Patent ID: 7741831

Claim:
A frequency component measuring device, comprising: a local oscillator capable of performing sweep in a predetermined frequency range; a first frequency conversion unit for mixing a local oscillation signal outputted from the local oscillator with a measured signal so as to perform frequency conversion to the measured signal; a plurality of intermediate-frequency filters for extracting components of different intermediate frequencies from a signal outputted from the first frequency conversion unit and outputting it; and an image removal processing unit for performing image removal based on a plurality of intermediate-frequency signals separately outputted from the plurality of intermediate-frequency filters corresponding to each of a plurality of frequency sweep operations performed by the local oscillator, wherein the image removal processing unit compares levels of the plurality of intermediate-frequency signals to select the intermediate-frequency signal obtained from one predetermined frequency sweep operation among the plurality of frequency sweep operations when a difference between the levels is not larger than a predetermined reference value, and in the other cases, selects the intermediate-frequency signal having a smaller signal level.