Research And Design Of Millimeter Wave Power Amplifier Based On Silicon Technology

With the rapid development of 1G to 4G communication systems,sub 6GHz radio frequency band is increasingly crowded.Due to the advantages of high data rate and relatively clean spectrum of mm-wave frequency band,many applications of mm-wave frequency band have been promoted,such as mm-wave frequency band of 5G communication and vehicle radar.Due to the high manufacturing cost of traditional III-V semiconductor process,its application in the field of civil consumption is limited;Meanwhile,with the rapid development of silicon-based technology,the cut-off frequency of its transistor has exceeded 200GHz,which makes it's possible to realize millimeter wave circuit in silicon-based technology.Due to the advantages of low manufacturing cost and high integration,and the disadvantages of low voltage pressure and high loss,many scholars at home and abroad have carried out in-depth research on millimeter wave circuits using silicon technology.This paper mainly studies how to design a power amplifier with high gain and high output power under the limitation of silicon-based technology.Based on the silicon-based technology,this paper introduces and analyzes common passive and active devices,focusing on the theoretical derivation of transformer and analyzing the characteristics of transformer impedance transformation.It provides a solid foundation for the subsequent circuit design with transformer.In order to design a power amplifier wit good performance,the basic content of the amplifier must be analyzed according to the design practice.In this paper,the relationship between input impedance and stability is expounded by means of theoretical derivation.The output impedance of the common gate and the cascode amplifier is derived,and the reason why S₂₂ of the cascode amplifier is poor is explained according to the loadpull principle.The linearity of amplifier is analyzed theoretically.Firstly,the 35GHz power amplifier introduced in the paper is designed and taped out based on the 0.13um SiGe BiCMOS process.The amplifier adopts the structure of two stages cascade and power combining of two ways.The power gain of the 35GHz power amplifier is greater than 30dB,the 3dB bandwidth range is 27.5-38.5GHz,and the relative bandwidth is 33%.The in-band input and output matching networks are completed.The saturated output power at 35GHz is 21dBm,and the peak PAE is27.3%.Secondly,the 94GHz power amplifier is designed and taped out based on the TSMC 65nm CMOS process.In order to improve the output power of the amplifier,the output stage adopts power combining of four ways cascode differential amplifiers.In order to improve the power gain,the amplifier adopts cascade structure of four-stage amplifers,each stage adopting neutralization capacitance technology.In order to reduce the gain loss due to impedance mismatch in inter-stage matching,the three stages except the output stage adopt the common source structure.The power gain of the 94GHz power amplifier is 24dB,the 3dB bandwidth range is 82-105GHz,and the relative bandwidth is 24.6%.The in-band input and output matching networks are completed.The saturated output power at 94GHz is 17.2dBm and the peak PAE is 8.3%.