A wideband transformer-coupled frequency quadrupler using an asymmetrical balun in 0.25μm SiGe for backhaul communication. - Sudipta Chakraborty; Xi Zhu 001; Oya Sevimli; Michael Heimlich (ISCAS, 2015)

An Edge-Coupled Marchand Balun With Partial Ground for Excellent Balance in 0.13 μm SiGe Technology. - Sudipta Chakraborty; Leigh E. Milner; Xi Zhu 001; Oya Sevimli; Anthony E. Parker; Michael C. Heimlich (IEEE Trans. Circuits Syst. II Express Briefs, 2021)