US Patent:
20120163627, Jun 28, 2012
Inventors:
Michael Joseph Goodson - Bloomingdale IL, US
Thomas J. Kundmann - Cary IL, US
Jeffrey Arthur Meunier - Deerfield IL, US
Assignee:
Shure Incorporated - Niles IL
International Classification:
H04B 15/00
Abstract:
A communications system, e.g., a wireless microphone, incorporates a quadrature modulator system to reduce power consumption with respect to traditional approaches and is general in nature to support any two-dimensional digital technique. The quadrature modulator system comprises different subsystems, including a digital-analog transformation circuit, a baseband filter, and a quadrature modulator. The digital-analog transformation circuit converts discrete time samples to a continuous time signal, and further includes an oversampling noise-shaping modulator such as a sigma-delta modulator. The baseband filter then removes out-of-band energy including sampling images and quantization noise. Some of the circuit components may comprise discrete devices that may result in a reduction of power consumption for the quadrature modulator system. Alternatively, some or all of the circuit components may be incorporated in a single electronic device. For example, an in-phase/quadrature-phase (I/Q) converter and oversampling noise-shaping modulator may be implemented within one field-programmable gate array.