| 摘要 |
PROBLEM TO BE SOLVED: To provide an antenna input unit which can ensure relatively stabilized practical sensitivity in the entire receiving frequency band. SOLUTION: In the antenna input unit comprising an impedance matching circuit 5 for matching the input impedance between an antenna 1 and a receiver 2, the impedance matching circuit 5 comprises a plurality of reactance elements L1-Ln, VC1, VC2 capable of switching the connection mode, a switch circuit 51 for varying the reactance stepwise by switching the connection mode of the reactance elements, and an impedance control circuit 52 for controlling the switch circuit 51 depending on the tuning frequency band to be received. COPYRIGHT: (C)2007,JPO&INPIT
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