English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/46680

Simple nonlinearity evaluation and modeling of low-noise amplifiers with application to radio astronomy receivers

AutorCasas-Reinares, F. J. ; Pascual, J. P.; Fuente, Luisa de la; Artal, E.; Portilla, J.
Fecha de publicaciónjul-2010
EditorAmerican Institute of Physics
CitaciónReview of Scientific Instruments 81(7): 074704 (2010)
ResumenThis paper describes a comparative nonlinear analysis of low-noise amplifiers (LNAs) under different stimuli for use in astronomical applications. Wide-band Gaussian-noise input signals, together with the high values of gain required, make that figures of merit, such as the 1 dB compression (1 dBc) point of amplifiers, become crucial in the design process of radiometric receivers in order to guarantee the linearity in their nominal operation. The typical method to obtain the 1 dBc point is by using single-tone excitation signals to get the nonlinear amplitude to amplitude (AM-AM) characteristic but, as will be shown in the paper, in radiometers, the nature of the wide-band Gaussian-noise excitation signals makes the amplifiers present higher nonlinearity than when using single tone excitation signals. Therefore, in order to analyze the suitability of the LNA’s nominal operation, the 1 dBc point has to be obtained, but using realistic excitation signals. In this work, an analytical study of compression effects in amplifiers due to excitation signals composed of several tones is reported. Moreover, LNA nonlinear characteristics, as AM-AM, total distortion, and power to distortion ratio, have been obtained by simulation and measurement with wide-band Gaussian-noise excitation signals. This kind of signal can be considered as a limit case of a multitone signal, when the number of tones is very high. The work is illustrated by means of the extraction of realistic nonlinear characteristics, through simulation and measurement, of a 31 GHz back-end module LNA used in the radiometer of the QUIJOTE (Q U I JOint TEnerife) CMB experiment.
Descripción6 páginas, 8 figuras, 1 tabla.
Versión del editorhttp://dx.doi.org/10.1063/1.3463295
Aparece en las colecciones: (IFCA) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
http___scitation.aip.org_10.1063_1.pdf644,8 kBAdobe PDFVista previa
Mostrar el registro completo

Artículos relacionados:

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.