Research of balanced network measurement based on Vector Network Analyzer

Balanced device is becoming more and more common in communication system. The characteristic of a balanced network is described by mixed-mode S parameters. Traditional two-port Vector Network Analyzer (VNA) is used to measure S parameters which describe single ended network. So how to measure the mixed-mode S parameters is of great challenge to engineers. With the coming up of new four-port VNA and new test method, getting mixed-mode S parameters becomes much easier. In this paper, the balanced network and the definition of mixed-mode S parameters were introduced at first, and two ways of measuring mixed-mode S parameters were presented. Then the method of transmitting single ended S parameters to mixed-mode S parameters was researched. Finally, the true mode stimulation measurement was analyzed. Finally an example was given to demonstrate the measurement process.