit is described which may excite more than one C-mode frquency in a crystal simultaneously such as the fundamental, used as a clock driver frequency, and a beat frequency between the third harmonic and the third overtone frequency, simultaneously. Each signal is thereafter passed through a separate amplifier means to further enhance those outputs for use.

Abstract: A microstrip switch is provided comprising a rectangular ferrite rod having pair of ramp-shaped dielectric waveguide members at the ends thereof. The ramp members are made of dielectric waveguide material having a dielectric constant which is substantially the same as the dielectric constant of the ferrite. The rod and ramp members are mounted on one surface of a microstrip dielectric substrate having a dielectric constant substantially less than the dielectric constant of the ramp members and a ground plane on the other surface thereof. Input and output sections of microstrip conductor are mounted on the surface of the substrate and the sloping surfaces of the ramp members in axial alignment with the rod and ramp members.

Abstract: Optical fibers are used in a utility piping system containing oil, water or as by coating the fibers after drawing with an inorganic hermetic coating which is impervious to both moisture and whatever fluid is contained in the system. The hermetic coating permits the fibers to undergo the mechanical stresses encountered during insertion in the piping system without causing degradation of either the mechanical or optical performance of the fibers.

Abstract: A master/slave opto-electrical telephone communication system utilizes a single optical fiber line to transmit out to the subordinate or slave unit from the superior or master unit two light energy carrier waves of different wavelengths, one being modulated and the other unmodulated. At the slave station, the modulated wave is demodulated and translated into sensible signals and the unmodulated wave is modulated and retransmitted to the master station where it is demodulated and translated into sensible indicia.