A 77-GHz Marchand balun for antenna applications in BiCMOS technology

Abstract

In this article, the design and measurement of a 77-GHz Marchand balun matched to 50 Ω single-ended and 100 Ω differential-ends using multiple metal layers in silicon technology is discussed. The balun is measured with an insertion loss of 1.8 dB at 77 GHz, an amplitude imbalance of ±1.8 dB, and phase imbalance of ±1.5°. Also, this article presents the effect of parasitic reactance in the load terminations and dummy metal fills on balun's performance. It was found that the interlevel dummy metal fills and increase the insertion and also cause significant amplitude imbalance in the balun especially at frequencies above 50 GHz. © 2011 Wiley Periodicals, Inc.