Abstract: A communications transmitter includes a combination modulator and a baseband processor configured to generate amplitude, angle, in-phase and quadrature signals. The combination modulator is configured to modulate in the quadrature domain or the polar domain, depending on an output power level of the transmitter and/or the type of modulation scheme being used. When configured to modulate in the quadrature domain, the baseband processor is configured to generate time-varying in-phase and quadrature modulating signals and time-invariant amplitude and angle signals for the combination modulator. When configured to modulate in the polar domain, the baseband processor is configured to generate time-varying amplitude and angle modulating signals and time-invariant in-phase and quadrature signals for the combination modulator. In another embodiment of the invention, the communications transmitter is configurable to operate in three different operational modes: linear, envelope tracking and switch modes.

Abstract: A solid-state lighting system comprises a plurality of light-emitting devices (e.g., light-emitting diodes) and an alternating current to direct current (AC-DC) converter that converts AC power to DC power for powering the plurality of light-emitting devices. The AC-DC converter is configured to perform AC-DC conversion directly, without the need for or use of a bridge rectifier or step-down transformer. According to one aspect of the invention, the light-emitting devices of the solid-state lighting system are autonomous and individually powered by a plurality of DC power supplies generated from the DC power produced by the AC-DC converter. According to another aspect, a plurality of phase-offset dimmer control signals are generated based on waveform distortions in a dimming signal produced by a conventional dimmer switch. The phase-offset dimmer control signals are used to individually control the dimming of the light-emitting devices.

Abstract: A communications transmitter includes a combination modulator and a baseband processor configured to generate amplitude, angle, in-phase and quadrature signals. The combination modulator is configured to modulate in the quadrature domain or the polar domain, depending on an output power level of the transmitter and/or the type of modulation scheme being used. When configured to modulate in the quadrature domain, the baseband processor is configured to generate time-varying in-phase and quadrature modulating signals and time-invariant amplitude and angle signals for the combination modulator. When configured to modulate in the polar domain, the baseband processor is configured to generate time-varying amplitude and angle modulating signals and time-invariant in-phase and quadrature signals for the combination modulator. In another embodiment of the invention, the communications transmitter is configurable to operate in three different operational modes: linear, envelope tracking and switch modes.

Abstract: A solid-state lighting system comprises a plurality of light-emitting devices (e.g., light-emitting diodes) and an alternating current to direct current (AC-DC) converter that converts AC power to DC power for powering the plurality of light-emitting devices. The AC-DC converter is configured to perform AC-DC conversion directly, without the need for or use of a bridge rectifier or step-down transformer. According to one aspect of the invention, the light-emitting devices of the solid-state lighting system are autonomous and individually powered by a plurality of DC power supplies generated from the DC power produced by the AC-DC converter. According to another aspect, a plurality of phase-offset dimmer control signals are generated based on waveform distortions in a dimming signal produced by a conventional dimmer switch. The phase-offset dimmer control signals are used to individually control the dimming of the light-emitting devices.

Abstract: A communications transmitter includes a combination modulator and a baseband processor configured to generate amplitude, angle, in-phase and quadrature signals. The combination modulator is configured to modulate in the quadrature domain or the polar domain, depending on an output power level of the transmitter and/or the type of modulation scheme being used. When configured to modulate in the quadrature domain, the baseband processor is configured to generate time-varying in-phase and quadrature modulating signals and time-invariant amplitude and angle signals for the combination modulator. When configured to modulate in the polar domain, the baseband processor is configured to generate time-varying amplitude and angle modulating signals and time-invariant in-phase and quadrature signals for the combination modulator. In another embodiment of the invention, the communications transmitter is configurable to operate in three different operational modes: linear, envelope tracking and switch modes.

Abstract: A DC-DC converter for delivering electrical power to a load includes an output filter having an inductor and an output capacitor, a first switch, and a second switch. The first switch is configured to alternately couple and decouple the inductor to and from a DC input voltage as power is being delivered to the load. The second switch is configured to electrically disconnect the output capacitor when the load is removed or deactivated. Disconnecting the output capacitor allows the DC-DC converter to rapidly transition from an operating state to a disabled state, obviating any need to discharge the output capacitor in order to fully disable the DC-DC converter. Residual energy stored in the electric field of the output capacitor and/or the magnetic field of the inductor at the time the load is next reactivated is available to hasten transition back to the operating state.

Abstract: An AC/DC power conversion apparatus comprises an AC/DC converter for converting AC power to DC power for a load and a controller that maintains a power factor of the load as the load varies. The AC/DC converter includes an inductor and a plurality of switches that alternately connects and disconnects the inductor to and from an AC power source, to generate the DC power for the load. The plurality of switches is controlled by a plurality of switch drive signals generated by the controller, based on comparisons of an AC voltage from the AC power source to a DC output voltage produced by the AC/DC converter. To maintain the power factor of the load, the controller is configured to adjust the frequency of the plurality of switch drive signals in response to variations in the load while holding the duty cycles of the switch drive signals constant.

Abstract: An electronic measuring system for extending the effective measurement input frequency range of an electronic measuring instrument includes an electronic measuring instrument and a plurality of downconverting frequency extenders from which two or more downconverting frequency extenders can be selected and configured in series between a test signal output of a device under test (DUT) and a measuring input of the electronic measuring instrument, to selectively and effectively extend the permissible input frequency range of the electronic measuring instrument. The electronic measuring system may optionally include a plurality of upconverting frequency extenders from which one or more upconverting frequency extenders can be selected to selectively and effectively extend the maximum output frequency range of a signal generator used to generate stimulus signals for the DUT.

Abstract: A wideband phase modulator comprises a multiphase generator, a phase selector, and a phase adjuster. The wideband phase modulator is configured to receive an N-bit digital phase-modulating signal comprising a timed sequence of N-bit phase-modulating words, where N is a positive integer representing the bit resolution of the N-bit digital phase-modulating signal. The multiphase generator generates a plurality of coarse carrier phases, all having the same carrier frequency but each offset in phase relative to the other. The M most significant bits of the N-bit phase-modulating words are used to form M-bit phase select words that control the output phase of the phase selector. The phase adjuster performs a precision rotation operation, whereby a selected coarse carrier phase is adjusted so that the phase of the resulting final precision phase-modulated signal more closely aligns with a desired precision phase.

Abstract: A power conversion and control system suitable for use with solid-state lighting and conventional TRIAC dimmer switching includes an alternating current to direct current (AC-DC) converter configured to convert AC power from the AC mains to DC power and a controller configured to control dimming of a light-emitting load depending on the magnitude of a distorted AC voltage from an external TRIAC dimmer switch relative to the magnitude of the DC voltage Vdc produced by the AC-DC converter. To prevent the TRIAC in the external TRIAC dimmer switch from turning off in situations where the AC-DC converter is disconnected from the AC mains or not drawing any current from the AC mains, the power conversion and control system may further include circuitry that maintains the current through the TRIAC above its minimum holding current.

Abstract: A wideband phase modulator comprises a multiphase generator, a phase selector, and a phase adjuster. The wideband phase modulator is configured to receive an N-bit digital phase-modulating signal comprising a timed sequence of N-bit phase-modulating words, where N is a positive integer representing the bit resolution of the N-bit digital phase-modulating signal. The multiphase generator generates a plurality of coarse carrier phases, all having the same carrier frequency but each offset in phase relative to the other. The M most significant bits of the N-bit phase-modulating words are used to form M-bit phase select words that control the output phase of the phase selector. The phase adjuster performs a precision rotation operation, whereby a selected coarse carrier phase is adjusted so that the phase of the resulting final precision phase-modulated signal more closely aligns with a desired precision phase.

Abstract: An electronic measuring system for extending the effective measurement input frequency range of an electronic measuring instrument includes an electronic measuring instrument and a plurality of downconverting frequency extenders from which two or more downconverting frequency extenders can be selected and configured in series between a test signal output of a device under test (DUT) and a measuring input of the electronic measuring instrument, to selectively and effectively extend the permissible input frequency range of the electronic measuring instrument. The electronic measuring system may optionally include a plurality of upconverting frequency extenders from which one or more upconverting frequency extenders can be selected to selectively and effectively extend the maximum output frequency range of a signal generator used to generate stimulus signals for the DUT.

Abstract: A solid-state lighting system comprises a plurality of light-emitting devices (e.g., light-emitting diodes) and an alternating current to direct current (AC-DC) converter that converts AC power to DC power for powering the plurality of light-emitting devices. The AC-DC converter is configured to perform AC-DC conversion directly, without the need for or use of a bridge rectifier or step-down transformer. According to one aspect of the invention, the light-emitting devices of the solid-state lighting system are autonomous and individually powered by a plurality of DC power supplies generated from the DC power produced by the AC-DC converter. According to another aspect, a plurality of phase-offset dimmer control signals are generated based on waveform distortions in a dimming signal produced by a conventional dimmer switch. The phase-offset dimmer control signals are used to individually control the dimming of the light-emitting devices.

Abstract: A phased array transmitter includes a plurality of vector modulators, an in-phase/quadrature (I/Q) signal generator, and a multiphase generator. The output phases of the plurality of vector modulators, and hence the direction of transmission of the phased array transmitter, are set and controlled by adjusting both the magnitude ratios of I/Q signal pairs generated by the I/Q signal generator and applied to I and Q inputs of the plurality of vector modulators and phases of a plurality of local oscillator (LO) signal phases generated by the multiphase generator and applied to LO inputs of the plurality of vector modulators.

Abstract: A solid-state lighting system comprises a plurality of light-emitting devices (e.g., light-emitting diodes) and an alternating current to direct current (AC-DC) converter that converts AC power to DC power for powering the plurality of light-emitting devices. The AC-DC converter is configured to perform AC-DC conversion directly, without the need for or use of a bridge rectifier or step-down transformer. According to one aspect of the invention, the light-emitting devices of the solid-state lighting system are autonomous and individually powered by a plurality of DC power supplies generated from the DC power produced by the AC-DC converter. According to another aspect, a plurality of phase-offset dimmer control signals are generated based on waveform distortions in a dimming signal produced by a conventional dimmer switch. The phase-offset dimmer control signals are used to individually control the dimming of the light-emitting devices.

Abstract: Methods and apparatus for translating duty cycle information in duty-cycle-modulated signals to higher frequencies or higher data rates. An exemplary duty cycle translator includes a duty cycle evaluator, a high-speed digital counter, and a comparator. The duty cycle evaluator generates a first digital number representing a duty cycle of a low-frequency input duty-cycle-modulated (DCM) signal. The comparator compares the first digital number to a second digital number generated by the high-speed digital counter, and generates, based on the comparison, an output DCM signal having a higher frequency or data rate than the frequency or data rate of the low-frequency input DCM signal but a duty cycle that is substantially the same as the duty cycle of the low-frequency input DCM signal.

Abstract: Methods and apparatus for translating duty cycle information in duty-cycle-modulated signals to higher frequencies or higher data rates. An exemplary duty cycle translator includes a duty cycle evaluator, a high-speed digital counter, and a comparator. The duty cycle evaluator generates a first digital number representing a duty cycle of a low-frequency input duty-cycle-modulated (DCM) signal. The comparator compares the first digital number to a second digital number generated by the high-speed digital counter, and generates, based on the comparison, an output DCM signal having a higher frequency or data rate than the frequency or data rate of the low-frequency input DCM signal but a duty cycle that is substantially the same as the duty cycle of the low-frequency input DCM signal.

Abstract: A wideband phase modulator comprises a multiphase generator, a phase selector, and a phase adjuster. The wideband phase modulator is configured to receive an N-bit digital phase-modulating signal comprising a timed sequence of N-bit phase-modulating words, where N is a positive integer representing the bit resolution of the N-bit digital phase-modulating signal. The multiphase generator generates a plurality of coarse carrier phases, all having the same carrier frequency but each offset in phase relative to the other. The M most significant bits of the N-bit phase-modulating words are used to form M-bit phase select words that control the output phase of the phase selector. The phase adjuster performs a precision rotation operation, whereby a selected coarse carrier phase is adjusted so that the phase of the resulting final precision phase-modulated signal more closely aligns with a desired precision phase.

Abstract: An electronic measuring system for extending the effective measurement input frequency range of an electronic measuring instrument includes an electronic measuring instrument and a frequency downconverting subsystem, separate from the electronic measuring instrument, having one or more cascaded (i.e., series-connected) downconverting frequency extending units (FEU-Ds). Each FEU-D of the frequency downconverting subsystem includes a downconverting circuit (e.g., a block downconverter) enclosed within a housing. The frequency downconverting subsystem operates to downconvert a test signal from a device under test (DUT) to a downconverted test signal having a frequency within the permissible input frequency range of the measuring instrument, thereby extending the effective measurement input frequency range of the electronic measuring instrument.

Abstract: A radio frequency power amplifier (RF PA) apparatus includes an RF PA and a waveform converter. The waveform converter is configured to receive a sinusoidal RF signal and generate a nonsinusoidal RF signal, which is used to drive an active device (e.g., a field effect transistor (FET) or bipolar junction transistor (BJT)) of the RF PA. The nonsinusoidal RF signal, which may comprise a square wave or a substantially-square wave signal, has signal characteristics that result in less leakage through the active device's input-output parasitic capacitance, compared to the leakage that would result if the sinusoidal RF signal was used to drive the active device. The leakage control methods and apparatus of the present invention may be advantageously employed in a variety of applications including, for example, RF polar transmitters.