Research On Silicon-based Terahertz Low Noise Amplifier

As one of the important emerging science and technology fields in the 21 st century,terahertz technology has great application potential in wireless communication,terahertz imaging,medical monitoring and other fields at high data rate.Terahertz communication has the excellent characteristics of both microwave communication and optical communication,with wide bandwidth,large capacity,high transmission rate and narrower beam,strong directivity,high anti-interference and high confidentiality,so it has become a research hotspot in recent years.Terahertz transceiver system is the cornerstone of terahertz communication development,and the noise performance of terahertz receiver mainly depends on the front-end low noise amplifier.However,limited by the current process level,the operating frequency of the terahertz amplifier is close to the maximum oscillation frequency of the transistor,so it is faced with the problem of insufficient amplification capacity and higher noise figure.On the other hand,from the application level,the spectrum resources available in terahertz wireless communication system are much larger than the traditional communication frequency band,which is especially suitable for broadband wireless mobile communication.Based on the lack of terahertz band amplification capacity and the demand of terahertz communication for broadband and high speed,this thesis studies the gain enhancement technology and broadband technology of silicon-based terahertz low noise amplifier.In order to improve the insufficient amplification capacity of terahertz band,the gain enhancement technology of silicon-based terahertz low noise amplifier is studied in this thesis.Based on the gain plane,the gain enhancement mechanism of the traditional cascode amplifier with gate level gain enhancement inductor is studied.On this basis,a new cascode structure with double gain boost inductor is proposed by introducing linear reciprocal network to further improve the power gain.Finally,based on the TSMC65 nm CMOS process,a 180 GHz high-gain terahertz amplifier is designed and implemented,and the peak gain reaches 7.7d B.Compared with the cascode structure before optimization,the gain is significantly improved.Based on the requirement of broadband and high speed for terahertz communication,the broadband technology of silicon-based terahertz low noise amplifier is studied in this thesis.Firstly,the influence of interleaved tuning broadband and inter-stage matching mismatch on bandwidth is analyzed,and then based on Si Ge130 nm Bi CMOS process,a D-band broadband low noise amplifier working in 150GHz-170 GHz is designed and tested.In the design process,the noise and gain performance are optimized by emitter degradation inductor and base gain enhancement inductor,and higher-order matching network and interleaved tuning broadband are used to achieve wider bandwidth and inband flat gain.Finally,the simulation results achieve the 3d B bandwidth of 30 GHz and the peak gain of 24.6d B.The in-band noise figure is 6.93-7.45 d B,and the third-order Intermodulation point of in-band linearity input is greater than-11.15 d Bm.The final measurement results show that the small signal gain is from 19.3d B to 22.3d B within the working bandwidth 150GHz-170 GHz,the 3d B bandwidth is 23 GHz,which completely covers the target working frequency band of 150GHz-170 GHz,and the input1 d B compression point at 160 GHz is-19 d Bm.