| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an antenna matching circuit for shortening time required for matching a transmitter output circuit and an antenna. <P>SOLUTION: A CPU 10 turns ON/OFF capacitors 12 and 14 and a coil 13 so that reactance between the output circuit of the transmitter 1 and the antenna 3 is canceled by a signal from a matching sensor 7 to make the reactance to zero. An antenna impedance is calculated from a signal and a transmission output value from an antenna current sensor 22 at that time. Values of the capacitors 12 and 14 and the coil 13 which match to 50 Ω are calculated from the antenna impedance, and the CPU turns ON/OFF the capacitors 12 and 14 and the coil 13 so that they become equal to the values. <P>COPYRIGHT: (C)2012,JPO&INPIT |
