Analog Pre-Distortion Circuit for Radio Over Fiber Transmission

This letter presents a novel analog predistortion circuit based on two Schottky diodes that can suppress both the third- and fifth-order nonlinear distortions simultaneously. This circuit is simple, of low cost, and of low power consumption. The predistortion circuit is verified in two radio over fiber (RoF) transmission systems. It is shown that spurious free dynamic range is improved significantly from 1 to 6 GHz. Using the circuit for Wi-Fi wireless signal over RoF, error vector magnitude is improved by up to 3.9 dB.