On the Recovery Time of Highly Robust Low-Noise Amplifiers

A. Liero¹, M. Dewitz¹, S. Kühn¹, N. Chaturvedi¹, J. Xu², and M. Rudolph¹

¹ Ferdinand-Braun-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany
² Nanowave Technologies Inc., Etobicoke, ON, Canada M8W 4W3

Published in:
IEEE Trans. Microwave Theory Tech., vol. 58, no. 4, pp. 781-787 (2010).
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Abstract:
Recently, GaN-based low-noise amplifiers (LNAs) were shown to provide high ruggedness together with low noise figure. Since no limiter is required to protect the input, these LNAs allow for simplified receiver architectures. This paper presents an in-depth analysis of the recovery time of a highly rugged LNA. Recovery time is measured in the time domain, and an analytical approximation is developed that allows to estimate and optimize recovery. A new measurement setup is established in order to determine the impact of the overdrive pulse on LNA gain. An X-band LNA is shown as an example. It survives input overdrive powers of up to 46 dBm under pulsed and 40 dBm under continuous wave conditions, with a noise figure of 2.8 dB. Extremely short recovery times below were simulated and measured.

Index Terms:
Amplifier noise, integrated circuit noise, microwave field-effect transistor (FET) amplifiers, monolithic microwave integrated circuit (MMIC) amplifiers, noise, semiconductor device noise.

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