Microwave harmonic generation in fiber-optical links

Optical transmission of microwave (MW) and millimeter-wave (MMW) signals have become an intensive research area in the last decade. There is a growing interest in optical processing of MW signals, phased array applications and wireless distribution of broadband data in fiber-fed MMW subscriber access systems. This paper extends the existing models of MW/MMW optical link that are based on optical intensity (see Frigyes, I. et al., Proc. of the 27th EuMC, 1997; Cox III, C.H. et al., MTT, vol.38, no.5, p.501-9, 1990). The model is suitable for estimating harmonic levels of the MW modulation signal generated in the optical path. Considering a MW fiber-optic link, both the optical transmitter and the receiver are responsible for harmonic generation. Furthermore the optical fiber itself inserted between the transmitter and receiver induces harmonics due to dispersion. Exact modelling of harmonic generation requires a calculation based on the optical field instead of purely on a intensity basis (see Hilt, A. et al., 1999; Maury, G. et al., 1999)