Research On InP HBT Modeling And Terahertz Monolithic Amplifier Circuit Design

There are broad application prospects of terahertz technology in ultra-fast communication system,radar system,security and biological technology.Solid-state terahertz technology has gradually become an international research hot-spot.Solid-state terahertz technology has many advantages like lightweight,miniaturization,military uses,and broad commercial application prospects.The research of solid-state terahertz technology starts relatively late,and there are still many technical problems to be solved.This dissertation focuses on the solid-state terahertz technology,and main works of which are InP HBT modeling and terahertz monolithic integrated circuit(TMIC)design.It is a challenge to design TMICs with domestic HBT devices with limited gain and output power,so precise device models are very important.Therefore,we have to develop novel and practicable terahertz transistor models at the first step.Then we achieve some good-performance TMIC amplifiers.We also conclude the developed TMIC amplifier design methodology.A research on the TMIC packaging is proposed at last to complete the whole research system.Main focuses of this dissertation include:(1)Research on InP HBT inter-electrode parasitic effects.Parasitic effects seriously affect the terahertz device performance,and they are not fully considered in low frequency InP HBT models.We develop the dispersion inter-electrode impedance model with the improved multi-assisted-construction full-wave electromagnetic simulation method.The parasitic parameter model is put forward corresponding with the proposed dispersion inter-electrode impedance equivalent-circuit model up to 220 GHz.(2)InP HBT double base resistances small-signal equivalent-circuit model.To further describe the distributed base of the multi-mesa terahertz InP HBT/DHBT,we propose the double base resistances small-signal equivalent-circuit model.The new model topology could give a better presentation of the distributed base.A modified intrinsic parameter extraction process is also proposed with the intrinsic parameter initial method.The achieved small-signal model covers the 0-325 GHz frequency band.(3)InP HBT large-signal equivalent-circuit model.With the assistance base resistance equivalent-circuit model topology,a more precise inter-electrode impedancenetwork and a dispersion emitter-collector RF current source,a modified large-signal model is presented.We improve the commercial model in terahertz spectrum,and especially focus on the S-parameter consistency of the large-signal model and the small-signal model at high frequencies.The large-signal model performs good fitting scattering parameters up to 220 GHz.This model can support the 220 GHz TMIC amplifier design.(4)Terahertz monolithic integrated circuit(TMIC)amplifier design.The TMIC amplifier design method named “amplifier core integral design method” is concluded.At 140 GHz,220 GHz and 300 GHz,we design and achieve some good-performance TMIC amplifiers.In thin film microstrip TMIC design environment,commercial power combiners face challenges like high loss and low isolation,so we propose the terahertz integrated planar spacial(IPS)power combiner.The terahertz IPS power combiner has good isolation character even without the isolation resistance.The achieved 140 GHz TMIC amplifier has 20 mW output power with relatively high power added efficiency;The achieved 220 GHz IPS combiner TMIC amplifier is the first moderate output power TMIC amplifier using 0.5 ?m InP DHBT technology in the world,and it is also the first reported 10 dBm output power 220 GHz InP HBT TMIC amplifier in China;A 300 GHz TMIC PA is also designed.(5)Flip-assembled co-planer wave-guide(CPW)transition structure.We develop a wireless flip-assembled CPW transition structure for the TMIC packaging to solve the high loss problem of the gold wire bonding.We carry out an experiment on the flip-assembled CPW transition,and achieve a 140 GHz TMIC module.