Femtocells set to bring more GaAs home
An increasing amount of data gushing through cellphones is driving the uptake of femtocells, to shift the flow to cable rather than overwhelming wireless network operators. These low-power base stations, designed for use in the home or small business, promise optimal call quality and reliable download speeds.
The clamor for data is already increasing the dollar content of compound semiconductor chips in handsets, but now femtocells will further increase the demand for power amplifiers.
“It s taking a bit longer to come to market than initial activity suggested, but I think 30 million units per annum by 2012 is a safe bet,” said Stuart Carlaw, research director of mobile wireless at ABI Research.
According to Carlaw the technology will spread to 70 million homes across the world and create a $4.5 billion annual femtocell market by 2012.
Currently, the largest scale femtocell deployments have been made for citywide trials being run in Indianapolis and Denver by US carrier Sprint. Several other trials are ongoing around the world and Carlaw predicts that 2008 will see a number of “soft launches” before a broader commercial lift-off at the end of the year.
The rapid uptake of femtocells from this point will result from a combination of business need on the side of carrier networks and consumer hunger for faster phones, according to Carlaw.
“When they launched the iPhone, the data demand went up by 30 percent in a very short period of time, which put a lot of pressure on networks,” he said. “Femtocells offload a lot of their traffic onto [cable] DSL and improves the economics of providing mobile data.”
Skyworks Solutions says it has more than 20 customers in this market, and is already supplying transmitters, receivers, low noise amplifiers and PAs for femtocells to Samsung. The Korean firm is in turn producing the Airave femtocells that are currently in use in the Sprint deployment.
Sumit Tomar, who looks after Skyworks femtocell marketing, sees a very similar commercial landscape to Carlaw.
“The carriers have a vested interest because the technology helps them increase their overall network capacity, reduce overall infrastructure cost and increase revenue while solving coverage problems,” he said.
Tomar says the total RF chip content Skyworks is selling per femtocell varies from $20-$25, when including transceivers fabricated from SiGe and CMOS, with around $5-$7 of GaAs.
Although some may feel that the low power output of femtocells might make the product well suited to silicon CMOS PAs, Tomar is confident that they will remain the preserve of GaAs chips.
“Our customers require linear output power close to 22dBm and linearity similar to pico base stations,” he said. “With existing silicon PA technologies, it can be challenging to meet those requirements.”