| US 7,489,948 B2 | ||
| Receiver capable of receiving radio signal with high quality | ||
| Makoto Taromaru, Kyoto (Japan); Takashi Ohira, Kyoto (Japan); Takuma Sawaya, Kyoto (Japan); and Hiroki Tanaka, Kyoto (Japan) | ||
| Assigned to Advanced Telecommunications Research Institute International, Kyoto (Japan) | ||
| Filed on Jan. 27, 2005, as Appl. No. 11/50,890. | ||
| Claims priority of application No. 2004-022956 (JP), filed on Jan. 30, 2004; and application No. 2004-022957 (JP), filed on Jan. 30, 2004. | ||
| Prior Publication US 2005/0170800 A1, Aug. 04, 2005 | ||
| Int. Cl. H04M 1/00 (2006.01) | ||
| U.S. Cl. 455—562.1 [455/13.3; 342/368; 343/835] | 16 Claims |
| 1. A receiver for receiving radio signals having a plurality of frequencies and being transmitted by radio communication in
a predetermined frequency range, comprising:
an antenna having an electrically switchable directivity;
a directivity pattern setting unit holding a table having a plurality of directivity patterns corresponding to said plurality
of frequencies and each formed of a plurality of directivities, and setting said directivity patterns corresponding to said
plurality frequencies, respectively; and
a directivity switching unit extracting an appropriate directivity from said plurality of directivities included in said set
directivity pattern such that said radio signal received by said antenna has a received signal quality equal to or greater
than a threshold, and switches the directivity of said antenna to said appropriate directivity,
wherein
said antenna includes:
a feeder element, and
at least one passive element arranged around said feeder element;
said directivity pattern setting unit sets said directivity patterns corresponding to said plurality of frequencies by changing
the set of values of reactances loaded in said at least one passive element; and
said directivity switching unit switches the directivity of said antenna to said appropriate directivity by changing the set
of said reactance values, wherein
said set of values of reactances changes the directivity of said antenna to a maximum extent.
|