Photonic Generation of M-QAM/M-ASK Signals at Microwave/Millimeter-Wave Band Using Dual-Drive Mach-Zehnder Modulators With Unequal Amplitudes

• Published in: Journal of lightwave technology 2008-08, Vol.26 (15), p.2604-2610
• Main Authors: Zhang, Ye, Xu, Kun, Zhu, Ran, Li, Jianqiang, Wu, Jian, Hong, Xiaobin, Lin, Jintong
• Format: Article
• Language: English
• Subjects: Amplitude modulation; Amplitude shift keying; Amplitude shift keying (ASK); Amplitudes; Applied sciences; Architecture; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Information, signal and communications theory; Integrated optics. Optical fibers and wave guides; Keying; Mach-Zehnder modulator (MZM); Microwave generation; Microwave theory and techniques; Microwaves; Millimeter wave technology; Modulation; Modulation, demodulation; Modulators; Optical and optoelectronic circuits; Optical attenuators; Optical fiber communications; Optical modulation; Optical telecommunications; photonic vector modulation (PVM); Photonics; Quadrature amplitude modulation; quadrature amplitude modulation (QAM); radio-over-fiber (RoF); Signal and communications theory; Signal generation; Signal generators; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Tunable circuits and devices
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2008.927597

Based on photonic vector modulation (PVM) techniques, several novel schemes are proposed to generate 4-ary amplitude shift keying (4-ASK), 16-ary quadrature amplitude modulation (16-QAM), and 16-ary amplitude shift keying (16-ASK) signals at microwave/millimeter-wave (mm-wave) band. First, a 4-ASK signal generation architecture based on dual-drive Mach-Zehnder modulators (MZMs) with unequal amplitudes is proposed and experimentally demonstrated. Then by combining two 4-ASK signal generation schemes in parallel, PVM architectures for 16-QAM and 16-ASK signal generation are proposed employing three MZMs, a tunable optical delay line (ODL), and an optical attenuator. The detailed theoretical analysis, experiment, and simulation certification of these structures are carried out. Compared with the conventional methods, the electronic driven circuits in the proposed schemes are simplified by employing PVM techniques.