Impact of pointing errors on performance of an intersatellite microwave photonics link with an optical preamplifier under dual-tone modulation.

The intersatellite microwave photonics link with an optical preamplifier is affected by third-order intermodulation distortion under dual-tone modulation and pointing errors due to beam wander, which would greatly degrade the link performance. An exact analytical expression for signal-to-noise and distortion ratio (SNDR) is derived considering the signal fade caused by the pointing errors of transceiver. It is shown that, given the desired SNDR and the rms random pointing jitter, an optimum modulation index of Mach-Zehnder modulator exists that minimizes laser output power.

Optimization of an analog intersatellite microwave photonics link with an optical preamplifier.

An exact analytical expression of the signal-to-noise ratio (SNR) for an intersatellite microwave photonics link with an optical preamplifier is derived considering the signal fade caused by the pointing errors of the transceiver, and an optimized model for laser output power and direct current (DC) bias phase shift of the Mach-Zehnder modulator is established. It is shown that, given the desired SNR and the root mean square (rms) random pointing jitter, an optimal DC bias phase shift exists that minimizes laser output power. The effects of the optical preamplifier parameters on the minimum laser output power and optimal DC bias phase shift are also examined.

Optimization of intersatellite microwave photonic links by utilizing an optical preamplifier under dual-tone modulation.

An optical preamplifier is utilized to improve the signal-to-noise and distortion ratio (SNDR) of intersatellite microwave photonic links employing a Mach-Zehnder modulator under dual-tone modulation. The resulting SNDR at an appropriate direct current (DC) bias phase shift is additionally investigated without small-signal approximation in order to optimize the performance of all the links. It is observed that the most limiting factor degrading the SNDR performance is changed, and the fundamental power is seen to increase more compared with the power of third-order intermodulation (IM3) plus noise due to the optical preamplifier.