ANTENNA DEVICE OF CORDLESS TELEPHONE SYSTEM

摘要

PURPOSE:To realize an antenna device capable of obtaining excellent gain and sharing two frequencies by combining an incorporated antenna with an external antenna trimmer. CONSTITUTION:The antenna device is provided with an incorporated antenna 13 for sharing two frequencies which is formed by pattern and parts on a substrate 17, a stretchable external antenna 12 and a pipe 18 which is composed of non-conductive material and is for the storage of the external antenna. The antenna device where the degradation of gain at the time of the contraction of the external antenna is reduced and two frequencies are possible to be shared and realized by bringing a conducting part 12a into contact with a contact 12c of the external antenna 12 and connecting the external antenna with the incorporated antenna 13 via a conducting line 21 from a joint part 19 when the external antenna is stretched for a transmission, and by disconnecting this connection and performing a reception only by the incorporated antenna 13 when the external antenna is contracted for a reception of the antenna device baving little deterioration of gain at the time of outer antenna contraction.