Recently, due to development of mobile communication services, there is increasing need for a multi-band antenna that can be used in two or more frequency bands instead of only one frequency band. The same is true for repeater antennas and base station antennas as well as embedded antennas.
However, since conventional antennas are designed to be used only in a single frequency band, it is inevitable to use different antennas according to individual frequency bands in order to use the antenna in two or more frequency bands. Accordingly, to secure the length value of an antenna used in a low frequency band. In this case, however, manufacturing costs increase due to increase in size of the entire antenna resulting from the long length of the radiating element, and installers of the repeater antenna and the base station antenna should install antennas for respective frequency bands. As a result, an issue is raised in terms of installation space and installation cost increases. In addition, since the frequency band in which the antenna operates is also narrow, it is difficult to obtain satisfactory characteristics.
Accordingly, the present invention proposes a multi-band radiation device which can be used both in a high-frequency band and a low-frequency band, has a wide-band characteristic and can reduce manufacturing costs and installation costs by reducing the size of the entire antenna.