5.8-GHz merged LNA-mixer with on-chip balun

In this paper, the design and application of an on-chip transformer balun for RFIC is presented. Single-ended primary and differential secondary are constructed without using three individual windings for simple layout. Besides, this new topology has the same physical common visual ground point for second winding, which eliminates imbalance due to the potential difference at the ground from a conventional trifilar. Furthermore, this new on-chip balun is successfully applied to the integration of a 5.8-GHz low-noise amplifier (LNA) mixer implemented on SiGe 0.35-μm BiCMOS process then achieves 4.15-dB noise figure (NF), 34.61-dB conversion gain, and a −9.5-dBm input 3rd-order intercept-point with low power consumption of 9 mW. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 508–511, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21394