The Large Signal Model of Enhancement–Mode pHEMT and Microwave Tripler Circuit DesignThe Large Signal Model of Enhancement–Mode pHEMT and Microwave Tripler Circuit Design

• Main Authors: Shao Wei Lin, 林劭瑋
• Other Authors: Hsien Chin Chiu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/95886604736216491955

碩士 === 長庚大學 === 電子工程研究所 === 95 === InGaP/InGaAs pHEMT device is one of the most important device of Ⅲ-Ⅴsemiconductors in military and commercial communication applications at microwave and millimeter-wave frequencies. It is extremely important to model the characteristics of the transistors before you use the transistors to design a MMIC circuit. To know the dc, RF or noise characteristics of the transistors accurately are the essential issues of designing the MMIC circuits, such as low noise amplifiers. This thesis contains both the small-signal and large-signal modeling methods of the InGaP/InGaAs pHEMT. The determined small- signal equivalent circuit by using the small-signal modeling method described in this thesis fits the S-parameters very well up to 20 GHz. The nonlinearity of dc characteristics and intrinsic elements of the InGaP/InGaAs pHEMT are investigated. several empirical nonlinear equations, which are used in the modified Angelov model, are adapted to model these nonlinear effects and give a good agreement both in dc and RF characteristics of the devices. A Ka band tripler have been realized in a 0.15μm GaAs pHEMT technology. The circuits are based on different 180 power divider structures. The circuits achieve minimum conversion loss of -16 dB.