Antenna apparatus, communication apparatus, and image capturing system
An antenna apparatus that comprises an antenna array in which a plurality of active antennas each including an antenna and a semiconductor structure configured to generate or detect an electromagnetic wave are arranged in an array, a coupling line configured to mutually couple two antennas respectively included in at least two active antennas among the plurality of active antennas, and an impedance variable device configured to make an impedance of the coupling line variable is provided.
1 . An antenna apparatus comprising:
an antenna array in which a plurality of active antennas each including an antenna and a semiconductor structure configured to generate or detect an electromagnetic wave are arranged in an array;
a first coupling line configured to mutually couple two antennas respectively included in at least two active antennas among the plurality of active antennas;
a second coupling line bonded to at least one antenna; and
a first impedance variable device coupled to the first coupling line or the second coupling line, and configured to make an impedance of the first coupling line or an impedance of the second coupling line variable,
wherein the second coupling line includes one end portion coupled to the antenna included in one active antenna among the plurality of active antennas and another end portion with an open end not coupled to any of the antennas of the active antennas,
wherein the first impedance variable device is coupled to the open end of the second coupling line.
2 . An antenna apparatus comprising:
an antenna array in which a plurality of active antennas each including an antenna and a semiconductor structure configured to generate or detect an electromagnetic wave are arranged in an array;
a first coupling line configured to mutually couple two antennas respectively included in at least two active antennas among the plurality of active antennas;
a second coupling line bonded to at least one antenna;
a first impedance variable device coupled to the second coupling line, and configured to make an impedance of the second coupling line variable; and
a second impedance variable device coupled to the first coupling line and configured to make an impedance of the first coupling line variable,
wherein the second impedance variable device is coupled to a position that is not an end portion of the first coupling line.
3 . The apparatus according to claim 2 , wherein for first the coupling line that couples the antennas respectively included in the at least two active antennas arranged adjacent to each other in the array arrangement among the plurality of active antennas, a length of a path in a case where the semiconductor structures respectively included in the at least two active antennas are connected via the first coupling line is set based on an electrical length of the electromagnetic wave in the first coupling line.
4 . The apparatus according to claim 3 , wherein for the first coupling line, the length of the path is set to be the electrical length of the electromagnetic wave which is equal to an integer multiple of 2π.
5 . The apparatus according to claim 2 , wherein the position is set such that each of lengths between the position and the semiconductor structures respectively included in the at least two active antennas including the antennas coupled by the first coupling line is based on a wavelength of the electromagnetic wave in the first coupling line.
6 . The apparatus according to claim 5 , wherein the position corresponds to a position of a node of a standing wave of the electromagnetic wave in the first coupling line.
7 . The apparatus according to claim 5 , wherein the position corresponds to a position different from a node of a standing wave of the electromagnetic wave in the first coupling line.
8 . The apparatus according to claim 2 , wherein the first impedance variable device is coupled to each of the antennas respectively included in the plurality of active antennas.
9 . The apparatus according to claim 2 , wherein the first impedance variable device acts to adjust an electrical length of the electromagnetic wave in the second coupling line.
10 . The apparatus according to claim 2 , wherein the first impedance variable device includes a varactor diode.
11 . The apparatus according to claim 2 , wherein the first impedance variable device includes a transistor.
12 . The apparatus according to claim 2 , further comprising a first wiring configured to connect the semiconductor structure and a bias control unit configured to supply a bias signal to the semiconductor structure, and a second wiring configured to connect the first impedance variable device and a phase control unit configured to supply a control signal to the first impedance variable device,
wherein the first wiring and the second wiring are individually controlled.
13 . The apparatus according to claim 2 , wherein in the antenna array, the plurality of active antennas are arranged in a matrix.
14 . The apparatus according to claim 2 , wherein in the antenna array, the plurality of active antennas are arranged at an interval not larger than a wavelength of the electromagnetic wave.
15 . The apparatus according to claim 2 , wherein in the antenna array, the plurality of active antennas are arranged at an interval that is equal to an integer multiple of a wavelength of the electromagnetic wave.
16 . The apparatus according to claim 2 , wherein the antenna is a patch antenna.
17 . The apparatus according to claim 2 , wherein the antenna is a slot antenna.
18 . The apparatus according to claim 2 , wherein the semiconductor structure includes a negative resistance element.
19 . The apparatus according to claim 18 , wherein the negative resistance element is a resonant tunneling diode.
20 . The apparatus according to claim 2 , wherein the second coupling line is capacitively coupled to the antenna.
21 . The apparatus according to claim 2 , wherein the second coupling line is directly coupled to the antenna.
22 . The apparatus according to claim 2 , wherein the electromagnetic wave is an electromagnetic wave in a terahertz band.
23 . A communication apparatus comprising:
an antenna apparatus that comprises
an antenna array in which a plurality of active antennas each including an antenna and a semiconductor structure configured to generate or detect an electromagnetic wave are arranged in an array,
a first coupling line configured to mutually couple two antennas respectively included in at least two active antennas among the plurality of active antennas,
a second coupling line bonded to at least one antenna, and
a first impedance variable device coupled to the first coupling line or the second coupling line, and configured to make an impedance of the first coupling line or an impedance of the second coupling line variable;
a second impedance variable device coupled to the first coupling line and configured to make an impedance of the first coupling line variable, wherein the second impedance variable device is coupled to a position that is not an end portion of the first coupling line;
a transmission unit configured to emit the electromagnetic wave; and
a reception unit configured to detect the electromagnetic wave.
24 . An image capturing system comprising:
an antenna apparatus that comprises
an antenna array in which a plurality of active antennas each including an antenna and a semiconductor structure configured to generate or detect an electromagnetic wave are arranged in an array,
a first coupling line configured to mutually couple two antennas respectively included in at least two active antennas among the plurality of active antennas,
a second coupling line bonded to at least one antenna,
a first impedance variable device coupled to the second coupling line and configured to make an impedance of the second coupling line variable, and
a second impedance variable device coupled to the first coupling line and configured to make an impedance of the first coupling line variable, wherein the second impedance variable device is coupled to a position that is not an end portion of the first coupling line;
a transmission unit configured to emit the electromagnetic wave to an object; and
a detection unit configured to detect the electromagnetic wave reflected by the object.
25 . A communication apparatus comprising:
an antenna apparatus that comprises
an antenna array in which a plurality of active antennas each including an antenna and a semiconductor structure configured to generate or detect an electromagnetic wave are arranged in an array,
a first coupling line configured to mutually couple two antennas respectively included in at least two active antennas among the plurality of active antennas,
a second coupling line bonded to at least one antenna, wherein the second coupling line includes one end portion coupled to the antenna included in one active antenna among the plurality of active antennas and another end portion with an open end not coupled to any of the antennas of the active antennas, and
a first impedance variable device coupled to the first coupling line or the second coupling line, and configured to make an impedance of the first coupling line or an impedance of the second coupling line variable, wherein the first impedance variable device is coupled to the open end of the second coupling line;
a transmission unit configured to emit the electromagnetic wave; and
a reception unit configured to detect the electromagnetic wave.
26 . An image capturing system comprising:
an antenna apparatus that comprises
an antenna array in which a plurality of active antennas each including an antenna and a semiconductor structure configured to generate or detect an electromagnetic wave are arranged in an array,
a first coupling line configured to mutually couple two antennas respectively included in at least two active antennas among the plurality of active antennas,
a second coupling line bonded to at least one antenna, wherein the second coupling line includes one end portion coupled to the antenna included in one active antenna among the plurality of active antennas and another end portion with an open end not coupled to any of the antennas of the active antennas, and
a first impedance variable device coupled to the first coupling line or the second coupling line, and configured to make an impedance of the first coupling line or an impedance of the second coupling line variable, wherein the first impedance variable device is coupled to the open end of the second coupling line;
a transmission unit configured to emit the electromagnetic wave to an object; and
a detection unit configured to detect the electromagnetic wave reflected by the object.