| 摘要 |
There are included a first quadrature modulation part (5) that divides an input signal into an I signal and a Q signal having a phase orthogonal to the phase thereof and uses a baseband frequency to perform frequency conversions of the I and Q signals, thereby performing a quadrature modulation; and a second quadrature modulation part (8) that uses in-phase and quadrature carriers of FM frequencies, which are 90 degrees out of phase with respect to each other, to perform frequency conversions of the I and Q signals, which are generated by the first quadrature modulation part (5), thereby performing a quadrature modulation. Thus, the phases of the I and Q signals, which are shifted by 90 degrees with respect to each other by the first quadrature modulation part (5), are further shifted by 90 degrees with respect to each other by the second quadrature modulation part (8), thereby providing frequency components the phases of which have been inverted, whereby the unwanted harmonic components at the spurious sides of a target frequency can be attenuated.
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