Improving Radio-Over-Fiber Systems Using Modulation Instability Phenomenon for Satellite Communication Application

This letter proposes a low-cost, high-gain, low-noise microwave photonic structure using the modulation instability (MI) phenomenon for radio-over-fiber (RoF) systems. Conventionally, in modern satellite communication, the RoF structures always suffer from limitations of modulators that work at the high half-wave voltage (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$V_{\pi}$</tex>) in high frequency and high noise, especially in case of weak signal reception. We demonstrate how the MI phenomenon improves the modulator's bias voltage. Therefore it is also possible to obtain acceptable gain and reduce optical shot noise without any complications by employing the proposed structure. Our suggested RoF structure can operate in the desired frequency band using a fiber switching control system. Therefore, this system can reach a high gain by increasing the fiber length without needing external pumps. As a result, the SNR and the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$V_{\pi}$</tex> improve noticeably.