Design Of Transformer Coupling Millimeter-wave Power Amplifier In 40nm CMOS

In recent years,the wireless communication technology developed rapidly.At the same time,with the development of multimedia technology,the requirements of wireless communication system are higher than before.With the development of electronic technology,thereby some problems appearing in the low frequency band,such that the spectrum resources appear increasingly crowded and low data transmission rate.Fortunately the millimeter wave(mm-wave)frequency has abundant spectrum resource and it can achieve high data rate transmission.Hence mm-wave technology will bring new research direction and more choices for wireless communication.In recent years,much research has been done in the area of CMOS RF circuit design.Power amplifier as one of the most difficult parts for design in mm-wave transmitter has attracted wide attention in academia and industry.Mm-wave power amplifier designed with CMOS processing has advantages and at the same time it also faced difficulties,such as low output power of the power amplifier in mm-wave frequencies,low power gain of the transistor in mm-wave frequencies,mm-wave passive components designing and modeling.A series of new circuit design techniques are proposed to overcome the problems:pseudo-differential common source amplifier is adopted due to its high power gain,stability and high isolation;capacitive neutralization to decrease transistor parasitic;Transformer matching to reduce the insertion loss of matching network.The basic theory of power amplifier was discussed in this paper,including method to enhance the performance of CMOS power amplifier,passive elements in CMOS power amplifier design,basic of millimeter wave CMOS power amplifier design.Based on TSMC 40nm CMOS process,a two stage 38-GHz band transformer-coupled power amplifiers is designed,and the core chip area is 230μx590μm.Simulation shows that at 38GHz,1dB compression point output power and saturated output power is 14.6dBm and 18dBm,respectively.The achieved 1dB PAE and peak PAE is 15%and 25%respectively,and small signal gain is 25dB.