GILBERT UPCONVERSION MIXERS USING SINGLE-BAND/DUAL-BAND LC CURRENT COMBINERS

Abstract

The 0.35-mu m SiGe BiCMOS high linearity Gilbert upconverters are demonstrate in this article by utilizing NMOS and PMOS transconductance amplifiers (TCAs), respectively. To improve the linearity of a Gilber upconverter, the IF input TCA is rerplaced by a bias-offset differential pair. A reactive LC current combiner is used as the load of the Gilber mixer to double the output current. The upconverter with an NMOS TCA archieves the conversion gain of -4 dB, the OP(ldB) of -11 dBm, and the OIP(3) of 5.5 dBm, whereas the other one with a PMOS TCA has the conversion gain, OP(ldB), and OIP(3) of -6 dB, -11 dBm, and 9.5 dBm, respectively. Furthermore, the LC current combiner can be extended to a dual-band version. The 2.4/5.7 GHz dual-band upconverters is also demonstrated in this work. The conversion gain at 2.4/5.7 GHz is -3/-3.5 dB with the OP(ldB) of -15.5/-15 dBm and the OIP(3) of -2.5/-3 dBm, respectively. (C) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1718-1722, 2009; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/mop.24433