Vibrating RF MEMS for Low Power Communications

Abstract

Micromechanical communication circuits fabricated via IC-compatible MEMS technologies and capable of low-loss filtering, mixing, switching, and frequency generation, are described with the intent to miniaturize wireless transceivers. Possible transceiver front-end architectures are then presented that use these micromechanical circuits in large quantities to substantially reduce power consumption. Technologies that integrate MEMS and transistor circuits into single-chip systems are then reviewed with an eye towards the possibility of single-chip communication transceivers.

Elastic PMLs for resonator anchor loss simulation

“…Though designers currently use quartz, ceramic, and surfaceacoustic wave devices, surface-micromachined microelectromechanical system resonators (MEMS resonators) in development offer an attractive alternative. Because they can be integrated into standard complementary metal-oxide semiconductor (CMOS) technology, MEMS resonators have the potential to use less area and power, and cost less money than existing commercial devices [1]. But to be viable, energy losses in these MEMS resonators must be minimized.…”

“…But to be viable, energy losses in these MEMS resonators must be minimized. The usual measure of this energy loss is the quality factor Q of a resonant peak, defined as Q = 2 Stored energy Energy lost per period (1) For an ideal linear single degree of freedom oscillator Q = | |/2 Im[ ], where is the oscillator's complex-valued eigenvalue [2, p. 158]. Resonators in cell phone filters, for example, require Q values greater than 1000 for good performance, and higher values are preferable [1,3].…”

“…The usual measure of this energy loss is the quality factor Q of a resonant peak, defined as Q = 2 Stored energy Energy lost per period (1) For an ideal linear single degree of freedom oscillator Q = | |/2 Im[ ], where is the oscillator's complex-valued eigenvalue [2, p. 158]. Resonators in cell phone filters, for example, require Q values greater than 1000 for good performance, and higher values are preferable [1,3]. Depending on scale, geometry, and materials, the energy losses that lower Q may come from material damping, air damping, thermoelastic damping, or radiation of elastic waves from an anchor [4].…”

Model Reduction for RF MEMS Simulation

“…For RF engineers using quartz, ceramic, and surface acoustic wave devices, surface-micromachined MEMS resonators in development offer an attractive alternative. Because they can be integrated into CMOS, MEMS resonators have the potential to cost less area, power, and money than existing alternatives [10]. Such integrated high-frequency filters could qualitatively change the design of cell phones, making it possible to build a cheap phone to work with multiple networks operating at different carrier frequencies, and lowering power and size constraints to the point that inexpensive "Dick Tracy" watch phones could be a reality.…”

Electromechanical resonances of SiC and AlN beams under ambient conditions

“…This requires small geometries which are conveniently provided by modern lithographic techniques. Among future applications of mechanical high-frequency resonators are ultrasensitive sensors for chemical or biological species [1,2] but also filters and other RF applications [3,4] that would benefit from the integration of active and passive components on the same chip.…”