Reduction of In-Band Intermodulation Distortion Products in Radio Frequency Power Amplifiers with Digital Predistortion Linearization

Digital predistortion linearization has been successfully utilized for the reduction of intermodulation distortion (IMD) products of radio frequency (RF) power amplifiers (PA). In a typical amplifier, the signal energy is located at the center of the amplifier passband, and the IMD products extend equally on either side. However, less attention has been paid to a completely different situation in which the signal energy is located at both edges of the amplifier operating bandwidth, and the IMD products are located at the center of its passband. This paper discusses the bandwidth-imposed limitations in digital predistortion of in-band IMD products, and provides experimental results to validate the study