The Key to SDR is the RF Front End
--be ultrawideband to handle 20 MHz to 60 GHz
--work with any softrware
--work with any waveform
--use tunable filters
Some solutions are already coming to market such as
The IMEC research center in Belgium proposes a CMOS solution to this problem. The solution promises a low-power, low-cost solution.
Microtune offers a chip for car radio applications called the MT3511 that provides a generic hardware platform to support AM/FM, digital radio, CD audio, MP3 playback, navigation, as well as connectivity for iPod®, SD card, USB and Bluetooth.