Impact of Mach-Zehnder Modulator Chirp on Radio over Fiber Links



The impact of Mach-Zehnder modulator (MZM) chirp on single sideband (SSB) and carrier suppressed double sideband (CS-DSB) modulation radio over fiber (RoF) links are investigated and simulated. Finite extinction ratio and drive signal unbalanced ratio of non-ideal MZM are considered, power variation of target microwave signal and harmonic suppression are calculated and evaluated. Our results suggest that unbalanced ratio could be optimized to minimized the power variation owing to the finite extinction ratio and improve the harmonic suppress ratio in the two kinds of RoF links. However, harmonic suppression ratio declined rapidly with the decrease of extinction ratio in the CS-DSB RoF link. For a non-ideal modulator with low extinction ratio, high quality microwave signal could be obtained in the SSB RoF link while an additional filter is required to suppress the unwanted harmonic components in the CS-DSB RoF link.


Microwave photonics Radio over fiber Mach-Zehnder modulator Chirp modulation 


  1. 1.
    A. J. Seeds, Microwave photonics. IEEE Transactions on Microwave Theory and Techniques 50(3), 877–887 (2002).CrossRefGoogle Scholar
  2. 2.
    G. H. Qi, J. P. Yao, J. Seregelyi, S. Paquet, and C. Bélisle, Generation and distribution of a wide-band continuously tunable millimeter-wave signal with an optical external modulation technique. IEEE Transactions on Microwave Theory and Techniques 53(7), 3090–3097 (2005).Google Scholar
  3. 3.
    H. Schmuck, Comparison of optical millimetre-wave system concepts with regard to chromatic dispersion. Electronics Letters 31(21), 1848–1849 (1995).CrossRefGoogle Scholar
  4. 4.
    G. H. Smith, D. Novak et al., Overcoming chromatic dispersion effects in fiber-wireless systems incorporating external modulators. IEEE Transactions on Microwave Theory and Techniques 45(8), 1410–1415 (1997).CrossRefGoogle Scholar
  5. 5.
    J. J. O’Reilly, P. M. Lane, R. Heidemann, and R. Hofstetter, Optical generation of very narrow linewidth millimeter wave signals. Electronics Letters 28(25), 2309–2311 (1992).Google Scholar
  6. 6.
    J. L. Corral, J. Marti, and J. M. Fuster, General expressions for IM/DD dispersive analog optical links with external modulation or optical upconversion in a Mach–Zehnder electrooptical modulator. IEEE Transactions on Microwave Theory and Techniques 49(10), 1968–1976 (2001).CrossRefGoogle Scholar
  7. 7.
    H. Kim, and A. H. Gnauck, Chirp characteristics of dual-drive Mach-Zehnder modulator with a finite DC extinction ratio. IEEE Photonics Technology Letters 14(3), 298–301 (2002).CrossRefGoogle Scholar
  8. 8.
    B. Davies, and J. Conrad, Hybrid modulator structures for subcarrier and harmonic subcarrier optical single sideband. IEEE Photonics Technology Letters 10(4), 600–602 (1998).CrossRefGoogle Scholar
  9. 9.
    A. Loayssa, C. Lim et al., simple optical single-sideband modulator for fiber-radio applications. Electronics Letters 39(1), 97–99 (2003).CrossRefGoogle Scholar
  10. 10.
    J. J. O’Reilly, and P. M. Lane, Remote delivery of video services using mm-wave and optics. Journal of Lightwave Technology 12(2), 369–375 (1994).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.College of Science, China Three Gorges UniversityHubeiChina
  2. 2.Wuhan National Laboratory for Optoelectronics (WNLO)Huazhong University of Science and TechnologyHubeiChina

Personalised recommendations