Design of Doherty power Amplifier for telecommunications applications

Design of Doherty power Amplifier

1. Presentation By Abdulrazaq Abdulaziz XLIM Laboratory Angoulême 1 11/24/2021

2. Design of Doherty RFPA for VLP Mode 11/24/2021 2 The Circuit Diagram for the VLP Mode is shown below : Design Specifications for Doherty PA VLP Mode Zdmain Zd_AUX Ropt Zsource (main) 4Ropt OFF 38 ohms 45 ohms The tunable Capacitor C2 at the Load side is C2=4,07PF, Alpha=0,3, Zc2=30,8 ohms and Fo=2GHz

3. 11/24/2021 3 Results for Doherty PA at VLP Mode Plot of Zd_Main VS Pin Plot of Zd_Aux VS Pin Pout VS Pin PAE VS Pin Gp Vs Pin

4. Design of Doherty RFPA for VHP Mode 11/24/2021 4 The Circuit Diagram for the VHP Mode is shown below : Design Specifications for Doherty PA VHP Mode Zdmain Zd_AUX Ropt Zsource (main) Ropt /2 Ropt /2 38 ohms 45 ohms The tunable Capacitor C1 presented to the output of both Main and Aux.PA is C1=2,88PF, Alpha=0,41, Zc1= Ropt and Fo=2GHz

5. 11/24/2021 5 Results for Doherty PA at VHP Mode Plot of Zd_Main VS Pin Plot of Zd_Aux VS Pin Pout VS Pin PAE VS Pin Gp Vs Pin

6. Design of Doherty RFPA for Doherty Mode 11/24/2021 6 The Circuit Diagram for the Doherty Mode is shown below : Design Specifications for Doherty PA Doherty Mode Zdmain Zd_AUX Ropt Zsource (main) 2Ropt (Low input drive). Ropt (High power) OFF (at Low Power) Ropt (High power) 38 ohms 45 ohms No Tunable Capacitances Zc1= Ropt , Zc2=30,8 ohms and Fo=2GHz

7. 11/24/2021 7 Results for Doherty PA based on Doherty Mode Plot of Zd_Main VS Pin Plot of Zd_Aux VS Pin Pout VS Pin PAE VS Pin Gp Vs Pin

8. 11/24/2021 8 Comparison of the Results( by Applying High input Power) VLP VHP Doherty Zsource_Main 45 ohms 5 ohms 45 ohms Zdm 4Ropt Ropt /2 2Ropt-@LP Ropt @ HP Zda off Ropt /2 OFF-@LP Ropt @ HP C1(pf) off 2,88, Alpha=0,41 off C2 (pf) 4,07, Alpha=0,3 off off Summary of the results when ZS_main for VHP case = 5 ohms Plots of Zdm VS Pin for the 3 cases Where ; Yout1= Zdm for VLP case YoutHm = Zdm for VHP case YoutDm = Zdm for Doherty case Plots of ZdA VS Pin for the 3 cases Where ; Yout2= ZdA for VLP case YoutHa = ZdA for VHP case YoutDa = ZdA for Doherty case Pout VS Pin for all the 3 cases Where ; Pout1 for VLP case Pout2 for VHP case Pout3 for Doherty case PAE VS Pin for all the 3 cases Where ; PAE1 for VLP case PAE2 for VHP case PAE3 for Doherty case VS Pin for all the 3 cases Where ; Gp1 for VLP case GP2 for VHP case Gp3 for Doherty case

9. 11/24/2021 9 Comparison of the Results( by Applying High input Power) VLP VHP Doherty Zsource_Main 45 ohms 45 ohms 45 ohms Zdm 4Ropt Ropt /2 2Ropt-@LP Ropt @ HP Zda off Ropt /2 OFF-@LP Ropt @ HP C1(pf) off 2,88, Alpha=0,41 off C2 (pf) 4,07, Alpha=0,3 off off Summary of the results when ZS_main for VHP case = 45 ohms Plots of Zdm VS Pin for the 3 cases Where ; Yout1= Zdm for VLP case YoutHm = Zdm for VHP case YoutDm = Zdm for Doherty case Plots of ZdA VS Pin for the 3 cases Where ; Yout2= ZdA for VLP case YoutHa = ZdA for VHP case YoutDa = ZdA for Doherty case Pout VS Pin for all the 3 cases Where ; Pout1 for VLP case Pout2 for VHP case Pout3 for Doherty case PAE VS Pin for all the 3 cases Where ; PAE1 for VLP case PAE2 for VHP case PAE3 for Doherty case VS Pin for all the 3 cases Where ; Gp1 for VLP case GP2 for VHP case Gp3 for Doherty case

10. Observation It appears that a good performance was achieved when the source impedance ( Zs_Main ) presented to the input of Main Power Amplifier for VHP case equals to Zs_main = 5 ohms, w hile the Zs_Main for the other two cases I.e VLP and Doherty remain Zs_main = 45 ohms; Then the output power, PAE and Gp for VHP case gives a higher performance at high input drive compared to the other two cases. 11/24/2021 10

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