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

Image Number 5 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
Configurable memory controller/memory module communication system
Method for resource allocation in a wireless communication network, method for error-free transmission of information, node and wireless communication network
Washing-up bowl
Semiconductor memory device
Transfer of digital data through an isolation
Method for generating codewords
Liquid crystal display panel
  Randomly Featured Patents
Apparatus for the redundant power supply of at least one load
Laminectomy surgical process
Dry-break fuel receiver with integral back-flow prevention
A/D converter, digital PLL circuit using the same, and information recording apparatus using the same
Temperature gradient light waveguide
Green balls formed by agglomerating wet-collected fume produced in metallurgical furnaces
Selectively weighted golf ball
Method and system for e-commerce packages
Pinkered ribbon print form
Vehicle seat