Competitive Landscape for Cordless PhonesRelated Terms:
Competitive Landscape for Cordless Phone Power Amplifiers - February 7, 2005
We spoke with the lead designer for one of the largest cordless phone chipset makers in the world, and he said there is no market for standalone cordless phone power amplifiers. They do not use separate power amplifiers, but rather integrate them in the chipset. To the best of his knowledge, for cost-efficiency reasons, all of the competition does the same thing.
While the standalone PA market does not exist, he gave us some useful information about the overall cordless phone chip market. It is very cost focused, since handsets are a complete commodity. The price of the phone is everything. Quality was an issue a few years ago, where a lot of phones were very noisy receivers and thus had poor range. Today, nearly all modern chipsets for cordless phones work at very close to the theoretical best possible, given the FCC rules. In any case, the 900 MHz and the 2.4 GHz bands are very noisy, so background noise is almost always the limiting factor in range – not receiver sensitivity.
Power amp efficiencies are probably around 30%, where the power amp is integrated into the rest of the chipset. With FSK modulation, they can use very nonlinear power amps. They could design higher efficiency power amps, but do not do so based on cost. One reason is that the receiver requires more power than the transmitter, even at full transmit power. Also, they routinely use power control, so that the transmit power is turned down unless the handset is at the very limit of its range. According to the cordless phone designer, increasing the power amp efficiency would make very little difference in talk time. They are much more focused on reducing the power of the DSP (Digital Signal Processor).