| 摘要 |
In a doppler VOR, a plurality of antennas (1) are arranged equidistantly on a circle (20). Two opposite antenna pairs on the circle are simultaneously activated by a commutator (13) in a manner to simulate as uniform a rotation of two opposite antennas as possible. Reciprocal power dividers (12) are disposed in the lines (15) between the commutator and the antennas. They couple out a given portion of the transmitter signal and transfer it to the two next antennas but one (I, V) in relation to an active antenna (III). These two antennas (I, V), the active antenna (III), and the two intermediate antennas (II, IV), which act as parasitic elements, form an antenna group. Since two adjacent antennas are active simultaneously, two antenna groups are active simultaneously. Their radiation patterns are approximately elliptical. The portion of the extracted energy and the phase shift produced by the RF lines are so chosen that a user-due to the superposition of the two elliptical radiation patterns-sees an approximately circular radiation pattern in all spatial directions.
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