Design of active inductors in SiGe/SiGe:C processes for RF applications

Applicability of silicon‐based heterojunction bipolar processes is investigated for designing active inductors with high quality factors (Q). Results for grounded type one‐port active inductor incorporating frequency‐dependent as well as frequency‐independent negative resistances are examined. Later, the negative resistance aspect is extended from one‐port to two‐port active inductor circuit to ensure its use as a series element. The enhanced Q‐values of all the inductive circuits are observed in accordance with the theory. Moderately high‐Q values (～100) with considerable inductances (～0.2–1 nH) are obtained in the RF frequency ranges (～5–9 GHz). © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.