HANDHELD VECTOR NETWORK ANALYZER

摘要

A handheld vector network analyzer (VNA) (300) providing a wide bandwidth test signal Fo utilizing a narrowband test signal synthesizer (700) which provides the test signal through a frequency divider (710) or harmonic generator (802). With a 550-1100 MHz narrowband test signal synthesizer, a test signal Fo can range from 25 MHz to 3.3 GHz. To make a tracking synthesizer (720) operate more independent of the test signal synthesizer (700), a LO signal is produced using the tracking synthesizer (720) with its phase detector (726) input connected through a frequency divider (800) to the output of the test signal synthesizer. Synchronous detectors are further included which provide incident and reflected IF signals to take advantage of the maximum range of an A/D converter. To better enable operation in the presence of external signals, feedback is provided from the synchronous detectors to sweep the frequency of a reference oscillator (940).