Multi-octave power amplifier

1. A multi-octave power amplifier, comprising:

an impedance matching unit configured to match impedances of a pair of balanced radio frequency (RF) signals applied thereto and output a pair of impedance-matched balanced RF signals, wherein the pair of balanced RF signals comprises a first balanced RF signal and a second balanced RF signal, and wherein the pair of impedance-matched balanced RF signals comprises a first impedance-matched balanced RF signal and a second impedance-matched balanced RF signal;

a converting unit configured to convert the pair of the impedance-matched balanced RF signals to an unbalanced RF signal; and

a compensation unit configured to compensate at least one rolled-off frequency component of the unbalanced RF signal and output a compensated RF signal;

wherein the impedance matching unit comprises a first matching transformer that receives the first balanced RF signal and outputs the first impedance-matched balanced RF signal; and

wherein the first matching transformer comprises a first tapered transformer.

2. The multi-octave power amplifier of claim 1 ,

wherein the impedance matching unit comprises

a second matching transformer that receives the second balanced RF signal and outputs the second impedance-matched balanced RF signal.

3. The multi-octave power amplifier of claim 2 , wherein a real part of the impedances of the pair of balanced RF signals are between about 3 ohm to about 5 ohm.

4. The multi-octave power amplifier of claim 2 , wherein the second matching transformer comprises a second tapered transformer.

5. The multi-octave power amplifier of claim 4 , wherein the first tapered transformer and the second tapered transformer are substantially identical.

6. The multi-octave power amplifier of claim 4 , wherein the converting unit comprises a balun.

7. The multi-octave power amplifier of claim 6 , wherein the balun comprises:

a first input connected to the first matching transformer to receive the first impedance-matched balanced RF signal therefrom;

a second input connected to the second matching transformer to receive the second impedance-matched balanced RF signal therefrom; and

an output connected to the compensation unit to output the unbalanced RF signal thereto.

8. The multi-octave power amplifier of claim 7 , wherein the compensation unit comprises a matching filter connected to the output of the balun.

9. The multi-octave power amplifier of claim 8 , wherein the matching filter comprises a high pass and low pass (HP/LP) matching filter that compensates the at least one rolled-off frequency component of the unbalanced RF signal.

10. The multi-octave power amplifier of claim 9 , wherein the at least one rolled-off frequency component of the unbalanced RF signal comprises:

a rolled-off high frequency component that occupies a high frequency range of the unbalanced RF signal between about 2900 MHz and about 3200 MHz; and

a rolled-off low frequency component that occupies a low frequency range of the unbalanced RF signal between about 800 MHz and about 1000 MHz.

11. The multi-octave power amplifier of claim 1 , wherein the at least one rolled off frequency component of the unbalanced RF signal is compensated by about 10% to about 20% of bandwidth.

12. A method for amplifying a radio frequency (RF) signal, the method comprising the steps of:

receiving a pair of balanced RF signals;

matching impedances of the pair of balanced RF signals to generate a pair of impedance-matched balanced RF signals, wherein the pair of balanced RF signals comprise a first balanced RF signal and a second balanced RF signal, and the pair of impedance-matched balanced signals comprise a first impedance-matched balanced RF signal and a second impedance-matched balanced RF signal;

converting the pair of impedance-matched balanced RF signals to an unbalanced RF signal; and

compensating at least one rolled-off frequency component of the unbalanced RF signal to output a compensated RF signal;

wherein the first balanced RF signal is transformed to the first impendence-matched balanced RF signal by a first tapered transformer.

13. The method of claim 12 , wherein the second balanced RF signal is transformed to the second impendence-matched balanced RF signal by a second tapered transformer.

14. The method of claim 13 , wherein the first tapered transformer and the second tapered transformer are substantially identical.

15. The method of claim 13 , wherein a real part of the impedances of the pair of balanced RF signals is between about 3 ohm to about 5 ohm.

16. The method of claim 13 , wherein the first and second impedance-matched balanced RF signals are converted to the unbalanced RF signal by a balun connected to the first and second tapered transformers.

17. The method of claim 16 , wherein the at least one rolled-off frequency component of the unbalanced RF signal comprises:

a rolled-off high frequency component that occupies a high frequency range of the unbalanced RF signal between about 2900 MHz and about 3200 MHz; and

a rolled-off low frequency component that occupies a low frequency range of the unbalanced RF signal between about 800 MHz and about 1000 MHz.

18. The method of claim 17 , wherein the rolled-off high and low frequency components of the unbalanced RF signal are compensated by a matching filter.

19. The method of claim 18 , wherein the matching filter comprises a high pass and low pass (HP/LP) matching filter connected to the balun.

20. The method of claim 18 , wherein the step for compensating compensates the at least one rolled-off frequency component by about 10% to about 20% of bandwidth.