Switchable up-conversion loop for a transmitting stage of a mobile phone

• US 6,470,191 B1
• Filed: 10/29/1999
• Issued: 10/22/2002
• Est. Priority Date: 11/06/1998
• Status: Expired due to Term

• Current Assignee: IPCom GmbH & Co KG
• Original Assignee: Robert Bosch GmbH
• Inventors: Nielsen, Anders S., Thomsen, Pia
• Primary Examiner(s): Vo., Nguyen T.
• Assistant Examiner(s): Orgad, Edan
• Application Number:
  US09/430,264
• Time in Patent Office: 1,089 Days
• Field of Search: 455/146, 455/552, 455/553, 455/118, 455/123, 455/259, 455/260, 455/264, 455/265, 455/76, 331/179, 331/331.2, 375/375, 375/376
• US Class Current: 455/552.1
• CPC Class Codes: H03J 5/244 using electronic means
• CPC Class Codes: H03L 7/099 concerning mainly the controlled oscillator of the loop
• CPC Class Codes: H03L 7/10 for assuring initial synchronisation or for broadening the capture range
• CPC Class Codes: H03L 7/102 the additional signal being directly applied to the controlled loop oscillator
• CPC Class Codes: H03L 7/185 using a mixer in the loop H03L7/187 - H03L7/195 take precedence

Abstract

The switchable up-conversion loop device for a transmitting stage of a mobile phone having multiple transmitting frequency bands includes a phase detector (21) for generating a phase detector output signal in response to a phase difference between an input signal and a mixing product signal, multiple switchable voltage controlled oscillators (35, 37; 100, 101, 102; 111, 112; 120), each connected to the phase detector (21) and each generating an output oscillating signal, the frequency of which depends on the phase detector output signal, and a coupling device (44; 110; 119; 121) for coupling the output oscillating signal to a mixer (26) for mixing said output oscillating signal with a locally generated oscillating signal to produce the mixing product signal.

Claims

1. A switchable up-conversion loop device for a transmitting stage of a mobile phone having multiple transmit frequency bands, said up-conversion loop device comprising:

a phase detector (21) generating a phase detector output signal in response to a phase difference between an input signal and a mixing product signal, multiple switchable voltage controlled oscillators (35, 37;

100, 101, 102;

111, 112;

120), each of said voltage controlled oscillators being connected to the phase detector (21) via a low pass filter (32) for generating an output oscillating signal at a frequency which depends on the phase detector output signal, and

coupling means (44;

110;

119;

121) for coupling the output oscillating signal to a mixer (26) for mixing said output oscillating signal with a locally generated oscillating signal to produce said mixing product signal.

2. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 1, further comprising a switching unit (40) including means for connecting or interrupting a supply voltage to said multiple switchable voltage controlled oscillators in order to switch the multiple switchable voltage controlled oscillators (35, 37;

100, 101, 102;

111, 112;

120) on or off by means of the switching unit (40).

3. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 2, wherein the multiple switchable voltage controlled oscillators (35, 37;

100, 101, 102;

111, 112;

120) include one-band voltage controlled oscillators (35;

100, 101, 102) covering one transmit frequency band and/or multiple-band voltage controlled oscillators (37;

112;

120) covering a plurality of transmit frequency bands.

4. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 3, wherein said multiple-band voltage controlled oscillators (37;

112;

120) are switchable between said transmit frequency bands in response to a band switch control signal.

5. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 4, further comprising a control unit (23) including means for generating the band switch control signal.

6. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 2, further comprising a control unit (23) connected to said switching unit (40) and said control unit (23) connects or interrupts a supply voltage to said voltage controlled oscillators (35, 37;

100, 101, 102;

111, 112;

120) in response to an oscillator switching control signal from said control unit (23).

7. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 6, wherein said multiple switchable voltage controlled oscillators (37;

112;

120) comprise at least one multiple-band voltage controlled oscillator (135) consisting of an oscillator transistor (135), multiple resonance circuits (130a, 130b, . . . 103n) forming an oscillator circuit device together with the oscillator transistor (135), and a switching element (132) responsive to said oscillator switching control signal; and

wherein a respective one of said resonance circuits is connectable to said oscillator transistor (135) by means of said switching element (132) according to said oscillator switching control signal.

8. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 1, wherein the coupling means (44;

110;

109;

121) couples the output oscillating signal into said mixer (26).

9. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 8, wherein said mixer (26) multiplies said locally generated oscillating signal with the output oscillating signal received from said coupling means (44;

110;

109;

121).

10. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 1, further comprising a loop filter (32) connected between said phase detector (21) and said multiple switchable voltage controlled oscillators.

11. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 1, further comprising a modulation means (5) for generating an input signal for said phase detector (21).

12. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 11, wherein said modulation means (5) is a minimum shift keying modulator.

13. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 12, further comprising frequency dividing units (20,24) for dividing respective frequencies of the input signal and the mixing product signal and wherein said control unit (23) includes means for controlling the frequency dividing units.

14. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 3, wherein each of said multiple-band voltage controlled oscillators is a two-band voltage controlled oscillator (37;

112) covering two transmit frequency bands.

15. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 3, wherein each of the multiple-band voltage controlled oscillators is a three-band voltage controlled oscillator (120) covering three transmit frequency bands.

16. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 3, wherein three of said one-band voltage controlled oscillators (100, 101, 102) are connected to said phase detector (21) each covering one transmit frequency band.

17. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 3, wherein one of said one-band voltage controlled oscillators (35;

111 ) covering one transmit frequency band and one two-band voltage controlled oscillator (37;

112) covering two transmit frequency bands are connected to said phase detector (21).

18. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 15, wherein said three-band voltage controlled oscillator (120) covering three transmit frequency bands is connected to said phase detector (21).

19. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 1, wherein said transmit frequency bands are transmit frequency bands of a GSM system.

20. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 19, wherein said transmit frequency bands of said GSM system consist of GSM 900, GSM 1800 and GSM 1900.

21. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 1, further comprising a power amplifier (53,55) including means for amplifying the output oscillating signal from said coupling means (44;

110;

119;

121) to form an amplified output oscillating signal.

22. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 1, wherein the amplified output oscillating signal is input to an antenna switching unit (66) which switches said amplified output oscillating signal to a transmitting antenna (67) according to an antenna control signal from said control unit (23).

23. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 1, further comprising a low pass filter (28) for filtering the mixing product signal produced by said mixer (26) to suppress unwanted mixing products.

24. The switchable up-conversion loop device for a transmitting stage of a mobile phone as defined in claim 1, further comprising a PLL circuit (49) for generating the locally generated oscillating signal in response to a controlling signal generated by said control unit (23).