| 摘要 |
PROBLEM TO BE SOLVED: To propose constitution taking no time for battery replacement and enlarging an operation area in a portable radio telephone for a vehicle entry control system. SOLUTION: An entry communication circuit 6 is housed in a case 2 of a portable telephone so as to be constituted integrally with the portable telephone. An antenna 5 of the portable telephone is provided with a feeding point 52 for the entry communication circuit 6 as well as a feeding point 51 for a telephone circuit 3 of the portable telephone. A matching circuit 7 for matching antenna input impedance is provided to appropriate the antenna 5 of the portable telephone of high profit, and a current is applied to the entry communication circuit 6 relatively less in power consumption than the telephone circuit 3, from a battery 4 for applying a current to the telephone circuit 3 so as to substantially dispense with a power source of the entry communication circuit 6. |
