The STEVAL-IKR002V4B evaluation daughterboard is based on the SPIRIT1, a sub-GHz low power, low data rate transceiver suitable for ISM bands and wireless M-BUS. The board is equipped with external balun, matching and filter in a single BALF-SPI-01D3 device which optimizes size, RF performances and number of external RF components (from 16 SMD passive components to just 1).