摘要:
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.
摘要:
A method and apparatus is disclosed for determining transaction attributes for software components which provide transaction data for the component itself and for any client of the component. The transaction attributes may be used for testing during component assembly and may be translated into transaction attributes of alternative runtime platforms.
摘要:
An amplification system and method is provided that reduces peaks associated with an input signal, and provides correction, in one or more spectral bands, to signal distortion and out-of-band emissions that result from the peak reduction. The correction signal that removes signal distortion and OOB emissions associated with the peak reduction can be calculated or electronically derived. The correction signal can be combined with the peak reduced signal prior to or after amplification of the peak reduced input signal.
摘要:
An amplifier system is provided that switches between operation in a polar mode and a signal restoration mode based on a characteristic of an input signal relative to a threshold level. The system includes a correction path that mitigates distortion and out-of-band (OOB) emissions in the polar mode and provides at least a substantial portion of the amplified output signal in the signal restoration.
摘要:
A user input device has a body portion extending from a first end to a second end and having a plurality of keys, for example keys that may be arranged and configured to be a keyboard, and an optical motion element. A wireless transmitter transmits data entered through the keys to a target component, for example a computer, a PDA, a digital watch, and the like. The user input device may include a hinged panel having some of the keys, and when the hinged panel is in an open configuration, the arrangement of the keys may be similar to an alphanumeric keyboard. The optical motion element may be an optical mouse for controlling a cursor on a display, when the hinged panel is open. When the hinged panel is closed the optical motion element may be configured to serve as a digital pen, for sensing natural writing, pen motions used to control a display, such as cursor location or to make selections on a menu, for example. The device may be sized so as to be easily portable, fit inside a pocket, and may be formed to have a shape similar to a writing instrument.
摘要:
An amplification system and method is provided that reduces peaks associated with an input signal, and provides correction, in one or more spectral bands, to signal distortion and out-of-band emissions that result from the peak reduction. The correction signal that removes signal distortion and OOB emissions associated with the peak reduction can be calculated or electronically derived. The correction signal can be combined with the peak reduced signal prior to or after amplification of the peak reduced input signal.
摘要:
Systems and methods are provided for determining and providing an appropriate variable voltage supply to a power amplifier. A power amplifier is operative to amplify an input signal. A digital buffer stores a copy of the input signal representing a predetermined interval of time. An envelope profiler analyzes the buffered interval of the input signal and determines an appropriate supply signal profile for the power amplifier over the predetermined time interval. A supply control provides a supply signal according to the determined profile.
摘要:
Systems and methods are provided for converting a digital signal into an analog signal. A digital-to-analog converter assembly comprises a delta-sigma modulator, a digital-to-analog converter, an analog filter, and a comb filter. The delta-sigma modulator processes a digital input signal to produce a digital output signal having at least one associated high dynamic range frequency band. The digital-to-analog converter converts the digital output signal into an analog output signal having at least one associated high dynamic range frequency band. The associated high dynamic range bands have respective frequency characteristics. An analog filter assembly filters the analog signal. The analog filter has at least one passband. A comb filter assembly attenuates the analog signal output of the filter assembly to improve signal to noise ratio.
摘要:
Systems and methods for signal conversion are provided. Signals are spread in a continuous spectrum by a spread spectrum signal, such as a direct sequence spread spectrum (DS-SS) signal. The signals are then processed, which may include but is not limited to analog-to-digital conversion, digital-to-analog conversion, frequency conversion, clipping, filtering or a plurality of processes. The processed signal is then despread using substantially the same spreading signal that was used to spread the signal.
摘要:
An amplification system and method is provided that reduces peaks associated with an input signal, and provides correction, in one or more spectral bands, to signal distortion and out-of-band emissions that result from the peak reduction. The correction signal that removes signal distortion and OOB emissions associated with the peak reduction can be calculated or electronically derived. The correction signal can be combined with the peak reduced signal prior to or after amplification of the peak reduced input signal.