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 network and harmonics filter. IPD technology to get the most out of RF performance.
· 50 Ω (Ohm) Input · 2.45GHz ISM matched Nordic Semiconductor chips with ultralow power transceivers · Low profile: 595μm after reflow