Study On Modeling Of Millimeter Wave Schottky Diodes And Applications

Diodes are widely used in millimeter wave nonlinear circuits, such as mutipliers, mixers. Diode’s parasitic parameters influence application circuits’ performance with the increasing of application frequency. Therefore, it is important to establish an accurate and effective diode model for circuit design.Different kinds of models of Schottky diode are discussed in this thesis, and the main contributions are listed as follows.1. Equivalent circuit model and 3-D physical model of MA46H146, a Schottky varactor fabricated by MACOM, are established to study commercial Schottky diodes. The linear part of diode is built in HFSS(High Frequency Structure Simulator) and cosimulated with the nonlinear spice model in ADS(Advance Design System). The equivalent circuit model is built in ADS with passive resistance, inductance and capacitance, as well as the nonlinear spice model. The simulation results show that the S21 parameter of two models are in the same trend in the range of 5～40 GHz. However the S21 parameter of the 3-D electromagnetic model is lower than that of the equivalent model.2. The 8 and 12 terms error models are introduced in the S parameter test. And the way to extract error model parameters are analyzed with calibration methods. The TRL(Through Reflect Line) calibration method is discussed and three kinds of calibration kits are designed as well. The S21 parameter of MA46H146 is measured with TRL calibration method. The results show that the S21 of the 3-D electromagnetic model are consistent with the measured result.3. A Q-band mutiplier is designed with the 3-D electromagnetic model of MA46H146. The input and output network circuit, as well as the diode’s 3-D electromagnetic model are established to an united structure in HFSS. The measured output power of the Q-band frequency doubler is in the same trend with the simulated one, and the output power is larger than-1dBm and peak conversion efficiency is 13.93% when the input power is 12.5dBm and Vbias is OV from 38 GHz to 50 GHz.4. The thermal characterization of MA46H146 is studied using simulations. And COMSOL is the elected software for the simulations. Different methods of thermal characterization have been introduced. The transient and steady responses are simulated, and the different thermal characteristics like junction temperature, thermal resistance and thermal time constant have been investigated through simulations.