A Fully Integrated 5-6 GHz CMOS Variable-Gain LNA Using Helix-stacked Inductors

This paper presents the design and implementation of a 5-6 GHz CMOS variable-gain low noise amplifier (VGLNA) for IEEE 802.11a WLAN application, fabricated on TSMC 0.18-mum 1P6M standard CMOS process. In this design, miniature chip size and wide gain-control range are achieved by using helix-stacked inductors and current steering technology, respectively. This VGLNA exhibits a noise figure of 3.1 dB, small signal gain of 19 dB, and IIP3 of -9 dBm while in its high gain mode. A gain of -19 dB with IIP3 of -4 dBm were measured while switching into its low gain mode. The chip size is only 0.56 mm
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