Cavity resonator for reducing phase noise of voltage controlled oscillator and method for fabricating the same

摘要

A cavity resonator for reducing the phase noise of microwaves or millimeter waves output from a monolithic microwave integrated circuit (MMIC) voltage controlled oscillator (VCO) by using silicon (Si) or a compound semiconductor and a micro electro mechanical system (MEMS), and a method for fabricating the cavity resonator are provided. In the cavity resonator, instead of a conventional metal cavity, a cavity, obtained by finely processing silicon or a compound semiconductor, is coupled to a microstrip line to allow the cavity resonator to be adopted in a reflection type voltage controlled oscillator. A pole is provided to connect the edge of the microstrip line to a predetermined location of a cavity lower thin film. A coupling slot is formed by removing a predetermined width of a cavity upper thin film adjacent to the pole which comes in contact with the cavity upper thin film. A resistive thin film for impedance matching is formed around the cavity lower thin film which comes in contact with the pole. Consequently, the cavity resonator reduces the phase noise of microwaves or millimeter waves which are output from a voltage controlled oscillator.