Power amplification device, in particular for a cellular mobile telephone

1. A power amplification device comprising:

an input for receiving a signal having a desired frequency band; and

power amplification means of the delta-sigma type connected to the input, and having an order greater than or equal to one in the desired frequency band and having an order greater than or equal to one outside the desired frequency band.

2. A power amplification device according to claim 1 , wherein said power amplification means comprises:

at least one first frequency selector network tuned to a frequency within the desired frequency band; and

at least one second frequency selector network tuned to a frequency outside the desired frequency band.

3. A power amplification device according to claim 1 , further comprising at least one signal amplifier connected between the input and said power amplification means.

4. A power amplification device according to claim 3 , wherein said at least one signal amplifier comprises a plurality of signal amplifiers.

5. A power amplification device according to claim 4 , wherein a number of said plurality of signal amplifiers is equal to the order in the desired frequency band and the order outside the desired frequency band of said power amplification means plus one.

6. A power amplification device according to claim 5 , wherein the received signal has a noise transfer function associated therewith; and wherein each signal amplifier has a respective gain, and a value of each respective gain is set to locate zeros of the noise transfer function outside the desired frequency band.

7. A power amplification device according to claim 6 , wherein each signal amplifier is programmable for setting its respective gain.

8. A power amplification device according to claim 1 , wherein said power amplification means is configured so that the power amplification device is an integrated circuit.

9. A power amplification device comprising:

an input for receiving a signal having a desired frequency band; and

power amplifier circuitry connected to the input and comprising

at least one first frequency selector network tuned to a frequency within the desired frequency band and having an order greater than or equal to one, and

at least one second frequency selector network tuned to a frequency outside the desired frequency band and having an order greater than or equal to one.

10. A power amplification device according to claim 9 , further comprising at least one signal amplifier connected between the input and said power amplifier circuitry.

11. A power amplification device according to claim 10 , wherein said at least one signal amplifier comprises a plurality of signal amplifiers.

12. A power amplification device according to claim 11 , wherein a number of said plurality of signal amplifiers is equal to the order in the desired frequency band plus and the order outside the desired frequency band of said power amplifier circuitry plus one.

13. A power amplification device according to claim 10 , wherein the received signal has a noise transfer function associated therewith; and wherein each signal amplifier has a respective gain, and a value of each respective gain is set to locate zeros of the noise transfer function outside the desired frequency band.

14. A power amplification device according to claim 13 , wherein each signal amplifier is programmable for setting its respective gain.

15. A cellular telephone comprising:

transmission circuitry for receiving a signal having a desired frequency band to be transmitted; and

a power amplification device connected to said transmission circuitry and comprising having an order greater than or equal to one in the desired frequency band and having an order greater than or equal to one outside the desired frequency band.

16. A cellular telephone according to claim 15 , wherein said power amplification device comprises:

at least one first frequency selector network tuned to a frequency within the desired frequency band; and

at least one second frequency selector network tuned to a frequency outside the desired frequency band.

17. A cellular telephone according to claim 15 , further comprising a plurality of signal amplifiers connected between an input of said power amplification device and said at least one first and second frequency selector networks.

18. A cellular telephone according to claim 17 , wherein a number of said plurality of signal amplifiers is equal to the order in the desired frequency band and the order outside the desired frequency band of said power amplification device plus one.

19. A cellular telephone according to claim 17 , wherein the received signal has a noise transfer function associated therewith; and wherein each signal amplifier has a respective gain, and a value of each respective gain is set to locate zeros of the noise transfer function outside the desired frequency band.

20. A cellular telephone according to claim 17 , wherein each signal amplifier is programmable for setting its respective gain.

21. A method for forming a power amplification device, the method comprising:

providing an input for receiving a signal having a desired frequency band;

connecting power amplification circuitry of the delta-sigma type to the input, the power amplification circuitry having an order greater than or equal to one in the desired frequency band and having an order greater than or equal to one outside the desired frequency band.

22. A method according to claim 21 , wherein the order of the power amplification circuitry in the desired frequency band is based upon at least one first frequency selector network tuned to a frequency within the desired frequency band; and wherein the order of the power amplification circuitry outside the desired frequency band is based upon at least one second frequency selector network tuned to a frequency outside the desired frequency band.

23. A method according to claim 21 , further comprising connecting a plurality of signal amplifiers between the input and the power amplification circuitry.

24. A method according to claim 23 , wherein a number of the plurality of signal amplifiers is equal to the order in the desired frequency band and the order outside the desired frequency band of the power amplification circuitry plus one.

25. A method according to claim 23 , wherein the received signal has a noise transfer function associated therewith; and wherein each signal amplifier has a respective gain, and a value of each respective gain is set to locate zeros of the noise transfer function outside the desired frequency band.

26. A method according to claim 25 , further comprising programming each signal amplifier for setting its respective gain.