| 摘要 |
PCT No. PCT/US93/02445 Sec. 371 Date Apr. 11, 1994 Sec. 102(e) Date Apr. 11, 1994 PCT Filed Mar. 12, 1993 PCT Pub. No. WO93/18578 PCT Pub. Date Sep. 16, 1993A low-power digital frequency synthesizer combining direct digital frequency synthesis techniques with serrodyne frequency translation principles to produce a wideband frequency response with high spectral purity. A conventional direct digital synthesizer is used to generate a high-resolution analog carrier signal from a low-speed digital clock signal. The carrier signal is phase modulated by a low-resolution signal generated from a high-speed digital clock signal. The modulation signal is a higher frequency signal than the carrier signal. The phase modulation is accomplished by exact decoded gain elements. The spectral purity of the resulting high-resolution output signal is unobtainable by conventional direct digital synthesizers, while providing significant power savings.
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