| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-precision amplitude/phase modulator which performs, with high precision, amplitude/phase modulation upon a reference signal while using a D-A converter of which the number of bits is relatively small. <P>SOLUTION: The high-precision amplitude/phase modulator comprises: a first distributor which distributes a reference signal to output a first reference signal and a second reference signal; a first D-A converter which performs D-A conversion for a first digital signal to output a first analog signal; a first amplitude/phase modulator which performs amplitude/phase modulation for the first reference signal based on the first analog signal to output a first modulated signal; a second D-A converter which performs D-A conversion for a second digital signal to output a second analog signal; a second amplitude/phase modulator which performs amplitude/phase modulation for the second reference signal based on the second analog signal to output a second modulated signal; a first composer which combines the first modulated signal and the second modulated signal to output a modulated signal; and an amplitude modulator which relatively reduces an amplitude of the second modulated signal rather than that of the first modulated signal. <P>COPYRIGHT: (C)2009,JPO&INPIT |
