Dual-band dual linear polarization reconfigurable folded transmissive-refractive array antenna

Abstract

This invention discloses a dual-band, dual-linear polarization, reconfigurable foldable transmission-reflection array antenna, comprising: an upper metasurface, a lower metasurface, and a feed antenna; the upper metasurface has 12×12 first element structures, each element structure comprising: a first metasurface metal patch, a first dielectric substrate, a second metasurface metal patch, a second dielectric substrate, and a third metasurface metal patch connected from top to bottom; the lower metasurface has 12×12 second element structures, each second element structure comprising: an annular slot metal patch, a third dielectric substrate, and a bottom feed line connected from top to bottom; two PIN diodes are integrated within the annular slot of the annular slot metal patch, and the annular slot metal patch is connected to the bottom feed line located on the upper surface of the third dielectric substrate via a feed probe; a 2×2 element size is left in the center of the lower metasurface for placing the feed antenna. This invention achieves dual-band, dual-linear polarization, bidirectional beam scanning and also features low profile characteristics.

Description

Technical Field

[0001] This invention belongs to the field of information processing technology, specifically relating to a dual-band dual-linear polarization reconfigurable foldable transmission-reflection array antenna. Background Technology

[0002] Antennas are key components in modern communication systems. With advancements in military communications and radar detection, the demand for highly directional antennas is increasing. However, traditional highly directional antennas, such as parabolic antennas, still face significant limitations in practical applications due to their high manufacturing costs and large size. Therefore, how to reduce the size of antennas while maintaining high directivity to adapt to more application scenarios has become an important research topic.

[0003] High-directivity antenna design mainly includes technologies such as phased array antennas and reflector antennas. Phased array antennas (PA) primarily achieve multi-angle scanning at specific frequencies by controlling the phase of the excitation current; this design method is classic but costly. Reflector antennas control the reflection phase of the antenna. They are characterized by curved structures and large dimensions, leading to the development of metasurface-loaded reflector array antennas (RA). Reflector array antennas are planar structures that achieve specific phase compensation by loading different types of reflective elements at different locations, thus focusing the beam. However, being passive, they cannot achieve beam scanning. Therefore, some researchers have combined reconfigurable reflective elements to design reflector array antennas, enabling beam reconfiguration, i.e., beam scanning. Similar to reflector array antennas are transmission array antennas (TA), which perform beam scanning by controlling the transmission phase. Even though reflective array antennas have many advantages, such as low cost and planar structure, their profile is still relatively high, which is not conducive to integration. Therefore, some researchers have proposed folded reflective array antennas (FRA), which reduce the profile by half by placing a polarization grid on top to achieve secondary reflection of the beam. With this design, a planar feed antenna can also be integrated into the reflective array. However, due to the single polarization selection characteristic of the upper polarization grid, current folded reflective array antennas can only adapt to one electromagnetic wave polarization and operate in a single frequency band. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention proposes a dual-band dual-linear polarization reconfigurable foldable transmission-reflection array antenna.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A dual-band, dual-linearly polarized, reconfigurable foldable transmission-reflection array antenna includes: an upper metasurface with polarization selection characteristics, a lower metasurface with phase modulation characteristics and a feed antenna, wherein the upper and lower metasurfaces are connected by nylon pillars and an air layer is in between.

[0007] Preferably, the upper metasurface has 12×12 first unit structures, each first unit structure comprising: a first metasurface metal patch, a first dielectric substrate, a second metasurface metal patch, a second dielectric substrate, and a third metasurface metal patch connected from top to bottom; the first metasurface metal patch is an elliptical metal patch, the second metasurface metal patch is an elliptical slotted metal patch, and the third metasurface metal patch is an elliptical metal patch.

[0008] Preferably, the lower metasurface has 12×12 second unit structures, each second unit structure including: an annular slot metal patch and a third dielectric substrate and a bottom feed line connected from top to bottom; two PIN diodes are integrated in the annular slot of the annular slot metal patch, and the annular slot metal patch and the bottom feed line located on the other side of the third dielectric substrate are connected by a feed probe; a 2×2 unit size is left in the center of the lower metasurface for placing the feed antenna.

[0009] Preferably, the feed antenna includes: a rectangular metal patch in the y-direction, a discontinuous rectangular metal patch in the x-direction, and four symmetrically distributed rectangular metal patches connected from top to bottom; a fourth dielectric substrate; a rectangular metal patch in the x-direction; a fifth dielectric substrate; and a metal ground. The discontinuous rectangular metal patch in the x-direction and the x-direction metal patch are connected by two metallized vias x penetrating the fourth dielectric substrate. The fourth and fifth dielectric substrates are connected by an FR4 adhesive layer. The four symmetrically distributed rectangular metal patches are connected by four metallized vias z and a metal ground, respectively. The two metallized vias f power the antenna.

[0010] Preferably, the side length of the first dielectric substrate is... p The thickness is 20mm; the substrate thickness of the first dielectric substrate is... h d It is 1.524mm; r 1 4.9 2 * r 3 ; r 2 8.1 for 2 * r 4 ; r 1 The minor axis of the ellipse is the first metasurface metal patch; r 2 The major axis of the ellipse is the first metasurface metal patch; r 3 The minor axis of the ellipse is the metal patch of the second metasurface; r 4 The major axis of the ellipse is defined by the second metasurface metal patch. The second dielectric substrate and the first dielectric substrate have the same dimensions; the second metasurface metal patch and the first metasurface metal patch have the same dimensions.

[0011] Preferably, the side length of the third dielectric substrate p The thickness is 20mm; the thickness of the third dielectric substrate is... h t The inner ring radius of the annular slit patch is 0.4mm. r is 7mm; Annular gap width w 0.9mm; bottom feeder width t It is 0.2mm.

[0012] Preferably, the length of the rectangular metal patch in the x-direction... m The side length of the symmetrically distributed rectangular metal patches is 4.2mm. a The width of the symmetrically distributed rectangular metal patch slots is 8.3mm. b The length of the rectangular metal patch in the y-direction is 1.8mm. c 8.3mm; width of the discontinuous rectangular metal patch in the x-direction d It is 2.2mm; the side length of the physical space occupied by the patch. l The thickness is 19.4 mm; the thickness of the fourth dielectric substrate is... h u The thickness is 0.762 mm; the fifth dielectric substrate thickness is... h l The thickness is 4mm; the adhesive layer thickness is... h pp It is 0.1mm.

[0013] Preferably, the distance between the upper metasurface and the lower metasurface is... H It is 70mm.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] This invention includes an upper metasurface with polarization selectivity and a lower metasurface with phase modulation and a feed antenna. The upper and lower metasurfaces are connected by nylon pillars with an air layer in between. The technical solution of this invention has the characteristics of low cost and low profile, and also has a dual-band dual-polarization bidirectional beam scanning function. Attached Figure Description

[0016] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a structural diagram of a dual-band, dual-linearly polarized, reconfigurable foldable transmission-reflection array antenna according to an embodiment of the present invention.

[0018] Figure 2 This is an exploded view of the upper metasurface structure;

[0019] Figure 3 This is a schematic diagram of the three-dimensional structure of the lower metasurface;

[0020] Figure 4 This is a view of the top patch of the lower metasurface;

[0021] Figure 5 This is a three-dimensional structural diagram of the feed antenna;

[0022] Figure 6 Views of the top and middle layer patches of the feed antenna;

[0023] Figure 7 This is a schematic diagram illustrating the performance of the upper metasurface.

[0024] Figure 8 This is a schematic diagram of the performance of the lower metasurface; where (a) is the amplitude and (b) is the phase.

[0025] Figure 9 This is a schematic diagram of the performance of the feed antenna;

[0026] Figure 10 The image shows the scanning radiation pattern; where (a) shows the antenna operating at 6.4 GHz. yoz (b) shows the area scan radiation pattern when the antenna is operating at 7.7 GHz. xoz Surface scan pattern;

[0027] Figure 11 This is the gain-frequency curve. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] like Figure 1As shown, this invention provides a dual-band, dual-linearly polarized, reconfigurable foldable transmission-reflection array antenna, comprising: an upper metasurface with polarization-selective characteristics and a lower metasurface with phase-modulation characteristics and a feed antenna, wherein the upper and lower metasurfaces are connected by nylon pillars with an air layer in between; the distance between the upper and lower metasurfaces is... H It is 70mm.

[0032] As one embodiment of the present invention, such as Figure 2 As shown, the upper metasurface has 12×12 first unit structures. The first unit structure includes: a first metasurface metal patch, a first dielectric substrate, a second metasurface metal patch, a second dielectric substrate, and a third metasurface metal patch connected from top to bottom; the first metasurface metal patch is an elliptical metal patch, the second metasurface metal patch is an elliptical slotted metal patch, and the third metasurface metal patch is an elliptical metal patch.

[0033] Furthermore, the side length of the first dielectric substrate p The thickness is 20mm; the substrate thickness of the first dielectric substrate is... h d It is 1.524mm; r 1 4.9 2 * r 3 ; r 2 8.1 for 2 * r 4 ; r 1 The minor axis of the ellipse is the first metasurface metal patch; r 2 The major axis of the ellipse is the first metasurface metal patch; r 3 The minor axis of the ellipse is the metal patch of the second metasurface; r 4 Let be the major axis of the ellipse of the second metasurface metal patch. The second dielectric substrate and the first dielectric substrate have the same dimensions; the second metasurface metal patch and the first metasurface metal patch have the same dimensions; the dielectric constants of the first dielectric substrate and the second dielectric substrate are... ε r = 2.2, and the loss tangent tan δ is 0.0009.

[0034] As one embodiment of the present invention, such as Figure 3 , 4As shown, the lower metasurface has 12×12 second unit structures. The second unit structure includes: an annular slot metal patch and a third dielectric substrate and a bottom feed line connected from top to bottom; two PIN diodes are integrated in the annular slot of the annular slot metal patch, and the annular slot metal patch and the bottom feed line located on the other side of the third dielectric substrate are connected through a feed probe; a 2×2 unit size is left in the center of the lower metasurface for placing the feed antenna.

[0035] Furthermore, the side length of the third dielectric substrate p The thickness is 20mm; the thickness of the third dielectric substrate is... h t The inner ring radius of the annular slit patch is 0.4mm. r is 7mm; Annular gap width w 0.9mm; bottom feeder width t The dielectric constant of the third dielectric substrate is 0.2 mm. ε r = 2.2, and the loss tangent tan δ is 0.0009.

[0036] As one embodiment of the present invention, such as Figure 5 , 6 As shown, the feed antenna is a dual-polarized magnetoelectric dipole antenna, comprising: a rectangular metal patch in the y-direction, a discontinuous rectangular metal patch in the x-direction, and four symmetrically distributed rectangular metal patches connected from top to bottom; a fourth dielectric substrate; a rectangular metal patch in the x-direction; a fifth dielectric substrate; and a metal ground. The discontinuous rectangular metal patch in the x-direction and the x-direction metal patch are connected by two metallized vias x penetrating the fourth dielectric substrate. The fourth and fifth dielectric substrates are connected by an FR4 adhesive layer. The four symmetrically distributed rectangular metal patches are connected by four metallized vias z and the metal ground, respectively. The antenna is fed by two metallized vias f. The two x-direction patches separated by the y-direction rectangular metal patches on the top layer of the feed antenna are the discontinuous rectangular metal patches in the x-direction. The intermediate layer patch between the fourth and fifth dielectric substrates is the rectangular metal patch in the x-direction.

[0037] Furthermore, the length of the rectangular metal patch in the x-direction m The side length of the symmetrically distributed rectangular metal patches is 4.2mm. a The width of the symmetrically distributed rectangular metal patch slots is 8.3mm. b The length of the rectangular metal patch in the y-direction is 1.8mm. c 8.3mm; width of the discontinuous rectangular metal patch in the x-direction d It is 2.2mm; the side length of the physical space occupied by the patch. l The thickness is 19.4 mm; the thickness of the fourth dielectric substrate is...h u The thickness is 0.762 mm; the fifth dielectric substrate thickness is... h l The thickness is 4mm; the adhesive layer thickness is... h pp The dielectric constant of the fourth and fifth dielectric substrates is 0.1 mm. ε r The dielectric constant of the FR4 adhesive layer is 2.65, and the loss tangent tan δ is 0.0007. ε r The loss angle is 4.4, and the loss tangent tan δ is 0.02.

[0038] As one embodiment of the present invention, such as Figure 7 As shown, R xx and R yy They represent x Polarized waves and y The reflection coefficient of polarized waves, T xx and T yy Then it means x Polarized waves and y The transmission coefficient of polarized waves. The frequency bands are defined as follows: low frequency band is 6–6.8 GHz, and high frequency band is 7.4–8 GHz. It can be clearly observed that within the specified frequency bands... R xx and R yy The values ​​are all greater than -1dB, while T yy and T xx The value is also close to -1dB. Therefore, this structure achieves ideal polarization selectivity: that is, it achieves polarization selectivity in the low-frequency range. x Polarized wave reflection, y Polarized wave transmission; in the high-frequency range, it achieves the opposite function, namely... x Polarized wave transmission, y Polarized wave reflection.

[0039] When excitation voltages Vf and −Vf are applied, the unit can achieve two independent operating states. In both states, the phase difference between transmission and reflection is close to 180°, thus enabling the metasurface to have a 1-bit reconfigurable function, such as... Figure 8 As shown in (a). Figure 8 (b) gives the transmission and reflection amplitudes of the unit structure in state 0. Wherein, R xy and Txy They represent x Polarization wave conversion to y The reflection coefficient and transmission coefficient of polarized waves, R yx and T yx Then corresponding y Polarization wave conversion to x The conversion coefficient of the polarized wave. As shown in the figure, in the 6–8 GHz frequency band, the transmission amplitude and reflection amplitude of this unit are basically the same, both about 0.4, which indicates that the unit structure has good transmission and reflection performance; in addition, the transmission and reflection amplitude performance in the two states are exactly the same.

[0040] Figure 9 The S-parameters of the feed antenna are given. It can be seen that in the 6–8 GHz frequency band, the S-parameters of both ports are below -10 dB, and the port isolation performance is excellent.

[0041] This invention simulates the antenna performance at a frequency of 6.4 GHz. yoz The radiation pattern of the plane was simulated at a frequency of 7.7 GHz. xoz The radiation patterns of the plane are shown below. Figure 10 As shown in (a) and (b), when Port2 is excited, the antenna can radiate different scanning angles by controlling the operating state of the diodes. y Polarized waves, possessing bidirectional beam scanning capability, such as Figure 10 As shown in (a), the antenna's radiated beam can achieve a scanning angle of 40° in the yoz plane, and its performance is good; when Port1 is excited, x The polarized radiation beam can scan at an angle of up to 45° in the xoz plane, such as Figure 10 As shown in (b).

[0042] Figure 11 The gain versus frequency curves are presented. In the low-frequency band, the -3dB gain bandwidths of the reflected and transmitted beams are 8% and 11%, respectively; in the high-frequency band, the -3dB gain bandwidths of both the reflected and transmitted beams are 7.7%. In the low-frequency band, the peak gain of the reflected beam reaches 14.1 dBi (6.4 GHz), and the peak gain of the transmitted beam is 12.1 dBi (6.6 GHz); in the high-frequency band, the peak gains of the reflected and transmitted beams reach 14.2 dBi at 7.6 GHz and 7.4 GHz, respectively.

[0043] The present invention is compared with the prior art to highlight the unique advantages of the proposed design, as shown in Table 1. Reference [1] proposes a multifunctional antenna that can switch between reflective array (RA) / transmittive array (TA) / transmissive-reflective array (TRA) modes. Although it can achieve beam scanning, its profile height is relatively high. Reference [2] proposes a folded reflective antenna (FRA) that can support beam scanning, but can only radiate single-polarized waves. Reference [3] designs a dual-polarized FRA that achieves dual-linear polarization, but does not have beam scanning capability. The design in Reference [4] also has this defect. Reference [5] proposes a dual-frequency dual-circular polarized RA that cannot achieve dynamic beam scanning and has a relatively high profile height. The reconfigurable dual-band dual-polarized transmissive-reflective array antenna (RFTRA) proposed in this invention can achieve dual-frequency dual-linear polarization beam scanning and also has low profile characteristics.

[0044] Table 1

[0045] / type Beam scanning high polarization mode Operating frequency band [1] T / R / TRA YES F Dual polarization Single band [2] FRA YES F / 2 Single polarization Single band [3] FRA NO F / 2 Dual polarization Single band [4] FTA NO F / 3 Dual polarization Dual-band [5] RA NO F Dual polarization Dual-band This invention FTRA YES F / 2 Dual polarization Dual-band

[0046] The following documents are available:

[0047] [1]H. Yu, P. Li, J .Su, Z. Li, S. Xu, and F. Yang, “Reconfigurable bidirectional beam-steering aperture with transmitarray, reflectarray, and transmitreflect-array modes switching,” IEEE Trans. Antennas Propag ., vol.71, no. 1, pp. 581–595, Jan. 2023.

[0048] [2] Z. Wang et al , “1 Bit Electronically Reconfigurable FoldedReflectarray Antenna Based on pin Diodes for Wide-Angle Beam-ScanningApplications,” IEEE Trans. Antennas Propag ., vol. 68, no. 9, pp. 6806-6810, Sep. 2020.

[0049] [3] M. Wang, M. Yim and C. Chan, “Dual-Polarized Folded ReflectarrayAntenna With Active Components,” IEEE Trans. Antennas Propag., vol. 72, no.6, pp. 5289-5294, Jun. 2024.

[0050] [4] S. Xu, Y. Shen, S. Xue and S. Hu “26- / 39-GHz Low-Profile Dual-Circularly-Polarized Hybrid Antenna With Integrated Single Feed,” IEEE Transactions. Antennas Propag., vol. 71, no. 11, pp. 8548-8555, Nov. 2023.

[0051] [5] P. Xu et al., “Ultathin Single-Layer Dual-Band Dual-CircularlyPolarized Reflectarray for K- / Ka-Band Satellite Communications,” IEEE Transactions. Antennas Propag ., vol. 72, no.9, pp. 7122-7134, Sep. 2024.

[0052] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A dual-band, dual-linearly polarized, reconfigurable foldable transmission-reflection array antenna, characterized in that, include: The upper metasurface has polarization selectivity characteristics, and the lower metasurface has phase modulation characteristics and is a feed antenna. The upper and lower metasurfaces are connected by nylon pillars with an air layer in between. The feed antenna is a dual-polarized magnetoelectric dipole antenna; The upper metasurface has 12×12 first unit structures, each first unit structure including: a first metasurface metal patch, a first dielectric substrate, a second metasurface metal patch, a second dielectric substrate, and a third metasurface metal patch connected from top to bottom; the first metasurface metal patch is an elliptical metal patch, the second metasurface metal patch is an elliptical slotted metal patch, and the third metasurface metal patch is an elliptical metal patch. The lower metasurface has 12×12 second unit structures, each of which includes: an annular slot metal patch and a third dielectric substrate and a bottom feed line connected from top to bottom; two PIN diodes are integrated in the annular slot of the annular slot metal patch, and the annular slot metal patch and the bottom feed line located on the other side of the third dielectric substrate are connected by a feed probe; a 2×2 unit size is left in the center of the lower metasurface for placing the feed antenna.

2. The dual-band dual-linear polarization reconfigurable foldable transmission-reflection array antenna as described in claim 1, characterized in that, The feed antenna includes: a rectangular metal patch in the y-direction, a discontinuous rectangular metal patch in the x-direction, and four symmetrically distributed rectangular metal patches connected from top to bottom; a fourth dielectric substrate; a rectangular metal patch in the x-direction; a fifth dielectric substrate; and a metal ground. The discontinuous rectangular metal patch in the x-direction and the metal patch in the x-direction are connected by two metallized vias x through the fourth dielectric substrate. The fourth dielectric substrate and the fifth dielectric substrate are connected by an FR4 adhesive layer. The four symmetrically distributed rectangular metal patches are connected by four metallized vias z and the metal ground, respectively. The antenna is fed by two metallized vias f.

3. The dual-band dual-linear polarization reconfigurable foldable transmission-reflection array antenna as described in claim 2, characterized in that, Side length of the first dielectric substrate p The thickness is 20mm; the substrate thickness of the first dielectric substrate is... h d It is 1.524mm; r 1 4.9 mm is 2* r 3 ; r 2 It is 8.1 mm and 2 * r 4 ; r 1 The minor axis of the ellipse is the first metasurface metal patch; r 2 The major axis of the ellipse is the first metasurface metal patch; r 3 The minor axis of the ellipse is the metal patch of the second metasurface; r 4 The major axis of the ellipse is the second metasurface metal patch; the second dielectric substrate and the first dielectric substrate have the same dimensions; The third metasurface metal patch is the same size as the first metasurface metal patch.

4. The dual-band dual-linear polarization reconfigurable foldable transmission-reflection array antenna as described in claim 3, characterized in that, The third dielectric substrate has a side length of 20mm; the thickness of the third dielectric substrate is... h t It is 0.4mm; Inner ring radius of the annular gap patch r is 7mm; Annular gap width w 0.9mm; bottom feeder width t It is 0.2mm.

5. The dual-band dual-linear polarization reconfigurable foldable transmission-reflection array antenna as described in claim 4, characterized in that, x-direction rectangular metal patch length m The side length of the symmetrically distributed rectangular metal patches is 4.2mm. a The width of the symmetrically distributed rectangular metal patch slots is 8.3mm. b The length of the rectangular metal patch in the y-direction is 1.8mm. c 8.3mm; width of the discontinuous rectangular metal patch in the x-direction d The thickness is 2.2 mm; the thickness of the fourth dielectric substrate is... h u It is 0.762mm; Fifth dielectric substrate thickness h l The thickness is 4mm; the adhesive layer thickness is... h pp It is 0.1mm.

6. The dual-band dual-linear polarization reconfigurable foldable transmission-reflection array antenna as described in claim 5, characterized in that, Distance between the upper metasurface and the lower metasurface H It is 70mm.

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