Abstract: The present disclosure relates to optical switching devices and switch modules that are designed for long-term security monitoring of high-value infrastructure access entry points. Embodiments in accordance with the present disclosure include optical switches based on fiber-Bragg gratings whose operating wavelengths are based on the presence or absence of magnetic coupling between an embedded permanent magnet and an external element. By monitoring the spectral position of the operating wavelengths and/or the magnitude of a light signal at the operating wavelengths, the state of the magnetic coupling can be determined and used as an indicator of whether the security switch has been actuated.

Abstract: The present disclosure relates to optical switching devices and switch modules that are designed for long-term security monitoring of high-value infrastructure access entry points. Embodiments in accordance with the present disclosure include optical switches based on fiber-Bragg gratings whose operating wavelengths are based on the presence or absence of magnetic coupling between an embedded permanent magnet and an external element. By monitoring the spectral position of the operating wavelengths and/or the magnitude of a light signal at the operating wavelengths, the state of the magnetic coupling can be determined and used as an indicator of whether the security switch has been actuated.

Abstract: A non-reciprocal gyromagnetic phase shift device for microwave signals is provided. The device has a section of waveguide with at least two stacked chambers in each of which ferrite-containing slabs are arranged opposite one another on top and bottom walls of the stacked chambers along a common axis, in use a magnetic field being applied to the section of waveguide along the common axis along which are positioned the ferrite-containing slabs. The phase shift device proposed may be used in different microwave circuits. For example, it may be combined with a folded magic tee and a 3 dB hybrid coupler in order to form a 4-port differential phase shift circulator.

Abstract: An audio amplifier is operated in an audio system with optimized source impedance to minimize distortion in a loudspeaker that is paired with the audio amplifier. The audio amplifier provides an amplified audio signal to drive the loudspeaker. A variable output impedance of the audio amplifier is controlled using a feedback control loop to allow negative output impedance at low frequencies that changes to positive output impedance at higher frequencies. The change from negative output impedance to positive output impedance occurs at a determined threshold frequency or determined transitional frequency band.

Abstract: There has been a problem that the distortion characteristic of a switch circuit for a high frequency is deteriorated. A switch circuit in accordance with one aspect of the present invention includes a transistor connected in series between input and output terminals, a control terminal that receives a signal to control the conductive state of the transistor, a first resistor connected between the control electrode of the transistor and the control terminal, and a series circuit of a diode and a second resistor, the series circuit being connected in parallel with the first resistor between the control terminal and the control electrode of the transistor.

Abstract: A transceiver capable of processing signals having wavelengths of less than 1 millimeter and/or more than 1 millimeter comprising a mixer/filter circuit coupled to an IF filter where said mixer/filter circuit is positioned within a mixer block to receive incoming signals guided into one or more feed horn openings of the mixer block by an optical arrangement. The IF filter is also disposed within the mixer block, but is positioned substantially orthogonal with respect to the mixer/filter circuit for efficient use of space.

Abstract: A switching circuit includes switching transistors connected to one of an input terminal and an output terminal of the switching circuit, and a control bias supply circuit that supplies a control bias for cutting off all the switching transistors to the switching transistors when all of the switching transistors are in a non-selected state.

Abstract: An electronic signal processing apparatus has a signal switch with a first and a second transistor of normally-on type, having main current channels coupled between an internal node and a switch input and output, respectively. A diode provides a switchable signal coupling between the internal node and ground. A switch control circuit has a control output that is DC coupled to the main current channel of the first and the second transistor via the internal node to control conduction of the main current channels. The diode is also DC-coupled to the internal node so that a DC potential of a terminal of the diode that controls whether the diode is on or off is determined by a potential of the internal node. The diode is preferably incorporated in the DC current path from the control output to the internal node, so that the diode is forward-biased when a control voltage that makes the main current channels non-conductive is applied.

Abstract: The invention provides a composite high frequency component constituting a part of a microwave circuit having plural signal paths corresponding to their respective frequencies, comprising: a diplexer for coupling transmitting signals from the plural signal paths for transmission and distributing receiving signals into said plural signal paths for reception; plural high frequency switches for separating the plural signal paths into a transmission section and a reception section, respectively; plural filters introduced in the signal paths; said diplexer, said high frequency switch, and said filters being integrated into a ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers. According to the above described composite high frequency component, the diplexer, the high frequency switches, and the filters which constitute the composite high frequency component are integrated into the ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers.

Abstract: A system is provided for rapidly prototyping monolithic microwave integrated circuit modules to provide an experimental structure that can be physically made to operate by stereolithographically rendering an SLA part directly from the designer's drawings and by coating the part with a conductive layer, with the smoothness being better than 0.001 inch and with the dimensional accuracy being better than 3 mils for some applications. In one embodiment, the coating for the SLA model is made from either rhodium or gold having a thickness of less than 1/10,000th of an inch, with a nickel barrier being first deposited followed by the gold. The particular SLA plastic is a high temperature plastic to prevent bubbling during the metal deposition step which in one embodiment involves sputtering. The coated model has a microfinish of Ra<0.001 inch, with active devices being electrically attached to the coating through the use of conductive adhesives or eutectic solder.

Abstract: A system is provided for rapidly prototyping monolithic microwave integrated circuit modules to provide an experimental structure that can be physically made to operate by stereolithographically rendering an SLA part directly from the designer's drawings and by coating the part with a conductive layer, with the smoothness being better than 0.001 inch and with the dimensional accuracy being better than 3 mils for some applications. In one embodiment, the coating for the SLA model is made from either rhodium or gold having a thickness of less than 1/10,000th of an inch, with a nickel barrier being first deposited followed by the gold. The particular SLA plastic is a high temperature plastic to prevent bubbling during the metal deposition step which in one embodiment involves sputtering. The coated model has a microfinish of Ra<0.001 inch, with active devices being electrically attached to the coating through the use of conductive adhesives or eutectic solder.

Abstract: Disclosed are one method and one apparatus which enable a non-reciprocal microwave resonator to be coupled in and out at various positions showing the circular symmetry. As such, the transmission phase, but not the amplitude, can be varied, resulting in the operation of a digital phaser. The resonator is electrically connected to two network feeders each of which provides separate phase selectivity. The overall phase selectivity of the phaser is the product of the selectivities of these two network feeders, resulting in a less volume, and hence reduced fabrication costs.

Abstract: A point-to-point microwave radio link that operates in a Frequency Division Duplex (FDD) mode using direct digital modulation with a Continuous Phase Shift Keyed (PSK) scheme. The transmit signal is generated by a circuit that uses a Voltage-Control Oscillator (VCO) operating in a microwave radio band to obtain the modulated signal. The VCO output is fed to a phase modulator to obtain the modulated signal. The output of the VCO is then frequency multiplied by the predetermined factor to produce the modulated microwave output signal at the desired band.

Abstract: The invention is a low loss multiple pole multiple throw microwave switch having a transmission line for each of a plurality of outputs. A phase shifting device is provided in each transmission line operable between first and second states to shift the phase of a microwave signal transmitted therethrough. A matrix of signal dividers and cross-over networks cooperate with the phase shifting devices to produce additive and substractive vertical signal components such that all of the components at one output are additive and the signal components at all the other outputs have a vector sum of zero.

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: A tetrahedral junction waveguide switch is provided having two axially juxtaposed sections of hollow rectangular waveguide which are mutually cross-polarized by being rotated 90 degrees with respect to each other. A rod of a ferrite material having gyromagnetic properties is axially disposed within the juxtaposed ends of the waveguide sections and is selectively axially magnetized to control transmission of RF electromagnetic wave energy through the sections. A permanent magnet structure having a unique cladding arrangement which minimizes flux leakage and produces a magnet of high coercive force is employed to produce a unidirectional magnetic bias field along the longitudinal axis of the rod to keep the switch in a low loss transmission state by virtue of Reggia-Spencer effect signal rotation. A selectively operable helical coil is utilized to produce another axial magnetic field which nullifies the bias magnetic field when it is desired to place the switch in a high loss or cut-off transmission state.

Abstract: A transmission line comprising a multi-layer dielectric slab structure including: a dielectric substrate layer (30) having a thickness d.sub.s and permittivity .epsilon..sub.s ; a conductive ground plane (31) on the bottom surface of the dielectric substrate layer (30); a dielectric guiding layer (32) having a thickness h and permittivity .epsilon..sub.g, where .epsilon..sub.g >.epsilon..sub.s, attached to the top surface of dielectric substrate layer (30); at least one elongated and relatively narrow dielectric loading strip layer (33) having a width W, thickness d.sub.1, and permittivity .epsilon..sub.1, where .epsilon..sub.g >.epsilon..sub.1, attached to the top surface of the dielectric guiding layer (32); and a conductive coating (34) on the top surface of the dielectric loading strip layer (32). Such a structure permits single mode propagation over a relatively wide band.

Abstract: Single-pole, multi-throw reciprocal RF switches are arranged using fixed and switchable three-port and four-port non-reciprocal circulators.

Abstract: A ferrite modulator/switch is disclosed for use in a dielectric waveguide ansmission line. A ferrite guide section inserted in a dielectric transmission line is longitudinally magnetized to cause a 90.degree. rotation of a wave traveling through the guide thereby inhibiting further propagation and resulting in the scattering out of wave energy away from the dielectric line.

Abstract: The present invention is for an apparatus and method of fast-switching a dual-toroid microwave ferrite phase shifter. A first circuit is provided for controllably switching the ferrite in one of the toroids between a saturated and partially saturated states. A second conduit is provided for controllably switching the ferrite in the other of the toroids between a saturated and partially saturated states. A control circuit is provided for controlling the first and second circuits such that the ferrite in at least one of the toroids is maintained in the saturated state at any given time such that any desired phase shift may be achieved with only one switching operation for each toroid. The present invention provides new reference states such that there are two reciprocal phase states for any given phase state such that a reciprocal phase state may always be achieved with only one switching operation for each toroid.

Abstract: An electronic waveguide switch of a latching type particularly suitable for the microwave and millimeter range. The switch comprises a standard three port housing connected to three waveguides. A switchable junction ferrite is disposed in the center of the housing, the ferrite being of the latching type. A driver ferrite is disposed outside of the housing. All ferrite elements have a substantially cylindrical shape.