STMicroelectronics offer a Balun Transformer BAL-NRF01D3. The ultra-miniature balun is customised for the Nordic Semiconductor circuits such as nRF51422, nRF51822, nRF24AP2-1CH, nRF24AP2-8CH and nRF24LE1 (QFN-32 pins). The balun integrates a matching netw