LimeFEA mPCIe Full is a combination of an adapter which allows LimeSDR XTRX to be used in a full-size PCIe x4 or larger slot, and a 2x2 MIMO RF front-end (RFE) which integrates low noise amplifiers (LNAs) in the receive paths (100 MHz to 4 GHz receive frequency range) and power amplifier (PA) drivers in the transmit paths (100 MHz to 6 GHz transmit frequency range).

LimeFEA mPCIe Lite is a cost-reduced variant that does not populate the the RF front-end and other features.

Full vs Lite

LimeFEA mPCIe Full

LimeFEA mPCIe Lite

LimeFEA mPCIe Full RF Path

Measurements in the above table were made by feeding a -30 dBm signal to the TXin A/B connectors and then measuring signal power at TRX A/B. The results compared with the amplifier (TQP3M9018) manufacturer specified gain value is shown. Note that the results do not account for any cable losses.

TDD switching is controlled via a LimeSDR XTRX GPIO pin and enables a single RF connection to be used for transmit and receive, e.g., with LTE-TDD and 5G NR TDD operation.

Any RF cables, such as SMA-to-U.FL pigtails for the PCIe bracket, should be ordered separately.

JTAG Programming

The JTAG feature can be used to program the LimeSDR XTRX if the flash has somehow become corrupted or an incorrect programming file used. It also goes without saying that this will prove invaluable to those developing custom FPGA gateware for LimeSDR XTRX.

Support & Documentation

For more information, including pinouts and component lists, see the MyriadRF documentation for LimeFEA mPCIe.