Abstract:
Systems and methods are provided for providing high dynamic range operation over a variable range of frequencies. A delta-sigma modulator, having associated frequency characteristics, produces a digital output signal. A digital-to-analog converter converts the digital output signal into an analog signal. A clock circuit provides a clock signal to the delta-sigma modulator and the digital-to-analog converter. A frequency control controls one or more of the clock circuit, the delta-sigma modulator, and the digital-to-analog converter to alter the frequency characteristics of the delta-sigma modulator. A filter circuit can provide one or more passbands to one or more downstream amplifiers ensuring that out of band quantization noise is removed before amplification.
Abstract:
A communication system and method is provided that modifies a signal for transmission at a transmitter to reduce peaks associated with the signal. The signal can be modified employing signal shaping, signal clipping, signal decomposition or other techniques to remove peaks associated with the signal. The communication system can also correct the modified signal at a receiver to reconstruct the originally wanted signal.
Abstract:
A portable system is provided for sensing and training a user to maintain correct posture while seated in a chair with a seat portion and a back portion. The system includes a first pad attachable to the seat portion of a chair, said first pad having a front area and a rear area, and a second pad attachable to the back portion of a chair and having a lower area and an upper area. There is a first sensor located in the first pad capable of sensing that a user is seated in the seat portion of the chair, a second sensor located in the first pad capable of sensing whether the lower posterior portion of the user's body is in contact with the rear area of the first pad, a third sensor operably attached to the lower area of the second pad capable of sensing whether the user's lumbar region is in contact with the second pad, a fourth sensor operably attached to the upper area of the second pad capable of sensing the distance between the user's upper back and the upper area of the second pad and a neck-position sensor operably attached to the second pad and capable of sensing the distance between the neck-position sensor and the user's neck. The system also includes a microprocessor operably connected to the first sensor, second sensor, third sensor, fourth sensor and neck-position sensor and capable of collecting data from each of the first sensor, second sensor, third sensor, fourth sensor and neck position sensor. The system also includes software for a personal computer, which configures the personal computer to receive the data from the microprocessor and to display the data received from the microprocessor, so that the user can utilize the ergonomic seat pad to receive feedback regarding his posture and over time, improve his posture.
Abstract:
An amplifier system is provided that switches between a linear mode of operation, an envelope tracking mode of operation and a polar mode of operation. The amplifier system switches between modes of operation based upon a characteristic of an input signal relative to a first threshold level and a second threshold level. A mode selector selects the operation mode by transmitting an amplitude modulated signal plus a variable headroom voltage to a supply terminal of a power amplifier during the envelope tracking mode, an amplitude modulated signal to the supply terminal and phase modulated input signal during the polar mode and a substantially constant amplitude signal to the supply terminal during the linear mode.
Abstract:
A supply voltage and/or bias of a switching amplifier is modified based on at least one characteristic of the input signal relative to a threshold level. A binary waveform converter converts the input signal into a binary waveform for inputting into the switching amplifier. The switching amplifier amplifies the input signal, while the supply voltage and/or bias is modified in response to changes of the at least one characteristic of the input signal.
Abstract:
An amplification architecture or system is provided having a multiple amplifier system that switches modes of operation between operation in a component mode and a composite mode based on a characteristic of an input signal relative to a threshold level. In the component mode, the components of the input signal are employed to different terminals of the multiple amplifier system that provide a reconstructed amplified representation of the input signal. In the composite mode, the input signal is amplified to provide an amplified representation of the input signal.
Abstract:
An apparatus for the treatment of gases in a positive crankcase ventilation (PCV) system, in an internal combustion engine, is provided with a housing defining a gas treatment chamber. At least one gas filtering medium is disposed in the treatment chamber, and the gases from the engine crankcase are passed through the gas filtering medium in the treatment chamber, before the gases are routed into the air intake portion of the engine. In addition, the gases, after passage through the gas filtering medium, are passed through an ionization device.
Abstract:
A portable system is provided for sensing and training a user to maintain correct posture while seated in a chair with a seat portion and a back portion. The system includes a first pad attachable to the seat portion of a chair, said first pad having a front area and a rear area, and a second pad attachable to the back portion of a chair and having a lower area and an upper area. There is a first sensor located in the first pad capable of sensing that a user is seated in the seat portion of the chair, a second sensor located in the first pad capable of sensing whether the lower posterior portion of the user's body is in contact with the rear area of the first pad, a third sensor operably attached to the lower area of the second pad capable of sensing whether the user's lumbar region is in contact with the second pad, a fourth sensor operably attached to the upper area of the second pad capable of sensing the distance between the user's upper back and the upper area of the second pad and a neck-position sensor operably attached to the second pad and capable of sensing the distance between the neck-position sensor and the user's neck. The system also includes a microprocessor operably connected to the first sensor, second sensor, third sensor, fourth sensor and neck-position sensor and capable of collecting data from each of the first sensor, second sensor, third sensor, fourth sensor and neck position sensor. The system also includes software for a personal computer, which configures the personal computer to receive the data from the microprocessor and to display the data received from the microprocessor, so that the user can utilize the ergonomic seat pad to receive feedback regarding his posture and over time, improve his posture.
Abstract:
A communication system and method is provided that modifies a signal for transmission at a transmitter to reduce peaks associated with the signal. The signal can be modified employing signal shaping, signal clipping, signal decomposition or other techniques to remove peaks associated with the signal. The communication system can also correct the modified signal at a receiver to reconstruct the originally wanted signal.
Abstract:
An amplifier system is provided that switches between operation in a polar mode and a linear mode based on a characteristic of an input signal relative to a threshold level. The system operates as a polar amplifier in the polar mode, and as a linear amplifier in the linear mode. A mode selector controls whether polar components of the input signal are sent to a power amplifier or whether a composite signal is amplified.