Versatile RF front-end multiband mobile terminals

• US 6,751,470 B1
• Filed: 04/08/2002
• Issued: 06/15/2004
• Est. Priority Date: 04/08/2002
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Ellä, Juha, Pohjonen, Helena
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Chow, C.
• Application Number:
  US10/118,657
• Time in Patent Office: 799 Days
• Field of Search: 455/552.1, 455/86, 455/267, 455/315, 455/188.1, 455/575.1, 455/561.1, 455/562.1, 455/550.1, 455/130, 455/132, 455/190.1, 455/209, 455/339, 455/346, 455/348, 455/349, 455/73, 455/307, 455/293, 375/316.334, 375/150, 375/344, 375/347, 375/131, 332/101, 332/100, 332/117, 343/700.R, 343/702
• US Class Current: 455/552.1
• 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

A function-oriented manufacturing approach in RF front-end architecture for use in a multi-band mobile phone. Electronic components in a front-end module, such as low-noise amplifiers that require the demanding silicon bipolar process, are fabricated separately from those components in an RF-ASIC that require the less demanding, yet more costly, Bi-CMOS process. When the transmission frequency band and the receiving band overlap, separate receiving antenna and transmitting antenna are used, instead of an antenna switch module with a duplexer, connected to separate bandpass filters for band selection. Differential Rx antennas are used so that the whole Rx-chain can be made differential. Furthermore, different impedances for Tx out and Rx in can be realized.

Claims

1. A radio-frequency front-end (100) for use with a radio-frequency signal processor (200) in a multi-band mobile terminal, the mobile terminal capable of operating in a plurality of frequency bands including a first frequency band and a different second frequency band, the front-end adapted to convey signals to and from the signal processor via a connection means (150), wherein the mobile terminal comprises:

an antenna system (10);

a first receiver (52₂) for receiving first signals in the first frequency band from the antenna system;

a second receiver (52₃) for receiving second signals in the second frequency band from the antenna system;

a first transmitter (53₁) for providing third signals in the first frequency band to the antenna system for transmission; and

a second transmitter (53₂) for providing fourth signals in the second frequency band to the antenna system for transmissions, characterized in that

the antenna system comprises;

a first receiving antenna (12_a, 12_b), operable in the first frequency band and operatively connected to the first receiver (52₂), for allowing the first receiver to receive the first signals;

a second receiving antenna (12_c, 12_d), operable in the second band and operatively connected to the second receiver (52₃), for allowing the second receiver to receive the second signals;

a first transmitting antenna (12_g), operable in the first band and operatively connected to the first transmitter (53₁), for transmitting the third signals; and

a second transmitting antenna (12_h), operable in the second band and operatively connected to the second transmitter (53₂), for transmitting the fourth signals, said front-end further characterized by;

a first frequency filter (32₂), operatively connected to the first receiver (52₂) and the first receiving antenna (12_a, 12_b), for frequency filtering the first signals;

a second frequency filter (32₃), operatively connected to the second receiver (52₃) and the second receiving antenna (12_c, 12_d), for frequency filtering the second signals;

a third frequency filter (32₄), operatively connected to the first transmitter (53₁) and the first transmitting antenna, for frequency filtering the third signals; and

a fourth frequency filter (32₅), operatively connected to the second transmitter (53₂) and the second transmitting antenna (12_h), for frequency filtering the fourth signals.

2. The front-end of claim 1, further characterized by

a first down-converting element (55₃, 55₄), operatively connected to the first receiver (52₂), for down-converting the first signals for providing down-converted first signals to the signal processor.

3. The front-end of claim 1, further characterized by

a second down-converting element (55₅, 55₆), operatively connected to the second receiver (52₃), for down-converting the second signals for providing down-converted second signals to the signal processor.

4. The front-end of claim 1, characterized in that

the first and second frequency filters are bulk acoustic wave filters.

5. The front-end of claim 1, characterized in that

the third and fourth frequency filters are bulk acoustic wave filters.

6. The front-end of claim 1, characterized in that

the first frequency filter is a balanced filter.

7. The front-end of claim 6, characterized in that

the second frequency filter is a balanced filter.

8. The front-end of claim 1, wherein said plurality of frequency bands further includes a third frequency band, and wherein the mobile terminal further comprises:

a third receiver (52₁) for receiving fifth signals in the third frequency band from the antenna system; and

a third transmitter (53₃) for providing sixth signals in the third frequency to the antenna system for transmission, said front-end further characterized in that

the antenna system further comprises;

a third receiving antenna (12_e, 12_f), operable in the third band and operatively connected to the third receiver (52₁), for allowing the third receiver to receive the fifth signals; and

a third transmitting antenna (12_i), operable in the third band and operatively connected the third transmitter (53₃), for transmitting the sixth signals, and further characterized by

a fifth frequency filter (32₁), operatively connected to the third receiver (52₁) and the third receiving antenna (12_e, 12_f), for frequency filtering the fifth signals; and

a sixth frequency filter (32₆), operatively connected to the third transmitter (53₃) and the third receiving antenna (12_i), for transmitting the sixth signals.

9. The front-end of claim 8, wherein the sixth frequency filter (32₆) is fed by an up-converting element (210_n).

10. The front-end of claim 1, wherein said plurality of frequency bands further includes a third frequency band, and wherein the mobile terminal further comprises:

a third receiver (52₁) for receiving fifth signals in the third frequency band from the antenna system; and

a third transmitter (53₃) for providing sixth signals in the third frequency to the antenna system for transmission, said front-end further characterized in that

the first receiving antenna (12_a, 12_b) is also operable in the third frequency band, and

the antenna system further comprises a third transmitting antenna (12_i), operable in the third band and operatively connected to the third transmitter (53₃), for transmitting the sixth signals, and further characterized by

a fifth frequency filter (32₁), operatively connected to the third receiver (52₁) and the first receiving antenna (12_a, 12_b), for frequency filtering the fifth signals;

a sixth frequency filter (32₆), operatively connected to the third transmitter (53₃) and the third receiving antenna (12_i), for frequency filtering the sixth signals; and

a phase shifter (14), operatively connected between the first frequency filter (32₂) and the fifth frequency filter (32₁) for matching the first and fifth frequency filters.

11. A method of improving the flexibility in use of a radio-frequency front-end (100) with a radio-frequency signal processor (200) in a multi-band mobile terminal, the mobile terminal capable of operating in a plurality of frequency bands including a first frequency band and a different second frequency band, the front-end adapted to convey signals to and from the signal processor via a connection means (150), wherein the mobile terminal comprises:

an antenna system (10);

a first receiver (52₂) for receiving first signals in the first frequency band, from the antenna system;

a second receiver (52₃) for receiving second signals in the second frequency band from the antenna system;

a first transmitter (53₁) for providing third signals in the first frequency band to the antenna system for transmission; and

a second transmitter (53₂) for providing fourth signals in the second frequency band to the antenna system for transmission, said method characterized by

providing in the antenna system a first receiving antenna (12_a, 12_b), operable in the first frequency band and operatively connected to the first receiver (52₂), for allowing the first receiver to receive the first signals, and a first frequency filter (32₂), operatively connected to the first receiver (52₂) and the first receiving antenna (12_a, 12_b), for frequency filtering the first signals;

providing in the antenna system a second receiving antenna (12_c, 12_d), operable in the second band and operatively connected to the second receiver (52₃), for allowing the second receiver to receive the second signals, and a second frequency filter (32₃), operatively connected to the second receiver (52₃) and the second receiving antenna (12_c, 12_d), for frequency filtering the second signals;

providing in the antenna system a first transmitting antenna (12_g), operable in the first band and operatively connected to the first transmitter (53₁), for transmitting the third signals, and a third frequency filter (32₄), operatively connected to the first transmitter (53₁) and the first transmitting antenna (12_g), for frequency filtering the third signals; and

providing in the antenna system a second transmitting antenna (12_h), operable in the second band and operatively connected to the second transmitter (53₂), for transmitting the fourth signals, and a fourth frequency filter (32₅), operatively connected to the second transmitter (53₂) and the second transmitting antenna (12_h), for frequency filtering the fourth signals.

12. The method of claim 11, further characterized by

providing a first down-converting element (55₃, 55₄), operatively connected to the first receiver (52₂), for down-converting the first signals for providing down-converted first signals to the signal processor.

13. The method of claim 11, further characterized by

providing a second down-converting element (55₅, 55₆), operatively connected to the second receiver (52₃), for down-converting the second signals for providing down-converted second signals to the signal processor.

14. The method of claim 11, characterized in that

the first and second frequency filters are balanced filters.

15. The method of claim 11, wherein said plurality of frequency bands further includes a third frequency band, and wherein the mobile terminal further comprises:

a third receiver (52₁) for receiving fifth signals in the third frequency band from the antenna system; and

a third transmitter (53₃) for providing sixth signals in the third frequency to the antenna system for transmission, said method further characterized by

providing in the antenna system a third receiving antenna (12_e, 12_f), operable in the third band and operatively connected to the third receiver (52₁), for allowing the third receiver to receive the fifth signals, and a fifth frequency filter (32₁), operatively connected to the third receiver (52₁) and the third receiving antenna (12_e, 12_f), for frequency filtering the fifth signals; and

providing a third transmitting antenna (12_i), operable in the third band and operatively connected to the third transmitter (53₃), for transmitting the sixth signals, and a sixth frequency filter (32₆), operatively connected to the third transmitter (53₃) and the third receiving antenna (12_i), for transmitting the sixth signals.

16. The method of claim 11, wherein said plurality of frequency bands further includes a third frequency band, and wherein the mobile terminal further comprises:

a third receiver (52₁) for receiving fifth signals in the third frequency band from the antenna system;

a third transmitter (53₃) for providing sixth signals in the third frequency to the antenna system for transmission, said method further characterized in that

the first receiving antenna (12_a, 12_b) is also operable in the third frequency band, and

the antenna system further comprises a third transmitting antenna (12_i), operable in the third band and operatively connected to the third transmitter (53₃), for transmitting the sixth signals, said method further characterized by

providing in the antenna system;

a fifth frequency filter (32₁), operatively connected to the third receiver (52₁) and the first receiving antenna (12_a, 12_b), for frequency filtering the fifth signals;

a sixth frequency filter (32₆), operatively connected to the third transmitter (53₃) and the third receiving antenna (12_i), for frequency filtering the sixth signals; and

a phase shifter (14), operatively connected between the first frequency filter (32₂) and the fifth frequency filter (32₁) for matching the first and fifth frequency filters.