GaAs Substrate Coplanar Waveguide Discontinuity Structure Modeling Techniques

Because of advantages of performance and convenience of fabrication, coplanar waveguide(CPW) is playing a increasingly important role in MMIC design. Especially in millimeterwave band, coplanar waveguide is the only ideal transmission line, for the limitation of microstrip in high frequency. Presently the primary check point of the CPW circuits design is the absence of various CPW discontinuities models with high efficiency and practicability. Taking GaAs back-grounded CPW as an object, research has been evolved for modeling of various discontinuities. The innovations and valuable works in this dissertation as follows:1. Inheriting and developing advantages of EC model and EM-ANN model, A novel accurate and efficient equivalent circuit trained artificial neural-network (EC-ANN) modeling approach has been developed. It provides a new resolvent for future passive element engineering modeling.2. For the first time the EC-ANN model is applied to GaAs back-grounded CPW discontinuities modeling, including spiral inductor, MIM capacitor, resistor and other 9 kind of discontinuities. These models are applicable up to 40GHz and verified by on wafer measurement.3. Based on Agilent ADS, the first design kit (HIEE_CPW_kit) for GaAs back-grounded CPW discontinuities EC-ANN models has been successfully developed, which makes models more practical for circuits design and optimization.4. With more efficiency than international advanced congeneric kit, firstly HIEECPW kit is applied for circuits design of GaAs back-grounded CPW 4dB power divider and 20GHz band pass filter. The former is verified by full wave simulation, the latter is fabricated and verified by on wafer measurement.Based on domestic GaAs MMIC foundry and Agilent ADS, the whole technical process of back-grounded CPW discontinuities EC-ANN models' development has been achieved.