AM/FM noise in fiber optic links for radar antenna remoting

The authors examined the noise performance of several optical links using off-the-shelf components used principally for the cable TV industry. AM and FM noise performance was measured in circuits containing components and fiber lengths that would be encountered in a real antenna application. Attention was focused on noise in the close-to-carrier region (in the frequency domain), which is of concern in radars using Doppler processing. The noise performance close to the carrier is shown to be sensitive to optical reflections in the link as well as to noise from the laser source. Well-engineered links of either type are adequate to support clutter suppression requirements in airborne and ground-based radar antenna remoting applications.<>