IIIH
US007130603B2
(12) United States Patent ao) Patent No.: Us 7,130,603 B2
Futamura et al. (45) Date of Patent: Oct. 31,2006
(54) RADIO EQUIPMENT COMMUNICATABLE
IN TWO FREQUENCY BANDS AND
METHOD FOR GENERATING LOCAL
OSCILLATOR SIGNAL IN RADIO
EQUIPMENT
(75) Inventors: Kazuhiro Futamura, Kawasaki (JP);
Shinsuke Shimahashi, Kawasaki (JP)
(73) Assignee: Fujitsu Limited, Kawasaki (JP)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 366 days.
(21) Appl. No.: 10/817,410
(22) Filed: Mar. 30, 2004
(65) Prior Publication Data
US 2004/0192240 Al Sep. 30, 2004
Related U.S. Application Data
(63) Continuation of application No. PCT/JP01/08729, filed on Oct. 3, 2001.
(51) Int. CI.
H04B 1/06 (2006.01)
H03L 7/00 (2006.01)
(52) U.S. CI 455/260; 455/552.1; 455/183.1;
455/76; 331/22; 331/25
(58) Field of Classification Search 455/260,
455/183.1, 552.1, 76, 75, 255, 209, 553.1, 455/118; 331/2,25, 16,22,46 See application file for complete search history.
(56) References Cited
U.S. PATENT DOCUMENTS
4,518,929 A * 5/1985 Owen 331/22
4,965,531 A * 10/1990 Riley 331/25
5,374,902 A * 12/1994 Bradley 455/260
5,497,128 A * 3/1996 Sasaki 455/255
5,535,432 A * 7/1996 Dent 455/76
Radio equipment enabling radio communication with frequency conversion corresponding to signals of different frequency bands is disclosed. A local oscillator signal generator included in this radio equipment having a first signal generator, a second signal generator, and a frequency synthesizer generating a local oscillator signal. A first signal having first frequency is generated in the first signal generator, and a second signal having second frequency smaller than the first frequency is generated in the second signal generator. These first and second signals are synthesized, and the local oscillator signal either having the frequency derived from adding the second frequency to the first frequency, or having the frequency derived from subtracting the second frequency from the first frequency is generated.
17 Claims, 10 Drawing Sheets
