Patent ID: 6891904

Claim:
A modulation signal analysis apparatus comprising: a frequency converter for converting a frequency of a modulation signal inputted from outside to an intermediate frequency; a resolution bandwidth (RAW) filter for receiving the modulation signal outputted from said frequency converter and limiting a frequency component with a bandwidth determined by a designated resolution; a level converter for converting the modulation signal having a band limited by said RBW filter to a digital level signal to perform frequency analysis; a signal selection circuit for selecting either one modulation signal from the modulation signal before having the band limited by said RBW filter or the modulation signal after having the band limited by said RBW filter; an A/D converter for receiving the modulation signal selected by said signal selection circuit and converting the modulation signal to a digital signal; an operation input section for operating and inputting outside a frequency analysis instruction for said modulation signal, a modulation analysis instruction for said modulation signal, and a modulation type of said modulation signal; an analysis operation section for using the digital signal converted by said A/D converter and performing frequency analysis for said modulation signal and modulation analysis for the modulation signal selected by the signal selection circuit in order to modulate and analyze a level signal outputted from said level converter; and a controller for instructing said analysis operation section to execute the analysis instruction operated and inputted via said operation input section, sending a selection instruction to said signal selection circuit in accordance with the modulation type of the operated and inputted modulation signal, and setting the bandwidth of said RBW filter in accordance with the modulation type of said modulation signal when the modulation signal having the band limited by said RBW filter is selected as the modulation signal inputted to said A/D converter, and the modulation analysis instruction for said modulation signal is inputted to said operation input section.