A New Scalable De-embedding Method with a Distributed Pad Model and Lumped Compensation for Pad-Line Discontinuities in RF On-Wafer Characterization

This paper presents a scalable cascaded deembedding technique for precise RF device characterization. The method utilizes the LINE and LINE-PAD-LINE structures to extract pad parasitics without the inaccuracies introduced by lumped assumptions. A T-model is then constructed by combining the extracted pad parasitic model with the LINE and 2LINE structures to compensate for the discontinuities between the interconnection and the pad. By combining transmission line theory with the cascade-configuration concept to characterize the line properties, the method can achieve scalability. The proposed de-embedding method has been validated on the RF parameters of inductor device up to 120 GHz, with an average S -parameter error below 1.4%. The results show that the proposed method achieves higher accur acy compared to traditional lumped-element-based approaches.