As commercial, military/aerospace, and other communications designs extend into the millimeter-wave (mmWave) spectrum, engineers must adapt their testing procedures and require more from instruments such as vector network analyzers (VNAs). Shorter wavelengths associated with mmWave frequencies place more weight on phase measurements, while also emphasizing the need for proper calibration.
Phase measurements have even gained in importance when verifying passive-component measurements. Phase differences can be very small, depending on the material, so a VNA must measure even the slightest variations. It does so by comparing the incident signal, leaving the analyzer with either the signal that’s transmitted through the device under test (DUT) or the signal reflected from its input.