ANTENNA FOR TWO FREQUENCY BANDS

摘要

An antenna which operates in two frequency bandes even when its sliding antenna section (30) is housed in or pulled out from an enclosure. The antenna system is provided with a fixed antenna section (20) and the sliding antenna section (30). The fixed antenna section (20) is provided with a helical antenna (21) and the sliding antenna section (30) is provided with a first mono-pole antenna (31) which is coaxial with the helical antenna (21), a second mono-pole antenna (32), and an antenna cover (33) which holds the antenna (32) on the extension of the axis of the antenna (31). When the sliding antenna section (30) is pulled out from the enclosure, the antenna (31) is in a position where the antenna (31) is not electromagnetically coupled with the antenna (21) and the antenna (32) is in another position where the antenna (32) is electromagnetically coupled with the antenna (21). On the contrary, when the antenna section (30) is housed in the enclosure, the antenna (31) is in a position where the antenna (31) is electromagnetically coupled with the antenna (21) and the antenna (32) is electromagnetically coupled with the antenna (21).