by Christopher L. Grachanen
Vector Network Analyzers (VNA) are used to measure a variety of RF parameters such as transmission loss, reflection loss, phase and group delay for a variety of passive RF devices and signal interconnections. RF devices span from attenuators and terminations to power splitters and directional couplers. Interconnections include RF cables, adapters, fixtures, probes as well as PCB signal traces. These RF devices and interconnections as measured by VNAs yields s-parameters. S-parameters describe the response of a RF device or interconnection to a stimulus (incident signal) applied to any or all of its connections (ports). S-parameters are essentially ratios comparing port stimuli to port responses to the applied stimuli.
