STMicroelectronics BALFHB-WL-xxD3 Input/Conjugate Matched Balun is an ultra-miniature balun. This device integrates a matching network, balun, and harmonics filter. Matching impedance has been customized for the STM32WL sub-GHz wireless microcontrollers. It uses STMicroelectronics IPD technology on a nonconductive glass substrate, which optimizes RF performances.