We just added the highlighted U.FL connector for connecting an external clock.

Firstly, we’d just like to say how thrilled we are at the interest shown in LimeSDR Mini, with all 500 of the early bird boards pledged within just 24 hours. One week in, we’re now over 85% towards the goal and on-track to meeting our target very soon at the current rate of pledges.

We have received some enquiries as to why prototype boards have 4x RF connectors, whereas the final boards will have just 2x. Well, by popular request we changed to using SMA connectors as these are more rugged, with cables and accessories for them also being more readily available. However, the connectors are larger and take up more space, so the design was also updated with additional RF switching, enabling us to switch a single port between low and high bands.

A number of you also asked whether it would be possible to add support for using an external clock source, enabling systems to be assembled with multiple boards synchronised to a common clock, or perhaps to just use an external high accuracy clock source, such as GPSDO or atomic clock. Well, we’re pleased to say that in the last week, despite all odds, our engineering team has managed to squeeze in a U.FL connector on the underside of the board for just this very purpose!

A few people have also asked whether the 2nd transmit and receive channels of the LMS7002M FPRF IC could be connected to additional RF connectors, turning it into a 2x2 MIMO platform. This would mean making the board and power supply circuitry bigger, and designing in additional RF matching networks, etc. And of course the LimeSDR Mini is highly cost optimised, with a smaller FPGA and different USB 3.0 IC also, preventing us to make such substantial changes.

The team are currently busy working on a number of exciting demos and we hope to be able to share these with you very soon, along with the complete hardware design database.

Stay tuned for future updates and once again, thank you for your excitement and support!

Jessica and the LimeSDR Mini Team