Reconfigurable SiGe low-noise amplifiers with variable miller capacitance
Journal
IEEE Transactions on Circuits and Systems I: Regular Papers
Journal Volume
53
Journal Issue
12
Pages
2567-2577
Date Issued
2006
Author(s)
Abstract
A new input matching method making use of shunt-shunt feedback capacitance is introduced. Based on the new input matching method, reconfigurable SiGe low-noise amplifiers (LNAs) by varying shunt-shunt feedback capacitance are proposed. Two approaches are used to vary the shunt-shunt feedback capacitance. One approach is to switch between two different bias currents while the other is to use a series combination of a switch and a capacitor. Miniaturized fully monolithic reconfigurable SiGe LNAs without emitter degenerative inductors were realized by the above two approaches. The reconfigurable SiGe LNA achieved by switching bias currents only occupies a very small area of 355 μm × 155 μm, excluding measurement pads. This LNA achieves an input return losses (S11) of 27.6 dB, a voltage gain (Av) of 19.8 dB, and a noise figure (NF) of 3.18 dB for 2.4-GHz band when biased at a current of 3.8 mA and can be reconfigured to obtain Av = 20.4/20.3 dB, S11 =-47.1/-24.6 dB and NF = 3.42/3.21 dB for 5.2/5.7-GHz band when bias current is switched to 3 mA. In addition, a 2.4/4.9/5.2/5.7-GHz reconfigurable SiGe LNAs for WLAN applications, whose variable shunt-shunt feedback capacitance is controlled by a switch and a capacitor, was also realized. © 2006 IEEE.
SDGs
Type
journal article