Experimental assessment of modulated S-parameters reliability in modeling and testing wideband radiofrequency amplifiers

The paper intends to show the inadequacy of traditional S-parameters in modeling and testing radiofrequency (RF) amplifiers when operating with wideband signals, such as those involved in emerging wireless and/or wireline communication systems. The use of new parameters, the so-called modulated S-parameters, is encouraged and supported. Their measurement no longer requires a sinusoidal signal as test stimulus but a digitally modulated signal of the same type the RF amplifier has to operate with. The reliability of the new parameters is assessed through a number of experiments conducted on a RF amplifier, mainly addressed to very wide bandwidth industrial and commercial applications. Both sinusoidal and modulated S-parameters are evaluated and their ability in describing the real performance of the amplifier when operating with typical wideband signals, such as those involved in third-generation (3G) communication systems, is compared.