| 摘要 |
<p>PURPOSE:To attain ideal demodulation with simple configuration by obtaining a non-modulation processing VCO output synchronously with an input angular modulation wave from a demodulation system PLL, obtaining a spread code generating clock through the frequency division of the said output as a signal equivalent to a local oscillation output at modulation. CONSTITUTION:A synchronization type spread spectrum (SS) modulation wave signal from an input terminal In2 is fed to a loop filter 24 as a signal subject to inverse spread by an inverse spread use multiplier 3 or the like, the loop filter 24 eliminates a phase error in a phase locked loop locking an angular modulation wave after the inverse spread and a carrier signal subject to no modulation is outputted from a VCO 22. The signal is frequency-divided by 1/N1 and 1/N2 frequency dividers 26, 27 and a clock equivalent to a local oscillation output at modulation is obtained, then jitter in a spread code generator 47 and the multiplier 3 or the like is suppressed and ideal demodulation of the synchronization SS spread modulation wave is attained with simple configuration.</p> |
