Abstract: A design for a Tunable Cable Simulator with a minimum number of components and low insertion loss.

Abstract: A half duplex amplifier for a cable network.

Abstract: A design for a Tunable Cable Simulator with a minimum number of components and low insertion loss.

Abstract: Devices, systems, and methods for amplifying full duplex signals that include a first frequency band shared between an FDX upstream signal and a downstream FDX signal, and a second frequency band having a legacy upstream signal, where the legacy upstream signal and the FDX upstream signal are amplified by a common amplifier.

Abstract: A half duplex amplifier for a cable network.

Abstract: An optical homodyne communication system and method in which a side carrier is transmitted along with data bands in an optical data signal, and upon reception, the side carrier is boosted, shifted to the center of the data bands, and its polarization state is matched to the polarization state of the respective data bands to compensate for polarization mode dispersion during transmission. By shifting a boosted side carrier to the center of the data bands, and by simultaneously compensating for the effects of polarization mode dispersion, the provided system and method simulate the advantages of homodyne reception using a local oscillator. The deleterious effects of chromatic dispersion on the data signals within the data bands are also compensated for by applying a corrective function to the data signals which precisely counteracts the effects of chromatic dispersion.

Abstract: An optical homodyne communication system and method in which a side carrier is transmitted along with data bands in an optical data signal, and upon reception, the side carrier is boosted, shifted to the center of the data bands, and its polarization state is matched to the polarization state of the respective data bands to compensate for polarization mode dispersion during transmission. By shifting a boosted side carrier to the center of the data bands, and by simultaneously compensating for the effects of polarization mode dispersion, the provided system and method simulate the advantages of homodyne reception using a local oscillator. The deleterious effects of chromatic dispersion on the data signals within the data bands are also compensated for by applying a corrective function to the data signals which precisely counteracts the effects of chromatic dispersion.

Abstract: An optical homodyne communication system and method in which a side carrier is transmitted along with data bands in an optical data signal, and upon reception, the side carrier is boosted, shifted to the center of the data bands, and its polarization state is matched to the polarization state of the respective data bands to compensate for polarization mode dispersion during transmission. By shifting a boosted side carrier to the center of the data bands, and by simultaneously compensating for the effects of polarization mode dispersion, the provided system and method simulate the advantages of homodyne reception using a local oscillator. The deleterious effects of chromatic dispersion on the data signals within the data bands are also compensated for by applying a corrective function to the data signals which precisely counteracts the effects of chromatic dispersion.

Abstract: A drive circuit (18) produces a drive signal for a pump (10) having a piezoelectric actuator (14), with the piezoelectric actuator (14) forming a part of the drive circuit (18) and serving to shape a waveform of the drive signal. The drive circuit (18) comprises a pulse generator (100) which generates pulses; a converter circuit (102) which receives the pulses and produces charge packets at a rate which equals a desired drive frequency; and, the piezoelectric actuator (14). The piezoelectric actuator (14) receives the charge packets and, by its capacitive nature, integrates the charge packets to shape the waveform of the drive signal. Preferably, the piezoelectric actuator (14) integrates the charge packets to yield a drive field that approximates a sine wave. In one non-limiting example embodiment, the pulse generator (100) comprises a microcontroller-based pulsed width modulator (PWM) circuit (116) and the converter circuit (102) comprises a flyback circuit.

Abstract: A sensor module (1) for measuring the distance to a target and/or the velocity of the target (50), the sensor module (1) comprising at least one laser source (100), at least one detector (200) being adapted to detect modulated laser light and at least one control element the control element (400) being adapted to vary the focus point of the laser light and/or the intensity of the laser light and/or the direction of the laser light. The control of the laser light emitted by the laser source (100) either by active optical devices as variable focus lenses or controllable attenuators or passive optical elements in combination with arrays of laser sources (100) and detectors (200) enable flexible and robust sensor modules.

Abstract: An optical homodyne communication system and method in which a side carrier is transmitted along with data bands in an optical data signal, and upon reception, the side carrier is boosted, shifted to the center of the data bands, and its polarization state is matched to the polarization state of the respective data bands to compensate for polarization mode dispersion during transmission. By shifting a boosted side carrier to the center of the data bands, and by simultaneously compensating for the effects of polarization mode dispersion, the provided system and method simulate the advantages of homodyne reception using a local oscillator. The deleterious effects of chromatic dispersion on the data signals within the data bands are also compensated for by applying a corrective function to the data signals which precisely counteracts the effects of chromatic dispersion.

Abstract: A method and apparatus for a wavelength division multiplexing (WDM) optical transmission system wherein the optical transmission system has an optical signal transmitter which functions as a passive hub, in which only optical signal processing is performed, while associated electronic signal processing is performed outside the passive hub. The passive hub includes upconverter devices that place the optical signal bands at frequencies that allow separation of the bands at a detector. The detectors are thus loaded with more than one wavelength at a time. The optical transmission signals are optically combined and/or amplified onto a single fiber that is fed to a headend device, where the wavelengths of the optical transmission signals are demultiplexed and fed to the receivers.

Abstract: A transmission lone filter having low reflectivity and Gaussian characteristics includes at least one inductive element aligned along the transmission line and at least one shunt configuration branching off the transmission line including a capacitive element and a resistive element. The transmission line filter is embodied in complete and incomplete Gaussian filters, and in both lumped element and distributed-element configurations. A method of designing a transmission line filter having low reflectivity and Gaussian characteristics is provided in which values for desired filter parameters are ascertained, formulas for the values of the inductive, capacitive and resistive elements are derived in terms of the desired filter parameters and the number of half-cells, a number of half-cells for the filter required to achieve the desired filter parameters is selected, and lumped element values for the inductive, capacitive, and resistive elements are estimated using the selected number of half-cells.

Abstract: A switching power supply that can operate in critical conduction mode as self-oscillating power supply (SOP) during moderate load, and in discontinuous conduction mode (DCM) under the control of a pulse-width modulated signal under small load, whereby the power consumption of the supply is decreases continuously as the load is decreased. A frequency modulated self-oscillating switching power supply (FMSOP) having a power switch, the switch being held OFF, after a zero-current detector detects that an output current falls to zero, until allowed to turn ON after a pulse having a load-modulated width that corresponds to the load. The FMSOP operates with a switch controller that may include a flip-flop to latch the detector's signal, a load-modulated pulse generator, and a combinatorial logic gate to combine the pulse and the latched signal.

Abstract: An optical signal is transmitted and received from an optical wave guide, the optical signal including an in-phase (I) component, a quadrature (Q) component and a carrier signal, and converted to an electrical signal. The electrical signal is phase-filtered to compensate for dispersion and phase locked.

Abstract: A method and structure for generation of signal distortion. In a first embodiment, a first signal distortion generator (SDG) receives a pair of balanced input currents +X and −X, each having a same angular frequency &ohgr;. The first SDG generates a pair of output currents +X+&Dgr;X1 and −X+&Dgr;X2, wherein &Dgr;X1−&Dgr;X2=G2X2+G3X3. G2 and G3 are each independent of X, and at least one of G2 and G3 is nonzero. In a second embodiment, a second SDG receives an unbalanced input current P having an angular frequency &ohgr;. The second SDG generates an output current UOUT of a form P+(&agr;P+&bgr;P2+&ggr;P3)/2. &agr;, &bgr;, and &ggr; are each nonzero and each independent of P. The second SDG includes a distortion generating circuit path that has an input impedance ratio of at least 5 and an output impedance ratio of at least 5.

Abstract: A laser transmitter bias circuit for a laser diode transmitter, for use in a optical transmission system, e.g. in commercial CATV systems. The laser transmitter bias circuit reduces power consumption and heat dissipation by eliminating the conventional need for a distinct constant DC current supply for biasing the laser diode. Radio frequency (RF) circuitry, e.g., a radio frequency amplifier (e.g., a Hybrid Amplifier), connected in series to the laser diode supplies both a DC bias-current (IB) and an RF drive-current (IP) through the laser diode. The DC bias current through the laser diode in turn powers (and/or biases) the radio frequency amplifier and, optionally, other radio frequency circuitry. An optional diode-bypass current (IBP) path may be connected in parallel with the laser diode, and in series with the radio frequency amplifier to control bias current.

Abstract: A method and apparatus for enhancing the effective dynamic range of an RF-to-optical-to-RF link. The transmission through an optical link of RF digital signals having magnitudes outside of the dynamic range of the link is performed by changing the amplitude of (e.g., attenuating) such signals prior to transmission, and restoring such signals to their original amplitude after transmission. Signal-to-Noise Ratio (e.g., Noise Power Ratio (NPR)) of such digital signals is thereby maintained above a predetermined minimum level. The method and apparatus have advantageous applications in bi-directional commercial CATV systems.

Abstract: A radio frequency stabilization system (e.g., for use with a laser transmitter) in an optical communication system is provided. The present invention relates to maintaining a stable RF level in an optical link despite temperature fluctuations, including a transmitter section, a receiver section, a plurality of feedback loops connected to each of the transmitter section and the receiver section. The present invention further discloses a method of stabilizing an RF level in an optical link which method include providing an optical signal transmitter, an optical signal receiver, and a plurality of feedback loops to the optical transmitter section and the optical receiver section.

Abstract: A cable television (CATV) distribution system, and a method of forming and using the CATV distribution system. In a first embodiment, a narrowcast optical signal is generated by an uncooled laser and converted by a receiver into a narrowcast electrical signal. In a second embodiment, a narrowcast optical signal generated by an uncooled laser is combined with a broadcast optical signal by an optical coupler at a hub of the CATV distribution system to generate a composite optical signal, which at a CATV node is: split into the broadcast and narrowcast optical components, respectively converted into broadcast and narrowcast electrical components, and combined into a composite electrical signal. In a third embodiment, a narrowcast optical signal is generated by an uncooled laser and then combined with the broadcast optical signal by a single receiver.