Look at a hybrid splitter/combiner magnetics. This is a 50 Ohm 1:1 power splitter/ combiner with coil orientation to offer isolation when balanced.
These are also called DC3's.. With higher turns ratios, we get DC6, DC12, DC20, DC32 etc.
TDK will have data now shared with partner companies. **broken link removed**
But due to non-linearities, generally used for noise suppression not energy storage or conversion.
Usually air coil or printed coil transformers are better for controlled impedances for power coupling transformers or coaxial resonators.