Research And Design Of High Efficiency Dual-band Power Amplifier

With the development of communication systems,in order to meet the demand for high transmission rates,the peak-to-average ratio of the signal is getting higher and higher,so that the power amplifier must work in a range with a deep power backoff to ensure the signal quality,resulting in a decrease in the efficiency of the power amplifier;At the same time,the coexistence of multiple generations of communication systems has resulted in many and scattered communication bands.In order to transmit the signal with higher efficiency,it is important to study the power amplifier with multi-broadband.In this paper,the high-efficiency dual-band power amplifier has been deeply studied,and the bandwidth and efficiency of the dual-band power amplifier has been improved.It mainly includes the exploration and verification of band-stop dual-band matching structure and dual-channel dual-band matching structure,design of dual-band Doherty power amplifier based on improved dual-band matching structure,and design and verification of dual-broadband Doherty based on continuous Doherty principle.The main work and innovations of this paper are as follows:(1)A band-stop dual-band matching structure is proposed,and a semianalytical solution to the overall structure is given based on genetic algorithm.Based on this structure,a 1.8/2.6 GHz dual-band power amplifier is designed and completed.The test results show that the drain efficiency is greater than 60%in the bandwidth of the two passbands greater than 200 MHz,and the drain efficiency at two center frequencies are 72.3%and 70.2%respectively.(2)A dual-channel dual-band matching structure is proposed,and the semi-analytical solution of the overall structure is completed by genetic algorithm.A dual-band power amplifier is verified.The test results show that in the two passbands of 1.55-2.05 GHz and 2.2-2.8 GHz,the dual-channel dualband power amplifier achieves a drain efficiency of more than 50%,and in the middle frequency of 2.05 GHz-2.2 GHz,there is obvious effect of inter-band isolation.The highest efficiencies for the two bands are 69.7%at 1.65 GHz and 65%at 2.5 GHz,respectively.In the two passbands,the output power is around 40dBm,the output power of 1.55-2.05 GHz is between 39.3 to 41.4 dBm,and the output power of 2.2-2.8 GHz is between 39.2 to 41.8 dBm.(3)An improved dual-band matching structure is proposed and based on this structure,a 1.8/2.6 GHz dual-band Doherty power amplifier is designed and implemented.The test results show that at 1.8 GHz,the dual-band Doherty power amplifier achieves an output power of 43.3 dBm,a drain efficiency of 72.9%,and at back-off of 6 dB,the amplifier achieves a drain efficiency of 61%.At 2.6 GHz,the dual-band Doherty PA achieves an output power of 43.3 dBm with a drain efficiency of 69.9%,and at back-off of 6 dB,the amplifier achieves a drain efficiency of 52.3%.The dual-band Doherty power amplifier achieves better performance at two frequency points of 1.8 GHz and 2.6 GHz,and the bandwidths where both saturation and back-off efficiency are good about 50 MHz.(4)Apply the continuous Doherty principle to the design of the dual-band Doherty power amplifier,and use the band-stop dual-band matching structure to design and realize the dual-broadband Doherty power amplifier.The test results show that within 1.6-1.9 GHz,the output power of the dual-band Doherty power amplifier is 42.7-44 dBm,the saturated output power is between 50%to 65%,and the efficiency of the 6 dB back-off is between 40%to 48%.In 2.4-2.7 GHz,the output power of the dual-band Doherty power amplifier is 42.1-44.1 dBm,the saturated output power is between 53.4%to 70.7%,and the efficiency of the 6 dB back-off is between 41.8%to 54%.The test results show that the dual-band Doherty power amplifier achieves high efficiency in the fallback state with a bandwidth of 300MHz in each of the two frequency bands.High efficiency dual-band power amplifier can achieve high efficiency in a wide range of frequency bands,which can reduce the number of hardware to reduce construction costs,as well as save energy and reduce operating costs.