Method and system for performing vector spectral measurements of a radio frequency (RF) signal having a repetitive waveform

A system for performing vector spectral measurements of a wideband radio frequency (RF) signal, the system comprising:

• a receiver having a frequency span less than a total bandwidth of an output RF signal, provided by a device under test (DUT) in response to a stimulus RF signal, each of the stimulus RF signal and the output RF signal having a repetitive waveform, the receiver being configured to capture a plurality of frequency segments of the output RF signal, externally triggered by marker signals occurring in at least one waveform repetition of the repetitive waveform, respectively, wherein each frequency segment has a corresponding segment bandwidth less than the total bandwidth of the output RF signal;
• and
• a processing unit configured to concatenate the plurality of frequency segments in frequency domain into a combined bandwidth substantially the same as the total bandwidth of the output RF signal in response to the external triggering for preserving phase continuity among the plurality of frequency segments.