The charge on the Galaxy Note 3 is going to last a lot longer than you think – and not just because of the slightly larger battery Samsung is shipping with the handset. Buried within the radio guts of the phone is a tiny chip called an envelope tracker, and it will reduce the power necessary to keep the Note connected to the network by as much as 30 percent.
The envelope tracker in the Note was developed by Qualcomm, and it’s the first commercial implementation of the technology that I know of. What it does is essentially match the power pushed through the phone’s signal amplifier to the actual power needed to transmit a signal. That might sound obvious, but in practice it’s a very difficult thing to accomplish.
A mobile signal is a waveform riddled with peaks and valleys, so a typical phone amp maintains a uniform “envelope” of power that can capture its highest amplitudes. The problem is particularly pronounced with LTE, which suffers from what’s known as a high peak-to-average ratio.
The best explanation was given to me last year by Jeremy Hendy
, VP of sales and marketing at envelope tracking pioneer Nujira
: LTE is classical music. 3G is heavy metal. Classical music has long quiet interludes punctuated with wild crescendos, while heavy metal is pretty uniform in loudness. Heavy metal is going to sound just as good (or bad) on any amp, but classical music requires much higher power to capture its nuance.