STMicroelectronics BAL-NRF01D3/NRF02D3 50 Ohm Balun Transformer is an ultra miniature balun. They both integrate a matching network and harmonics filter. Matching impedance has been customized for the following Nordic Semiconductor circuits: nRF24LE1 QFN-32 pins, nRF24AP2-1CH, nRF24AP2-8CH, nRF51422, nRF51822, nRF51422-CEAA and nRF51822-CEAA. They use STMicroelectronics IPD technology on non-conductive glass substrate which optimize RF performances. These Balun Transformers have been tested and approved by Nordic Semiconductor in their nRFgo modules.