Phased-array antenna system

Abstract

To achieve low cost and low power consumption in a phased-array antenna system that electronically scans a radiation beam, and to realize it as a satellite communication antenna, in which low power consumption is particularly desirable.SOLUTION: The present disclosure relates to a phased-array antenna system S including a phased-array antenna A having a plurality of antenna elements 1 and a plurality of electronic phase shifters 2, and a beam tilting metasurface B having conductor structures 4 periodically arranged on a dielectric substrate 5, arranged in front of the phased-array antenna A, and tilting the radiation beam of the phased-array antenna A.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a phased array antenna that electronically scans a radiation beam. [Background technology]

[0002] A phased array antenna that electronically scans a radiation beam is disclosed in Patent Document 1. In Patent Document 1, the phased array antenna includes a plurality of antenna elements and a plurality of electronic phase shifters, and electronically scans the radiation beam according to the setting values ​​of the plurality of electronic phase shifters. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-200950 A [Non-patent literature]

[0004] [Non-Patent Document 1] Muhammad U.Afzal,etc.,“Steering the Beam of Medium-to-High Gain Antennas Using Near-Field Phase Transformation”,IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION,VOL.65,NO.4,APRIL 2017. [Non-Patent Document 2] Muhammad U.Afzal, etc., “A Low-Profile Printed Planar Phase Correcting Surface to Improve Directive Radiation Characteristics of Electromagnetic Band Gap Resonator Antennas”, IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL.64, NO.1, January 2016. Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, the phased array antenna includes a plurality of electronic phase shifters that are active elements, and electronically scans the radiation beam according to the set values ​​of the plurality of electronic phase shifters. Therefore, the phased array antenna in Patent Document 1 cannot achieve low cost and low power consumption, and cannot be realized as a satellite communication antenna, for which low power consumption is particularly desirable.

[0006] Therefore, in order to solve the above problems, an object of the present disclosure is to realize a phased array antenna system that electronically scans a radiation beam at low cost and with low power consumption, and to realize the same as a satellite communication antenna in which low power consumption is particularly desirable. [Means for solving the problem]

[0007] To solve the above problem, a beam tilt metasurface, which is a passive element, is placed in front of a phased array antenna having multiple electronic phase shifters, which are active elements.

[0008] Specifically, the present disclosure relates to a phased array antenna system comprising: a phased array antenna having a plurality of antenna elements and a plurality of electronic phase shifters; and a beam tilting metasurface having conductor structures periodically arranged on a dielectric substrate, disposed in front of the phased array antenna, and tilting a radiation beam of the phased array antenna.

[0009] According to this configuration, in a phased array antenna system, multiple electronic phase shifters and beam tilt metasurfaces can be used in combination to achieve low cost and low power consumption.

[0010] The present disclosure also relates to a phased array antenna system, wherein the phased array antenna electronically scans an emission beam within a predetermined angular range, and the beam tilting metasurface further tilts the emission beam electronically scanned by the phased array antenna within the predetermined angular range by a predetermined fixed angle.

[0011] With this configuration, the beam tilt metasurface can be used to control the general tilt angle of the radiation beam, while multiple electronic phase shifters can be used to finely control the tilt angle of the radiation beam.

[0012] The present disclosure also relates to a phased array antenna system, characterized in that the phased array antenna and the beam tilting metasurface rotate themselves with a rotation axis direction that is perpendicular to the in-plane direction of the phased array antenna and the beam tilting metasurface, thereby rotating the phased array antenna's electronically scanned radiation beam within the specified angle range.

[0013] According to this configuration, the beam tilt metasurface can be used to control the rotation angle of the radiation beam over a wide range, with the in-plane direction of the beam tilt metasurface and the direction perpendicular to it as the rotation axis direction.

[0014] The present disclosure also relates to a phased array antenna system, wherein the phased array antenna expands a spacing between the plurality of antenna elements to more than 0.5 times the radiation wavelength of the phased array antenna, and suppresses grating lobes of a radiation beam electronically scanned within the specified angular range.

[0015] According to this configuration, even if the spacing between the multiple antenna elements is expanded and the number of multiple electronic phase shifters is reduced in order to narrow the angular range of electronic scanning of the radiation beam, it is possible to suppress grating lobes in the radiation beam, and low cost and low power consumption can also be achieved.

[0016] Here, in order to control the passing phase with high precision in the beam tilt metasurface, it is necessary to input a plane wave. However, in a phased array antenna, since the antenna elements are arranged discontinuously, multiple spherical waves are radiated. Therefore, the distance between the phased array antenna and the beam tilt metasurface needs to be about twice the wavelength used in the phased array antenna system, and therefore it is not possible to make it thin.

[0017] To solve the above problem, a separate passive element, a plane wave transformation metasurface, is placed in front of a phased array antenna including active elements and between the phased array antenna and a passive element, a beam tilting metasurface.

[0018] Specifically, the present disclosure is a phased array antenna system comprising a conductor structure concentrically arranged on a dielectric substrate, and further comprising a plane wave transformation metasurface disposed in front of the phased array antenna, between the phased array antenna and the beam tilt metasurface, for transforming the radiation beam of the phased array antenna into a plane wave.

[0019] With this configuration, in a phased array antenna system, a long propagation distance is not required to form a plane wave, and the plane wave transforming metasurface can be used to reduce the thickness.

[0020] The present disclosure also relates to a phased array antenna system, wherein the distance between the phased array antenna and the plane wave conversion metasurface and the distance between the plane wave conversion metasurface and the beam tilting metasurface are greater than or equal to 1 / 4 of the wavelength used by the phased array antenna system, and the distance between the phased array antenna and the beam tilting metasurface is less than twice the wavelength used by the phased array antenna system.

[0021] According to this configuration, in a phased array antenna system, the plane wave conversion metasurface can be used to reduce the thickness to about one-quarter of the conventional thickness.

[0022] The present disclosure also relates to a phased array antenna system that is applied as a satellite communication antenna.

[0023] According to this configuration, it can be realized as a satellite communication antenna in a phased array antenna system, in which low power consumption is particularly desirable.

[0024] The above disclosed inventions can be combined to the greatest extent possible. Effect of the Invention

[0025] In this manner, the present disclosure realizes low cost and low power consumption in a phased array antenna system that electronically scans a radiation beam, and can be realized as a satellite communication antenna, in which low power consumption is particularly desirable. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram showing a configuration of a phased array antenna system according to the present disclosure. [Diagram 2] FIG. 2 illustrates elevation control of a radiation beam according to the present disclosure. [Diagram 3] FIG. 2 illustrates elevation control of a radiation beam according to the present disclosure. [Figure 4] FIG. 2 illustrates the azimuthal control of a radiation beam of the present disclosure. [Diagram 5] FIG. 1 is a diagram illustrating the effect of the phased array antenna system of the present disclosure. [Figure 6] FIG. 1 is a diagram illustrating a problem to be solved in a phased array antenna system of a comparative example. [Figure 7] FIG. 1 is a diagram showing the directivity of a phased array antenna system of a comparative example. [Figure 8]FIG. 1 illustrates a phased array antenna system solution of the present disclosure. [Figure 9] FIG. 2 illustrates the directivity of the phased array antenna system of the present disclosure. [Figure 10] FIG. 13 is a diagram showing the detailed configuration of the plane wave transforming metasurface of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure will be described with reference to the accompanying drawings. The embodiments described below are examples of the present disclosure, and the present disclosure is not limited to the following embodiments.

[0028] (Configuration of the phased array antenna system of the present disclosure) The configuration of the phased array antenna system of the present disclosure is shown in Figure 1. The phased array antenna system S includes a phased array antenna A and a beam tilting metasurface B, and can be applied as a satellite communication antenna in which low power consumption is particularly desired.

[0029] The phased array antenna A includes a plurality of antenna elements 1 and a plurality of electronic phase shifters 2, and electronically scans a radiation beam according to the setting values ​​of the plurality of electronic phase shifters 2. In the present disclosure, the plurality of antenna elements 1 are patch antenna elements disposed on a dielectric substrate 3. As a modified example, the plurality of antenna elements 1 may be slot antenna elements formed in a rectangular waveguide.

[0030] The beam-tilting metasurface B includes conductor structures 4 periodically arranged on a dielectric substrate 5, and is arranged in front of a phased array antenna A to tilt the radiation beam of the phased array antenna A. The conductor structures 4 change the phase of the radiation beam according to the size of the rectangular conductor. Non-Patent Document 1 discloses a technology for tilting the radiation beam of a single patch antenna element using only a beam-tilting metasurface arranged in front of the single patch antenna element.

[0031] Here, in the phased array antenna A, the distance between adjacent antenna elements 1 is d, and the wave number of the radiation beam in the front direction is k0. In the beam tilt metasurface B, the phase change difference between adjacent conductor structures 4 is Δφ, and the wave number of the radiation beam tilted by an angle θ from the front direction is k0. Then, between them, Δφ=k0dsinθ holds.

[0032] In other words, a beam tilt metasurface B, which is a passive element, is placed in front of a phased array antenna A which has a plurality of electronic phase shifters 2, which are active elements.

[0033] Therefore, in the phased array antenna system S, by using multiple electronic phase shifters 2 and beam tilt metasurface B in combination, low cost and low power consumption can be achieved, and it can be realized as a satellite communication antenna in which low power consumption is particularly desired.

[0034] (Control of Elevation Angle of Radiation Beam According to the Present Disclosure) The control of the elevation angle direction of the radiation beam according to the present disclosure is shown in Figures 2 and 3. The phased array antenna A electronically scans the radiation beam within a predetermined angle range (here, the elevation angle). The beam tilting metasurface B further tilts the radiation beam, which has been electronically scanned within the predetermined angle range (here, the elevation angle) by the phased array antenna A, by a predetermined fixed angle (here, the elevation angle).

[0035] In the first column of Figure 2, a phased array antenna A forms a radiation beam in the z direction (front direction and vertical direction), and a beam-tilting metasurface B is not placed in front of it.

[0036] In the second column of Fig. 2, the phased array antenna A forms a radiation beam in the z direction (front and vertical direction), and the beam tilt metasurface B1 tilts the radiation beam in the z direction (front and vertical direction) by a fixed angle θ in the xz plane (vertical horizontal plane). The direction of the tilt angle θ of the radiation beam will be explained using Fig. 4.

[0037] In the third column of Fig. 2, in addition to the second column of Fig. 2, in the beam tilt metasurface B2 which is the same as the beam tilt metasurface B1, the radiation beam in the z direction (front direction and vertical direction) is further tilted by a fixed angle θ in the xz plane (in the vertical horizontal plane), so that the total tilt angle of the radiation beam is 2θ. The tilt direction of the radiation beam tilt angle 2θ will be explained using Fig. 4.

[0038] In the fourth column of Fig. 2, in addition to the third column of Fig. 2, in the beam tilt metasurface B3 which is the same as the beam tilt metasurface B1, the radiation beam in the z direction (front direction and vertical direction) is further tilted by a fixed angle θ in the xz plane (vertical horizontal plane), so that the total tilt angle of the radiation beam is 3θ. The tilt direction of the tilt angle 3θ of the radiation beam will be explained using Fig. 4.

[0039] In the lower part of FIG. 3, in the phased array antenna A, an emission beam is formed in the xz plane (vertical horizontal plane) within an angle range of 0 to α, starting from the z direction (front direction and vertical direction). The incidence angle to the beam-tilting metasurface B1 is from 0 to α. The tilt direction of the tilt angle (0 to α) of the emission beam will be explained using FIG. 4.

[0040] In the middle part of Fig. 3, the radiation beam of the phased array antenna A is tilted by a fixed angle θ in the xz plane (vertical horizontal plane) in the beam tilt metasurface B1. The incident angle to the beam tilt metasurface B2 ranges from θ to θ+α, not including 0 to θ. The tilt direction of the radiation beam tilt angle (θ to θ+α) will be explained using Fig. 4.

[0041] In the upper part of Fig. 3, the beam tilting metasurface B2 further tilts the radiation beam of the phased array antenna A by a fixed angle θ in the xz plane (vertical horizontal plane). The beam angle in the beam tilting metasurface B2 is from 2θ to 2θ+α, not including 0 to 2θ. The tilt direction of the radiation beam tilt angle (2θ to 2θ+α) will be explained using Fig. 4.

[0042] In other words, the beam tilt metasurface B can be used to control the general tilt angle of the radiation beam, while multiple electronic phase shifters 2 can be used to finely control the tilt angle of the radiation beam.

[0043] In order to precisely control the tilt angle of the radiation beam, the beam tilt metasurfaces B1 and B2 can be rotated in opposite directions by the same angle, but this does not allow for high-speed control of the tilt angle of the radiation beam. Therefore, in order to precisely and quickly control the tilt angle of the radiation beam, it is desirable to electronically scan the radiation beam according to the setting values ​​of multiple electronic phase shifters 2.

[0044] Furthermore, depending on the approximately constant elevation angle of the geostationary satellite captured by the satellite communication antenna, the number of beam tilt metasurfaces B may be one, two, three, etc., as shown in Figures 2 and 3.

[0045] Azimuthal Control of Radiation Beams of the Present Disclosure The control of the azimuth angle direction of the radiation beam according to the present disclosure is shown in Fig. 4. The phased array antenna A and the beam tilting metasurface B rotate the radiation beam electronically scanned by the phased array antenna A within a predetermined angle range (here, the elevation angle) by rotating the phased array antenna A and the beam tilting metasurface B themselves with the in-plane direction (here, the azimuth angle direction) and the vertical direction (here, the vertical direction) of the phased array antenna A and the beam tilting metasurface B as the rotation axis directions.

[0046] The left column of Fig. 4 shows a perspective view of the phased array antenna system S, and the right column of Fig. 4 shows a plan view of the phased array antenna system S. In the phased array antenna A, a radiation beam in the z direction (front direction and vertical direction) is formed, in the beam tilting metasurface B1, the radiation beam in the z direction (front direction and vertical direction) is tilted by a fixed angle θ in the xz plane (vertical horizontal plane), and in the beam tilting metasurface B2, the radiation beam in the z direction (front direction and vertical direction) is further tilted by a fixed angle θ in the xz plane (vertical horizontal plane).

[0047] Then, the phased array antenna A and the beam tilt metasurfaces B1 and B2 are rotated in the same direction and by the same angle with the in-plane direction (xy direction) and the vertical direction (z direction) of the phased array antenna A and the beam tilt metasurfaces B1 and B2 as the rotation axis direction (rotation angle φ A =φ B1 =φ B2 ). Then, the electronically scanned radiation beam is rotated in the same direction and by the same angle as the phased array antenna A and the beam tilt metasurfaces B1 and B2, with the in-plane direction (xy direction) and the vertical direction (z direction) of the phased array antenna A and the beam tilt metasurfaces B1 and B2 as the rotation axis direction (rotation angle φ A =φ B1 =φ B2 ).

[0048] Here, the direction of the inclination of the radiation beam inclination angle shown in FIG. 2 and FIG. 3 is the rotation angle φ of the phased array antenna A and the beam inclination metasurfaces B1 and B2 shown in FIG. A =φ B1 =φ B2 =0°, 180°.

[0049] In other words, by using the beam tilting metasurface B, the rotation angle of the radiation beam can be controlled over a wide range, with the in-plane direction of the beam tilting metasurface B and the direction perpendicular to it as the rotation axis direction.

[0050] In order to precisely control the rotation angle of the radiation beam, the radiation beam can be electronically scanned according to the setting values ​​of the multiple electronic phase shifters 2, but the rotation angle of the radiation beam cannot be controlled over a wide range without degrading the side lobe of the radiation beam. Therefore, in order to control the rotation angle of the radiation beam over a wide range, it is desirable to rotate the phased array antenna A and the beam tilt metasurfaces B1 and B2 in the same direction and by the same angle.

[0051] In addition, when installing the satellite communication antenna, it is desirable to perform horizontal adjustment, and when rotating the phased array antenna A and the beam tilt metasurfaces B1 and B2, a stepping motor or the like can be used.

[0052] (Effects of the phased array antenna system of the present disclosure) The effect of the phased array antenna system of the present disclosure is shown in Fig. 5. The phased array antenna A expands the spacing d between multiple antenna elements 1 to more than 0.5 times the radiation wavelength λ of the phased array antenna A compared to the prior art, and suppresses grating lobes in the electronically scanned radiation beam within a predetermined angle range (here, the elevation angle).

[0053] In the upper part of Fig. 5, when the angular range of electronic scanning of the phased array antenna A is 2θ+α=60° as in the upper part of Fig. 3, it is desirable that the spacing d between the multiple antenna elements 1 be 0.54λ or less in order to suppress grating lobes in the radiated beam. On the other hand, when the angular range of electronic scanning of the phased array antenna A is α=20° as in the lower part of Fig. 3, it is sufficient that the spacing d between the multiple antenna elements 1 be 0.75λ or less in order to suppress grating lobes in the radiated beam.

[0054] In the middle part of Fig. 5, when the angular range of electronic scanning of the phased array antenna A is 2θ+α=60° as in the upper part of Fig. 3, it is desirable that the number of the multiple antenna elements 1 be 1600 or more for a given arrangement area of ​​the multiple antenna elements 1. On the other hand, when the angular range of electronic scanning of the phased array antenna A is α=20° as in the lower part of Fig. 3, it is sufficient that the number of the multiple antenna elements 1 is 800 or more for a given arrangement area of ​​the multiple antenna elements 1, and the number can be reduced by almost half.

[0055] In the lower part of Fig. 5, when the angular range of electronic scanning of the phased array antenna A is 2θ+α=60° as in the upper part of Fig. 3, it is desirable that the number of the multiple electronic phase shifters 2 is 200 or more for the number of channels, 8, of each electronic phase shifter 2. On the other hand, when the angular range of electronic scanning of the phased array antenna A is α=20° as in the lower part of Fig. 3, it is sufficient that the number of the multiple electronic phase shifters 2 is 100 or more for the number of channels, 8, of each electronic phase shifter 2, and the number can be reduced by almost half.

[0056] In other words, even if the spacing between the multiple antenna elements 1 is expanded and the number of multiple electronic phase shifters 2 is reduced in order to narrow the angular range of electronic scanning of the radiation beam, it is possible to suppress the grating lobes of the radiation beam and also achieve low cost and low power consumption.

[0057] (Problems to be solved by the phased array antenna system of the comparative example) The problem to be solved by the phased array antenna system of the comparative example is shown in Fig. 6. The directivity of the phased array antenna system of the comparative example is shown in Fig. 7. The phased array antenna system S of the comparative example includes a phased array antenna A and a beam tilting metasurface B, similar to the phased array antenna system S shown in Fig. 1.

[0058] Here, in order to precisely control the passing phase in the beam tilt metasurface B, it is necessary to input a plane wave. However, in the phased array antenna A, since the antenna elements are arranged discontinuously, multiple spherical waves are radiated.

[0059] In the left column of Fig. 6, the distance between the phased array antenna A and the beam tilt metasurface B is about twice the wavelength λ used by the phased array antenna system S. Therefore, a nearly plane wave can be incident on the beam tilt metasurface B, and the passing phase can be controlled with high precision. The solid line in Fig. 7 shows the directivity in the case of the left column of Fig. 6, which forms a main lobe in the direction of about 15° and suppresses side lobes in other directions.

[0060] In the right column of Fig. 6, the distance between the phased array antenna A and the beam tilt metasurface B is about 1 / 2 the wavelength λ used by the phased array antenna system S. Therefore, an imperfect plane wave is incident on the beam tilt metasurface B, and the passing phase cannot be controlled with high precision. The dashed line in Fig. 7 shows the directivity in the case of the right column of Fig. 6, where a main lobe is formed in the direction of about 15° and side lobes are also generated in other directions.

[0061] Thus, in the phased array antenna system S of the comparative example, the distance between the phased array antenna A and the beam tilt metasurface B needs to be approximately twice the wavelength λ used by the phased array antenna system S, and therefore the system cannot be made thin.

[0062] (Solution of the phased array antenna system of the present disclosure) A solution of the phased array antenna system of the present disclosure is shown in Fig. 8. The directivity of the phased array antenna system of the present disclosure is shown in Fig. 9. The phased array antenna system S of the present disclosure is different from the phased array antenna system S shown in Fig. 1 and includes a phased array antenna A, a beam tilting metasurface B, and a plane wave conversion metasurface P. In the right column of Fig. 8, a configuration similar to that in the left column of Fig. 6 is shown for comparison with the left column of Fig. 8.

[0063] The plane wave converting metasurface P includes conductor structures arranged concentrically on a dielectric substrate (in FIG. 10, in the plane wave converting metasurface P, a single concentric arrangement of conductor structures is arranged for the entire phased array antenna A), and is arranged in front of the phased array antenna A and between the phased array antenna A and the beam tilt metasurface B, and converts the radiation beam of the phased array antenna A into a plane wave. The conductor structures change the phase of the radiation beam depending on the size of the rectangular conductor. Non-Patent Document 2 discloses a technology for plane wave conversion of the radiation beam of a single patch antenna element using only a plane wave converting metasurface arranged in front of the single patch antenna element.

[0064] Here, in the plane wave conversion metasurface P, the rectangular conductors arranged at the center of the concentric circle arrangement are larger in size and have a larger phase delay, while the rectangular conductors arranged at the periphery of the concentric circle arrangement are smaller in size and have a smaller phase delay. Therefore, in the plane wave conversion metasurface P, the radiation beam of the phased array antenna A can be converted into a plane wave.

[0065] In other words, a separate passive element, a plane wave conversion metasurface P, is placed in front of a phased array antenna A including an active element, and between the phased array antenna A and a beam tilt metasurface B which is a passive element.

[0066] In this way, in the phased array antenna system S, a long propagation distance is not required to form a plane wave, and the phased array antenna system S can be made thin by using the plane wave transforming metasurface P.

[0067] In the left column of Fig. 8, the distance between the phased array antenna A and the plane wave conversion metasurface P and the distance between the plane wave conversion metasurface P and the beam tilting metasurface B are equal to or greater than 1 / 4 times the operating wavelength λ of the phased array antenna system S. However, unlike the right column of Fig. 8, the distance between the phased array antenna A and the beam tilting metasurface B is less than twice the operating wavelength λ of the phased array antenna system S.

[0068] Therefore, even if an imperfect plane wave is incident on the plane wave conversion metasurface P, an almost plane wave will be incident on the beam tilt metasurface B, and the passing phase can be controlled with high precision. The dashed line in Fig. 9 shows the directivity in the case of the left column of Fig. 8, which forms a main lobe in the direction of about 15° and suppresses side lobes in other directions.

[0069] In this way, by using the plane wave conversion metasurface P, the phased array antenna system S can be made thinner to about 1 / 4 of the conventional thickness.

[0070] (Details of the configuration of the plane wave transforming metasurface of the present disclosure) The detailed configuration of the plane wave conversion metasurface of the present disclosure is shown in Fig. 10. In the phased array antenna A, the spacing between antenna elements is d, as in Fig. 1, and in the plane wave conversion metasurface P, the size of the single concentric arrangement of conductor structures 6 (arranged on the dielectric substrate 7) is equivalent to the overall size of the phased array antenna A. Therefore, in the plane wave conversion metasurface P, the single concentric arrangement of conductor structures 6 (arranged on the dielectric substrate 7) is arranged relative to the entire phased array antenna A.

[0071] Here, since antenna elements are discontinuously arranged in the vicinity of the phased array antenna A, multiple spherical waves are radiated. The distance between the phased array antenna A and the plane wave conversion metasurface P is 1 / 4 or more the wavelength λ used by the phased array antenna system S. Therefore, in the vicinity of the plane wave conversion metasurface P, the multiple spherical waves are combined to form a single spherical wave. Then, in the plane wave conversion metasurface P, the phase of the single spherical wave is changed to form an approximately plane wave.

[0072] In Non-Patent Document 2, since a single patch antenna element is arranged in the antenna, a partial reflecting surface (resonant structure) is arranged in addition to the plane wave conversion metasurface P so as to further improve the radiation gain, but in the present disclosure, since multiple antenna elements are arranged in the phased array antenna A, the radiation gain does not need to be further improved, and a partial reflecting surface (resonant structure) does not need to be arranged in addition to the plane wave conversion metasurface P. Therefore, in the phased array antenna system S, although the plane wave conversion metasurface P is used, a partial reflecting surface does not need to be used, and the system can be made thinner.

[0073] In FIG. 2, a plane wave conversion metasurface P is disposed between the phased array antenna A and the beam tilt metasurface B1. Here, a spherical wave having a directivity in a nearly frontal direction is incident on the plane wave conversion metasurface P, and is converted into a plane wave having a directivity in a nearly frontal direction. The distance between the beam tilt metasurfaces B1 and B2 and the distance between the beam tilt metasurfaces B2 and B3 may be less than 1 / 4 of the wavelength λ used by the phased array antenna system S, but not more than 1 / 4, as long as the effect of synthesis of the incident wave and the reflected wave at the beam tilt metasurfaces B2 and B3 is small.

[0074] In FIG. 3, a plane wave conversion metasurface P is disposed between the phased array antenna A and the beam tilt metasurface B1. Here, a spherical wave having a directivity with a small tilt angle is incident on the plane wave conversion metasurface P, and is converted into a plane wave having a directivity with a small tilt angle. This is because it is considered that the effect of the synthesis of the incident wave and the reflected wave is small on the plane wave conversion metasurface P. Therefore, it is not necessary to give the tilt angle of the plane wave conversion metasurface P to match the tilt angle of the radiation beam. And, the distance between the beam tilt metasurfaces B1 and B2 may be less than 1 / 4 times the wavelength λ used by the phased array antenna system S, not more than 1 / 4 times, as long as the effect of the synthesis of the incident wave and the reflected wave on the beam tilt metasurface B2 is small.

[0075] In Fig. 4, similarly to Figs. 2 and 3, a plane wave conversion metasurface P is placed between the phased array antenna A and the beam tilt metasurface B1. The phased array antenna A, the plane wave conversion metasurface P, and the beam tilt metasurfaces B1 and B2 are rotated in the same direction and by the same angle with the in-plane direction (xy direction) and the vertical direction (z direction) as the rotation axis direction (rotation angle φ A =φ P =φ B1 =φ B2 , φ P (Not shown in FIG. 4). Then, the electronically scanned radiation beam is rotated in the same direction and by the same angle as the phased array antenna A, the plane wave conversion metasurface P, and the beam tilt metasurfaces B1 and B2, with the in-plane direction (xy direction) and the vertical direction (z direction) as the rotation axis direction (rotation angle φ A =φ P =φ B1 =φ B2 , φ P not shown in Figure 4). [Industrial Applicability]

[0076] The phased array antenna system disclosed herein uses multiple electronic phase shifters and beam tilting metasurfaces in combination to electronically scan the radiation beam, achieving low cost and low power consumption, and can be realized as a satellite communication antenna in which low power consumption is particularly desirable. [Explanation of symbols]

[0077] S: Phased array antenna system A: Phased array antenna B, B1, B2, B3: Beam tilt metasurface P: Plane wave transforming metasurface 1: Antenna element 2:Electronic phase shifter 3: Dielectric substrate 4: Conductor structure 5: Dielectric substrate 6: Conductor structure 7: Dielectric substrate

Claims

1. a phased array antenna including a plurality of antenna elements and a plurality of electronic phase shifters; a beam tilt metasurface including conductor structures periodically arranged on a dielectric substrate, the beam tilt metasurface being arranged in front of the phased array antenna and tilting a radiation beam of the phased array antenna; A phased array antenna system comprising:

2. The phased array antenna electronically scans a radiation beam within a predetermined angular range; The beam tilting metasurface further tilts the radiation beam electronically scanned by the phased array antenna within the predetermined angle range by a predetermined fixed angle.

2. The phased array antenna system according to claim 1 .

3. The phased array antenna and the beam tilt metasurface rotate themselves around a rotation axis direction that is a direction perpendicular to an in-plane direction of the phased array antenna and the beam tilt metasurface, so that the phased array antenna rotates the radiation beam electronically scanned within the predetermined angle range.

3. A phased array antenna system according to claim 2 .

4. The phased array antenna extends the spacing between the antenna elements to more than 0.5 times the radiation wavelength of the phased array antenna, and suppresses grating lobes of the electronically scanned radiation beam within the predetermined angular range.

4. A phased array antenna system according to claim 2 or 3.

5. The present invention further includes a plane wave transformation metasurface that includes a conductor structure concentrically arranged on a dielectric substrate, the plane wave transformation metasurface being arranged in front of the phased array antenna and between the phased array antenna and the beam tilt metasurface, and that transforms the radiation beam of the phased array antenna into a plane wave.

2. The phased array antenna system according to claim 1 .

6. The distance between the phased array antenna and the plane wave conversion metasurface and the distance between the plane wave conversion metasurface and the beam tilt metasurface are equal to or greater than ¼ of the wavelength used by the phased array antenna system, and the distance between the phased array antenna and the beam tilt metasurface is less than twice the wavelength used by the phased array antenna system.

6. A phased array antenna system according to claim 5.

7. The phased array antenna system is applied as a satellite communication antenna.

6. A phased array antenna system according to claim 1 or 5.

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