New mechanism of antenna as an electromagnetic device

The operating mechanism of an antenna, especially the dipole is discussed in this paper, wherein the antenna is considered as an electromagnetic wave transmission device. It is different with the traditional radiation mechanism of antenna which is based on the radiation of oscillating electric current. According to the new operating mechanism, dipole antenna is regarded as a resonator of Sommerfeld line. To confirm it, the port impedance, radiation efficiency of the dipole antenna are analyzed by the method of the electromagnetic circuit. The results show new theory is more effective and more accurate than the previous one.