Monolithic GaAs oscillator development

The goal of this program was to develop an 8 GHz monolithic voltage controlled stabilized oscillator on gallium arsenide (GaAs) suitable for monolithic integration with an 8 GHz satellite communications band receiver front-end. The monolithic microwave integrated circuit (MMIC) design is based on microstrip circuitry fabricated on a semi-insulating GaAs substrate with resistivity as high as 10 to the 9th power omega-cm. Active devices (FETs and varactors), bias networks, and microwave circuitry and fabricated on a single GaAs chip. Ion implantation doping technology facilities control of doping densities for optimization of FET and varactor active devices and also permits fabrication of highly planar circuits to achieve superior yields. The monolithic stabilized oscillator fabricated under this program contains a varactor tuned common-drain oscillator, a common-source buffer amplifier for gain and load isolation, and an active output coupler which provides a sample output to facilitate phase locked operation. This report is organized as follows. Section 2.0 describes the program objectives, the design approach, and a detailed circuit design. A discussion of the fabrication technology is contained in Section 3.0, followed by test results and further in Section 4.0. Finally, Section 5.0 provides a summary and recommendations for work under Phase 2 of this program.