摘要：

IBER-OPTIC microwave and millimeter-wave (MW)links, which are subject to a still increasing interest, can be implemented either by the use of direct detection (DD) techniques or remote heterodyne detection (RHD) techniques.' Many such links have been proposed, analyzed, and experimented. In the DD-links, the MW-signal is intensity modulated onto the optical carrier from a laser. The optical signal is then transmitted through the optical fiber, and the MW-signal is recovered by DD in a photo-diode. In the RHD- links, two phase correlated optical carriers are generated, in a dual-frequency laser transmitter, with a frequency offset equal to the desired MW-frequency. Further, one of the optical carriers is modulated by the information to be contained in the MW-signal. Both optical signals are then transmitted through the optical fiber, and the MW-signal is generated by heterodyning of the two optical signals in a photo-diode. In both approaches the chromatic fiber-dispersion becomes a limiting factor for the transmission distance when the microwave signals are in the above 20 GHz regime.The effect of chromatic dispersion is well described for both DD and coherent optical communication systems for transmission of digital baseband signals (see [l], [2] and

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