Envelope tracking technology will be essential for 4G mobile phones to work, says Tim Haynes, CEO, Nujira.
The Cambridge-based company has developed an IC for use in mobile phones which reduces the consumption of the RF power amplifier (PA) by tracking the power requirements of the PA output and modulates the power supply accordingly.
“Using standard power architectures, 4G terminals will use 75% more power than today’s 3G terminals, and require up to seven PA modules to cover the whole of the allocated spectrum,” said Haynes.
As download data rates increase with 4G systems, the power efficiency of the PA decreases, says Haynes.
Haynes claims Nujira’s envelope-tracking IC can reduce power consumption by 30-50% and it will even reduce the number of PAs needed to cover the necessary frequency bands.
It does this by allowing broadband PAs to be used, which are presently seen as too power inefficient to be practical.
By matching the power requirement of the PA to transmit power using a patented design of very high speed switching regulator, Nujira claims to be able to significantly increase the efficiency of the PA during HSUPA and W-CDMA transmissions.
The technology could also cut the cost of handset design by reducing the number of power amplifiers needed to cover all the WCDMA and LTE frequency bands.
“The case for envelope tracking is overwhelming,” said Haynes, “which is why we are in detailed discussions with OEMs and partners representing more than 70% of the handset market.”
Nujira has already licensed its handset technology, called Coolteq.L, to what Haynes calls a market-leading semiconductor supplier.
But Haynes says Nujira will be first and foremost a fabless chip supplier rather than licence its technology across the industry. “This is the only licensing deal we will do,” said Haynes.
Yet Haynes knows it takes time to get new semiconductor technology accepted and then designed into commercial mobile phones.
“I do not expect to see the first commercial handset with the technology inside before December 2012,” said Haynes.
But the company is not standing still. It will unveil its second-generation handset chip which covers the full 20MHz LTE bandwidth, at Mobile World Congress in Barcelona this month.
Based on this device, Nujira is developing a commercial envelope tracking processor IC (EPIC) for release later this year,
The device, known as EPIC (Envelope Tracking Processor IC) is currently in test, and is due to be delivered to customers in the next few months.
The device has a 500MHz clock and is manufactured on the TSMC 0.18G process. It is packaged in a 104-pin aQFN.
To sit alongside EPIC, the company has also designed a switch mode power system IC which integrates two 5MHz PWM (pulse width modulation) controllers.
EPIC incorporates a 2.5Gbit/s JESD204A control data interface which Nujira is hoping to promote as an open standard in the industry.
The company hopes to create a MIPI-style cross-industry alliance, called the OpenET Alliance, with chip vendors and handset OEMs supporting and contributing to the interface standard.
“Making the control interface an open standard is key for us,” said Haynes.
These are important times for the Cambridge-based fabless chip company which is aiming to get its patented power supply modulation technology into next generation mobile phones and basestations. To support its design activities with specific handset makers, it has expanded its engineering team to 66.
According to Haynes, this number could reach 80 by the end of the year.
Nujira has secured an additional £5m in funding from its investors and it is opening a third design centre in Scotland to sit alongside its existing Cambridge and Bath development facilities.
The future is not just about the handset market. Nujira has a version of the envelope tracking processor for cellular network infrastructure, which it supplies in modules it has manufactured.
These Coolteq.L power modulators are designed to reduce power in LTE basestations. “They enable a single multiband, multimode PA module to transmit 20MHz 4G signals using less power than today’s single-band 3G PAs,” said Haynes.
It has modules for the broadcast market and a military device is also being developed.
“Coolteq.L will replace the DC-DC converter and become the standard power architecture for the next generation of handsets,” said Haynes.
www.nujira.com