| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a portable communication terminal which is constituted to receive a broadcast-communication signal having a frequency of 1 segment broadcasting or lower with high sensitivity even if a comparatively short rod antenna is used. <P>SOLUTION: A portable communication terminal 101 comprises a rod antenna 11, an external matching circuit 12, and the ground electrode 13 of a substrate. The external matching circuit 12 performs impedance matching between a transmission/reception circuit and the antenna. The rod antenna 11 is a monopole antenna but since an equivalently long ground electrode is provided by extending the ground electrode 13 of the substrate by the wire in an earphone cord 15, element length of the antenna is lengthened when the rod antenna, the ground electrode 13 and the mirror image (image) of the rod antenna by the earphone cord act as a dipole antenna. As a result, reception sensitivity of communication service in low frequency zone such as terrestrial digital radio broadcasting is enhanced without lengthening the rod antenna. <P>COPYRIGHT: (C)2009,JPO&INPIT |
