Compact D-band Differential Single-Inductor Power Divider with 0.0059 mm2 Silicon Area and 0.35-dB Minimum Insertion Loss

This paper presents a differential compact power divider realized with a single-inductor footprint in a silicon-germanium (SiGe) back-end-of-line (BEOL) technology for D-band applications. Conventional differential transmission lines (TLs) suffer from parasitic coupling, losses, and area inefficiency. By synthesizing the TLs with lumped components, the proposed design achieves low area occupation, while reducing the inductor dimensions. An analysis confirms the design choice and discuss the selection of the isolation impedance. Three different structures are fabricated and measured to validate the proposed divider with a back-to-back balun configuration is employed to de-embed the loss. This differential divider achieves a minimum loss of 0.35 dB at 166 GHz and 90 μm × 65 μm of area occupation, resulting, to the best knowledge of the authors, in the smallest differential power divider demonstrated at D-band to date.