Microwave Journal

Cell Phone Antenna Troubles? Radio Frequency MEMS Come to the Rescue

September 1, 2010

Help may be on the way for iPhone 4 users frustrated by dropped calls with the arrival of Radio Frequency Microelectromechanical Systems (RF MEMS), semiconductors that can improve the performance of antennas in cell phones, according to the market research firm iSuppli Corp.

Long plagued by technological hurdles and other disappointing setbacks, RF MEMS are finally ready for the big time, with revenue projected to double in 2010 and more than triple in 2011.

From slightly less than $4 M in 2006, global RF MEMS revenue is anticipated to climb to $8.1 M this year—and then surge to $27.9 M in 2011, according to iSuppli. By 2014, revenue will reach a whopping $223.2 M—a far cry from the industry’s extremely modest beginnings.

“More than 50 percent of cell phones shipped in 2014 will feature some form of front-end-module tuning using RF MEMS technology,” said Jérémie Bouchaud, Principal Analyst for MEMS and sensors at iSuppli.

“The implementation of RF MEMS switches and varactors in mobile phones could help boost the performance of smart phones like the iPhone 4, which made news headlines recently because of a problematic antenna that resulted in dropped signal strength. RF MEMS are also ideal for impedance matching of the power amplifier.”

Although other technologies will address antenna issues, including SoS FETs and BST varactors, MEMS deliver the best performance in terms of insertion loss.

RF MEMS switches have been used in small volumes in instrumentation applications because of their small form factor and excellent RF performance. However, despite initial promise, they failed to take off on a large scale because of myriad commercialization and technological obstacles. All that is about to change as RF MEMS technology begins to realize its potential because of strong product offerings from a number of major suppliers.

Seven firms are sampling RF MEMS products.

California-based WiSpry Inc. and Japan’s TDK-Epcos are offering RF MEMS for high-volume cell phone applications. On another front, US firms Analog Devices Inc., Radant Technologies Inc. and XCOM Wireless Inc.—in cooperation with relay manufacturer Teledyne Technologies Inc.—as well as Japanese supplier Omron Corp. are targeting high-end applications for testing and instrumentation such as ATE and RF test. US startups Radant MEMS and MEMtronics focus on defense applications.

In particular, interest is growing among mobile handset manufacturers on how RF MEMS can be used for the front-end tuning of cell phones to improve antenna performance, given the advent of new wireless standards like LTE for 4G technology. WiSpry—which has garnered several design wins for its MEMS varactors—is expected to commence volume production by the fourth quarter this year.

Outside of cell phone antennas and instrumentation, a pair of smaller—but still untapped—opportunities also exists for RF MEMS switches and varactors in the foreseeable future. One of these areas is in wireless infrastructure gear—e.g., for femto cells—and cellular base stations, where the current switches being used could be supplanted by cheaper and higher-performing RF MEMS devices.

Another area is in defense and aerospace applications, including radio systems and phased array antennas, especially after 2014. This represents a high-volume opportunity for RF MEMS numbering in the millions of units.