As smartphone screen sizes become bigger and mobile apps communicate constantly with the network, vendors are looking to get power savings wherever they can. That’s starting to draw attention, especially from green-tech investors, to companies that specialize in a new type of battery-conserving technology called envelope tracking. On Tuesday one of those companies, Nujira, announced it has raised $20 million in new funding.
Though it sounds ridiculous to say it, envelope tracking has become a hot technology lately as its made its way into many high-end smartphones, including the Nexus 5, the Galaxy Note 3 and HTC’s newly launched One M8. The obscure technology basically optimizes the power flowing through a smartphone’s radio, decreasing the power drain on the battery.
The round was led by existing investors Amadeus Capital Partners, Climate Change Capital, Environmental Technologies Fund, SAM Private Equity and NES Partners, as well as new investors GAM and Investec. The funding comes 18 months after Nujira closed a $12 million round, bringing its total to around $92 million.
A lot of companies that build smartphone radio frequency components have been building their own envelope trackers, including Qualcomm, Intel, RFMD, Texas Instruments and fellow ET specialist Quantance. Qualcomm has scored all of the publicly announced design wins so far, but there should be plenty of room in the market for many players. The technology will likely make it into every future generation of LTE handset, tablet, modem and module. It’s basically an inexpensive way to cut down power consumption on one of the phone’s must energy-hungry components by as much as 25 percent.
So what the hell is envelope tracking, you might ask? Nujira’s Jeremy Hendy probably explained it best using a rather unorthodox analogy when I first spoke with him in 2012:
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.