Abstract
Small antennas for terminal stations in mobile communication are proposed. The proposed antennas consist of a vertical inner straight conductor and a close wound coil shape outer conducting wire. The antennas are fed by a coaxial cable between the lower port of the inner conductor and the lower port of the outer conductor. As the terminal conditions at the top end of two conductors, the short type and the open type are proposed. The short termination antenna has a height of about 1/20 wavelength, and the open termination antenna has a height of about 1/80 wavelength. Both antennas have a good matching to the 50Ω coaxial cable without any matching circuit. The proposed antennas have an omnidirectional radiation pattern which is the same as the radiation pattern of the monopole antenna. The antennas have a gain of -8 dBi and -18 dBi, respectively.
