Low-Voltage Operational Active Inductor for LNA Circuit

Masaaki SODA
Ningyi WANG

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E93-A    No.12    pp.2609-2615
Publication Date: 2010/12/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E93.A.2609
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on VLSI Design and CAD Algorithms)
Category: Circuit Design
LNA,  active inductor,  low voltage,  

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A low voltage operational active inductor circuit is attractive for spiral-inductor-less LNA because of realizing high gain and low voltage operation simultaneously. In this paper, a simply structured low-voltage operational active inductor to enhance the amplifier gain is introduced and analyzed. This active inductor, which utilizes a transistor load operated in the triode region and a source follower, features a small DC voltage drop suitable for low voltage LNAs. An LNA using the active inductor load was designed with an input matching circuit using 90 nm CMOS technology. The LNA tuned to 2.4 GHz operation has 19.5 dB of the internal gain. In addition, the frequency characteristics are easily varied by changing the capacitance value in the active inductor circuit. The core circuit occupies only 0.0026 mm2 and consumes 2.8 mW with 1.2 V supply voltage.