Antenna device and communication system

Abstract

This antenna device is provided with a first array antenna provided with a plurality of antenna elements, a first horn antenna for performing at least one of transmission to and reception from the first array antenna, a second horn antenna being a primary radiator, a transfer path for transferring a signal between the first horn antenna and the second horn antenna, and an adjustment mechanism for adjusting directivity of at least one of an output signal from the second horn antenna and an input signal to the second horn antenna. The adjustment mechanism is at least one of a parabolic antenna and a lens.

Description

Antenna Device and Communication System

[0001] The present invention relates to an antenna device and a communication system. This application claims priority based on Japanese Patent Application No. 2024-173269 filed in Japan on October 2, 2024, and incorporates its content herein by reference.

[0002] Conventionally, an antenna device for performing wireless communication has been used (see, for example, Patent Document 1). When performing wireless communication between an aircraft and the ground, the gain of the antenna mounted on the aircraft is limited. Therefore, for the antenna device installed on the ground, an antenna having a large gain, such as a large-scale array antenna, is used.

[0003] Japanese Patent No. 6409676

[0004] In the above antenna device, since a large-scale array antenna or the like is used, the device may become large. Also, when performing wireless communication with an aircraft, a long communication distance requires a large amount of power. Therefore, an antenna having a plurality of RFICs is often used. Due to such circumstances, the device may become large.

[0005] An aspect of the present invention aims to provide an antenna device and a communication system that can be miniaturized.

[0006] The antenna device according to the first aspect of the present invention includes a first array antenna including a plurality of antenna elements, a first horn antenna that performs at least one of transmission and reception with respect to the first array antenna, a second horn antenna that is a primary radiator, a transmission line that transmits a signal between the first horn antenna and the second horn antenna, and an adjustment mechanism that adjusts the directivity of at least one of an output signal from the second horn antenna and an input signal to the second horn antenna, wherein the adjustment mechanism is at least one of a parabolic antenna and a lens.

[0007] According to this configuration, the second horn antenna has a smaller aperture area and a wider directivity than the array antenna. Therefore, the focal length can be shortened compared to the case where an array antenna is used as the primary radiator. Thus, the antenna device can be miniaturized.

[0008] An antenna device according to a second aspect of the present invention is an antenna device according to the first aspect, wherein the aperture area of ​​the second horn antenna is smaller than the aperture area of ​​the first horn antenna.

[0009] An antenna device according to a third aspect of the present invention is an antenna device according to the first or second aspect, wherein the aperture area of ​​the first horn antenna is 0.9 to 1.1 times the area of ​​the radiating surface of the first array antenna.

[0010] An antenna device according to a fourth aspect of the present invention is an antenna device according to any one of the first to third aspects, wherein the distance L between the first horn antenna and the first array antenna is L < 2D, where D is the maximum straight-line distance of the radiating surface of the first array antenna and λ is the wavelength of the frequency used. ２ It satisfies / λ.

[0011] An antenna device according to a fifth aspect of the present invention is an antenna device according to any one of the first to fourth aspects, wherein the plurality of antenna elements comprises one or more inner antenna elements and outer antenna elements adjacent to the outer side of the inner antenna elements, and the phase of the signal radiated from the outer antenna elements is ahead of the phase of the signal radiated from the inner antenna elements.

[0012] An antenna device according to the sixth aspect of the present invention is an antenna device according to any one of the first to fifth aspects, further comprising a bandpass filter provided in the transmission line.

[0013] An antenna device according to the seventh aspect of the present invention is an antenna device according to any one of the first to sixth aspects, wherein the first array antenna is an antenna module on which an RFIC equipped with a phase shifter and an amplifier is mounted.

[0014] An antenna device according to the eighth aspect of the present invention is an antenna device according to any one of the first to seventh aspects, wherein the first array antenna, the first horn antenna, and the second horn antenna correspond to a plurality of polarizations, and the plurality of transmission lines are provided in accordance with the plurality of polarizations.

[0015] An antenna device according to the ninth aspect of the present invention is an antenna device according to any one of the first to eighth aspects, wherein the antenna device further comprises the adjustment mechanism and an attitude adjustment mechanism for adjusting the orientation of the second horn antenna.

[0016] An antenna device according to the tenth aspect of the present invention is an antenna device according to any one of the first to ninth aspects that can transmit to and receive from an aerial object.

[0017] A communication system according to an eleventh aspect of the present invention comprises a first antenna device which is an antenna device according to the tenth aspect, and a second antenna device mounted on the aircraft, wherein the first antenna device and the second antenna device are equipped with the same type of phase shifter, the same type of amplifier, and the same type of frequency converter.

[0018] A communication system according to a twelfth aspect of the present invention is a communication system according to an eleventh aspect, wherein the second antenna device comprises a second array antenna, the first array antenna of the first antenna device and the second array antenna of the second antenna device are antenna modules on which an RFIC is mounted, and the antenna module of the first antenna device and the antenna module of the second antenna device are antenna modules of the same type.

[0019] A communication system according to a thirteenth aspect of the present invention is a communication system according to an eleventh or twelfth aspect, wherein the aircraft is capable of flying at an altitude of 60,000 feet or more.

[0020] One aspect of the present invention provides an antenna device and a communication system that can be miniaturized.

[0021] This is a configuration diagram of a communication system equipped with a first antenna device according to an embodiment. This is a configuration diagram of the array antenna of the first antenna device according to the first embodiment. This is a schematic diagram of the antenna elements, RFIC, and frequency converter of the array antenna of the first antenna device according to the first embodiment. This is a schematic diagram of the second antenna device of the communication system according to an embodiment. This is a configuration diagram of the array antenna of the second antenna device. This is a schematic diagram of the antenna elements, RFIC, and frequency converter of the second antenna device. This is a configuration diagram of the first antenna device according to the second embodiment. This is a configuration diagram of the first antenna device according to the third embodiment. This is a configuration diagram of the first antenna device according to the fourth fifth embodiment.

[0022] The antenna device and communication system according to the embodiment will be described below with reference to the drawings.

[0023] [Communication System] Figure 1 is a configuration diagram of a communication system 300 according to an embodiment. Figure 2 is a configuration diagram of the array antenna 1 of the first antenna device 100. Figure 3 is a schematic diagram of the antenna element 11, RFIC 12 and frequency converter 13 of the array antenna 1.

[0024] As shown in Figures 1 and 4, the communication system 300 includes a first antenna device 100 (antenna device) and a second antenna device 200.

[0025] [First Antenna Device] (First Embodiment) The first antenna device 100 according to the first embodiment includes an array antenna 1 (first array antenna), a first horn antenna 2, a second horn antenna 3, a transmission line 4, and a parabolic antenna 5 (adjustment mechanism). The first antenna device 100 is installed, for example, on the ground.

[0026] As shown in Figures 2 and 3, the array antenna 1 comprises a plurality of antenna elements 11, one or more RFICs 12, one or more frequency converters 13, and a substrate 14. The array antenna 1 is, for example, a phased array antenna.

[0027] The X and Y directions are parallel to the first main surface 14a of the substrate 14. The X and Y directions are orthogonal to each other. The Z direction is orthogonal to the X and Y directions. That is, the first main surface 14a of the substrate 14 is parallel to a plane orthogonal to the Z direction. A plan view is a view in the Z direction. +Z is one direction along the Z direction, which is the direction towards the viewer in Figure 2. One side in the Z direction (the viewer in Figure 2) is called the +Z side.

[0028] In a plan view, the substrate 14 is rectangular in shape, having a pair of sides that align with the X direction (extending parallel to the X direction) and a pair of sides that align with the Y direction (extending parallel to the Y direction). The first main surface 14a is the +Z side surface of the substrate 14. The substrate 14 is, for example, square in shape.

[0029] The antenna element 11 is formed on the first main surface 14a of the substrate 14. The antenna element 11 is rectangular in shape, for example, having a pair of sides that align with the X direction (extending parallel to the X direction) and a pair of sides that align with the Y direction (extending parallel to the Y direction). The antenna element 11 is made of a conductive material such as metal (copper, etc.).

[0030] Multiple antenna elements 11 are arranged in a rectangular grid (matrix) in the X and Y directions. In this embodiment, the antenna elements 11 are arranged in a total of 64 rectangular grids, with 8 in the Y direction and 8 in the X direction. The +Z side of the antenna element 11 is the radiating surface 11a.

[0031] Multiple antenna elements 11 form a first antenna element group 21, a second antenna element group 22, a third antenna element group 23, and a fourth antenna element group 24. In Figure 2, the first antenna element group 21 is shown in the darkest color. The second antenna element group 22, the third antenna element group 23, and the fourth antenna element group 24 are shown in colors that increase in brightness in that order. Here, the brightness of the colors representing the antenna element groups 21, 22, 23, and 24 in Figure 2 is represented by the density of points (number of points per unit area). That is, in Figure 2, a large number of points per unit area attached to the antenna elements 11 constituting the antenna element groups 21, 22, 23, and 24 is referred to as "shown in a dark color," and a small number of points per unit area is referred to as "shown in a light color."

[0032] The first antenna element group 21 is located in the central part of the substrate 14. The first antenna element group 21 consists of four antenna elements 11 (inner antenna elements). The four antenna elements 11 are arranged in a rectangular grid pattern, with two in the Y direction and two in the X direction. The antenna elements 11 that make up the first antenna element group 21 are "antenna elements 11A".

[0033] The second antenna element group 22 consists of 12 antenna elements 11 (outer antenna elements) adjacent to the first antenna element group 21 on its outside. The antenna elements 11 constituting the second antenna element group 22 are arranged in a rectangular shape surrounding the first antenna element group 21. The antenna elements 11 constituting the second antenna element group 22 are "antenna elements 11B".

[0034] The third antenna element group 23 consists of 20 antenna elements 11 adjacent to the second antenna element group 22 on the outside. The antenna elements 11 constituting the third antenna element group 23 are arranged in a rectangular shape surrounding the second antenna element group 22. The antenna elements 11 constituting the third antenna element group 23 are "antenna elements 11C". If antenna elements 11B are considered inner antenna elements, then antenna elements 11C correspond to outer antenna elements.

[0035] The fourth antenna element group 24 consists of 28 antenna elements 11 adjacent to the outside of the third antenna element group 23. The antenna elements 11 constituting the fourth antenna element group 24 are arranged in a rectangular shape surrounding the third antenna element group 23. The antenna elements 11 constituting the fourth antenna element group 24 are "antenna elements 11D". If antenna elements 11C are considered inner antenna elements, then antenna elements 11D correspond to outer antenna elements.

[0036] As shown in Figure 3, the antenna element 11 is electrically connected to the RFIC 12 via the signal line 15. The antenna element 11 receives an RF signal and emits electromagnetic waves.

[0037] The RFIC (Radio Frequency Integrated Circuit) 12 is an integrated circuit that processes RF (Radio Frequency) signals. The RFIC 12 supplies RF signals to the antenna element 11 via the signal line 15. The RFIC 12 includes a phase shifter 16 and an amplifier 17. The phase shifter 16 can set the phase of the RF signal. The amplifier 17 amplifies the RF signal as needed.

[0038] The RFIC 12 is mounted, for example, on the side of the substrate 14 opposite to the first main surface 14a. The array antenna 1 is an antenna module on which the RFIC 12 is mounted.

[0039] As shown in Figure 2, the antenna element 11A constituting the first antenna element group 21 and the antenna element 11B constituting the second antenna element group 22 are connected to different RFICs 12 (see Figure 3). By adjusting the phase shifter 16, the phase of the RF signal radiated from antenna element 11B can be made to advance the phase of the RF signal radiated from antenna element 11A.

[0040] Similarly, the phase of the RF signal radiated from antenna element 11C can be made to advance the phase of the RF signal radiated from antenna element 11B. The phase of the RF signal radiated from antenna element 11D can also be made to advance the phase of the RF signal radiated from antenna element 11C.

[0041] Thus, by advancing the phase of the RF signal radiated from the outer antenna element 11 with respect to the phase of the RF signal radiated from the adjacent inner antenna element 11, the RF signal radiated from the array antenna 1 can be aligned with the equiphase surface of the first horn antenna 2.

[0042] The frequency converter 13 is provided on the input side (i.e., the output side during reception) of the RFIC 12 during transmission. The frequency converter 13 can convert the frequency of the RF signal input to the RFIC 12 during transmission of the RF signal. The frequency converter 13 can convert the frequency of the RF signal output from the RFIC 12 during reception of the RF signal.

[0043] As shown in FIG. 1, the first horn antenna 2 is arranged with the aperture 2a facing the radiation surface 1a of the array antenna 1. The first horn antenna 2 performs at least one of transmission and reception with respect to the array antenna 1. It is desirable that the first horn antenna 2 can perform both transmission and reception, but it may have only a transmission function or only a reception function.

[0044] The aperture area (the area of the aperture 2a) of the first horn antenna 2 is preferably 0.9 times to 1.1 times the area of the radiation surface 1a of the array antenna 1. The area of the radiation surface 1a of the array antenna 1 is the same as the sum of the areas of the radiation surfaces 11a of the plurality of antenna elements 11.

[0045] The maximum linear distance of the radiation surface 1a of the array antenna 1 is, for example, the maximum outer dimension of the radiation surface 1a of the array antenna 1. In the present embodiment, since the radiation surface 1a is rectangular, the maximum linear distance is the length of the diagonal of the radiation surface 1a. Let the maximum linear distance of the radiation surface 1a be D. Let the wavelength of the RF signal to be used be λ. The distance L between the first horn antenna 2 and the array antenna 1 satisfies L < 2D ２ / λ is desirable.

[0046] The second horn antenna 3 is arranged with its aperture 3a facing the parabolic antenna 5. The second horn antenna 3 is an example of a primary radiator. The second horn antenna 3 performs at least one of transmission and reception with respect to the parabolic antenna 5. It is desirable that the second horn antenna 3 can perform both transmission and reception, but it may also have only a transmission function or only a reception function.

[0047] It is desirable that the aperture area (the area of the aperture 3a) of the second horn antenna 3 is smaller than the aperture area of the first horn antenna 2. Thereby, the focal length can be shortened.

[0048] The transmission line 4 connects the first horn antenna 2 and the second horn antenna 3. The transmission line 4 transmits an RF signal between the first horn antenna 2 and the second horn antenna 3. Examples of the transmission line 4 include a coaxial cable or a waveguide.

[0049] The parabolic antenna 5 can adjust the directivity for at least one of the output signal from the second horn antenna 3 and the input signal to the second horn antenna 3. The parabolic antenna 5 performs wireless communication (at least one of transmission and reception) with respect to the second antenna device 200 (see FIG. 4) of the flying object 400.

[0050] [Second Antenna Device] FIG. 4 is a schematic diagram of the second antenna device 200. FIG. 5 is a configuration diagram of the array antenna 201 of the second antenna device 200. FIG. 6 is a schematic diagram of the antenna element 11, RFIC 12, and frequency converter 13 of the second antenna device 200. Among the configurations of the second antenna device 200, the configurations common to the first antenna device 100 are denoted by the same reference numerals and the description thereof is omitted.

[0051] As shown in FIG. 4, the second antenna device 200 includes an array antenna 201 (second array antenna). The array antenna 201 performs wireless communication (at least one of transmission and reception) with respect to the first antenna device 100 (see FIG. 1).

[0052] As shown in Figures 5 and 6, the array antenna 201, like the array antenna 1 (see Figure 2), comprises a plurality of antenna elements 11, one or more RFICs 12, one or more frequency converters 13, and a substrate 14. The array antenna 201 may have the same configuration as the array antenna 1. The array antenna 201 is an antenna module on which the RFICs 12 are mounted.

[0053] It is desirable that array antenna 1 (see Figure 2) and array antenna 201 (see Figure 5) are of the same type of antenna module. For example, array antenna 1 and array antenna 201 may be antenna modules of the same model.

[0054] It is desirable that array antenna 1 and array antenna 201 have the same type of phase shifter 16, the same type of amplifier 17, and the same type of frequency converter 13 (see Figures 3 and 6). For example, the phase shifter 16 of the first antenna device 100 and the phase shifter 16 of the second antenna device 200 may be the same model. The amplifier 17 of the first antenna device 100 and the amplifier 17 of the second antenna device 200 may be the same model. The frequency converter 13 of the first antenna device 100 and the frequency converter 13 of the second antenna device 200 may be the same model. "Same model" means, for example, that the product model numbers are the same.

[0055] It is desirable that the aircraft 400 be able to fly at an altitude of 60,000 feet (18,288 meters) or higher. At altitudes above 60,000 feet, there are fewer clouds, so sunlight is less likely to be blocked by clouds. Therefore, when the aircraft 400 flies at an altitude of 60,000 feet or higher, the efficiency of power generation by the solar power generation equipment mounted on the aircraft 400 can be increased.

[0056] [Effects of the First Antenna Device and Communication System According to the First Embodiment] The first antenna device 100 uses a second horn antenna 3 (primary radiator). The second horn antenna 3 has a smaller aperture area and wider directivity compared to an array antenna. Therefore, the focal length can be shortened compared to when an array antenna is used as the primary radiator. Thus, the first antenna device 100 can be miniaturized.

[0057] It is desirable that the aperture area of ​​the second horn antenna 3 be smaller than that of the first horn antenna 2. This allows for an even shorter focal length. Therefore, the first antenna device 100 can be miniaturized.

[0058] If the aperture area of ​​the first horn antenna 2 is 0.9 to 1.1 times the area of ​​the radiating surface 1a of the array antenna 1, the coupling efficiency between the first horn antenna 2 and the array antenna 1 can be increased during both transmission and reception.

[0059] The distance L between the first horn antenna 2 and the array antenna 1 is L < 2D ２ It is desirable to satisfy / λ. This can increase the coupling efficiency between the first horn antenna 2 and the array antenna 1.

[0060] In the array antenna 1, by making the phase of the RF signal radiated from the outer antenna element 11 advance the phase of the RF signal radiated from the inner antenna element 11, the radiated RF signals can be aligned with the equiphase plane of the first horn antenna 2. Therefore, the coupling efficiency with the first horn antenna 2 can be increased.

[0061] Since the array antenna 1 is an antenna module on which an RFIC 12 equipped with a phase shifter 16 and an amplifier 17 is mounted, it can perform phase adjustment and amplification of RF signals, resulting in good transmission and reception characteristics for the array antenna 1.

[0062] Since the first antenna device 100 can transmit and receive to the flying object 400 (more specifically, the second antenna device 200), it can perform wireless communication with the flying object 400.

[0063] In the communication system 300, it is desirable that the first antenna device 100 and the second antenna device 200 have the same type of phase shifter 16, the same type of amplifier 17, and the same type of frequency converter 13. When the two antenna devices 100 and 200 use the same type of phase shifter 16, a phase shift of the RF signal between the transmitting antenna device and the receiving antenna device is less likely to occur. When the two antenna devices 100 and 200 use the same type of amplifier 17, it becomes easy to optimize the strength of the transmitted RF signal to match the receiving antenna device. When the two antenna devices 100 and 200 use the same type of frequency converter 13, it becomes easy to optimize the frequency of the transmitted RF signal according to the receiving antenna device. Therefore, the transmission and reception characteristics between the first antenna device 100 and the second antenna device 200 are good.

[0064] If the array antenna 1 (antenna module) of the first antenna device 100 and the array antenna 201 (antenna module) of the second antenna device 200 are of the same type, it becomes easy to optimize the characteristics of the transmitted RF signal according to the receiving antenna device. Therefore, the transmission and reception characteristics between the first antenna device 100 and the second antenna device 200 are good.

[0065] [First Antenna Device] (Second Embodiment) Figure 7 is a configuration diagram of the first antenna device 500 (antenna device) according to the second embodiment. As shown in Figure 7, the first antenna device 500 includes an array antenna 1, a first horn antenna 2, a second horn antenna 3, a transmission line 4, a parabolic antenna 5 (adjustment mechanism), and a bandpass filter 6. The first antenna device 500 differs from the first antenna device 100 (see Figure 1) in that it includes a bandpass filter 6.

[0066] The bandpass filter 6 attenuates spurious wavelength components in the RF signal. This increases the gain of the RF signal. The bandpass filter can also be installed in the transmission path of the second antenna device.

[0067] [First Antenna Device] (Third Embodiment) Figure 8 is a configuration diagram of the first antenna device 600 (antenna device) according to the third embodiment. As shown in Figure 8, the array antenna 1, the first horn antenna 2, and the second horn antenna 3 may be configured to support multiple polarizations. For example, the array antenna 1, the first horn antenna 2, and the second horn antenna 3 can transmit and receive at least one of two polarizations (H polarization and V polarization) whose vibration directions are orthogonal to each other.

[0068] The first antenna device 600 includes an array antenna 1, a first horn antenna 2, a second horn antenna 3, two transmission lines 604 (604A, 604B), and a parabolic antenna 5 (with adjustment mechanism). The first antenna device 600 differs from the first antenna device 100 (see Figure 1) in that it has two transmission lines 604. The number of transmission lines is not particularly limited and may be any number of two or more.

[0069] The two transmission lines 604 transmit signals with H polarization and V polarization, respectively. That is, the first transmission line 604A transmits signals with H polarization, and the second transmission line 604B transmits signals with V polarization.

[0070] The first antenna device 600 has multiple transmission lines 604 arranged to match multiple polarizations, which allows for good transmission characteristics of signals for each polarization.

[0071] [First Antenna Device] (Fourth Embodiment) Figures 9 and 10 are configuration diagrams of the first antenna device 700 according to the fourth embodiment. As shown in Figures 9 and 10, the first antenna device 700 includes an array antenna 1, a first horn antenna 2, a second horn antenna 3, a transmission line 4, a parabolic antenna 5 (adjustment mechanism), and an attitude adjustment mechanism 7. The first antenna device 700 differs from the first antenna device 100 (see Figure 1) in that it has an attitude adjustment mechanism 7.

[0072] The attitude adjustment mechanism 7 comprises a support section 71, a base 72, and a direction changing section 73. The support section 71 supports the parabolic antenna 5. The support section 71 supports the second horn antenna 3 by a support column 8. The direction changing section 73 can arbitrarily adjust the orientation of the support section 71 relative to the base 72. For example, the attitude adjustment mechanism 7 can adjust the orientation of the parabolic antenna 5 and the second horn antenna 3 by rotating the support section 71 with the direction changing section 73 as a pivot point. The attitude adjustment mechanism 7 is driven by a drive unit (not shown), such as a motor. The attitude adjustment mechanism 7 can adjust the orientation of the parabolic antenna 5 and the second horn antenna 3 according to the position of the flying object 400, for example.

[0073] The first antenna device 700 is equipped with an attitude adjustment mechanism 7 that can adjust the orientation of the parabolic antenna 5 and the second horn antenna 3, so that the orientation of the parabolic antenna 5 and the second horn antenna 3 can be optimized according to the position of the flying object 400. Therefore, the transmission and reception characteristics between the first antenna device 700 and the second antenna device 200 are good.

[0074] [First Antenna Device] (Fifth Embodiment) Figure 11 is a configuration diagram of the first antenna device 800 according to the fifth embodiment. As shown in Figure 11, the first antenna device 800 includes an array antenna 1, a first horn antenna 2, a second horn antenna 3, a transmission line 4, and a lens 805 (adjustment mechanism). The first antenna device 800 differs from the first antenna device 100 (see Figure 1) in that it uses a lens 805 instead of a parabolic antenna 5.

[0075] Lens 805 is, for example, a dielectric lens. Lens 805 can adjust the directivity of at least one of the output signal from the second horn antenna 3 and the input signal to the second horn antenna 3. The second horn antenna 3 and lens 805 perform wireless communication (at least one of transmission and reception) to the second antenna device 200 (see Figure 4) of the flying object 400.

[0076] The technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. In the first antenna device 100 shown in Figure 1, a second horn antenna 3 is used as the primary radiator, but the primary radiator is not limited to a horn antenna; a lens antenna or the like may also be used. Even in this case, the focal length can be shortened compared to when an array antenna is used as the primary radiator. Therefore, the first antenna device can be miniaturized.

[0077] In the first antenna devices 100 and 800 shown in Figures 1 and 11, a parabolic antenna or a lens is used as an adjustment mechanism, but at least one of the parabolic antenna and the lens can be used as the adjustment mechanism. That is, only one of the parabolic antenna and the lens may be used, or both may be used.

[0078] As shown in Figure 2, the array antenna 1 has 64 antenna elements 11, but the number of antenna elements is not limited to this. The number of antenna elements may be any number of 2 or more. The number of inner antenna elements is not particularly limited. The number of inner antenna elements may be one or more. The number of outer antenna elements is not particularly limited. The number of outer antenna elements may be one or more.

[0079] Furthermore, without departing from the spirit of the present invention, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments and modifications may be combined as appropriate.

[0080] 1...Array antenna (first array antenna), 1a...Radiation surface, 2...First horn antenna, 3...Second horn antenna (primary radiator), 4, 604...Transmission line, 5...Parabolic antenna (adjustment mechanism), 6...Bandpass filter, 7...Attitude adjustment mechanism, 11, 11A, 11B, 11C, 11D...Antenna elements, 11A...Antenna element (inner antenna element), 11B...Antenna element (outer antenna element), 12...RFIC, 13...Frequency converter, 16...Phase shifter, 17...Amplifier, 100, 500, 600, 700, 800...First antenna device (antenna device), 200...Second antenna device, 201...Array antenna (second array antenna), 300...Communication system, 400...Aircraft, 805...Lens

Claims

1. An antenna device comprising: a first array antenna having a plurality of antenna elements; a first horn antenna that transmits and receives signals to the first array antenna; a second horn antenna which is a primary radiator; a transmission path for transmitting signals between the first horn antenna and the second horn antenna; and an adjustment mechanism for adjusting the directivity of at least one of the output signal from the second horn antenna and the input signal to the second horn antenna, wherein the adjustment mechanism is at least one of a parabolic antenna and a lens.

2. The antenna device according to claim 1, wherein the aperture area of ​​the second horn antenna is smaller than the aperture area of ​​the first horn antenna.

3. The antenna device according to claim 1 or 2, wherein the aperture area of ​​the first horn antenna is 0.9 to 1.1 times the area of ​​the radiating surface of the first array antenna.

4. Let D be the maximum straight-line distance from the radiating surface of the first array antenna, and let λ be the wavelength of the frequency used. The distance L between the first horn antenna and the first array antenna is L < 2D. ２ An antenna device according to any one of claims 1 to 3, satisfying / λ.

5. The antenna device according to any one of claims 1 to 4, wherein the plurality of antenna elements comprises one or more inner antenna elements and outer antenna elements adjacent to the outer side of the inner antenna elements, and the phase of the signal radiated from the outer antenna elements is ahead of the phase of the signal radiated from the inner antenna elements.

6. The antenna device according to any one of claims 1 to 5, further comprising a bandpass filter provided in the transmission line.

7. The antenna device according to any one of claims 1 to 6, wherein the first array antenna is an antenna module on which an RFIC comprising a phase shifter and an amplifier is mounted.

8. The antenna device according to any one of claims 1 to 7, wherein the first array antenna, the first horn antenna, and the second horn antenna correspond to a plurality of polarizations, and the plurality of transmission lines are provided to match the plurality of polarizations.

9. The antenna device according to any one of claims 1 to 8, further comprising the adjustment mechanism and an attitude adjustment mechanism for adjusting the orientation of the second horn antenna.

10. An antenna device according to any one of claims 1 to 9, which is capable of transmitting and receiving to an aerial object.

11. A communication system comprising: a first antenna device which is the antenna device described in claim 10; and a second antenna device mounted on the flying object, wherein the first antenna device and the second antenna device are equipped with the same type of phase shifter, the same type of amplifier, and the same type of frequency converter.

12. The communication system according to claim 11, wherein the second antenna device comprises a second array antenna, the first array antenna of the first antenna device and the second array antenna of the second antenna device are antenna modules on which an RFIC is mounted, and the antenna module of the first antenna device and the antenna module of the second antenna device are antenna modules of the same type.

13. The communication system according to claim 11 or 12, wherein the aircraft is capable of flying at an altitude of 60,000 feet or more.

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