Patent ID: 7631030

Claim:
An electronic circuit for signal processing, comprising: (a) a first multiplication section, configured to multiply a first analog signal by a sine wave signal, and comprising (1) a first weighting section having n weighting cofficients, each having a unique value, for multiplying the first analog input signal by the weighting coefficients and outputting a first weighted analog signal, n being an integer equal to or greater than 2, (2) a first polarity changeover section for changing the polarity of the first weighted analog signal outputted from said weighting section, and (3) a first control section for performing changeover among the n weighting coefficients and changeover of the polarity after every sampling period equal to ½k of one period of the sine wave signal by which the first analog input signal is multiplied, k being an integer, 2k being equal to or greater than 6 but equal to or smaller than 4n; (b) a second multiplication section, configured to multiply a second analog signal by a cosine wave signal, and comprising (1) a second weighting section having n weighting coefficients for multiplying the second analog input signal by the weighting coefficients and outputting a weighted analog signal, n being an integer equal to or greater than 2, (2) a second polarity changeover section for changing over the polarity of the weighted analog signal outputted from said weighting section, and (3) a second control section for performing changeover among the n weighting coefficients and changeover of the polarity after every sampling period equal to ½k of one period of the cosine wave signal by which the analog input signal is multiplied, k being an integer, 2k being equal to or greater than 6but equal to or smaller than 4n; wherein output signals of said first and second multiplication sections are orthogonal to each other; and (c) an addition section for adding the output signals of said first and second multiplication sections.