How to reduce impedance during high-frequency grounding of a power DTU?

Reducing the high-frequency grounding impedance of the DTU requires optimizing the ground plane design and via layout. A multilayer board with a complete ground plane and a layer thickness ≥35μm is used. High-frequency grounding vias are arranged in an array, with a diameter of 0.3mm and a spacing of 1.5mm, ensuring full connection between the vias and the ground plane. A low-dielectric-constant board material (FR-4, Dk=4.4) is used. The grounding path is short and wide, with a length less than λ/10 (λ being the highest frequency wavelength) and a width ≥5mm. A high-frequency capacitor (100pF) is connected in parallel along the grounding path. During testing, a vector network analyzer is used to measure the grounding impedance; at 100MHz, the impedance should be less than 0.5Ω. Reducing the high-frequency grounding impedance can reduce radiated emissions and improve signal integrity.