Designing bias tee and phase shifter for low frequency

hi,
i need help in designing phase shift and bias tee circuit. my RF signal have bandwidth of from ~1kHz to 20khz. maximum DC signal around 4V.

How can I calculate the value of inductor and capacitors needed for bias tee circuit?

where can i find any examples of phase shift schematic?

another question is how to calculate DC block capacitor for low frequency bandwidth with DC value of 2.5V?

thanks