Hello,
I have a question about your LimeSDR mini 2.0, the board with the ECP5. I’d like to use your board as inspiration to create my own product, also with an ECP5. Looking at your schematic, I don’t understand why you don’t use channel 2 of the LMS7002M chip? Is it not possible to do MIMO with the ECP5? And why don’t you use the RX1_L?
LimeSDR Mini is cost-optimized and I’m also not sure what the max throughput is of the FTDI USB 3.0 controller. @Zack may be able to comment further.
Thanks and in the same vein, I compared the LIMESDR-USB schematic with that of the LIMESDR mini 2.0, and found another strange thing. In the LIMESDR-USB, with the RX1_W circuit, the range is from 700MHz to 2.6 Ghz whereas with the LIMESDR mini 2.0, you have changed the circuit limiting the range from 700MHz to 900Mhz. Can you explain this change? Because I’d like to have the widest range for my product.
Links to LIMESDR-USB schematic: https://github.com/myriadrf/LimeSDR-USB/blob/master/hardware/plug/1v4/Project%20Outputs%20for%20LimeSDR-USB_1v4_LMS031pad/LimeSDR-USB_1v4_schematic_r7.PDF
Sometimes the labelling is a little misleading in that it indicates the frequency range the matching network has been optimised for. Meaning that you can tune to frequencies outside that range and it will work, albeit with reduced performance.
You should design the matching network(s) to meet your requirements. Of course everyone would love to have the widest possible range, but it’s a trade-off with bandwidth vs. noise figure.
