Design Of Terahertz Wide Tuning Signal Source In 130nm SiGe Process

Currently,the terahertz spectrum region between millimeter wave and infrared light is a research hotspot in the academia.Due to the lack of efficient terahertz radiation sources,detectors and functional devices,its rich spectrum resources have not been fully developed and utilized.Achieving radiation sources with high output power,continuous tunability and miniaturization will greatly promote the development of terahertz technology,and it is also an important goal in the research field of terahertz.In order to develop silicon-based radio transceivers and active imaging sensors in the200-300 GHz frequency range,the main goal of this dissertation is to achieve a 300GHz tunable high-power signal source.The basic principles of the various circuit modules in the terahertz signal source architecture are firstly introduced.After studying the frequency characteristics of the heterojunction bipolar transistor(HBT)in the 130 nm silicon germanium(Si Ge)process.The cascade circuit of 150GHz Colpitts voltage-controlled oscillator and frequency multiplier and the cascade circuit of 150GHz Colpitts voltage-controlled oscillator,buffer amplifier and frequency doubler were built re spectively for pre-simulation.The key difficulty encountered in layout design are summarized,mainly including:pad and grounding problems,transmission line width and length selection the skill of reducing parasitic effects.The interconnection lines and inductors mainly implemented by microstrip lines in the layout require to be modeling and EM(electromagnetic field)simulating.After designing different shapes and sizes of interconnects and inductors and comparing them with electromagnetic simulations to obtain better performance,the S-parameters are substituted into Cadence for circuit simulation to achieve co-simulation.Through the debugging and optimization of the circuit,the performance s of the two circuit architectures finally meet the requirements,and the output signal power of the THz signal source with buffer is greater than that without buffer,but it consumes more DC power and has worse phase noise.Two 300GHz wide tuning signal sources have been developed and manufacturedbased on the130-nm Si Ge Bi CMOS process.The areas of the two chips are 524×495μm~2(without buffer)and524×540μm~2(including buffer),respectively.The co-simulation results show that:(1)The signal source without buffer can achieve a output signal of 290.8～316.6 GHz,with a relative tuning bandwidth of 7.98%,and the highest output power can reach–5.2 dBm at 316 GHz with the highest DC-RF efficiency of 0.33%,also with a phase noise of–85.1 dBc/Hz@1-MHz offset.The total DC power consumption is 53.66 mW.(2)The signal source with buffer can achieve 289.8～313.9 GHz output signaland the relative tuning bandwidth is 7.98%.The output power can reach up to–2.89dBm at 302 GHz with the highest DC-RF efficiency of 0.96%.Its phase noise is–81.5 dBc/Hz@1-MHz offset,and the total DC power consumption is 90.3 mW.