| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmitting/receiving unit which contains an antenna having high receiving sensitivity with simple mounting of an antenna without possibility of violation of a radio law. SOLUTION: A feeble radio unit includes a transmitting unit 10 in which a circuit structure and a pattern antenna 13 are formed for example, on a 20 mm×40 mm substrate 14. A transmitting circuit 12 has an oscillation circuit using a SAW oscillator, and a modulating circuit for conducting an FM modulation or an FSK modulation. As a carrier frequency in the transmitting circuit 12, for example, 315 MHz is adopted, an amount of frequency deviation is set to 22.5 kHz, and a data transfer rate is set to 20 kbps. As the transmitting power, 500μV/m(at3m)max is set according to the radio law. Operating current is about 4mA to facilitate a battery drive. In this receiving unit 20, a receiving circuit 22 containing a connecting terminal 21, the oscillation circuit, a modulating circuit, and a demodulating circuit in a shield cover 25; and a tip antenna 23 disposed in a predetermined size on a substrate 24 of, for example, 20 mm×45 mm; are formed. COPYRIGHT: (C)2005,JPO&NCIPI
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