Symmetric Monolithic T-coils for Broadband IC Design

A monolithic T-coil fabricated on high-resistivity (2000 Omega-cm) silicon is presented. Mixed-mode S-parameters simplify circuit analysis needed for accurate parameter extraction over a wide bandwidth [19.5 GHz]. Measured |S₁₁| of the 120 mum x 275 mum coil is less than -21 dB [50 MHz-15 GHz] and -17 dB at 19.5 GHz, while the insertion loss is less than 2.2 dB across the full band. The quality of T-coil response is defined into frequency bands for practical use.