1. class B, AB and D rf power amplifiers in 0,40 um cmos teChnology
Daniele Agnese
MSICT – RF System On Chip 2006/’07

2. Summary General idea Technology comparison (CMOS, GaAsFET)
Power amplifiers topology
Class B
Class AB
Class D
Project description
Simulations/Results
Conclusion

3. General idea ADS Power amplifiers tutorial Transistor’s model
Circuit adaptation
Simulations change

4. Technology comparison
GaAsFET
0.4 μm CMOS
Vth
-2.5 V
0.5 V
VDS - IDS

5. Power amplifier - Class B
Circuit
Crossover distortion:
50% of cycle conducting

6. Power amplifier - Class AB
Circuit

7. Power amplifier - Class D
Circuit

8. Project description Power supply Working point (Bias ports)
Transistor’s parameters
Power input signal
Load adaptation

9. Simulations/Results Class B – 1/2 T=1/850 MHz = 1,2 ns
50%
T=1/850 MHz = 1,2 ns
Linear region: Vds < Vgs - Vth

10. Simulations/Results
Class B – 2/2
PAE = (Pload – Pin) / Psupply

11. Simulations/Results
Class AB – 1/2

12. Simulations/Results
Class AB – 2/2

13. Simulations/Results
Class D – 1/2

14. Simulations/Results
Class D – 2/2

15. Conclusion Improvements: Optimize transistors width Efficiency
Matching network
Reduce current leakage

16. Any questions?
Doubts?
or comments?

17. Thank you a lot for your attention!