ETA Devices, a spinoff company founded by two MIT professors, says it has found a large energy inefficiency problem in smartphones and knows how to rectify it. The company says that the power amplifiers built into smartphones are “grossly inefficient” in turning electricity into radio signals. ETA Devices estimate that “these chips waste more than 65 percent of their energy” sapping your battery life and perhaps making your phone useless when you need it the most.
“Power-sapping: The five power amplifiers denoted by red dots account for up to
60 percent of an iPhone 5’s total power consumption.”
ETA Devices is currently testing a new geared power amplifier technology in its labs in Cambridge, Massachusetts. The first commercial use of the tech is expected to be in 2013, aimed at LTE base stations in the developing world where they use diesel powered generators to provide smartphone coverage. Later a chip-scale version of the tech will be developed to target miniaturised devices like smartphones.
Current power amplifier transistors use power in active and standby mode. Manufacturers aim to use the least possible power in standby mode to get by, but if it’s too low there is distortion when the power spikes upon user demand. “It means you are pulling a lot of energy just to keep the thing on,” says Joel Dawson, one of the ETA Devices founders. “With high data rate communication, you wind up needing far more standby power than signal power. This is why the phone is warm” he explains.
The solution to the problem is what could be called “a blazingly fast electronic gearbox”. MIT Technology Review explains that “It chooses among different voltages that can be sent across the transistor, and selects the one that minimizes power consumption, and it does this as many as 20 million times per second. The company calls the technology asymmetric multilevel outphasing.”
It’s good to see battery life attacked from another angle, not just creating higher capacity batteries and looking at battery usage by the CPU. But it seems like smartphone manufacturers routinely aim for about a single day use battery capacity. If a smartphone design uses less power I can see many manufacturers making the battery smaller so they can make thinner/lighter phones, or making the chipsets faster or with more cores (for competitive marketing) in the end leaving users with a one day battery capacity again.