| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a bandpass type ΔΣ modulator which is designed for use with a desired frequency. <P>SOLUTION: A bandpass type ΔΣ modulator (except θ<SB POS="POST">0</SB>=±π/2×n; n is an integer equal to or greater than 1) by replacing z in the z region model of a low-pass type ΔΣ modulator with the z' given below. z'=f<SB POS="POST">cnv</SB>(z,θ<SB POS="POST">0</SB>), where f<SB POS="POST">cnv</SB>(z,θ<SB POS="POST">0</SB>) is a function θ<SB POS="POST">0</SB>=2π×(f<SB POS="POST">0</SB>/fs) with respect to arbitrary z and θ<SB POS="POST">0</SB>, in which the absolute value of f<SB POS="POST">cnv</SB>(z,θ<SB POS="POST">0</SB>) is always 1, where fs is a sampling frequency and f<SB POS="POST">0</SB>is the center frequency of the quantization noise stop band of the bandpass type ΔΣ modulator. <P>COPYRIGHT: (C)2013,JPO&INPIT |
