| 摘要 |
PURPOSE: An in-band spurious evading apparatus of a spectrum analyzer is provided to remove spurious of a direct digital integrator and implement zero lock and sweep functions. CONSTITUTION: A digital combiner(10) generates the reference frequency for the lock. A crystal filter(20) directly eliminates the comparison spurious of the digital combiner. A phase locked loop element(40) is electrically connected to the crystal filter. A loop filter(50) is electrically connected to the phase-locked loop device. A controller(70) directly outputs the control command to the digital combiner and the phase-locked loop device. |
