| 摘要 |
An array antenna is steered by moving a set of optical filters of different optical lengths between a number of light signal sources and an array antenna elements. By changing the lengths, hence the time delays, of a plurality of the signal paths between the light signal source and the antenna array elements, the wave front can be steered. Each delay path comprises a selected fiber optic line and a fixed electrical delay line. In one embodiment the fiber optical lines assume a parabolic distribution in time delay. In another embodiment, the fiber optical lines assume a cosinusoidal distribution in time delay. Signals are fed to the fiber optic path through a laser diode and exit from the path through a photo-diode. The fiber optic lines are mounted on a rotatable disk, with two ends diametrically located at two different radii. The laser diodes are mounted on a stationary disk and are aligned with one end of the fiber optic line on the rotatable disk, and the photo-diodes are mounted on the same stationary disk and are aligned to the second end of the fiber optic line. The rotatable disk is actuated by stepping motor to insure alignment of the two disks.
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