Analog Radio-Over-Fiber Transmitter with Optical Frequency Upconversion and Optimized Optical Carrier-to-Signal Ratio

The performance of an analog radio-over-fiber (A-RoF) transmitter with optical frequency conversion (OFC) is evaluated analytically and experimentally. It employs two push-pull Mach-Zehnder modulators (PP-MZM): one for intermediate frequency (IF) data modulation and another, biased at the null point (NP), for OFC. Results with RF tones and 5 G NR data in FR1 and FR2 bands using QPSK and 16-QAM up to 355 Mbps show enhanced chromatic dispersion tolerance and improved error vector magnitude (EVM). Successful transmission of 200 Mbps 5G NR data through 6 km fiber and 1 m wireless at 28 GHz was achieved with by 4 LO multiplication via MZM overmodulation.