Diamond RF Switch for Enhanced Communications

The next generation of military and civilian communication systems will require enhanced capabilities. As the numbers of bands and bandwidth requirements increase, a compact RF system will be essential to counter increases in the size of signal processing and memory chips and to reduce size and cost.

 Because most RF switches are fabricated by using a variety of technologies, integrating the functions with CMOS has proved too complex and costly. On the other hand, switches using MEMS technology have been shown to provide a single solution that integrates “passive” RF front-end functions with a CMOS chip.

The integration of functions – such as band selection, filters, mixers, frequency references (oscillators), and duplexers – into RF front-end systems generally requires the use of switches and resonators. Typically, this integration is accomplished through the use of expensive, often large components, gallium arsenide switches, on-chip integration with low-Q LC circuits, and active CMOS circuits. Until recently, RF MEMS switches were introduced in the market as individual components but not integrated with CMOS. RF MEMS switches consist of a membrane activated by an electric field applied between the membrane and a bottom electrode covered by a dielectric layer.

Electronic switching devices using UNCD based RF MEMS technology are expected to have many benefits over conventional semiconductor devices.

• Extremely low power consumption; prevents overcharge and improves safety
• Greater reliability — speed of charging/discharging eliminates the dielectric breakdown that generally occurs with conventional dielectrics over time
• Robust tribological interaction with actuating metal membrane eliminates adhesion-induced failures
• Intelligent bias control through on-chip CMOS circuitry allows device to operate 50 times longer than conventional switches
• Very low insertion loss
• Ultrahigh linearity

Mobile communications and devices

Proof of concept