vector network analyzer s parameters

Vector Network Analyzer.
A network analyzer is a device that can measure S parameters over a range of frequencies. There are two types:
1. Scalar network analyzer. Measures only the magnitude of the S parameters.
2. Vector network analyzer (VNA). Measures both the magnitude and phase of the S parameters. The latter is generally a much more expensive piece of equipment.
The VNA is basically a sophisticated transmitter and receiver pair with vast signal processing capabilities. Here is a block diagram of a typical vector network analyzer (text p. 183):

We will examine the basic subsystems of a VNA in this lecture and some important topics concerning the sources of error and calibration of the VNA.
The following pages are from “Network Analyzer Basics,” Agilent Product Note E206. (Agilent Technologies is the company that was formed when Hewlett Packard Corporation spun-off its test and measurement business.)