A Low EM Susceptibility VCO with Four-leaf-clover-shaped Inductor Verified via Chip-level 3D Near-field Measurement Technique

A low electromagnetic susceptibility voltage-controlled oscillator (VCO) utilizing a four-leaf-clover-shaped inductor is demonstrated at 5 GHz by 0.18-µm CMOS. A novel chip-level near-field coupling measurement setup resembling the modern 3D stacked packaging scheme is proposed using the integrated passive device (IPD) technology. The IPD coil embedded in the test carrier can generate EM interference on the flip-chip bonded VCO to verify the proposed high EMI immunity VCO. Compared to a VCO with the conventional spiral inductor, a significant improvement over 30 dB in a wide frequency range (maximum of 32.2 dB) in susceptibility is demonstrated by the VCO with the four-leaf-clover-shaped inductor.