Resources Contact Us Home
Quadrature modulation apparatus, method, program, and recording medium

Image Number 8 for United States Patent #7944989.

An RF signal, which has been obtained by a quadrature modulation, is corrected without performing quadrature demodulation. There are included an in-phase multiplier, a quadrature multiplier, an adder, a power detector, and an error determining part. The in-phase multiplier outputs an in-phase conversion signal by mixing an in-phase local signal of a predetermined local frequency with an in-phase correction user signal obtained by adding an in-phase user signal to an in-phase correction signal of a sinusoidal voltage outputted from an in-phase correction signal output unit. The quadrature multiplier outputs a quadrature conversion signal by mixing a quadrature local signal, which is different in phase by 90 degrees from the in-phase local signal, with a quadrature correction user signal obtained by adding a quadrature user signal to a quadrature correction signal, which is different in phase by 90 degrees from the in-phase correction signal, from a quadrature correction signal output unit. The adder adds the in-phase conversion signal to the quadrature conversion signal. The power detector measures an output voltage of the adder. The error determining part determines, based on the measurement result of the power detector, the error of the quadrature modulation.

  Recently Added Patents
Method and apparatus for reducing power consumption used in communication system having time slots
Composite high reflectivity layer
Biaxially oriented film which could be thermally laminated with paper and other substrates
Method and apparatus for web crawling
Intelligent sensor network
Semiconductor overlapped PN structure and manufacturing method thereof
Jacket liner
  Randomly Featured Patents
Methods and systems for resizing multimedia content based on quality and rate information
Method of controlling salmonella in shell eggs
User authentication for social networks
Mobile element
Bifurcated stent delivery system having retractable sheath
High voltage lateral FET structure with improved on resistance performance
Writing instrument
Pattern forming structure, pattern forming method, device, electro-optical device, and electronic apparatus
Nitrogen-free anionic softeners