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. Numerical results show that
the preamplifier noise figure determines the minimum laser output power needed
to achieve the desired SNR but affects the optimal DC bias phase shift little.
For a SNR of 20 dB, doubling the preamplifier noise figure results in a
6.36 dB increase in minimum laser output power for rms pointing jitter of
© 2012 Optical Society of America
Equations on this page are rendered with MathJax. Learn more.