Abstract
This article presents a novel Ka-band Marchand balun implemented in 0.13-mu m SiGe bipolar complementary metal-oxide-semiconductor (BiCMOS) process. By combining both edge- and broadside-coupled structures, the new hybrid balun is able to increase the coupling and minimize the balun insertion loss. As compared with conventional edge-coupled or broadside-coupled structures, the proposed balun achieves the lowest insertion loss of 1.02 dB across a wide 1-dB bandwidth from 29.0 GHz to 46.0 GHz, with a core size of 270 mu m x 280 mu m.