Back in March we posted about the LimeSDR Mini 1.0 becoming end of life due to component shortages, and a slightly upgraded LimeSDR Mini 2.0 was being planned. The LimeSDR Mini 2.0 has just been released for preorder over on the CrowdSupply crowdfunding website with a price of US$399 + shipping. The first 1000 units are expected to be ready within 14-weeks, with subsequent batches out at 32-weeks.

The new pricing is at quite a premium over the original LimeSDR Mini which released in 2017 for US$139, and the standard LimeSDR which released in 2016 for US$249. However we of course must to take into account the extreme inflation of electronic parts pricing that has occurred over the past few years.

Lime Micro have also noted that the standard LimeSDR has also now been discontinued due to the same supply shortages. The standard LimeSDR had 2x2 RX/TX channels and was capable of a bandwidth of up to 61.44 MHz. In comparison, both versions of the LimeSDR Mini are a 1x1 channel product with 40 MHz of bandwidth.

The LimeSDR Mini 2.0 is almost identical to the LimeSDR Mini 1.0, both still making use of the LMS7002 RF transceiver as the main chip and using the same overall design. The only change is an upgrade to the FPGA, which replaces the Intel MAX 10 16k logic gate FPGA with a significantly more capable Lattice ECP5 44k logic gate FPGA.

Given the new pricing, people on the lookout for a new hacker/research/experimenter SDR in this price range might want to consider this brief comparison to find the best suited SDR for your needs:

• LimeSDR Mini 2.0 - US$399
  1x1 channels, 40 MHz bandwidth, 10 MHz to 3.5 GHz, 12-bits.
   
• HackRF One - US$330 (~$150 clones)
  1x1 channels (half-duplex), 20 MHz bandwidth, 1 MHz to 6 GHz, 8-bits.
   
• PlutoSDR - US$229.18
  1x1 channels, 20 MHz bandwidth, 325 MHz to 3.8 GHz, 12-bits.
   
• bladeRF 2.0 Micro xA4 - US$540
  2x2 channels, 61.44 MHz bandwidth, 47 MHz to 6 GHz. 12-bits.

A recent firmware upgrade to bladeRF SDR devices has brought with it a feature that allows it to double it's instantaneous bandwidth from 61.44 MHz all the way up to 122.88 MHz. The trade off limitation is that the 122.88 MHz bandwidth mode runs at a lower 8-bit ADC bit depth.

This increase bandwidth comes from a discovery made on the AD9361 RF transceiver chip which allows it to essentially be overclocked. However, outputting 122.88 MHz of RF bandwidth at the original 16-bit ADC depth would be impossible due to USB 3.0 bandwidth limitations. So the data is reduced to 8-bits, and then packed into the 16-bit buffer.

One of the use cases of such a wide bandwidth is that now the entire 79 channels of the 2.4 GHz Bluetooth band can be viewed at once.