When [ik1xpv] sets out to build a software-defined radio (SDR), he doesn’t fool around. His Breadboard RF103 sports USB 3.0, and 16-bit A/D converter that can sample up to 105 Msps, and can receive from 0 to 1800 MHz. Not bad. Thanks to the USB 3.0 port, all the signal processing occurs in the PC without the limitations of feeding data through a common sound port. You can see the device in action in the video below.
The Cypress FX3 USB device is an ARM processor, but it is only streaming data, not processing it. You can find the slightly modified firmware, a driver for using PC software, and schematics and board layouts on GitHub.
We aren’t quite sure where the term breadboard factors into the name since there is a PC board involved and no solderless breadboard. The basic receiver covers 0 to 30 MHz, and a mixer downconverts higher frequencies to that range.
There’s enough information that you should be able to duplicate this project, although you’d need to do a little analysis of the material. This isn’t a step-by-step build tutorial. However, this should be much more sophisticated than the usual RTL-SDR dongle. This is more on par with the SDRPlay, although it has a higher maximum frequency and some additional hardware filtering. It also is a 12-bit digitizer instead of the RF103’s 16-bit one which is a point in the RF103’s favor.