Radio communication equipment

• US 6,393,299 B1
• Filed: 03/08/1999
• Issued: 05/21/2002
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tokunaga, Tatsuya, Mizumoto, Toru, Torii, Kenichi, Shimizu, Hiroaki
• Primary Examiner(s): Hunter, Daniel
• Assistant Examiner(s): LE, LANA N
• Application Number:
  US09/254,392
• Time in Patent Office: 1,170 Days
• Field of Search: 455/76, 455/86, 455/78, 455/84, 455/575, 455/552, 455/553, 455/31, 455/209
• US Class Current: 455/552.1
• CPC Class Codes: H03D 7/163 the local oscillations of at least two of the frequency changers being derived from a single oscillator
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/006 using switches for selecting the desired band H04B1/0057 takes precedence
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes

Abstract

In radiocommunication apparatus, two downconverters (41, 42) for use in reception system each heterodyne their respective received RF signal to an intermediate frequency. One of the downconverters employs a local signal generated by a synthesizer (19), and the other employs a signal obtained by dividing the frequency of the local signal by a factor of N. Two upconverters (161, 162) for use in transmission system each convert their respective input transmit signal to a transmit RF signal. One of the upconverters employs a local signal generated by the synthesizer (19) and the other employs a signal obtained by dividing the frequency of the local signal by a factor of N.

Claims

1. A radio communication apparatus which performs communication by selectively using at least one of a first frequency band and a second frequency band higher than the first frequency band, each frequency band respectively allocated for first and second radio communication systems, comprising:

local oscillator signal generating means for generating a local oscillator signal with an arbitrary frequency;

frequency dividing means for dividing the frequency of the local oscillator signal generated by the local oscillator signal generating means by a factor of N (N>

0) to produce a frequency-divided local signal having a frequency outside the first and second frequency bands;

first frequency conversion means for converting a communication signal in the first frequency band using the frequency-divided local signal from the frequency dividing means, wherein the first frequency conversion means includes;

first down-conversion means for down-converting a first radio-frequency (RF) signal, received on the first frequency band, to a first intermediate-frequency (IF) signal using the frequency-divided local signal from the frequency dividing means; and

first up-conversion means for up-converting a second IF signal, to be transmitted on the first frequency band, to a second RF signal using the frequency-divided local signal from the frequency dividing means; and

second frequency conversion means for converting a communication signal in the second frequency band using the local oscillator signal from the local oscillator signal generating means, wherein the second frequency conversion means includes;

second down-conversion means for down-converting a third RF signal, received on the second frequency band, to a third IF signal using the local oscillator signal.

4. The radio communication apparatus according to any one of claims 1 through 3, wherein the frequency dividing means divides the frequency of the local oscillator signal generated by the local oscillator signal generating means by a factor of three to a frequency lower than the second frequency band.

5. The radio communication apparatus according to any one of claims 1 through 3, wherein the first IF signal obtained by the first down-conversion means and the third IF signal obtained by the second down-conversion means are equal to each other in frequency.

2. A radio communication apparatus which performs communication by selectively using at least one of a first frequency band and a second frequency band higher than the first frequency band, each frequency band respectively allocated for first and second radio communication systems, comprising:

local oscillator signal generating means for generating a local oscillator signal with an arbitrary frequency;

frequency dividing means for dividing the frequency of the local oscillator signal generated by the local oscillator signal generating means by a factor of N (N>

0) to produce a frequency-divided local signal having a frequency outside the first and second frequency bands;

first frequency conversion means for converting a communication signal in the first frequency band using the frequency-divided local signal from the frequency dividing means, wherein the first frequency conversion means includes;

first down-conversion means for down-converting a first radio-frequency (RF) signal, received on the first frequency band, to a first intermediate-frequency (IF) signal using the frequency-divided local signal from the frequency dividing means; and

first up-conversion means for up-converting a second IF signal, to be transmitted on the first frequency band, to a second RF signal using the frequency-divided local signal from the frequency dividing means; and

second frequency conversion means for converting a communication signal in the second frequency band using the local oscillator signal from the local oscillator signal generating means, wherein the second frequency conversion means includes;

second up-conversion means for up-converting a fourth IF signal, to be transmitted on the second frequency band, to a fourth RF signal using the local oscillator signal.

3. A radio communication apparatus which performs communication by selectively using at least one of a first frequency band and a second frequency band higher than the first frequency band, each frequency band respectively allocated for first and second radio communication systems, comprising:

local oscillator signal generating means for generating a local oscillator signal with an arbitrary frequency;

frequency dividing means for dividing the frequency of the local oscillator signal generated by the local oscillator signal generating means by a factor of N (N>

0) to produce a frequency-divided local signal having a frequency outside the first and second frequency bands;

first frequency conversion means for converting a communication signal in the first frequency band using the frequency-divided local signal from the frequency dividing means, wherein the first frequency conversion means includes;

first down-conversion means for down-converting a first radio-frequency (RF) signal, received on the first frequency band, to a first intermediate-frequency (IF) signal using the frequency-divided local signal from the frequency dividing means; and

first up-conversion means for up-converting a second IF signal, to be transmitted on the first frequency band, to a second RF signal using the frequency-divided local signal from the frequency dividing means; and

second frequency conversion means for converting a communication signal in the second frequency band using the local oscillator signal from the local oscillator signal generating means, wherein the second frequency conversion means includes;

second down-conversion means for down-converting a third RF signal, received on the second frequency band, to a third IF signal using the local oscillator signal; and

second up-conversion means for up-converting a fourth IF signal, to be transmitted on the second frequency band, to a fourth RF signal using the local oscillator signal.