Research And Design Of RF Reconfigurable Power Amplifier

With the continuous change of wireless communication technology,more and more communication frequency bands and standards are proposed and applied.Power amplifier is an indispensable component in radio frequency communication system.Therefore,how to make the PA work in multiple communication frequency bands has become a hot research direction,so the research on the reconfigurable technology is very necessary.Based on the above background,this thesis has conducted researches on RF reconfigurable power amplifier(RPA),so that the PA can satisfy the design requirements of future communication systems.This thesis first gives a brief description of the development of mobile communication systems,and then analyzes the current research and publications of RPAs around the world,and then introduces the classification and various indicators of PAs.The characteristics of various reconfigurable devices are analyzed,and the basic principles and circuit structure of RPAs are described.Finally,we completed the design and verification of three PAs:(1)The basic characteristics of PIN diodes are analyzed,and a reconfigurable matching network(RMN)structure based on PIN switches is designed.PIN switches are added to the matching circuit of this structure,and the working state of the PIN switch is changed by adjusting the switch bias voltage,so that the PA realizes the function of reconfigurable center frequency.The test results show that the saturated output power(Pout)is greater than 40.8d Bm and the maximum drain efficiency(MDE)is greater than 64.6% at 1.75 GHZ and 2.6GHz.(2)Aiming at the working state of PIN diodes,there are only two states of "on" and "off",and a varactor diode is selected to replace the PIN diode.By analyzing the basic characteristics of varactors,a RMN based on varactors is designed.The capacitance of varactors can be changed by adjusting the external bias voltage,so as to realize the switching of matching circuits.Test results show that the saturated Pout is overall greater than 40.6d Bm,and the MDE is overall greater than66.4% under 1.75 GHz,2.1GHz and 2.45 GHz.(3)Aiming at the problem of low efficiency of the RPA,a new harmonic control structure based on PIN diodes is proposed.This structure realizes multiple harmonic control at different frequencies by changing the working state of the PIN diode.The actual measurement results show that at 1.75 GHz and 2.45 GHz,the Pout is greater than 40.5d Bm,and the MDE is greater than 69%.