SX1250 Multi-band Sub-GHz RF Front End Semtech SX1250 Multi-band Sub-GHz RF Front End is designed to work with the SX1302 baseband engine, to design a high-performing LoRa® or LoRaWAN gateway. Semtech SX1250 Front End covers any frequency band below 1GHz, making the device ideal for license-free band support.