S-Band MMIC Linear High Power Amplifier Devise

The development and progress of mobile communication systems are generating new value for human information exchange and sharing.In the 5G communication system,the RF front-end chip module occupies a crucial position,and the power amplifier（PA）as a very critical device directly determines the output power,efficiency,linearity,gain and working bandwidth of the transmitting system,affecting the communication quality of the entire communication system.In the development of the entire RF front-end module,how to improve the relevant performance of PA to generate better application value has become a practical problem that researchers urgently need to solve.In this thesis,the implementation of temperature-stable and small-size high-linear power amplifiers for5G communication is effectively studied.The key contents and innovations of this article are as follows:1.Based on AWSC’s 2μm InGaP/GaAs HBT process,a small-size power amplifier MMIC research applied to the RF front-end of 5G communication was carried out,using the whole chip integration method.The integrated module circuits include:HBT parallel transistor,output matching circuit,bias circuit,ESD circuit,feedback circuit,input and interstage matching circuit.2.In order to realize the linear high power output and good thermal stability of PA under small size,an adaptive bias circuit is proposed,which has a good effect on PA temperature stability through two sensor（temperature sensor）tubes and a suitable circuit structure,and adds a suitable size capacitor at the appropriate position of the linear compensation circuit to improve the linearity of PA.3.In order to match the PA input and output impedance to the standard impedance of 50Ωunder small size,and have a good harmonic suppression effect.The output matching circuit with harmonic suppression ability is designed by replacing some on-chip inductors with bondwire,so that the second harmonic and higher harmonics are well suppressed under the condition of good matching.In addition,the bonding wires of some inductors have been replaced in the input matching and choke inductor positions,making the realization of the small size of the chip a reality.After two tape-out tests,the PA MMIC designed in this thesis finally works at 3.3GHz～3.6 GHz,Chip area≤1.7×0.83 mm²,the small signal S11 and S22 are less than-10 dB,and S21 is in the range of （34±1）dB.In the operating frequency band,P_-1dBreaches 32 dBm,the saturated power P_sat reaches 33 dBm,and the ACPR reaches-35 dBc when the output power P_out=28 dBm.The second harmonic is less than-45 dBc@P_out=24dBm,At output power P_out=28 dBm,PAE>20%.In addition,the stability of DC current,saturated power P_sat,and Gain was verified over temperature-40～90℃.