Medium loaded high-isolation dual-polarized aperture-coupled antenna

Abstract

The application belongs to the technical field of wireless communication, and discloses a medium loading type high-isolation dual-polarization aperture coupling antenna, which comprises a first medium substrate, an upper surface of which is provided with a radiation patch; a second medium substrate, an upper surface of which is provided with a metal ground layer, and a pair of coupling slits are etched on the metal ground layer; wherein the first medium substrate is arranged in parallel above the second medium substrate, and an air gap is arranged between the first medium substrate and the second medium substrate; two microstrip feed lines are fixedly arranged on the lower surface of the second medium substrate, serving as two ports of the coupling antenna; and a medium loading block is fixedly arranged on the metal ground layer of the second medium substrate, and the medium loading block is arranged in a horizontal direction away from the first medium substrate. The application can improve the port isolation performance without changing the feed and increasing the lateral size of the unit.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, and specifically relates to a dielectric-loaded high-isolation dual-polarized aperture coupled antenna. Background Technology

[0002] Polarization diversity technology is a key technology in the field of wireless communication. Dual-polarized antennas can improve spectrum utilization and increase the channel capacity of communication systems. They are widely used in mobile communication base stations, satellite communication, electronic detection and other scenarios, and are currently a research hotspot in the antenna field.

[0003] Dual-polarized antennas are mainly divided into two categories: 90° orthogonal polarization and ±45° dual polarization. Typical structures include dipole antennas, microstrip patch antennas, and substrate integrated waveguide (SIW) antennas. The two core performance indicators for dual-polarized antenna design are port isolation and cross-polarization level. The key to improving isolation is suppressing coupling current between ports. Traditional dual-polarized aperture-coupled microstrip antennas exhibit current distortion at the edge of the radiating patch, and surface waves are generated at the open-circuit ends of the microstrip, exacerbating the coupling current between the two orthogonally fed ports, resulting in poor port isolation.

[0004] Existing decoupling and isolation improvement schemes mainly have the following drawbacks: (1) Feed network integrated filtering decoupling: Adding a second-order low-pass filter structure to each port of the antenna can improve the isolation to more than 25dB, but requires additional integrated resonant filter circuit, which increases the overall profile of the antenna and greatly increases the structural complexity. (2) Multi-cavity stacking decoupling: The three sets of resonators are integrated with the radiating patch to form a filter structure. The port isolation can reach 35dB, but the stacking of multiple resonant cavities will significantly increase the lateral size of the antenna unit, which cannot meet the requirements of large-scale dense array arrangement. The radiation of a rectangular microstrip patch antenna is generated by the edge field between the patch and the ground plane. The patch radiation is equivalent to two sets of vertical slot radiation. The open edge of the patch will generate current distortion and excite surface waves. The two types of effects together aggravate the electromagnetic coupling at the port. The isolation of conventional dual-polarized antennas without decoupling structure is generally lower than 35dB, which is difficult to meet the high isolation index of satellite and 5G base station array antennas.

[0005] In summary, current solutions for improving port isolation mainly rely on adding resonant filter circuits and stacking multiple resonant cavities in the feed network. These solutions significantly increase the overall cross-section and lateral dimensions of the antenna, resulting in complex structures that cannot meet the miniaturization requirements of large-scale dense array antennas for base stations and satellite communications. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a dielectric-loaded high-isolation dual-polarized aperture coupled antenna. By setting a dielectric-loaded block to block the non-orthogonal radiation field at the edge of the patch, the port coupling current is weakened, which can improve the port isolation performance without changing the feed or increasing the lateral size of the unit.

[0007] The technical solution provided by this invention is as follows: A dielectric-loaded, high-isolation dual-polarized aperture coupled antenna, comprising: A first dielectric substrate, on the upper surface of which a radiating patch is disposed; The second dielectric substrate has a metal ground layer disposed on its upper surface, and a pair of coupling slits are etched on the metal ground layer. The first dielectric substrate is disposed parallel above the second dielectric substrate, and an air gap exists between the first dielectric substrate and the second dielectric substrate. Two microstrip feed lines are fixedly disposed on the lower surface of the second dielectric substrate, serving as the two ports of the coupled antenna; A dielectric loading block is fixedly disposed on the metal ground layer of the second dielectric substrate, and the dielectric loading block is spaced apart from the first dielectric substrate in the horizontal direction.

[0008] Preferably, both the first dielectric substrate and the second dielectric substrate are square substrates, the dielectric loading block is a cuboid block, the long side of the dielectric loading block is disposed close to one side of the first dielectric substrate, and the long side of the dielectric loading block is parallel to the side of the first dielectric substrate it is close to.

[0009] Preferably, the dielectric loading block is made of polytetrafluoroethylene with a dielectric constant of 2.1.

[0010] Preferably, a foamed dielectric layer is disposed between the first dielectric substrate and the second dielectric substrate, and an air gap is formed through the foamed dielectric layer.

[0011] Preferably, the height of the air gap is 2.7 mm and the height of the medium loading block is 2.9 mm.

[0012] Preferably, the medium loading block has a length of 6 mm and a width of 2 mm.

[0013] Preferably, the size of the radiating patch is the same as the size of the first dielectric substrate.

[0014] Preferably, the horizontal distance between the medium loading block and the edge of the radiation patch is 5 mm.

[0015] Preferably, the grounding layer is made of copper.

[0016] Preferably, the foamed medium layer is made of expandable polystyrene with a dielectric constant of 1.03.

[0017] The beneficial effects of this invention are: The dielectric-loaded high-isolation dual-polarized aperture coupled antenna provided by this invention features a dielectric loading block. This block modulates the edge electric field of the patch and suppresses port coupling current, thereby improving port isolation. It requires no modification to the underlying feed, ground plane gaps, or the shape of the radiating patch, does not increase the antenna's lateral dimensions, and results in a minimal increase in antenna profile, while simultaneously improving array gain. The operating bandwidth is 2.36~2.54 GHz (S). 11 <-10dB), 2.37~2.63GHz full-band port isolation better than -35dB, simple structure and easy to process, can be directly used as array unit for satellite communication and mobile communication base station antenna. Attached Figure Description

[0018] Figure 1 This is a top view of the dielectric-loaded high-isolation dual-polarized aperture coupled antenna described in this invention; Figure 2 This is a schematic diagram of the upper surface structure of the second dielectric substrate described in this invention; Figure 3 This is a schematic diagram of the lower surface structure of the second dielectric substrate described in this invention; Figure 4 This is a front view of the dielectric-loaded high-isolation dual-polarized aperture coupled antenna described in this invention. Figure 5 A schematic diagram illustrating the effect of changing the height of the dielectric loading block on the port isolation of the antenna; Figure 6 A schematic diagram illustrating the effect of changing the height of the dielectric loading block on the return loss of the antenna; Figure 7 A schematic diagram illustrating the effect of changing the width of the dielectric loading block on the port isolation of the antenna; Figure 8 A schematic diagram illustrating the effect of changing the width of the dielectric loading block on the return loss of the antenna; Figure 9 A schematic diagram illustrating the effect of changing the length of the dielectric loading block on the port isolation of the antenna; Figure 10 A schematic diagram illustrating the effect of changing the length of the dielectric loading block on the return loss of the antenna; Figure 11 A schematic diagram illustrating the effect of changing the horizontal distance between the dielectric loading block and the edge of the radiating patch on the port isolation of the antenna; Figure 12 A schematic diagram illustrating the effect of changing the horizontal distance between the dielectric loading block and the edge of the radiating patch on the return loss of the antenna; Figure 13 Simulation results of the return loss of the antenna designed for an embodiment of the present invention; Figure 14 The simulation results of the port isolation of the antenna designed for an embodiment of the present invention are shown in the figure. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0020] Based on the analysis of the radiation characteristics of microstrip patch antennas, the radiated energy of the microstrip antenna is mainly concentrated in the edge region between the radiating patch and the ground plane. The radiation of the radiating patch can be equivalent to the radiation from two sets of mutually perpendicular slots. Due to edge current distortion and surface waves excited at the opening of the microstrip antenna, the coupling between ports is enhanced, thereby reducing the isolation. Based on electromagnetic theory, this invention provides a dielectric-loaded high-isolation dual-polarized aperture coupled antenna, which aims to reduce port coupling and improve isolation by setting a dielectric loading block to block non-orthogonal radiation fields in the edge field.

[0021] like Figures 1-4 As shown, the dielectric-loaded high-isolation dual-polarized aperture coupling antenna provided by the present invention includes two dielectric substrates and a dielectric loading block. Specifically, it includes: a first dielectric substrate 110, a second dielectric substrate 120, and a dielectric loading block 130. The planar dimensions of the second dielectric substrate 120 are larger than those of the first dielectric substrate 110. The first dielectric substrate 110 is disposed at the center above the second dielectric substrate 120, and the first and second dielectric substrates 110 are arranged parallel to each other, with an air gap between them. The upper surface of the first dielectric substrate 110 is covered with a radiating patch metal layer, the upper surface of the second dielectric substrate 120 is a complete copper ground layer, and the lower surface of the second dielectric substrate 120 is provided with dual orthogonal microstrip feed lines.

[0022] In one embodiment, a foamed dielectric layer is disposed between the first dielectric substrate 110 and the second dielectric substrate 120. The foamed dielectric layer is bonded and fixed between the first dielectric substrate 110 and the second dielectric substrate 120. Since the dielectric constant of the foamed dielectric layer is very close to that of air, an air gap is formed between the first dielectric substrate 110 and the second dielectric substrate 120.

[0023] As a preferred embodiment, the foamed medium layer is made of expandable polystyrene (EPS) with a dielectric constant of 1.03, which is very close to that of air.

[0024] The dielectric loading block 130 is a cuboid loading block, fixedly disposed on the second dielectric substrate 120, and there is a gap between the dielectric loading block 130 and the edge of the first dielectric substrate 110. The lower surface of the dielectric loading block 130 is tightly attached to the upper surface (ground layer) of the second dielectric substrate 120. The dielectric loading block 130 is mounted on the second dielectric substrate 120 by adhesive bonding. The dielectric loading block 130 is a core decoupling structure capable of modulating the edge electric field of the patch and weakening the two-port coupling current.

[0025] As a preferred option, the dielectric loading block 130 is made of polytetrafluoroethylene with a dielectric constant of 2.1.

[0026] As a preferred embodiment, the first dielectric substrate 110 is a square substrate, using FR4 dielectric substrate with a relative permittivity of 4.4, a loss tangent of 0.02, and a thickness of hs = 0.8 mm; a square metal radiating patch is printed on the upper surface of the first dielectric substrate 110 as the main radiating unit. The radiating patch has the same dimensions as the first dielectric substrate 110.

[0027] The second dielectric substrate 120 is a square substrate, using FR4 dielectric substrate, with a relative permittivity of 4.4, a loss tangent of 0.02, and a thickness of hs = 0.8 mm. The centers of the first dielectric substrate 110 and the second dielectric substrate 120 are aligned, and the four sides of the first dielectric substrate 110 and the second dielectric substrate are parallel. The long side of the dielectric loading block 130 is located close to one side of the first dielectric substrate 110, and the long side of the dielectric loading block 130 is parallel to the side of the first dielectric substrate 110 to which it is located.

[0028] The upper surface of the second dielectric substrate 120 is fully covered with copper foil as a ground layer. A pair (two) symmetrical H-shaped slots 121 are etched on the ground layer. Each H-shaped slot 121 includes two parallel vertical slots and a horizontal slot located between the two vertical slots, with both ends connected to the two vertical slots. The two H-shaped slots 121 are coupling slits. The axes of symmetry of the two H-shaped slots 121 (perpendicular to the direction of the horizontal slot in the H-shaped slot) are respectively arranged along two diagonals of the second dielectric substrate 120, and the two H-shaped slots 121 are respectively located near two adjacent apex corners of the second dielectric substrate 120. The bottom layer feed energy is coupled to the upper radiating patch through the H-shaped coupling slots. Two symmetrical orthogonal microstrip feed lines 122 are printed on the lower surface of the second dielectric substrate 120, serving as the first and second ports of the antenna, respectively, to excite two orthogonally polarized electromagnetic waves. The positions of the orthogonal microstrip feed line 122 and the H-shaped slit 121 are set in a one-to-one correspondence, and the setting direction of the corresponding orthogonal microstrip feed line 122 is the same as the setting direction of the H-shaped slit 121.

[0029] The field distribution and overall performance of antennas with and without dielectric loading blocks were compared. First, the decoupling effect of the dielectric loading block was compared intuitively from the perspective of electric field vector distribution. Without the dielectric loading block, the electric field vector distribution at the edge of the radiating patch was chaotic, and a large number of non-orthogonal electric field components formed coupling paths between the two polarization ports. After setting the loading rectangular dielectric block, the dielectric loading block played a role in constraining and blocking the electric field at the edge of the radiating patch. The cross-port coupled electric field components were significantly attenuated, and the coupling current between the ports was effectively suppressed. The feasibility of decoupling by dielectric loading was verified from the electromagnetic field level.

[0030] Without a dielectric loading block, the electric field vector at the edge of the radiating patch is chaotic, resulting in a large amount of cross-coupled current at the dual ports and poor port isolation. The two orthogonal feed lines at the bottom layer excite the patch to generate orthogonal polarization through the H-shaped gap, but the distortion field at the edge of the patch will form a cross-port coupling path.

[0031] After the loading medium block is set, the dielectric material changes the dielectric environment of the space below the radiating patch, reconstructs the electric field vector distribution at the edge of the radiating patch, blocks the coupling path of the non-orthogonal radiation field between the two polarizations, and suppresses the port coupling current. The bottom H-shaped orthogonal slit ensures the orthogonal characteristics of the basic polarization. The loading medium block further eliminates port coupling from the spatial field level, achieving high isolation. The loading medium block only changes the interlayer electric field distribution and does not change the resonant length of the radiating patch or the feed line matching structure. Therefore, the antenna return loss and operating bandwidth are almost unaffected.

[0032] The parameters of the medium loading block 130 are analyzed below using HFSS finite element full-wave simulation. The specific process is as follows.

[0033] First, set the parameter values ​​of the first dielectric substrate and the second dielectric substrate according to Table 1, and set the value range of each parameter of the dielectric loading block 130.

[0034] Table 1 Antenna parameters (unit: mm)

[0035] In Table 1, W represents the side length of the second dielectric substrate 120. The value of W needs to be close to the center free space wavelength of 2.4 GHz. λ 0≈125mm, to avoid mutual coupling of array units, W=110mm is set. W1 represents the side length of the first dielectric substrate 110. The value of W1 is determined according to the target frequency band 2.36~2.54GHz. The resonant length of the radiating patch is taken as half the wavelength inside the dielectric, FR4 ( ε r=4.4) After correcting for the effective dielectric constant, the calculated patch side length is 49mm, ensuring the resonant center falls at 2.45GHz. W2 represents the length of the dielectric loading block 130 (the length of the long side of the dielectric loading block 130), with a lower limit set to 6mm, which just covers the strongest stray coupling region at the patch edge, balancing decoupling effect and miniaturization. L2 represents the length of the short side of the dielectric loading block 130 (the width of the dielectric loading block 130), with a lower limit set to 2mm, which only covers local stray fields, achieving decoupling without excessively occupying interlayer space or degrading bandwidth. mp represents the horizontal distance between the dielectric loading block 130 and the first dielectric substrate 110 (i.e., the horizontal distance between the dielectric loading block and the edge of the radiating patch). W S1 W represents the height of the H-shaped slit (i.e., the length of the two parallel vertical grooves in the H-shaped slit 121). S2 W is the width of the transverse groove of the H-shaped slit. S Ls represents the width of the vertical slot in the H-shaped slit, and Ls represents the length of the horizontal slot in the H-shaped slit (i.e., the distance between the two vertical slots). The size of the H-shaped slit is set according to the classic aperture coupling structure, which has higher coupling efficiency and less back radiation compared to a rectangular slit. hs represents the thickness of the first dielectric substrate 110 and the second dielectric substrate 120, h1 is the height of the air gap formed by the first dielectric substrate 110 and the second dielectric substrate 120, and h2 represents the height of the dielectric loading block. W f This indicates the width of the microstrip feed line; the characteristic impedance of the microstrip feed line is 50Ω, the FR4 substrate thickness is 0.8mm, and the dielectric constant ε... r =4.4, W is accurately calculated using the microstrip impedance formula. f =2.5mm, matching the standard impedance of SMA RF ports.

[0036] (1) Scanning analysis of the height h2 parameter of the medium loading block Choose any value for W2, L2, and mp from the range given in Table 1, and set all parameters except h2 according to the parameters in Table 1. Only change the height h2 of the medium loading block (h2 is set to 2.3 mm, 2.5 mm, 2.7 mm, 2.96 mm, 3.1 mm, and 3.2 mm respectively) to perform parameter scanning. The simulation results are as follows. Figures 5-6 As shown, from the port isolation S 21 From the variation pattern, the port isolation changes only slightly when the height h2 of the dielectric loading block fluctuates a little; when the height h2 of the dielectric loading block exceeds the height of the air gap by 0.2 mm, the dielectric fully fills the coupling area between the patch and the ground layer, significantly enhancing the blocking effect on stray coupling fields and noticeably optimizing the port isolation; return loss S 11 The curve shows almost no shift with h2, proving that the height of the dielectric loading block only controls the port coupling field and has little effect on the return loss S. 11There is no impact, and it has no significant negative impact on antenna impedance matching. In the engineering design, h2=2.9 mm is selected as the optimal height for the dielectric loading block.

[0037] (2) Scanning analysis of the length and width dimensions (L2, W2) of the dielectric block Keeping the height h2 of the medium loading block at 2.9 mm and other parameter values ​​in (1) unchanged, the width L2 and length W2 of the medium loading block are scanned to analyze the influence of size variables on isolation and return loss. First, keeping the length W2 the same as in (1), only the width L2 of the medium loading block is changed (L2 values ​​are set to 2 mm, 4 mm, 6 mm, and 8 mm respectively) for parameter scanning. The simulation results are as follows. Figures 7-8 As shown, as the width L2 of the dielectric loading block increases, the area covered by the dielectric loading block over the coupling field at the edge of the radiating patch also widens, leading to a continuous deterioration in port isolation performance. The two exhibit a negative correlation. Considering the design constraint of the target operating bandwidth, selecting L2 = 2 mm can simultaneously balance antenna bandwidth and port isolation performance, and changes in the size of L2 will not alter the return loss S. 11 The overall shape of the curve ensures that the antenna impedance matching characteristics are largely unaffected. Therefore, considering both bandwidth performance and other factors, the optimal size L2 = 2mm is chosen.

[0038] Keeping L2 = 2 mm and other parameter values ​​unchanged, only the length W2 of the medium loading block was varied (W2 was set to 6 mm, 8 mm, 10 mm, 12 mm, and 14 mm respectively) to perform a parameter scan. Simulation results. Figures 9-10 As shown, the variation pattern of the dielectric loading block length W2 is similar to that of the width. The larger the value of W2, the wider the coverage area of ​​the dielectric loading block along the edge of the radiating patch, resulting in more coupling paths between ports and a gradual deterioration in isolation performance. When W2 = 6 mm, the antenna's full-band isolation meets the design requirements, and adjusting the dielectric length does not significantly affect the antenna's return loss. Therefore, the optimal size is W2 = 6 mm.

[0039] (3) Scanning analysis of the parameters of the dielectric loading block position (horizontal distance mp between the dielectric loading block and the edge of the radiation patch). The dimensions of the fixed medium loading block were h2 = 2.9 mm, L2 = 2 mm, and W2 = 6 mm, and other parameters were set according to Table 1. Only the horizontal distance mp between the medium loading block and the edge of the radiation patch was changed (mp values ​​were set to 0 mm, 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm respectively) for parameter scanning. The simulation curves are shown below. Figures 11-12 As shown, the port isolation S 21Simulation results show that mp is positively correlated with port isolation: the greater the distance between the dielectric loading block and the radiating patch, the stronger the blocking effect on stray coupling fields at the edge of the radiating patch, and the better the isolation index; when mp = 5 mm, the full-band isolation performance reaches its optimum; comparing the return loss S corresponding to different mp values... 11 The curves, with multiple curves completely overlapping, indicate that the position of the dielectric loading block only affects the port mutual coupling field and has no impact on the return loss S. 11 It has no impact and will not interfere with the antenna's own resonance and impedance matching characteristics. Therefore, the optimal spacing mp = 5mm.

[0040] Based on the above multi-parameter scanning simulation results, the following patterns can be observed: Setting a dielectric loading block can effectively block the cross-port coupling electric field at the patch edge, significantly improving the port isolation of the dual-polarized antenna, while almost without degrading the antenna impedance bandwidth; the dielectric loading block height h2, planar dimensions L2, W2, and the distance mp between the dielectric loading block and the edge of the radiating patch all change the port isolation performance to varying degrees, with larger dielectric loading block planar dimensions resulting in poorer isolation; a larger distance between the dielectric and the patch results in better isolation; the dielectric height needs to be slightly higher than the air gap height between the first and second dielectric substrates to achieve the optimal decoupling effect; each dielectric structure parameter affects the antenna return loss S. 11 With minimal impact; considering the constraints of bandwidth and isolation performance, the optimal medium loading parameters are determined as follows: h2=2.9 mm, L2=2 mm, W2=6 mm, mp=5 mm.

[0041] Example The overall structure of the antenna is as follows Figures 1-4 As shown, the first dielectric substrate 110 is square, using FR4 dielectric substrate with a thickness hs=0.8mm. A square radiating patch with the same planar dimensions as the first dielectric substrate 110 is printed on the upper surface. The side length of the first dielectric substrate 110 is W1=49mm, that is, the side length of the radiating patch is 49mm.

[0042] The second dielectric substrate 120 is square, made of FR4 dielectric substrate, with a thickness hs=0.8mm and a relative permittivity ε. r =4.4, loss tangent value is 0.02; the side length W of the second dielectric substrate 120 is 110mm, the upper surface is fully covered with copper as a ground layer, and a pair of symmetrical ±45° H-type coupling gaps are etched on the ground layer, the size of the H-type gaps is Ls=9.5mm, W S1 =7mm, W S =3.5mm, W S2 =2mm; Two orthogonal microstrip feed lines are set on the lower surface, with a microstrip feed line width W. f =2.5mm, corresponding to the first port and the second port of the antenna, respectively.

[0043] An interlayer air gap is formed between the first dielectric substrate 110 and the second dielectric substrate 120 by bonding expandable polystyrene (EPS), with an air gap height h1 = 2.7 mm. The expandable polystyrene (EPS) has the same planar dimensions as the first dielectric substrate 110, and the dielectric constant of the expandable polystyrene (EPS) is 1.03.

[0044] The rectangular dielectric loading block has a height h2 = 2.9 mm, a width L2 = 2 mm, a length W2 = 6 mm, and a distance mp = 5 mm between the edge of the dielectric block and the edge of the radiating patch. The dielectric loading block is made of polytetrafluoroethylene (PTFE) with a dielectric constant of 2.1.

[0045] Overall antenna operating frequency band: 2.36~2.54GHz (S 11 <-10dB), effective isolation frequency band 2.37~2.63GHz.

[0046] Figure 13 The S-axis of the antenna designed in this embodiment is shown. 11 Simulation curves show return loss: 2.36~2.54GHz full-band S 11 <-10dB, basically coincides with the matching curve of the unloaded antenna, with no resonance shift or matching deterioration. Figure 14 Simulation results for port isolation are presented, showing the port isolation S across the entire frequency band from 2.37 to 2.63 GHz. 21 Stable isolation below -35dB, representing an improvement of over 10dB compared to non-medium-loaded antennas.

[0047] This invention, based on electromagnetic theory, utilizes a dielectric loading block to alter the electric field vector distribution at the patch edge, blocking the propagation path of non-orthogonal radiated fields between ports, significantly reducing port coupling current, and improving port isolation. Furthermore, the dielectric loading block only changes the spatial electric field distribution and does not affect the resonant characteristics of the radiating patch itself; therefore, the antenna return loss S... 11 With essentially no changes and no sacrifice in operating bandwidth, the antenna array gain is synchronously increased by setting a dielectric loading structure, resulting in radiation performance superior to the unloaded control antenna. Testing showed that the measured S-parameter curves and HFSS simulation curves agree well, demonstrating the reliability of the proposed solution.

[0048] In summary, this invention, by setting a dielectric loading block, achieves a simulated antenna port isolation better than -35dB across the entire operating frequency band, meeting the high isolation requirements of satellite and base station arrays. The dielectric loading block affects the antenna return loss S. 11With virtually no impact, it stably achieves broadband matching from 2.36 to 2.54 GHz without any bandwidth narrowing. This invention only adds a small dielectric loading block to the underlying dielectric substrate, without increasing the antenna's lateral dimensions; the cross-sectional increase is minimal, making it suitable for large-scale dense array deployments. The invention has a simple structure; the feeding, patch, and grounding gaps follow the traditional aperture-coupled antenna structure, adding only a standard dielectric strip. It eliminates the need for multi-layer resonant cavities and complex filter feed lines, simplifying PCB fabrication and reducing manufacturing costs. The length, width, height, and patch spacing of the dielectric block can be adjusted according to the target frequency band and isolation requirements, adapting to various dual-polarized array scenarios in mobile and satellite communications.

[0049] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A dielectric-loaded, high-isolation dual-polarized aperture-coupled antenna, characterized in that, include: A first dielectric substrate, on the upper surface of which a radiating patch is disposed; The second dielectric substrate has a metal ground layer disposed on its upper surface, and a pair of coupling slits are etched on the metal ground layer. The first dielectric substrate is disposed parallel above the second dielectric substrate, and an air gap exists between the first dielectric substrate and the second dielectric substrate. Two microstrip feed lines are fixedly disposed on the lower surface of the second dielectric substrate, serving as the two ports of the coupled antenna; A dielectric loading block is fixedly disposed on the metal ground layer of the second dielectric substrate, and the dielectric loading block is spaced apart from the first dielectric substrate in the horizontal direction.

2. The dielectric-loaded high-isolation dual-polarized aperture coupled antenna according to claim 1, characterized in that, Both the first dielectric substrate and the second dielectric substrate are square substrates, and the dielectric loading block is a cuboid block. The long side of the dielectric loading block is located close to one side of the first dielectric substrate, and the long side of the dielectric loading block is parallel to the side of the first dielectric substrate it is close to.

3. The dielectric-loaded high-isolation dual-polarized aperture coupled antenna according to claim 2, characterized in that, The dielectric loading block is made of polytetrafluoroethylene with a dielectric constant of 2.

1.

4. The dielectric-loaded high-isolation dual-polarized aperture coupled antenna according to any one of claims 1-3, characterized in that, A foamed dielectric layer is disposed between the first dielectric substrate and the second dielectric substrate, and an air gap is formed through the foamed dielectric layer.

5. The dielectric-loaded high-isolation dual-polarized aperture coupled antenna according to claim 4, characterized in that, The height of the air gap is 2.7 mm, and the height of the medium loading block is 2.9 mm.

6. The dielectric-loaded high-isolation dual-polarized aperture coupled antenna according to claim 5, characterized in that, The medium loading block has a length of 6 mm and a width of 2 mm.

7. The dielectric-loaded high-isolation dual-polarized aperture coupled antenna according to claim 6, characterized in that, The size of the radiating patch is the same as the size of the first dielectric substrate.

8. The dielectric-loaded high-isolation dual-polarized aperture coupled antenna according to claim 7, characterized in that, The horizontal distance between the medium loading block and the edge of the radiation patch is 5 mm.

9. The dielectric-loaded high-isolation dual-polarized aperture coupled antenna according to claim 8, characterized in that, The grounding layer is made of copper.

10. The dielectric-loaded high-isolation dual-polarized aperture coupled antenna according to claim 9, characterized in that, The foamed medium layer is made of expandable polystyrene with a dielectric constant of 1.03.

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