Load variation tolerant radio frequency (RF) amplifier

1. An integrated power amplifier, comprising:

a plurality of amplification paths;

a first phase shift element at an input of each amplification path;

a second phase shift element at an output of each amplification path;

an impedance transformation element associated with the second phase shift element;

a power combiner configured to combine an output of each amplification path into a single output, wherein the first phase shift element, the second phase shift element, the impedance transformation element and the power combiner are integrated on a single multi-layer module; and

an active switch associated with each amplification path, each active switch configured to detect impedance of its respective amplification path and select an amplification path based on the detected impedance.

2. The circuit of claim 1 , wherein the first phase shift element applies a phase shift substantially opposite the phase shift applied by the second phase shift element and wherein the phase shift applied by the first phase shift element and the second phase shift element in each amplification path is substantially opposite the phase shift applied by the first phase shift element and the second phase shift element in another amplification path.

3. The circuit of claim 1 , wherein the impedance transformation element and the second phase shift element associated with each amplification path are combined into a single device.

4. The circuit of claim 3 , wherein the impedance transformation element and the second phase shift element substantially simultaneously alter the phase and impedance of a signal.

5. The circuit of claim 3 , wherein the impedance transformation element and the second phase shift element separately alter the phase and impedance of a signal.

6. The circuit of claim 3 , wherein the impedance transformation element and the second phase shift element are located on the same module as the plurality of amplification paths.

7. The circuit of claim 6 , wherein the impedance transformation element and the second phase shift element comprise an inductive (L) and capacitive (C) circuit.

8. The circuit of claim 1 , wherein under an impedance mismatch condition one amplification path has a high impedance and the other amplification path has a low impedance.

9. The circuit of claim 1 , wherein the power combiner further comprises an additional impedance transformation element.

10. A portable communication transceiver, comprising:

a balanced power amplifier having a plurality of amplification paths;

a first phase shift element at an input of each amplification path;

a second phase shift element at an output of each amplification path;

an impedance transformation element associated with the second phase shift element;

a power combiner configured to combine an output of each amplification path into a single output, wherein the first phase shift element, the second phase shift element, the impedance transformation element and the power combiner are integrated on a single multi-layer module; and

an active switch associated with each amplification path, each active switch configured to detect impedance of its respective amplification path and select an amplification path based on the detected impedance.

11. The transceiver of claim 10 , wherein the first phase shift element applies a phase shift substantially opposite the phase shift applied by the second phase shift element and wherein the phase shift applied by the first phase shift element and the second phase shift element in each amplification path is substantially opposite the phase shift applied by the first phase shift element and the second phase shift element in another amplification path.

12. The transceiver of claim 10 , wherein the impedance transformation element and the second phase shift element associated with each amplification path are combined into a single device.

13. The transceiver of claim 12 , wherein the impedance transformation element and the second phase shift element substantially simultaneously alter the phase and impedance of a signal.

14. The transceiver of claim 12 , wherein the impedance transformation element and the second phase shift element separately alter the phase and impedance of a signal.

15. The transceiver of claim 12 , wherein the impedance transformation element and the second phase shift element are located on the same module as the plurality of amplification paths.

16. The transceiver of claim 15 , wherein the impedance transformation element and the second phase shift clement comprise an inductive (L) and capacitive (C) circuit.

17. The transceiver of claim 10 , wherein under an impedance mismatch condition one amplification path has a high impedance and the other amplification path has a low impedance.

18. The transceiver of claim 10 , wherein the power combiner further comprises an additional impedance transformation element.

19. A method for altering the impedance of a power amplifier, comprising:

providing a plurality of amplification paths;

supplying a signal to each of the amplification paths;

altering the phase of the signal supplied to each amplification path;

substantially oppositely altering the phase of the signal at an output of each amplification path and with respect to each amplification path;

transforming the impedance of the signal;

combining the signal from each of the amplification paths into a single output;

detecting an impedance of each of the plurality of amplification paths; and

selecting an amplification path based on the detected impedance.

20. The method of claim 19 , further comprising substantially simultaneously altering the phase and impedance of the signal.

21. The method of claim 20 , further comprising performing the transformation and the phase shift on the same module on which the plurality of amplification paths are located.

22. The method of claim 19 , further comprising separately altering the phase and impedance of the signal.

23. The method of claim 19 , wherein under an impedance mismatch condition one amplification path has a high impedance and the other amplification path has a low impedance.

24. The method of claim 19 , wherein the power combiner performs an additional impedance transformation on the signal.