| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multiple-frequency common omni antenna suitable for a compact on-vehicle antenna. <P>SOLUTION: A multiple-frequency common monopole antenna 10 is provided with a monopole antenna 11 having one feeding point and a resonance frequency band set at a predetermined frequency band f<SB>M</SB>, and two monopole antennas 12 having the same feeding point as the above and a resonance frequency band set at a predetermined frequency band f<SB>L</SB>lower than the frequency band f<SB>M</SB>. These two monopole antennas 12 are disposed in parallel with each other with the monopole antenna 11 sandwiched therebetween so as to have an equal spacing L1 to the monopole antenna 11. The spacing L1 is set at not less than 2 mm nor more than 14 mm. The horizontal radiation pattern becomes omnidirectional after the occurrence of three resonances with the multiple-frequency common monopole antenna 10. <P>COPYRIGHT: (C)2008,JPO&INPIT |
