Network analyzer is a comprehensive microwave measuring instrument that can scan and measure in a wide frequency band to determine network parameters. The full name is microwave network analyzer. The network analyzer is a new instrument for measuring network parameters. It can directly measure the complex scattering parameters of active or passive, reversible or irreversible two port and single port networks, and give the amplitude and phase frequency characteristics of each scattering parameter in a swept frequency manner. The automatic network analyzer can correct the error of the measurement results point by point, and convert dozens of other network parameters, such as input reflection coefficient, output reflection coefficient, voltage standing wave ratio, impedance (or admittance), attenuation (or gain), phase shift, group delay and other transmission parameters, as well as isolation and orientation.