A bias tee's inductor and capacitor need reactance values set well apart from your system impedance to work correctly — but a single L/C pair only covers a limited frequency range before the inductor's self-resonant frequency (SRF) causes it to fail. Enter your frequency range and impedance below to size both components and check whether a single pair will actually work for your design.
How is this calculated?
Both components are sized against your minimum frequency, since that's where each has the hardest job: the inductor's reactance is at its lowest there (hardest to block RF), and the capacitor's reactance is at its highest there (hardest to pass RF). If both work at f_min, they only get better as frequency rises — at least until a real inductor's self-resonant frequency intervenes, which is what the feasibility check above accounts for separately.
Target reactances are set from your margin and impedance choice, then solved for component value: