While measuring S-parameters (reflection and transmission) remains the core of network analysis, modern Vector Network Analyzers (VNAs) have evolved into "nonlinear" instruments.
In modern highly integrated chipsets, the antenna is often built directly into the package (Antenna-in-Package or AiP), making traditional cabled testing impossible. Modern RF and Microwave Measurement Techniques
: Techniques like load-pull and source-pull are now essential for characterizing power amplifiers under realistic, large-signal conditions to optimize for efficiency and linearity. Modern RF and Microwave Measurement Techniques
: Standard calibrations like Thru-Reflect-Line (TRL) and Line-Reflect-Line (LRL) are critical for high-accuracy measurements, especially in waveguide or on-wafer setups where fixed standards can be manufactured to tighter tolerances than sliding terminations. Modern RF and Microwave Measurement Techniques