Research On The Key Technology Of Millimeter Wave CMOS Power Amplifier

Millimeter-wave radio frequency communication system is a hot research direction in recent years.The electromagnetic spectrum in the millimeter-wave band has the characteristics of high data-rate and less interference,and the relevant provisions are not perfect due to few related products,which has triggered the development and research in various countries.The future 5G communication system will also partially use the millimeter wave band,which also prompted competition of major companies to establishing standards.As the characteristic frequency of CMOS processes continues to increase,circuit modules for millimeter-wave RF transceivers that would otherwise have to be fabricated using compound processes can also be done using standard CMOS processes.Power amplifier is a key module in the radio frequency transmitter,its characteristic restricts the overall performance of the transmitter.However,due to the voltage capability and transconductance of CMOS technology and other factors,the performance of CMOS power amplifier is usually weak.In order to enhance its performance,a variety of technical measures have emerged in recent years to continuously utilize the potential of CMOS technology,making the practicality of millimeter-wave power amplifiers and transceivers continuously enhanced.This paper discusses the theory,technical specifications,modeling and simulation methods based on HFSS of on-chip transformer in detail.Two main types of transformers were designed and improvements were proposed.With simulation results,performance of transformer types was compared,and design experience was summarized.Based on the 40 nm standard CMOS technology,a three-level pseudo-differential power amplifier operating at 160 GHz is designed using a stacked single-stage structure.Neutralization capacitors and on-chip transformers are used to improve the performance.Compared with the common-source amplifier,this article introduces a variety of techniques gradually in the design process to compare the impact of different technologies on the final performance.In layout design,attention is paid to the symmetry and possible parasitic effects,using via layout schemes with better performance.The final simulation results show that the amplifier can achieve the highest gain of 17.57 dB at the frequency of 163.4GHz and a 3dB bandwidth of 7.7GHz.At 160 GHz,it achieves a saturated output power of 6.04 dBm,input 1dB compression point of-13.9dBm,and a DC power consumption of 141.2mA.