In-field calibration antenna using parasitic elements of a phased array antenna
Technologies directed to a customer terminal (CT) with an in-field calibration antenna using parasitic elements of a phased array antenna are described. Once deployed, the CT can establish a communication link with a satellite (SAT) in a satellite network. The CT can also calibrate the phased array antenna using the calibration antenna.
1 . A customer terminal (CT) comprising:
an array antenna comprising a repeating pattern of unit cells, wherein each unit cell comprises:
a first patch element located in a first layer of the array antenna, wherein the first patch element is coupled to a first feed point;
a second patch element located in the first layer, wherein the second patch element is coupled to a second feed point;
a third patch element located in the first layer, wherein the third patch element is coupled to a third feed point;
a metal element located in the first layer, wherein the metal element operates as a parasitic element in a first mode of the CT, the parasitic element to break a periodicity of the repeating pattern of unit cells in the first mode, wherein the metal element operates as a calibration antenna in a second mode of the CT, wherein the metal element is selectively coupled to a fourth feed point in the second mode;
beamforming circuitry coupled to the array antenna; and
a processing device coupled to the beamforming circuitry, wherein the processing device:
establishes, using the array antenna and the beamforming circuitry, a communication link with a satellite (SAT) in the first mode; and
calibrates, using the calibration antenna, the array antenna in the second mode.
2 . The CT of claim 1 , wherein a first metal element of a first unit cell of the repeating pattern of unit cells operates as a calibration antenna that transmits electromagnetic energy, wherein the calibration antenna further comprises a plurality of grounding points, wherein the plurality of grounding points are coupled to a ground potential in the second mode.
3 . The CT of claim 1 , wherein a first metal element of a first unit cell of the repeating pattern of unit cells operates as a calibration antenna that receives electromagnetic energy, wherein the calibration antenna further comprises one or more tuning elements located in one or more layers of the array antenna below the first metal element, wherein the one or more tuning elements are coupled to the fourth feed point.
4 . The CT of claim 3 , wherein the one or more tuning elements comprise:
a first tuning element located in a second layer of the array antenna below the first layer, wherein the first tuning element has a disk shape with a diameter that is less than a width of the metal element; and
a second tuning element located in a third layer of the array antenna below the first layer, wherein the second tuning element has a rectangular shape with a length that is less than the diameter of the first tuning element.
5 . A customer terminal (CT) comprising:
an array antenna comprising a repeating pattern of elements comprising:
one or more transmit (TX) or receive (RX) elements located in a first layer of the array antenna; and
a metal element located in the first layer, wherein the metal element operates as a parasitic element to break a periodicity of the array antenna in a first mode of the CT, and wherein the metal element operates as a calibration antenna in a second mode of the CT.
6 . The CT of claim 5 , wherein the one or more TX or RX elements comprises:
a first patch element located in the first layer, wherein the first patch element is coupled to a first feed point of a first transmitter;
a second patch element located in the first layer, wherein the second patch element is coupled to a second feed point of a second transmitter; and
a third patch element located in the first layer, wherein the third patch element is coupled to a third feed point of a first receiver, and wherein the metal element, in the second mode, is selectively coupled to a fourth feed point of a third transmitter or a second receiver.
7 . The CT of claim 6 , wherein the metal element comprises a same shape as the third patch element.
8 . The CT of claim 6 , wherein the first patch element, the second patch element, and the third patch element are part of unit cell that forms the array antenna.
9 . The CT of claim 5 , further comprising a transmitter, wherein the calibration antenna is a TX antenna, wherein the TX antenna comprises a plurality of grounding points on the metal element, wherein the metal element is coupled to the transmitter and the plurality of grounding points are coupled to a ground potential in the second mode.
10 . The CT of claim 9 , wherein the TX antenna has a percentage bandwidth of approximately 5% with at least 4 dB return loss.
11 . The CT of claim 5 , further comprising a receiver, wherein the calibration antenna is an RX antenna, wherein the RX antenna comprises one or more elements located in one or more layers of the array antenna below the metal element, wherein the metal element and the one or more elements are coupled to the receiver in the second mode.
12 . The CT of claim 11 , wherein the RX antenna has a percentage bandwidth of approximately 16% with at least 4 dB return loss.
13 . The CT of claim 11 , wherein the one or more elements comprise:
a first tuning element located in a second layer of the array antenna below the first layer, wherein the first tuning element has a disk shape with a diameter that is less than a width of the metal element; and
a second tuning element located in a third layer of the array antenna below the first layer, wherein the second tuning element has a rectangular shape with a length that is less than the diameter of the first tuning element.
14 . The CT of claim 11 , wherein the RX antenna further comprises:
a first ring located in the first layer, wherein the first ring surrounds the metal element;
a second ring located in a second layer of the array antenna below the first layer; and
a third ring located in a third layer of the array antenna below the second layer, wherein the second ring and the third ring are coupled to a plurality of grounding points, wherein the first ring and the second ring are coupled together at points in between the plurality of grounding points, wherein the one or more elements comprises a tuning element located in the second layer, and wherein the tuning element has a disk shape with a diameter that is less than a width of the metal element.
15 . The CT of claim 5 , further comprising:
beamforming circuitry coupled to the array antenna; and
a processing device coupled to the beamforming circuitry, wherein the processing device:
establishes, using the array antenna and the beamforming circuitry, a communication link with a satellite (SAT) in the first mode; and
calibrates, using the calibration antenna, the array antenna in the second mode.
16 . A customer terminal (CT) comprising:
an array antenna comprising a repeating pattern of elements comprising:
one or more transmit (TX) or receive (RX) elements located in a first layer of the array antenna;
a metal element located in the first layer, wherein the metal element operates as a parasitic element to break a periodicity of the array antenna in a first mode, and wherein the metal element operates as a calibration antenna in a second mode; and
a receiver coupled to the metal element in the second mode, wherein the calibration antenna comprises:
the metal element;
a first ring located in the first layer, wherein the first ring surrounds the metal element; and
one or more elements located in one or more layers of the array antenna below the first layer.
17 . The CT of claim 16 , wherein the calibration antenna further comprises:
a second ring located in a second layer of the array antenna below the first layer; and
a third ring located in a third layer of the array antenna below the second layer, wherein the second ring and the third ring are coupled to a plurality of grounding points, wherein the first ring and the second ring are coupled together at points in between the plurality of grounding points.
18 . The CT of claim 16 , wherein the one or more elements comprises a tuning element located in a second layer of the array antenna below the first layer, and wherein the tuning element has a disk shape with a diameter that is less than a width of the metal element.
19 . The CT of claim 16 , wherein the calibration antenna has a percentage bandwidth of approximately 16% with at least 4 dB return loss.
20 . The CT of claim 16 , further comprising:
beamforming circuitry coupled to the array antenna; and
a processing device coupled to the beamforming circuitry, wherein the processing device:
establishes, using the array antenna and the beamforming circuitry, a communication link with a satellite (SAT) in the first mode; and
calibrates, using the calibration antenna, the array antenna in the second mode.