Proceedings of the Asia-Pacific Microwave Conference 2006
Copyright 2006 IEICE
A CMOS Ultra-Wideband Differential Low Noise Amplifier
Timothy B. Merkin, Sungyong Jung, Jean Gao,
The University of Texas at Arlington, Arlington TX, USA 76019;
University, Tempe, AZ, USA 85287
Tel: +1-817-272-1210, E-mail:
This paper presents the design and
simulation of a CMOS Ultra-wideband Low noise
In the design, specific architecture decisions
were made in consideration of system-on-chip
The basic architecture of the LNA
designed herein exhibits a differential amplifier core
with active input and output impedance matching.
Simulations reveal that the LNA maintains a gain of
with a ±0.3
ripple over the band of
Despite the use of an active input matching
stage, the LNA achieved a simulated noise figure
ranging from 3.0-3.5
over the band of operation.
input and output active matching stages maintain less
reflection coefficients, thus successfully
matching with 50
over the bands of 3 – 12GHz and 3 –
— Ultra-Wideband, low noise
amplifiers, communications, analog integrated circuits.
Despite its long history in radio and radar systems,
Ultra-Wideband (UWB) technology just recently
stands poised to offer unprecedented high data rates
combined with low power consumption to many
different commercial application areas.
push for the development of UWB systems has been
fueled by the Federal Communications Commission’s
(FCC) decision to allow unlicensed spectrum usage of
3.1 – 10.6GHz in 2002.
The availability of this “huge
bandwidth” encourages a plethora of bandwidth
demanding, low power applications such as Wireless
Personal Area Networks (WPANs), sensor networks,
imaging systems, vehicular radar systems, and etc.
Also of late, there has been a thrust in research to
develop entire systems-on-chip (SoC).
of its cost advantage and ease of integrating
high-performance digital circuits and high-speed
analog/RF circuits, CMOS technology has emerged as
the top technology for SoCs.
However, one of the biggest impediments to CMOS
SoC development is the “noisy” influence (sometimes
called substrate noise) of nearby digital circuitry on
sensitive analog circuitry.
Although there have been
several other methods proposed for minimizing the
effect of substrate noise, a differential architecture is
known to aid in rejection of some of this type of noise.
By rejecting this noise, differential architectures
increase the robustness of the analog circuitry.
architecture of the Low Noise Amplifier (LNA)
developed in this paper was motivated by these issues.
Considerable research has developed CMOS Low
performance characteristics suitable for the analog
front-end of a UWB wireless system -.
these LNAs employs a differential architecture ,
but the power consumption and noise figure are
relatively high and can be improved upon.