While there’ve been significant improvements in battery technology over the last few years, most of these have translated into incremental performance increases. For the most part, longer battery life has required higher-capacity batteries. But as battery capacities have increased so have screen sizes, and that pretty much negates any gains.
So what’s using all the battery power? The signal power amplifier accounts for about 60 percent, and the average signal amplifier is only 30 percent efficient. That leaves enormous room for improvement. Interestingly, cellular base stations have the same problem, but on a much larger scale. At present, base stations consume around $36 billion worth of electricity per year, of which 65 percent is wasted because of signal amplifier design. To exacerbate the matter, that wasted power ends up being converted into heat, which increases air conditioning requirements, which account for 10 percent of the power bill.
Now an MIT spinoff, Eta Devices, hopes to change all this with a new power amplifier that uses what can loosely be described as an “electronic gear box.” The amplifier has the ability to rapidly switch voltages so that it delivers the precise amount of power required to maintain proper antenna performance. Its amplifiers can do this approximately 20,000,000 times per second and can be as much as 100 percent more efficient than conventional designs.
Obviously, the technology has enormous potential. It’s expected to find its way into base stations as early as next year. Meanwhile the company’s at work on a chip-scale version which could double the life of smartphone batteries. Chances are, though, we’ll have to suffer through a couple more generations of phones before that happens.