Analysis of a low noise amplifier with LC-ladder matching and capacitive shunt-shunt feedback

Author

Weststrate, Marnus ; Sinha, Saurabh

Author_Institution

Dept. of Electr., Electron. & Comput. Eng., Univ. of Pretoria, Pretoria, South Africa

fYear

2009

fDate

23-25 Sept. 2009

Firstpage

1

Lastpage

6

Abstract

In this paper a new low noise amplifier configuration is proposed to achieve wideband operation. This configuration consists of an LC-ladder filter and a common-emitter stage employing shunt-shunt capacitive feedback to realize wideband matching. Design equations for this configuration are derived, as well as equations for the important performance measures namely noise figure, gain and IIP3. The results of a design for achieving typical low noise amplifier specifications in the ultra-wideband are calculated from these equations and plotted. Without any optimization S₁₁ of less than -10 dB over the entire frequency band and a minimum noise figure of 2.87 dB are predicted when achieving S₂₁ of 20 dB. These results indicate that very good performance can be attained through the use of this technique.

Keywords

ladder filters; low noise amplifiers; optimisation; LC-ladder filter; LC-ladder matching; capacitive shunt-shunt feedback; common-emitter stage; low noise amplifier configuration; noise figure; optimization S₁₁; Broadband amplifiers; Equations; Feedback; Gain measurement; Low-noise amplifiers; Matched filters; Noise figure; Noise measurement; Operational amplifiers; Wideband; LC-ladder filter; capacitive feedback; input matching; low noise amplifier; ultra-wideband;

fLanguage

English

Publisher

ieee

Conference_Titel

AFRICON, 2009. AFRICON '09.

Conference_Location

Nairobi

Print_ISBN

978-1-4244-3918-8

Electronic_ISBN

978-1-4244-3919-5

Type

conf

DOI

10.1109/AFRCON.2009.5308169

Filename

5308169