Design And Research Of RF Power Amplifier Based On The Lateral Double-diffused Metal Oxide Semiconductor Device

With the rapid development of cellular wireless base stations and wireless communication systems in recent years,higher requirements have been placed on the performance of power amplifiers.As the main energy-consuming device in wireless base stations,the efficiency and linearity of the power amplifier directly determine the performance of the wireless communication system.Consequently,the trade-off between high efficiency and high linearity is one of the design goals of power amplifiers.Meanwhile,the design of the power amplifier involves multitudinous challenges such as gain,stability,harmonics,output power,cost and device type select and so on.Therefore,this paper aims to design a power amplifier with high efficiency,high linearity,high output power,high gain and high stability based on Lateral Double-diffused Metal Oxide Semiconductor（LDMOS）.1.An L-band class AB radio frequency power amplifier based on LDMOS is designed and researched.First,the DC analysis of the LDMOS transistor is carried out,the performance indicators such as efficiency and linearity are weighed,and the appropriate static operating point is selected.Next,the stability analysis was carried out and a stable circuit was designed.Following,the load-pull and source-pull of the transistor to obtain the optimal load impedance and optimal source impedance of the transistor,and a second-order L-type output matching circuit was designed to match the RF system impedance to the optimal load impedance,aπ-type input matching circuit to match the impedance to the optimal source impedance is also designed.Then,the overall circuit and joint optimization of the layout are optimized.Finally,the performances of the L-band class AB RF power amplifier are evaluated through the simulated and test results.The test results show that when the frequency is 1.96 GHz,the small signal gain of the power amplifier is 17 d B,the saturation output power is 5 W,and the power added efficiency is 40.2%,which has reached the expected design index.2.A a radio frequency power amplifier with harmonic-suppressed and harmonic control is designed.First,a low-pass circuit with multiple harmonic suppression is designed based on the structure of the SIR resonator,and the power amplifier with multiple harmonic suppression is completed by applying the low-pass circuit to the output network design of the power amplifier.The simulation results shows that the harmonic-suppressed power amplifier has good second-harmonic to fifth-harmonic suppression performance.Secondly,an output network with harmonic control is designed based on the low-pass circuit of multiple harmonic suppression,the capacitor whose self-resonant frequency is the fundamental frequency is replaced by the SIR resonator.An additional third harmonic adjustment line and a capacitor with third harmonic self-resonant frequency are added.The network can separate the third harmonic impedance from the fundamental impedance,and control the phase of the harmonic impedance to be located in the high-efficiency region.Based on the output network,a radio frequency power amplifier with harmonic control is designed.The simulation results show that the output power P_{1d B} of the harmonic control power amplifier is 40.4 d Bm,and the power added efficiency is 60%.The designed amplifier meets the established indicators.