The wireless industry is growing and changing rapidly. With the advent of new technology combined with the demand for more bandwidth and increased mobility, wireless applications are spreading to new markets – from radar-equipped passenger vehicles to biomedical devices that, when injected or inserted, send data to a receiver outside the body. As the wireless device market grows, so will the semiconductor products that support it.
More functionality but more components
Wireless system manufacturers compete to add more functionality to equipment. A 3G “smart” phone, PDA, or base station, for example, will require the functionality of as many as five radios – for TDMA, CDMA, 3G, Bluetooth and GSM operation. A huge increase in component count is required to accomplish this demand. And other wireless verticals are facing the same challenge. Yet while the market demands the new functions, it also expects smaller form factors, lower costs and reduced power consumption.
Towards a single-chip RF circuit
A solution with tighter and cost-effective integration is clearly needed. Integrating MEMS devices directly on the RF chip itself or within a module, can enable the replacement of numerous discrete components while offering such competitive benefits as higher performance and reliability, smaller form factors, and lower cost as a result of high-volume, high-yield IC-compatible processes.
Discrete passives such as RF-switches, varicaps, high-Q resonators and filters have been identified as components that can be replaced by RF-MEMS counterparts.
For radio frequency, or RF, applications there is the innovative “above-IC” (AIC) technology that enables the placement of RF MEMS devices directly on top of the IC by using a thick copper technology compatible with CMOS, BiCMOS and gallium arsenide processes.
The industry is just beginning to see the benefits of such integrated devices. And, over time, integration of RF-MEMS devices may be the means to replace all passive RF chips with on-chip devices, achieving the long-awaited single-chip RF solution.
Current technology and process limitations will prevent placement of all passive components with on-chip MEMS components. But placing even some components on-chip offers significant space and cost savings, allowing smaller form factors, benefiting cell phones for example, or added functionality such as Internet connectivity.
Higher performance, reliability, lower cost per unit
Higher speed and reliability are other likely improvements. Having components on-chip means they are more tightly integrated and can communicate faster with the IC. And because lighter MEMS components are really part of the chip and not attached to the board, they are less likely to be damaged if a phone is dropped.
Not the least of benefits is cost savings. A circuit board with as many as 800 components may cost close to $30 to manufacture. Using MEMS may eliminate as many as 200 discrete parts, saving approximately $8 per unit.
