Influence of the modulation index of Mach–Zehnder modulator on intersatellite microwave photonics links with multiple RF signals

A generalized intersatellite microwave photonics links model to study the influence of the modulation index of Mach–Zehnder modulator on the receiver sensitivity with multiple radio frequency (RF) signals is presented. An exact analytical solution of signal-to-noise and distortion ratio (SNDR) for optical double-sideband (ODSB) and optical single-sideband (OSSB) modulation is deduced with Bessel expansion and Graf's addition theorem. Numerical results show that the receiver sensitivity increases and then decreases as the increase in modulation index, there is an optimum modulation index that maximizes the receiver sensitivity and the larger channel numbers lead to lower receiver sensitivity for maintaining the SNDR at the desired level. In addition, ODSB modulation can be more attractive than OSSB modulation in intersatellite microwave photonics links, since the maximum receiver sensitivity for ODSB modulation is better than that for OSSB modulation.

► A generalized SCM-based intersatellite microwave photonics links model is presented.
► The influence of modulation index of MZM on receiver sensitivity is analyzed.
► An optimum modulation index exits that maximizes the receiver sensitivity.
► The maximum receiver sensitivity of ODSB modulation is better than OSSB modulation.