| 摘要 |
PROBLEM TO BE SOLVED: To expand a beam scannable range by providing a control means or the like which respectively switches the phase-shift quantity of 1st and 2nd phase shifters to specific angular ranges and controls left or right handed circularly polarized wave to be radiated from a radiation element. SOLUTION: A control circuit gives a 1st control signal s41 to a phase-shift circuit 12a constituting a 1st phase shifter 12, a 2nd control signal s42 is similarly given to a phase shift circuit 13 constituting a 2nd phase shifter, and the states of the circuits 12a and 13 are respectively controlled by the signals s41 and s42. When the operation of the two circuits 12a and 13 is controlled in this way, the radiation of a radiation element 11 can respectively be switched to 0 deg. left handed circularly polarized wave, 180 deg. left handed circularly polarized wave, 0 deg. right handed circularly polarized wave, 180 deg. right handed circularly polarized wave. Then, even though three phase shifters are needed in the conventional practice, only two phase shifters are needed so that the unit can be made small-sized and a beam scannable range can be expanded due to this miniaturization.
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