Publicated in MICROWAVE JOURNAL 2010

1. Flatness Improvement for a Shunt-Peaked
Ultra-Wideband Low Noise Amplifier
H. Garcia-Vazquez, S. L. Khemchandani, J. Arias-Perez and J. del Pino,
Dep. Ingeniería Electrónica y Automática / Instituto Universitario de Microelectrónica Aplicada (IUMA), Universidad de Las Palmas de Gran Canaria, Spain.
Publicated in MICROWAVE JOURNAL
vol. --, pp. --,
2010
Abstract
Abstract−A novel configuration to achieve flat gain in wideband low noise amplifiers is presented. It is composed by
a conventional shunt-peaking resistor decoupled from the cascode stage through a capacitor. A trade-off between
the voltage headroom and bandwidth is obtained improving the traditional shunt-peaking load. As example, two
LNAs for ultra-wideband operating for mode I (3.1-4.8 GHz) are designed in CMOS 0.35 mm technology. The
measured power gain is fairly flat around 10 dB for frequencies ranging from 3.1 to 5 GHz.
Feedback LNA
Measurements & Simulations
Fig. 5 Measured S-parameters for LNA with Fig. 6 Insertion gain (S21) simulation for
modified shunt-peaking and shunt-peaking different LL inductance using conventional
load. shunt-peaking.
Fig. 1Wideband LNA simplified schematic with a wideband input impedance matching.
0
Fig. 7 Measured NF for LNA with modified shunt-peaking and shuntpeaking load.
Figure 5. S11.
Conclusions
In this paper, a novel wideband load configuration is
Fig. 2 Conventional shunt peaking load (a), modified shunt peaking load (b). presented. It is based on a conventional shunt-
peaking resistor decoupled from the cascode stage
through a capacitor. It offers the advantages of
broadband operation and substantially higher gain
flatness than a conventional shunt-peaking load. Its
practical implementation in a standard low cost 0.35
µm process was discussed and verified. The
presented results make the LNA design suitable for
the 3.1 to 4.8 GHz UWB frequency range
Acknowledgement
Fig. 3 Microphotograph of the LNA
Fig. 4 Microphotograph of the This work is partially supported by the Spanish Ministry of
with shunt peaking load. LNA with modified shunt-peaking Science and Innovation (TEC2008-06881-C03-01) and the spanish
load
Ministry of Industry, Tourism and Trade (TSI-020400-2008-71).
INSTITUTO UNIVERSITARIO DE MICROELECTRÓNICA APLICADA (IUMA)
UNIVERSIDAD DE LAS PALMAS DE GRAN CANARIA (ULPGC)