Cross-Hierarchical Design of Compact RF-MEMS Oscillator Circuits on a Silicon-Ceramic Composite Substrate

The valuable performance figures of micro-electromechanical systems (MEMS) offer many improvements in the field of radio-frequency (RF) circuits for mobile communications compared to conventional microelectronic approaches. Especially, MEMS oscillators exhibit low phase noise together with a small form factor that are necessary for highly-integrated RF transceiver systems. However, the top-down design of the MEMS resonators in oscillator circuits is not yet as well established as of microelectronic circuits. Furthermore, special attention has to be paid to the layout of RF-MEMS circuits in the design phase to achieve a compact device with good RF performance. This paper presents a novel method for the cross-hierarchical design of multi-physical oscillators on a unique silicon-ceramic composite substrate, beginning on top-level and ending with the compact oscillator implementation. An optimisation method is included, which results in a low phase noise of -84 dBc/Hz at a 1 kHz offset from the frequency of oscillation at 578 MHz.