URSI 2009, XXIV Simposium Nacional de la Unión Científica Internacional de Radio, Santander
In this work, system level modelling and realistic
simulation and measurement results of a 31 GHz Back-End
Module (BEM) Low-Noise Amplifier (LNA), designed for the
QUIJOTE CMB (Q U I JOint TEnerife CMB) experiment
radiometer, are reported. The signals received by radiometers
can be identified as continuous spectre gaussian white noise
signals. This makes necessary time-domain simulation
techniques and appropriate models for the realistic analysis of
radiometers behaviour. The measured-based modelling of one
BEM´s LNA, its simulation in nominal conditions and the
measurement of the nonlinear characteristic by using filtered
white noise excitation signals, will be shown. Typically, in the
LNAs design process the linearity is not taken into account but,
as we will see, in the radiometers case, the nature of gaussian
noise excitation signals makes amplifiers to present higher
nonlinearity in their characteristics than when using single tone
excitation signals. Therefore, in order to analyze the suitability
of the LNAs nominal operation, linearity figures of merit have
to be obtained, but using realistic excitation signals. In this
paper, the LNAs nonlinear characteristics with gaussian noise
excitation signals have been obtained by simulation and
measurement.
; Pascual Gutiérrez, Juan Pablo
