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
Medical injector
Hot-press cushion material and manufacturing method of the same
Architecture, system and method for testing resistive type memory
Management of memory array with magnetic random access memory (MRAM)
Methods and apparatus for deactivating internal constraint curves when inflating an N-sided patch
  Randomly Featured Patents
Infra-red heater
Adjustable support for the forward edge of a wall supported washstand
Method for increasing utilizable surface of rugged polysilicon layer in semiconductor device
Releasable cord connection apparatus
Indirectly heated button cathode for an ion source
Medical assistant outer garment
Workpeice proximity plating apparatus
Dual mode measurement system with quartz crystal microbalance
Golf putting green ball ejector
Multistep water heater having a device for increasing combustion efficiency