A Ka-band MMIC oscillator stabilized with a micromachined cavity

Low-cost stable oscillators with good phase noise performance are in high demand for emerging millimeter (mm)-wave commercial applications. To overcome the problems of conventional DROs and cavity oscillators at mm-waves, a new type of oscillator based on micromachining techniques is developed at Ka-band. A cavity resonator is fabricated using micromachining techniques and is employed to stabilize a 33-GHz monolithic microwave integrated circuit (MMIC) oscillator. A micromachined cavity oscillator (MCO) showed a phase noise of -113 dBc/Hz at 1 MHz offset, which is an 18-dB improvement over an MMIC free-running oscillator (FRO). This work demonstrates the great potential of MCO for low-cost mm-wave frequency sources.