| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an antenna apparatus having a high radiation gain and a simple structure. Ž<P>SOLUTION: An antenna apparatus includes: a low-frequency antenna element 2 having a predetermined electrical length; a high-frequency antenna element 4 having an electrical length shorter than that of the low-frequency antenna element 2 and in which a PIN diode 3 is inserted in series; a radiation signal power feeding source 6 that supplies a radiation signal RF to a parallel antenna circuit 5 in which the high-frequency antenna element 4 and the low-frequency antenna element are connected in parallel; a direct current source 7 that applies the direct current signal by superposing a direct current signal to the radiation signal RF; and a switching controller 8 that superposes the direct current signal to cause the PIN diode 3 to conduct when desired that a high-frequency radiation signal RFH is radiated, and does not superpose the direct current to disconnect the PIN diode 3 when desired that a low-frequency radiation signal RFL is radiated. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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