In this fast-paced, mobile world, we have become increasingly dependent upon connection speed. The demand for data is driving faster wireless connections and greater network capacity, and this in turn is driving the demand for highly complex mobile devices that can operate over a wide range of frequency bands across a greater number of geographies. A typical mobile device must support up to 28 bands for worldwide 2G, 3G, 4G, LTE network connectivity, with more complex mobile devices supporting evolving network standards and frequency bands in the near future. At this pace, how will we support this demand to ensure the high quality end user experience that consumers expect?
Today, smart phones and tablets contain radio frequency (RF) front-end modules (FEM), which are typically built with power amplifiers (PAs), switches, tunable capacitors, and filters. As new high-speed network standards are introduced (such as LTE release 12), the latest equipment requires additional RF circuitry to support newer modes of operation. Technologies such as radio frequency silicon-on-insulator (RF SOI) help mobile devices tune and retain cellular signals– giving wireless devices consistently strong, clear connections from more places.
“The mobile market continues to favor RF SOI, as it delivers low insertion loss and harmonics and high linearity over a wide frequency range, good performance, and cost-effectiveness,” says Peter Rabbeni, director of RF Segment Marketing at GLOBALFOUNDRIES. RF SOI is a win-win technology option that can improve performance and data speed in smartphones and tablets, and it is expected to play a key role in the Internet of Things applications as well.
So, why all the hype? For RF chipmakers, it brings the benefits of silicon design and integration to the RF front end, and is a low cost alternative to the expensive gallium arsenide (GaAs) that is currently being used in PAs. And, for designers, RF SOI offers design flexibility by integrating multiple RF components onto a single chip without losing valuable circuit board real estate.
“This integration enables fewer chips and smaller footprints for mobile applications, that allows mobile makers to design less complex radios with the advanced features their customers expect,” said Rabbeni. Mobile devices that exploit RF SOI technologies for RF front end applications benefit from the same or better linearity and insertion loss against competing technologies, which translates to longer battery life, less dropped calls and higher data speeds.
More good news for RF market players, new technologies like FD-SOI have unique properties and capabilities that can enable RF circuit innovation, and achieve integration levels never before seen in silicon-based technologies. The key to this is the exploitation of the low voltage operating capability and well-bias features of FDSOI, “dynamic control of Vdd and the use of well-bias techniques can not only help reduce overall power consumption but can be used as a means to optimize RF circuit operation. This is not something that can be easily done in bulk technologies,” Rabbeni explains. When designing a complex SoC, another advantage is the ability to integrate multiple functionalities that results in a smaller form factor and simpler packaging which is much more cost-effective and in terms of power, more efficient for IoT applications, which is absolutely essential in order to meet the economic requirements of this market and keep pace with evolving network challenges.
In response to the strong demand for RF SOI, some foundries are expanding their capacities by acquiring other companies or forming alliances. Most recently, GF agreed to acquire IBM’s chip unit, which will enable GF to expand its leading-edge CMOS process portfolio, including IBM’s well-regarded RF SOI process technology. Also, GF has partnered with Peregrine Semiconductor—an RF chipmaker known for its long experience in bringing silicon-on-insulator based products to market )—to develop a proprietary, 130nm RF SOI technology.
Investing in the future is critical to address certain RF challenges such as radio architecture design in multiband, multimode mobile radios and ultra-low power (ULP) wireless devices. Case in point: in February of this year, GF announced it partnered with imec to develop innovative RF solutions and address the challenges of radio design in this era of mobility and big data. Leveraging GF CMOS technology platforms optimized to boost RF performance of ICs, the cooperation focuses on critical digital-intensive RF architectures and analog circuits for mobile communications and IoT sensor nodes.
“The relationship will bring some critical skills in both system and circuit level approaches using silicon technologies to address the subject of tunability,” Rabbeni noted. “We want to simplify mobile radio front ends so the first area of investigation will look at the next step leveraging tunability in FEMs, and the goal is to achieve the right performance and cost target for the application.”
“Another important area which we will be investigating will be at design optimization in order to develop low power RF blocks like digital PLLs and ADCs for low energy wireless (i.e. Bluetooth) applications like wearables.”
There is no doubt that demand on our networks will continue to grow. Now more than ever, the underlying communication networks matter and the need for speed is immediate. The mobile world is calling and it’s time for device manufacturers and component designers to capitalize on design flexibility and enablement and supply (capacity assurance) that RF SOI offers.
To learn more about GF breakthrough innovations in RF IC, please visit our booth 834 at the International Microwave Symposium from May 17-22, 2015, in Phoenix, Arizona.