Programmable metasurface array antenna based on real time delay

Abstract

The invention discloses a real-time-delay-based programmable metasurface array antenna, which comprises a metasurface antenna array and a real-time-delay feed network, and is characterized in that the metasurface antenna array comprises 8 * 8 metasurface antenna units formed by first dielectric layers, metal plate layers and second dielectric layers, the first dielectric layers are integrated with 7 metal patches, a first diode and a second diode, and the second dielectric layers are integrated with 7 metal patches; the on-off state of the diodes is controlled through the direct current bias circuit, and 0-degree, 90-degree, 180-degree and 270-degree four-state phase regulation and control are achieved. The second dielectric layer comprises five metal patches which are matched with the through holes and the copper columns to realize upper and lower layer electric connection; the real time delay feed network adopts a 1: 8 * 8 power divider feed network, feeds by attaching a metal patch, and provides initial time delay related to the position for each unit. The method solves the problems of discrete phase quantization and frequency dispersion of a traditional array, is suitable for 5G / 6G broadband communication, dynamic beam tracking and other scenes, and remarkably improves the beam scanning precision and reliability.

Description

Technical Field

[0001] The present invention relates to a programmable metasurface array antenna, and more particularly to a programmable metasurface array antenna based on true time delay. Background Art

[0002] As the core technology of modern radar and communication systems, phased array antennas achieve electronic beam scanning without mechanical rotation by precisely controlling the phase difference of each antenna element. They have a flexible pointing ability that cannot be compared with traditional mechanically scanned antennas, and can maintain operation by adjusting the radiation pattern in case of unit failure, with significantly better reliability than a single antenna.

[0003] As a revolutionary electromagnetic regulation material, a metasurface is composed of sub-wavelength-scale artificial structural units arranged. By adjusting the unit geometry, size, and material properties, the amplitude, phase, and polarization parameters of electromagnetic waves can be flexibly regulated. Its low-profile characteristics meet the requirements of equipment miniaturization and lightweight, and have unique advantages in space-constrained scenarios such as satellites and drones.

[0004] True time delay technology provides a frequency-independent linear phase delay for antenna elements by designing the transmission line length or using controllable delay devices, avoiding beam direction offset during broadband signal scanning. It is suitable for scenarios with high broadband adaptability requirements such as ultra-wideband radar and 6G communication, and can be integrated with planar structures such as microstrip lines to adapt to the low-profile design of metasurfaces.

[0005] However, existing programmable metasurface array antennas have obvious deficiencies in practical applications. Radiation performance defects caused by discrete phase quantization: Traditional metasurface arrays mostly use 1-bit discrete phase state coding arrays with in-phase feeding networks, resulting in discontinuous wavefront phase gradients. During wide-angle scanning, this discontinuity easily causes mirror lobe problems and it is difficult to suppress side lobes, seriously affecting the radiation efficiency and anti-interference ability of the antenna. Although the combination of true time delay technology and metasurface arrays is regarded as an important direction to solve the above problems, there are still key technical bottlenecks in existing integration schemes: the compatibility between the transmission line structure of the true time delay network and the metasurface unit is insufficient, resulting in a relatively large overall profile thickness; the lack of a cooperative mechanism for unit-level phase regulation and true time delay makes it impossible to achieve an accurate initial phase gradient design related to position, thereby affecting the beam pointing accuracy and broadband stability. Therefore, how to design a programmable metasurface array antenna with high-precision phase regulation, wide-frequency stable scanning, and low-profile integration has become an urgent technical problem in this field. Summary of the Invention

[0006] The object of the present invention is to provide a programmable metasurface array antenna based on true time delay, which uses a true time delay feeding network design to provide an initial time delay related to position for each metasurface antenna element with integrated active devices.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is as follows: a programmable metasurface array antenna based on true time delay, which includes a metasurface antenna array and a true time delay feeding network.

[0008] The described metasurface antenna array includes 8*8 metasurface antenna elements. The metasurface antenna element includes three layers. The first layer is called the first dielectric layer; the second layer is called the metal plate layer; the third layer is called the second dielectric layer. On the upper end face of the first dielectric layer, there are 7 metal patches, called the first metal patch, the second metal patch, the third metal patch, the fourth metal patch, the fifth metal patch, the sixth metal patch, and the seventh metal patch. The long side of the first metal patch is in the up-down direction, and the short side is in the left-right direction, and the center is at the center of the first dielectric layer; the long sides of the second and third metal patches are closely attached to the left and right sides of the first metal patch, and both are centered in the up-down direction; on the outer sides of the second and third metal patches, there are the fourth and fifth metal patches. The long sides of both are in the up-down direction, and the short sides are in the left-right direction, and they are centered in the up-down direction. There is a distance between the left side of the second metal patch and the right side of the fourth metal patch, and there is a distance between the left side of the third metal patch and the right side of the fifth metal patch; the long sides of the sixth and seventh metal patches are closely attached to the left side of the fourth metal patch and the right side of the fifth metal patch respectively, and both are centered in the up-down direction; on the second and third metal patches, there is a through hole respectively, called the first through hole and the second through hole. The center of the first through hole is centered in the long side direction of the metal patch and has a distance from the short side on the right side of the second metal patch; the center of the second through hole is centered in the long side direction of the metal patch and has a distance from the short side on the left side of the third metal patch. The first and second through holes penetrate the entire element; on the fourth and fifth metal patches, there is a through hole respectively, called the third through hole and the fourth through hole. The center of the third through hole is centered in the long side direction of the metal patch and has a distance from the short side on the left side of the fourth metal patch; the center of the fourth through hole is centered in the long side direction of the metal patch and has a distance from the short side on the right side of the third metal patch. The third and fourth through holes penetrate the first dielectric layer and the metal plate layer; in the first through hole, the second through hole, the third through hole, and the fourth through hole, there is a copper column respectively, called the first copper column, the second copper column, the third copper column, and the fourth copper column; on the lower end face of the second dielectric layer, there are 5 metal patches, called the eighth metal patch, the ninth metal patch, the tenth metal patch, the eleventh metal patch, and the twelfth metal patch. The long side of the eighth metal patch is in the up-down direction, and the short side is in the left-right direction. Its lower side is closely attached to the lower side of the dielectric layer and is centered in the left-right direction.The long sides of the ninth and tenth metal patches are in the left-right direction, and the short sides are in the up-down direction, and they are centered in the up-down direction. The first through-hole and the second through-hole are respectively included inside the two. In the ninth metal patch, there is a distance between the center of the first through-hole and the right side of the ninth metal patch; in the tenth metal patch, there is a distance between the center of the second through-hole and the left side of the ninth metal patch; the long sides of the eleventh and twelfth metal patches are in the up-down direction, and the short sides are in the left-right direction. The upper sides of both are closely attached to the upper side of the second dielectric layer, and the lower sides of both are closely attached to the lower side of the second dielectric layer. The right side of the eleventh metal patch is closely attached to the left side of the ninth metal patch, and the right side of the twelfth metal patch is closely attached to the right side of the tenth metal patch; on the first dielectric layer, two diodes are integrated, called the first diode and the second diode. The two ends of the first diode are respectively connected to the second metal patch and the fourth metal patch, and the two ends of the second diode are respectively connected to the third metal patch and the fifth metal patch; on the lower end face of the first dielectric layer, there is a DC bias circuit for controlling the first and second diodes. In the DC bias circuit, there are four DC lines, called the first DC line, the second DC line, the third DC line, and the fourth DC line, which are respectively connected to the first copper column, the second copper column, the third copper column, and the fourth copper column.

[0009] The true-time-delay feeding network includes a 1:8*8 power distribution feeding network and a feeding port. The 1:8*8 power distribution feeding network is formed by cascading 8 identical 1:8 power dividers through cascading ports. The cascading ports are located at the symmetric centers of each 1:8 power divider. The 1:8 power divider is formed by cascading 8 identical power dividers through power divider ports. The power divider is fed by closely attaching to the lower sides of the eleventh and twelfth metal patches; the feeding port is the power supply input port of the feeding network.

[0010] The side lengths of the first dielectric layer, the second dielectric layer, and the metal plate layer are all 18 mm; the thickness of the first dielectric layer is 3 mm, the thickness of the metal plate layer is 0.017 mm, and the thickness of the second dielectric layer is 0.5 mm; the long sides of the first, sixth, and seventh metal patches are 14 mm, the short sides are 2.5 mm, and the thickness is 0.017 mm; the long sides of the second, third, fourth, and fifth metal patches are 2.5 mm, the short sides are 1.35 mm, and the thickness is 0.017 mm. The long side of the eighth metal patch is 12 mm, the short side is 1.25 mm, and the thickness is 0.017 mm; the long sides of the ninth and tenth metal patches are 4.67 mm, the short sides are 2.5 mm, and the thickness is 0.017 mm; the long sides of the eleventh and twelfth metal patches are 18 mm, the short sides are 2.5 mm, and the thickness is 0.017 mm; the radii of the first, second, third, and fourth through-holes are 0.27 mm, and the radii of the first, second, third, and fourth copper posts therein are 0.1 mm; the lengths of the first and second through-holes are 3.551 mm, and the lengths of the third and fourth through-holes are 3.034 mm; the distance between the left side of the second metal patch and the right side of the fourth metal patch is 1.36 mm, and the distance between the left side of the third metal patch and the right side of the fifth metal patch is 1.36 mm; the distance between the center of the first through-hole and the short side on the right side of the second metal patch is 0.3 mm, the distance between the center of the second through-hole and the short side on the left side of the third metal patch is 0.3 mm, the distance between the center of the third through-hole and the short side on the left side of the fourth metal patch is 0.3 mm, the distance between the center of the fourth through-hole and the short side on the right side of the third metal patch is 0.3 mm, in the ninth metal patch, the distance between the center of the first through-hole and the right side of the ninth metal patch is 0.3 mm, and in the tenth metal patch, the distance between the center of the second through-hole and the left side of the ninth metal patch is 0.3 mm; the side lengths of the metasurface antenna unit are all 18 mm, the thickness is 3.551 mm, and the side lengths of the metasurface antenna array are all 144 mm, the thickness is 3.551 mm.

[0011] Compared with the prior art, the advantages of the present invention are as follows: through a unique metasurface antenna unit design and a true-time-delay feeding network architecture, a programmable array antenna function is realized. The metasurface antenna unit adopts a three-layer structure, including a first dielectric layer, a metal plate layer, and a second dielectric layer. The 7 metal patches on the first dielectric layer cooperate with the 5 metal patches on the second dielectric layer, and through the integrated first and second diodes and the DC bias circuit, flexible phase regulation is achieved. Specifically, the first diode connects the second metal patch and the fourth metal patch, and the second diode connects the third metal patch and the fifth metal patch. The above-mentioned metasurface antenna unit is a 2-bit (two-bit) programmable antenna unit, which has four states of "0", "1", "2", and "3", and can form phase differences of 0°, 90°, 180°, and 270° respectively. The unit state can be independently reconstructed. By controlling the on-off states of these two diodes through the DC bias circuit, the unit state can be switched and the unit phase can be changed. Therefore, the unit has a phase regulation function. The true-time-delay feeding network adopts a 1:8*8 power distribution feeding network, which is cascaded by 8 identical 1:8 power dividers through cascade ports. This network provides an initial time delay related to the position for each metasurface antenna unit, effectively eliminating the frequency dispersion effect. Thus, a single unit can achieve multi-state phase adjustment, significantly improving the phase resolution and providing the possibility for complex beamforming. At the same time, the true-time-delay feeding network makes the phase delay independent of frequency, realizes stable beam pointing within a wide frequency band, and significantly improves the beam scanning accuracy and reliability in broadband scenarios such as 5G / 6G. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is the overall structure diagram of the true-time-delay based programmable metasurface array antenna of the present invention; Figure 2 is the top view of the metasurface antenna unit of the present invention; Figure 3 is the front view of the metasurface antenna unit of the present invention; Figure 4 is the bottom view of the metasurface antenna unit of the present invention; Figure 5 is the top view of the DC bias circuit of the metasurface antenna unit of the present invention; Figure 6 is the top view of the metal plate layer of the metasurface antenna unit of the present invention; Figure 7 is the structure diagram of the true-time-delay feeding network of the present invention; Figure 8 is the structure diagram of the 1:8 power divider of the true-time-delay feeding network of the present invention; Figure 9 is the E-plane scanning pattern of the true-time-delay based programmable metasurface array antenna of the present invention; Figure 10 This is the H-plane scanning pattern of the programmable metasurface array antenna based on true time delay of the present invention; Specific embodiments

[0013] The present invention will be further described in detail below in conjunction with the embodiments with reference to the drawings.

[0014] Embodiment 1: As Figure 1 shown, through a unique metasurface antenna unit design and a true time delay feed network architecture, a programmable array antenna function is realized. Through a unique metasurface antenna unit design and a true time delay feed network architecture, a programmable array antenna function is realized. As Figure 3 shown, the metasurface antenna unit adopts a three-layer structure, including a first dielectric layer, a metal plate layer, and a second dielectric layer. As Figure 1 shown, the upper end face of the first dielectric layer includes: 7 metal patches, called the first metal patch 22, the second metal patch 32, the third metal patch 33, the fourth metal patch 31, the fifth metal patch 34, the sixth metal patch 21, and the seventh metal patch 23. Through the integrated first diode 35, the second diode 36, and the DC bias circuit, the first diode 35 connects the second metal patch 32 and the fourth metal patch 31, and the second diode 36 connects the third metal patch 33 and the fifth metal patch 34. On the lower end face of the first dielectric layer, there is a DC bias circuit for controlling the first diode 35 and the second diode 36. In the DC bias circuit, there are four DC lines, called the first DC line 102, the second DC line 103, the third DC line 101, and the fourth DC line 104, which are respectively connected to the first copper column 52, the second copper column 53, the third copper column 51, and the fourth copper column 54. As Figure 4 shown, the lower end face of the second dielectric layer includes: 5 metal patches, called the eighth metal patch 8, the ninth metal patch 71, the tenth metal patch 72, the eleventh metal patch 61, and the twelfth metal patch 62. The ninth metal patch 71 and the tenth metal patch 72 respectively contain the first through hole 42 and the second through hole 43, and are respectively connected to the second metal patch 32 and the third metal patch 33 on the upper end face of the first dielectric layer through the first copper column 52 and the second copper column 53.

[0015] The above-mentioned metasurface antenna unit is a 2-bit (two-bit) programmable antenna unit, which has four states of "0", "1", "2", and "3", and can respectively form phase differences of 0°, 90°, 180°, and 270°. The unit state can be independently reconstructed. By controlling the on-off states of these two diodes through the DC bias circuit, the unit state can be switched and the unit phase can be changed.

[0016] As Figure 7The true-time-delay feeding network shown adopts a 1:8*8 power distribution feeding network, which is cascaded by 8 identical 1:8 power dividers as shown in Figure 8 . This network provides position-related initial time delays for each metasurface antenna element, effectively eliminating the frequency dispersion effect. As a result, a single unit can achieve multi-state phase adjustment, significantly improving the phase resolution and making complex beamforming possible. At the same time, the true-time-delay feeding network makes the phase delay independent of frequency, achieving stable beam pointing within a wide frequency band and significantly improving the beam scanning accuracy and reliability in broadband scenarios such as 5G / 6G.

[0017] To verify the performance of the low-profile all-metal phased array radar antenna of the present invention, simulations were carried out on the programmable metasurface array antenna based on true time delay of the present invention. The E-plane scanning pattern of the programmable metasurface array antenna based on true time delay of the present invention is as shown in Figure 9 ; The H-plane scanning pattern of the programmable metasurface array antenna based on true time delay of the present invention is as shown in Figure 10 .

[0018] Analysis Figure 9 shows that the programmable metasurface array antenna based on true time delay of the present invention has a high gain in the E-plane and a large side lobe suppression effect. Therefore, the low-profile all-metal phased array radar antenna of the present invention has high anti-interference ability and low loss during signal transmission and reception. Analysis Figure 10 shows that the programmable metasurface array antenna based on true time delay of the present invention has a high gain in the H-plane and a large side lobe suppression effect. Therefore, the programmable metasurface array antenna based on true time delay of the present invention has high anti-interference ability and low loss during signal transmission and reception.

Claims

1. A programmable metasurface array antenna based on true time delay, characterized in that It includes a metasurface antenna array; the metasurface antenna array includes 8×8 metasurface antenna units, and each metasurface antenna unit includes a first dielectric layer, a second dielectric layer, and a metal plate layer; the cross-sections of the first dielectric layer, the second dielectric layer, and the metal plate layer are all the same square. On the upper end surface of the first dielectric layer, there are a first metal patch, a second metal patch, a third metal patch, a fourth metal patch, a fifth metal patch, a sixth metal patch, and a seventh metal patch. The first metal patch, the sixth metal patch, and the seventh metal patch are exactly the same in shape and size. The second metal patch, the third metal patch, the fourth metal patch, and the fifth metal patch are exactly the same in shape and size. The long side of the first metal patch is in the up-down direction, and the short side is in the left-right direction, and its center is at the center of the first dielectric layer. The long sides of the second and third metal patches are closely attached to the left and right sides of the first metal patch, and they are centered in the up-down direction. There are the fourth and fifth metal patches in the outward direction of the second and third metal patches. The long sides of the fourth and fifth metal patches are in the up-down direction, and the short sides are in the left-right direction, and they are centered in the up-down direction. There is a distance between the left side of the second metal patch and the right side of the fourth metal patch, and there is a distance between the left side of the third metal patch and the right side of the fifth metal patch. The long sides of the sixth and seventh metal patches are closely attached to the left side of the fourth metal patch and the right side of the fifth metal patch respectively, and they are centered in the up-down direction. There are a first through hole and a second through hole on the second and third metal patches respectively. The center of the first through hole is centered in the long side direction of the metal patch and has a distance from the short side on the right side of the second metal patch. The center of the second through hole is centered in the long side direction of the metal patch and has a distance from the short side on the left side of the third metal patch. The first and second through holes penetrate the entire unit. There are a third through hole and a fourth through hole on the fourth and fifth metal patches respectively. The center of the third through hole is centered in the long side direction of the metal patch and has a distance from the short side on the left side of the fourth metal patch. The center of the fourth through hole is centered in the long side direction of the metal patch and has a distance from the short side on the right side of the third metal patch. The third and fourth through holes penetrate the first dielectric layer and the metal plate layer. There are a first copper column, a second copper column, a third copper column, and a fourth copper column in the first through hole, the second through hole, the third through hole, and the fourth through hole respectively. On the lower end surface of the second dielectric layer, there are an eighth metal patch, a ninth metal patch, a tenth metal patch, an eleventh metal patch, and a twelfth metal patch. The long side of the eighth metal patch is in the up-down direction, and the short side is in the left-right direction. Its lower side is closely attached to the lower side of the dielectric layer and is centered in the left-right direction.The long sides of the ninth and tenth metal patches are in the left - right direction, and the short sides are in the up - down direction and are centered in the up - down direction. The first through - hole and the second through - hole are respectively included inside the two. In the ninth metal patch, there is a distance between the center of the first through - hole and the right side of the ninth metal patch; in the tenth metal patch, there is a distance between the center of the second through - hole and the left side of the tenth metal patch. The long sides of the eleventh and twelfth metal patches are in the up - down direction, and the short sides are in the left - right direction. The upper sides of both are closely attached to the upper side of the second dielectric layer, and the lower sides of both are closely attached to the lower side of the second dielectric layer. The right side of the eleventh metal patch is closely attached to the left side of the ninth metal patch, and the right side of the twelfth metal patch is closely attached to the right side of the tenth metal patch. On the first dielectric layer, a first diode and a second diode are integrated. The two ends of the first diode are respectively connected to the second metal patch and the fourth metal patch, and the two ends of the second diode are respectively connected to the third metal patch and the fifth metal patch. On the lower end face of the first dielectric layer, there is a DC bias circuit for controlling the first and second diodes. In the DC bias circuit, there are a first DC line, a second DC line, a third DC line, and a fourth DC line, which are respectively connected to the first copper post, the second copper post, the third copper post, and the fourth copper post.

2. The programmable metasurface array antenna based on true time delay according to claim 1, further characterized in that It includes a true time-delay feeding network, and the true time-delay feeding network includes a 1:8×8 power distribution feeding network and a feeding port. The 1:8×8 power distribution feeding network is formed by cascading 8 identical 1:8 power dividers through cascading ports, and the cascading ports are located at the symmetric centers of each 1:8 power divider. The 1:8 power divider is formed by cascading 8 identical power dividers through power divider ports, and the power divider is fed by being closely attached to the lower sides of the eleventh metal patch and the twelfth metal patch. The feeding port is the power supply input port of the feeding network.

3. The programmable metasurface array antenna based on true time delay according to claim 1, further characterized in that The side lengths of the first dielectric layer, the second dielectric layer, and the metal plate layer are all 18 mm. The thickness of the first dielectric layer is 3 mm, the thickness of the metal plate layer is 0.017 mm, and the thickness of the second dielectric layer is 0.5 mm. The long sides of the first, sixth, and seventh metal patches are 14 mm, the short sides are 2.5 mm, and the thickness is 0.017 mm. The long sides of the second, third, fourth, and fifth metal patches are 2.5 mm, the short sides are 1.35 mm, and the thickness is 0.017 mm. The long side of the eighth metal patch is 12 mm, the short side is 1.25 mm, and the thickness is 0.017 mm. The long sides of the ninth and tenth metal patches are 4.67 mm, the short sides are 2.5 mm, and the thickness is 0.017 mm. The long sides of the eleventh and twelfth metal patches are 18 mm, the short sides are 2.5 mm, and the thickness is 0.017 mm. The radii of the first, second, third, and fourth through holes are 0.27 mm, and the radii of the first, second, third, and fourth copper pillars therein are 0.1 mm. The lengths of the first and second through holes are 3.551 mm, and the lengths of the third and fourth through holes are 3.034 mm. The distance between the left side of the second metal patch and the right side of the fourth metal patch is 1.36 mm, and the distance between the left side of the third metal patch and the right side of the fifth metal patch is 1.36 mm. The distance between the center of the first through hole and the short side on the right side of the second metal patch is 0.3 mm, the distance between the center of the second through hole and the short side on the left side of the third metal patch is 0.3 mm, the distance between the center of the third through hole and the short side on the left side of the fourth metal patch is 0.3 mm, the distance between the center of the fourth through hole and the short side on the right side of the third metal patch is 0.3 mm. In the ninth metal patch, the distance between the center of the first through hole and the right side of the ninth metal patch is 0.3 mm. In the tenth metal patch, the distance between the center of the second through hole and the left side of the ninth metal patch is 0.3 mm. The side lengths of the metasurface antenna unit are all 18 mm, and the thickness is 3.551 mm. The side lengths of the metasurface antenna array are all 144 mm, and the thickness is 3.551 mm.

Images