How do I design the power distribution network for a mixed signal PCB with both RF and high speed digital?

How do I design the power distribution network (PDN) for a mixed-signal PCB with both RF and high-speed digital? The PDN must provide clean, low-impedance power to both the RF and digital circuits while preventing noise coupling between them: (1) PDN requirements: RF circuits need: very low noise on the power supply (≤ 1-10 μV/√Hz at the frequency of interest). The power supply noise directly affects the LO phase noise, PA linearity, and receiver sensitivity. Digital circuits generate: high-current transients (simultaneous switching noise, SSN) that create voltage ripple on the PDN. These transients have spectral content from DC to the clock harmonics (> 10 GHz). The challenge: keeping the digital noise out of the RF supply while sharing the same PCB ground and power infrastructure. (2) PDN architecture: separate voltage regulators: use independent LDO (Low Drop-Out) regulators for RF supplies. LDOs provide 40-70 dB of supply noise rejection (PSRR) at frequencies below 1 MHz. Above 1 MHz: LDO PSRR degrades; rely on decoupling capacitors. Never power RF circuits from a switching regulator (buck/boost) output without additional filtering (switcher noise is 30-50 dB worse than LDO noise). Ferrite bead isolation: place a ferrite bead between the digital and RF power planes (or traces). The ferrite bead provides 10-30 dB of isolation at 100 MHz-1 GHz. Below the ferrite bead: use a bulk capacitor (10-100 μF) on the digital side, and decoupling caps (100 nF, 10 nF) on the RF side. Decoupling capacitors: RF side: 100 pF-10 nF, placed within 2 mm of the IC power pins. Value selected for the RF operating frequency. Avoid X5R/X7R capacitors near RF circuits (piezoelectric noise). Use NP0/C0G dielectric for RF decoupling. Digital side: 100 nF, 10 nF, 1 nF multi-value decoupling for broadband impedance. Bulk capacitors (10-100 μF) for low-frequency transients. (3) Ground strategy: single ground plane (preferred): use one continuous ground plane for both RF and digital. Never split the ground plane (creates radiating slots and ground loops). Use ground stitching vias to maintain low-impedance ground between RF and digital. Isolate the return current paths: route digital signals away from the RF section so their return currents do not flow under the RF circuits.