This paper proposes a quaternary amplitude- shift-keying (4ASK) modulation circuit that suppresses amplitude distortion of the transmitting 4ASK signal. The performance of the proposed circuit is quantitatively verified through numerical calculation in comparison to a conventional alternative. The feasibility of the proposed circuit as integrated in a lithium niobate substrate is also demonstrated: the suppression of amplitude distortion is successfully demonstrated and minimum sensitivity of the transmitted 4ASK signal is 1.7 dB better than that offered by the conventional circuit.
- Amplitude distortion
- Eye-opening penalty
- Mach-Zehnder modulator (MZM)
- Quaternary amplitude shift keying (4ASK)
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics