When using frequency sweep meter to measure the input impedance of antenna, the balanced - unbalanced transformer must be connected between coaxial transmissionline and antenna.
用扫频仪测量天线的输入阻抗时，在同轴传输线与天线间应按平衡—不平衡变换器。
2
In this model, running state of transmissionline is divided into four states, and calculation method of state probability, state frequency and state duration in balanced state are given.