Nujira raises $12M to stem LTE’s hunger for energy

UK mobile silicon startup Nujira is trying to solve LTE’s notorious power drain problem, and it just got $12 million to help accomplish that goal. With a new investor and the new cash infusion, Nujira plans to get its envelope tracking technology into 4G handsets in 2013, cutting the energy requirements of smartphones by as much as 25 percent.

Envelope tracking isn’t a UPS or FedEx service. In the case of Nujira and competitor Quantance, the envelope describes the voltage every device’s power amplifier pushes out to support its radio signal. Typically that power envelope consumes much more power than necessary. The problem is particularly pronounced with LTE as it suffers from what is known as a high peak-to-average ratio, which means 4G waves have much more extreme peaks and dips than their 3G predecessors. It’s one of the big reasons why the first round of LTE handsets had such crappy battery life, and it’s why vendors are sticking mega-batteries on their new smartphones.

Confused yet? In an interview with GigaOM earlier this year, Nujira explained the envelope tracking concept best:

Think of LTE as classical music and 2G or 3G as heavy metal, said Jeremy Hendy, the VP of sales and marketing at Nujira, a Cambridge, U.K.–based maker of power-modulation chips. Classical music has long moments of quiet punctuated with wild crescendos, while heavy metal music is fairly uniform in loudness. Heavy metal will sound just as good (or bad) on any old amplifier, but to truly appreciate classical music you need a high-powered amp to capture the music’s nuance and delicacy, Hendy said.

“You need a high-powered amp for LTE otherwise the signal is distorted,” Hendy said. “That’s why the power on an LTE [handset] is so bad. For every 4 watts you put in you only get 1 watt out.”

The amp constantly pumps out enough power to fuel those extreme peaks, but most of the time the device actually needs far less wattage. That means a lot of energy just goes to waste. Nujira has created a power-modulation chip that wraps up the waveform in a “latex bondage suit” of sorts, Hendy said. The power the amplifier puts out closely follows the power contours of the waveform, creating an extremely energy-efficient transmission.

So if Nujira is so good at matching the power input to the power output, why only a 25 percent energy savings? There’s a lot more than just the power amp draining electricity from the battery – larger screens and powerful processors all take their toll. And as we’ve written before smartphones are becoming more complex, piling on multiple radios, multiple bands and even multiple antennas for 4G radios. When you factor in all of those demands on those demands on battery life, a 25 percent reduction is quite significant.

Based in Cambridge, UK, Nujira has now raised £45 million (US $72 million) in total, backed by Amadeus Capital Partners, Climate Change Capital, Environmental Technologies Fund, NES Partners and angel investors. The latest $12 million infusion includes new investor Zurich-based SAM Private Equity.

Nujira hasn’t revealed any customers yet, though it has said it is working with handset vendors and radio component makers to embed its envelope tracking technology into forthcoming smartphones, the first of which will appear next year. Quantance is on a similar timeline, having announced its first commercial chip shipments in June.