Theory-Based Contour Plot Analysis for Optimized Power Delivery Network Noise Absorber

Recently, a novel power delivery network (PDN) noise absorber with low | S ₂₁ | is proposed to match the radial port impedance of the incident cylindrical wave, thus preventing high-frequency power noise transmission and further avoiding the cavity resonances at the noise source end. Despite the excellent performance, no analytical formulas can quantify the improvements, and an optimized solution derived more scientifically to minimize power noises is expected. Therefore, this article dives into the cylindrical wave theory and constructs a contour-plot-based methodology for designing the optimized PDN noise absorbers. To validate the proposed method, parallel plates with a ring of optimized PDN noise absorbers are implemented, leading to 6.2% lower self impedance and up to 45.6% lower transfer impedance at 5.5 GHz when compared with the previous fully-matched absorbers’ case. All the measured results agree well with the theory and full-wave simulated results.