(
Radio
Frequency filter) An analog circuit that detects and filters out a single carrier frequency, such as a radio or TV channel. RF filters are increasingly a major component in smartphones, which are required to tune into a dozen or more frequency bands. While the cost to the phone manufacturer for RF circuits in a modern smartphone is considerably less than the storage or display screen, it is nevertheless as much as 30 times that of the RF filters in the cellphones of the 1980s. See
SAW filter.