Vector Network Analyzers

Vector network analyzers (VNAs) are precision RF and microwave instruments that measure the scattering parameters (S-parameters) of electrical networks — capturing both magnitude and phase of transmitted and reflected signals as a function of frequency. This capability allows engineers to fully characterize passive and active RF components including filters, amplifiers, cables, connectors, antennas, and impedance matching networks. Unlike scalar network analyzers, which measure amplitude only, VNAs enable vector error correction, time-domain analysis via inverse Fourier transform, and complex impedance measurements, making them the standard instrument for RF and microwave characterization in modern test laboratories.

VNAs operate from kHz to GHz frequencies, with high-end instruments reaching millimeter-wave frequencies above 100 GHz for 5G, automotive radar, and satellite applications. Key specifications include frequency range, dynamic range, trace noise, and port count. Most benchtop VNAs provide two test ports supporting four S-parameters (S11, S21, S12, S22), while multiport VNAs support more complex device characterization. Modular and handheld VNAs extend coverage to field applications and automated test systems.

Typical Applications

S-parameter characterization of RF filters, couplers, amplifiers, and passive components
Antenna impedance matching and return loss (VSWR) measurements
Cable and connector characterization including TDR and time-domain transmission (TDT)
Differential and balanced device measurements using mixed-mode S-parameters
On-wafer probing for semiconductor and MMIC device characterization
5G mmWave component testing and automotive radar module characterization above 77 GHz

Popular Brands

Keysight Technologies (formerly Agilent/HP) and Rohde & Schwarz are the market leaders in VNAs, offering broad portfolios from entry-level two-port instruments to 110+ GHz multiport systems. Anritsu provides competitive solutions including the widely used ShockLine and VectorStar series. Pico Technology offers accessible USB-based VNAs for laboratory and education use. Copper Mountain Technologies specializes in compact, PC-controlled VNA platforms suited for automated test environments.