| 摘要 |
PURPOSE:To maintain the oscillation stability and SN ratio of either of two PLL circuits at necessary quality, to set a necessary inductive frequency channel and a frequency interval (pitch) optically and eliminate deterioration in the relative precision of the frequency of a composite wave output, and to reduce higher harmonics by extracting the difference frequency between oscillation waves generated by the two PLL circuits. CONSTITUTION:A reference frequency fr is divided by frequency dividers 6-1 and 6-2 to 1/n1 and 1/n2 (n1 and n2: positive integer) to generate outputs of new reference frequencies fr1 and fr2. The fr1 and fr2 are synchronized with 2-5 phase-locked circuits (PLL) respectively to generate outputs of frequencies Fs1 and Fs2 and those outputs are inputted to a mixer 7, which generates a composite output containing the sum component of and the difference component between Fs1 and Fs2. An LPF 8 extract only the difference frequency component in M and remove other unnecessary higher harmonic components, but its output DELTAFs is a composite wave of necessary inductive radio frequency. |
