Document Type : Original Article
Authors
Arak University
Abstract
In this paper a low noise amplifier (LNA) in the frequency interval of [3-5] GHz is designed and optimized. The design process consists of three parts. At first, the stability of the bipolar junction transistor (BJT) is investigated. Simulation results show that it is unconditionally stable in the whole frequency interval. In the second part, the input and output matching networks are constructed in such a way that the desired transducer power gain (GT=10dB) and possible minimum noise figure (Fn) are achieved simultaneously. In order to achieve approximately constant GT and Fn in the desired frequency interval, the input and output matching networks are finally optimized using least mean square error technique. Once the optimization process is converged, variations of GT and Fn in the whole frequency interval are respectively less than 1dB and 0.5 dB. Besides, the variation of output phase is approximately linear.
Keywords
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