A 28-GHz CMOS Transmitter for Silicon Photonics mmWave-over-Fiber 5G Communications

A 28-GHz transmitter is demonstrated in a standard 90-nm CMOS technology for millimeter-wave-overfiber 5G mobile communications. The first stage of the transmitter is a low-noise amplifier performing good in-band noise compared to traditional transimpedance amplifiers. A power amplifier as the output stage provides sufficient output power for indoor wireless transmission. A 2.2 Gb/s on-off keying modulation signal is tested in this work with an eye diagram. In additional to electrical measurement, the transmitter is packaged with a photodiode and verified with an optical signal source to demonstrate the optical to electric signal transmission path. The proposed transmitter exhibits high gain of 36.6 dB, an output power of over 16 dBm, and a low noise Figure performance of 4.5 dB, facilitating a high data rate connection for 5G communication systems.