| US 7,542,007 B2 | ||
| Antenna, earphone antenna, and broadcasting receiver including earphone antenna | ||
| Motofumi Yamaguchi, Osaka (Japan); Eiji Suematsu, Nara (Japan); and Haruo Suzuki, Utsunomiya (Japan) | ||
| Assigned to Sharp Kabushiki Kaisha, Osaka (Japan) | ||
| Filed on Feb. 11, 2008, as Appl. No. 12/29,347. | ||
| Claims priority of application No. 2007-032748 (JP), filed on Feb. 13, 2007. | ||
| Prior Publication US 2008/0198090 A1, Aug. 21, 2008 | ||
| Int. Cl. H01Q 1/50 (2006.01) | ||
| U.S. Cl. 343—859 [343/702; 333/202; 333/26] | 11 Claims |
| 1. An antenna comprising:
an unbalanced power feeder line;
first and second antenna elements; and
an unbalanced/balanced converter which includes an input port and first and second output ports,
the unbalanced power feeder line being connected to the input port,
the first and second antenna elements being connected the first and second output ports, respectively,
the unbalanced/balanced converter having a first filter circuit provided between the input port and the first output port
and a second filter circuit provided between the input port and the second output port,
the first filter circuit rejecting frequencies within a first frequency range,
the first and second filter circuits passing frequencies within a second frequency range different from the first frequency
range,
in response to a signal, inputted to the input port, which falls within the second frequency range, the first and second filter
circuits outputting signals that are inverted in phase and equal in amplitude with respect to each other.
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