L-2L de-embedding method with double-T-type PAD model for millimeter-wave amplifier design

For millimeter-wave CMOS circuit design, accurate device models are necessary. Especially an accurate de-embedding method is very important. Hence, precise deembedding of pad parasitics is the first and valuable step to achieve accurate device models. In this work, a new pad modeling based on an L-2L de-embedding is proposed. The pad model is derived with an assumption that characteristic impedance of transmission line becomes constant at high frequency. Every device used in an amplifier is characterized with the proposed de-embedding method, and simulation and measurement results well agree with each other up to 110 GHz.