| CPC H01Q 21/0037 (2013.01) [H01Q 3/44 (2013.01); H01Q 9/0457 (2013.01); H01Q 21/0006 (2013.01); H01Q 21/065 (2013.01); H01Q 21/08 (2013.01)] | 5 Claims |
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1. An array antenna system capable of beam steering and impedance control, the array antenna system comprising:
an active radiation layer including a row of a plurality of unit cells and a control circuit to control properties of each unit cell from the plurality of unit cells, the row of the plurality of unit cells including a first unit cell and a second unit cell that is adjacent to the first unit cell in the row without another unit cell from the plurality of unit cells between the first unit cell and the second unit cell;
a plurality of patch antennas on the row of the plurality of unit cells, the plurality of patch antennas including a first patch antenna placed on the first unit cell and a second patch antenna placed on the second unit cell; and
a single feed line including a first end that extends in a first direction, a second end that extends in the first direction and is spaced apart from the first end, an upper surface that is between the first end and the second end and extends in a second direction that is different from the first direction, and one or more slots,
wherein the row of the plurality of unit cells is arranged on the upper surface of the single feed line and the first end is configured to receive waves that propagate from the first end to the second end and excite the plurality of patch antennas that are on the row of the plurality of unit cells through the active radiation layer and the one or more slots,
wherein the first unit cell includes a first liquid crystal and the second unit cell includes a second liquid crystal that is physically separated from the first liquid crystal, the first liquid crystal having a dielectric constant that varies based on an applied voltage to the first unit cell, and the second liquid crystal having a dielectric constant that varies based on applied voltage to the second unit cell,
wherein the control circuit applies a first voltage to the first unit cell such that the first liquid crystal has a first dielectric constant based on the first voltage and the first unit cell emits a wave having a first radiation property based on the first dielectric constant of the first liquid crystal, and the control circuit applies a second voltage to the second unit cell that is different from the first voltage such that the second liquid crystal has a second dielectric constant that is different from the first dielectric constant based on the second voltage and the second unit cell emits a wave having a second radiation property that is different from the first radiation property based on the second dielectric constant of the second liquid crystal, and beam steering and impedance control of the array antenna system is enabled by control of the active radiation layer such that the first unit cell and the second unit cell radiate a beam pattern in a broadside direction with respect to the single feed line and the beam pattern is controlled by a combination of the first dielectric constant of the first unit cell and the second dielectric constant of the second unit cell,
wherein the control circuit controls radiation properties of waves emitted by the plurality of unit cells including radiation amplitude and phase, and controls the impedance of the plurality of unit cells for impedance matching without a separate impedance tuner by independently applying different voltages to the plurality of unit cells.
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