Direct digital synthesizer driven phase lock loop spectrum analyzer

Abstract

A spectrum analyzer converts frequencies of an input signal using a local signal from a local signal generator, detects the frequency converted outputs, and sweeps the frequencies of said local signal generated by said local signal generator, to obtain a frequency-based output, wherein said local signal generator comprises a digital direct synthesizer for incrementing the output frequency for every input clock, a variable frequency oscillator for outputting an oscillation output as said local signal and a phase locked loop for controlling the oscillation frequency of said variable frequency oscillator using the output of said digital direct synthesizer as a reference signal.