Research And Design Of 2.4GHz Si-based High Efficiency Linear Power Amplifier

With the wide use of 4G-LTE wireless communication technology,RF transmitter system with superior performance is wanted.In the transmitter,the power amplifier with the maximum energy consumption.While with the high cost at the same time.So the high efficiency,high linearity and low-cost power amplifier products are strongly demanded in the market.While the advantage of silicon-based power amplifier lies in the low cost and advanced process technology.Therefore,the design of 2.4GHz Si-based high efficiency linear power amplifier has important theoretical significance and application value.In this paper,the high efficiency linear power amplifier based on 0.18?m SiGe BiCMOS is designed to operate at 2.4GHz.The high efficiency linear power amplifier consists of two linear power amplifiers and envelope tracking module.Linear power amplifier is synthesized with two identical AB class power amplifier.In the design of single linear power amplifier,cascode structure is adopted to solve the low voltage problem in the process of single HBT transistor,pseudo-differential symmetric structure is designed to reduce the influence of parasitic parameters.The whole linear power amplifier uses distributed LC power synthesis technology to improve the output power,input and output matching network is designed with discrete components.The envelope tracking module is composed of an envelope detector and an envelope modulator,The envelope detector is designed to detect the RF signal,the envelope modulator is responsible for power supply voltage modulation of the power amplifier,and its output is the supply power of amplifier power;In the low-power input condition,reduce the power amplifier power supply voltage automatically;and in the high-power input condition,automatically increase the power amplifier power supply voltage,achieve efficient output finally.The circuit design and layout design of the envelope tracking module and the linear power amplifier are given,and the pre-simulation and post-simulation are carried out.The simulation results show that when the linear power amplifier operates at 5V,in the TT process angle of the different temperatures,the power amplifier is always in a steady state,S11 less than-10dB,the output power is greater than 33dBm;At 27?,the PAE is 42.81%,and the output 1dB compression point is 29.61dBm.With the LTE 16QAM 5MHz input signal,enveloped tracking power amplifier achieve the output power of 27.8dBm,power added efficiency of 24.5%,the power gain at the maximum output power is 23.47 dB,which meet the target requirements.Above all,the post-simulation results of the highly efficient linear power amplifier designed in this paper meet all the design indexes,which can be optimized after further measurement.