Patent ID: 8161093

Claim:
A complex multiplier for multiplying an input complex number by a twiddle factor and outputting the resulting value, comprising: a first adder/subtracter that adds the real part of the complex number and a first twiddle factor or subtracts the first twiddle factor from the real part of the complex number according to a first signal; a second adder/subtracter that adds the imaginary part of the complex number and a second twiddle factor or subtracts the second twiddle factor from the imaginary part of the complex number according to a second signal; a first multiplier that multiplies the value obtained by the first adder/subtracter by a third twiddle factor and outputs the resulting value; a second multiplier that multiplies the value obtained by the second adder/subtracter by a fourth twiddle factor and outputs the resulting value; a multiplexer that selectively outputs the values output from the first and second multipliers as a real part output signal and an imaginary part output signal according to a third signal; and a controller that provides the first to third signals, wherein the first twiddle factor is obtained by multiplying the imaginary part by the value of a first function or a second function corresponding to a phase rotation value that is set in a first area in which the first function is linear and a second area in which the second function is linear, and the second twiddle factor is obtained by multiplying the real part by the value of the first or second function corresponding to the phase rotation value that is set in the first and second areas.