Accurate characterization of intermodulation noise in multi carrier wide band power amplifiers based on a digital synthesis of pseudo noise Gaussian stimuli

Abstract : This paper presents an accurate technique for the characterization of intermodulation noise in wide band multi carrier power amplifiers. Band limited pseudo noise stimuli which are generated by using a computer controlled arbitrary waveform generator (Awg) connected to anI/q modulator drive the input of the amplifier under test (Aut). The complex envelopes of the pseudo noises are measured using a sampling scope. A vector error correction is applied in order to remove systematic errors due to the imperfections of the measurement channels. Using this technique, the linearity of L and Ka band amplifiers was characterized by the noise power ratio criterion (Npr). This paper focuses also on the particular attention that must be paid to the statistical properties and peak to average ratio (Par) of pseudo noise test signals which significantly impact theNpr measurement accuracy.