Research And Implementation Of Bandwidth Expansion Methods For Dual-frequency Power Amplifier

With the development of communication technology,in order to obtain high-speed information transmission rate and compatible with different communication standards,communication equipment is developing in the direction of multifrequency and multi-mode.At the same time,even after peak clipping,the modulated signals need to be transmitted still have high peak-to-average power ratio(PAPR),and the signal bandwidth is wider and wider.In order to meet the needs of high efficiency amplification of multi-band and broadband PAPR signals,this paper studies the bandwidth expansion method of dual-band power amplifier,and includes mainly the research of dual-band impedance matching technology,the design of dual-band broadband single transistor power amplifier and the design of dual-band broadband Doherty power amplifier.The innovation and main work of this paper are as follows:(1)The impedance matching structure and design method of dual-wideband of multi-edge frequency are proposed.The structure is composed of cascaded L-shaped transmission line units.Because the design method contains parameters that affect the bandwidth,the bandwidth of each band can be expanded by adjusting the parameters.(2)Two class-AB and class-F dual-frequency power amplifiers are designed based on the dual-wideband of multi-edge frequency impedance matching structure and design method,and the bandwidth expansion of each frequency band of them is realized.The test results of class-AB power amplifier show that the average saturation output power is about 43.5dBm,the average gain is about 9.3dB and the average drain efficiency is about 63.8%at 1.6-1.95GHz,and the average saturation output power is about 43.7dBm,the average gain is about 10.3dB and the average drain efficiency is about 69.5%at 2.35-2.7GHz.And the bandwidth of the two bands is about 350 MHz.The simulation results of class-F power amplifier show that the output power is more than 43dBm,the gain is more than 14dB and the PAE is more than 61%in the 200MHz passband near 1.8GHz and 2.6GHz.(3)A dual-band high efficiency doherty power amplifier is designed based on the method of dual-wideband of multi-edge frequency impedance matching and quasi-T-shaped low-pass matching structure,and The bandwidth expansion of each frequency band is realized.The test results show that the average saturated output power is about 45.8dBm,the saturated drain efficiency is about 65.0%-75.0%,and the drain efficiency with 6dB back is about 51.5%-60.8%in the 1.7-2.0GHz band.In the frequency band of 2.35-2.65 GHz,the average saturated output power is about 44.3 dBm,the saturated drain efficiency is about 61.3%-71.3%,and the drain efficiency of 6 dB back is about 45.8%-53.7%.