DESIGN ANALYSIS AND CHARACTERIZATION OF HEMT BASED CASCODE OSCILLATOR

Abstract

In this dissertation a HEMT based cascode configuration oscillator is proposed. This report primarily focuses on the analysis and design of cascode oscillator using Advanced Design System (ADS). The oscillator generates signal of frequency 900MHz. Cascode configuration over common-source or common-gate configuration provides higher gain and hence higher output power. The idea is to generate large power so that it eliminates the need of power amplification devices and thus reduces the component count. The HEMT based cascode oscillator have been designed using three transistors, a pair of HEMT devices is used in a cascode configuration to achieve negative resistance and a PMOS is used to achieve the necessary bias current for the circuit. It can be used for the OSM applications. The matching network and resonator is designed by using micro strip lines. The biasing network with radial stub has been used, radial stub have the advantage of large bandwidth, low reflection loss. The dissertation provides an in-depth analysis of schematics, Momentum simulation and fabrication of proposed cascode oscillator.