A 3rd- and 5th-order intermodulation products generator for predistortion of base-station HPAs

This paper presents the design of a circuit to generate 3^rd- and 5^th-order intermodulation (IM3 and IM5) products used for predistortion of base-station high power amplifiers (HPAs). The circuit employs a mixer constructed using two Schottky diodes as a nonlinear device to generate the IM3 products and another mixer of the same configuration to generate the IM5 products using the IM3 products generated. The circuit has been studied using a two-tone signal at a center frequency of 2.2GHz. The simulation and measured results show that the circuit can generate the IM3 and IM5 products effectively and suitable for use in predistortion of base-station HPAs.