| 摘要 |
<P>PROBLEM TO BE SOLVED: To simplify the circuitry as much as possible with regard to a digital IQ detection method of high frequency signal. <P>SOLUTION: In the digital IQ detection method of high frequency signal subjected to discrete A/D conversion at a sampling interval T and having amplitude A, angular speed ω, and phase θ, value of the sampling interval T shown by formula (9) as a positive integer m including 0 is removed. The high frequency signal is multiplied, respectively, by cos(ωiT) and -sin(ωiT) as local signals to determine the I signal component s(iT)cos(ωiT) and the Q signal component s(iT)sin(ωiT). The I signal component and the Q signal component are multiplied by a coefficient a<SB>i</SB>determined by setting a<SB>1</SB>-a<SB>n</SB>=1 and substituting a<SB>0</SB>=a<SB>n+1</SB>to formula (5a), and n is determined to satisfy a relation 0<a<SB>0</SB><1. Smoothing is performed using a filter of n+2 samples and a signal component equal to two times of ω is removed thus outputting detection signals of I signal and Q signal represented by formula (8). <P>COPYRIGHT: (C)2006,JPO&NCIPI |
