High-gain broadband half-mode SIW filtering antenna based on metasurface

Abstract

The utility model belongs to the technical field of microwave communication, and specifically relates to a high-gain broadband half-mode SIW filtering antenna based on a metasurface. Comprising a dielectric substrate, a first metal layer and a second metal layer, wherein the first metal layer is attached to the upper surface of the dielectric substrate, and the second metal layer is attached to the lower surface of the dielectric substrate; the first metal layer comprises a coplanar waveguide feed structure, a rectangular metal patch, a metasurface metal patch and a metasurface array nested with CSRRs which are sequentially arranged from one end to the other end; the dielectric substrate is provided with periodic metalized through holes to form an HMSIW resonant cavity, the metalized through holes penetrate through the dielectric substrate and are connected with the first metal layer and the second metal layer, and N metalized short-circuit pins are arranged in the middle of the opening end of the right side of the HMSIW resonant cavity; the second metal layer is provided with a rectangular groove.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of microwave communication technology, concretely relates to a high gain wideband half mode SIW filtering antenna based on metasurface. BACKGROUND

[0002] In the traditional wireless communication system, the antenna and the filter are usually designed independently, and this way is easy to cause the overall size of the circuit to be large, and the mutual influence between the antenna and the filter will reduce the overall performance of the system. In order to solve these problems, the filtering antenna of integrated design of antenna and filter is proposed.

[0003] Substrate Integrated Waveguide (SIW) is a new type of waveguide structure, which has the advantages of high Q value, low loss and easy integration, and is widely used to realize the miniaturization and high performance of wireless communication components. The filtering antenna based on SIW technology can improve the system performance while simplifying the design and reducing the size, so it has become the focus of research in recent years.

[0004] In order to further realize the miniaturization of the antenna, the Half-Mode Substrate Integrated Waveguide (HMSIW) structure is introduced into the design of the filtering antenna. On the basis of inheriting the excellent performance of SIW filtering antenna, the size of HMSIW structure is significantly reduced.

[0005] In the literature "Design of Compact, Single-Layered Substrate Integrated Waveguide Filtenna With Parasitic Patch (IEEE Transactions on Antennas and Propagation 2 (2020): 1134-1139)", a compact filtering antenna using HMSIW technology is proposed, which realizes the filtering function by arranging a parasitic patch with a short-circuit pin near the HMSIW cavity. Although this design effectively reduces the size and maintains an ultra-low profile, its working bandwidth is narrow, which limits the radiation performance of the antenna.

[0006] In summary, SIW technology can realize the miniaturization and low loss of filtering antenna, but in order to meet the needs of wideband and high gain, further optimization of its design and performance is still needed. UTILITY MODEL CONTENTS

[0007] Therefore, the utility model provides a high gain wideband half mode SIW filtering antenna based on metasurface, which can solve the problem of limited bandwidth and gain of SIW low profile filtering antenna.

[0008] The utility model discloses a technical scheme that solves the above technical problem:

[0009] A high-gain broadband half-mode SIW filtering antenna based on a super surface, comprising a dielectric substrate, a first metal layer and a second metal layer, wherein the first metal layer is attached to the upper surface of the dielectric substrate, and the second metal layer is attached to the lower surface of the dielectric substrate.

[0010] The first metal layer comprises, from one end to the other end, a co-planar waveguide feed structure, a rectangular metal patch, a super surface metal patch array and a super surface array with CSRRs embedded therein.

[0011] The dielectric substrate is provided with a periodic metalized via hole to form an HMSIW resonant cavity, the metalized via hole penetrates through the dielectric substrate and connects the first metal layer and the second metal layer, and the middle part of the right opening end of the HMSIW resonant cavity is provided with N metalized short-circuit pins.

[0012] The second metal layer is provided with a rectangular groove.

[0013] As a further optimization scheme of the utility model, the rectangular metal patch is provided with a rectangular groove at one end facing the waveguide feed structure, and the waveguide feed structure extends into the rectangular groove and is connected with the metal patch.

[0014] As a further optimization scheme of the utility model, the super surface metal patch array is composed of 1x4 metal patch units.

[0015] As a further optimization scheme of the utility model, the super surface array with CSRRs embedded therein is composed of 1x4 CSRR patch units.

[0016] As a further optimization scheme of the utility model, the diameter D and the spacing S of the metalized via hole constituting the HMSIW cavity need to satisfy formula (2):

[0017] D≤0.2λ,S≤2D

[0018] Wherein, λ is the wavelength of electromagnetic wave.

[0019] As a further optimization scheme of the utility model, the middle part of the right opening end of the HMSIW resonant cavity is provided with 3 metalized short-circuit pins.

[0020] As a further optimization scheme of the utility model, the rectangular groove on the second metal layer is located below the co-planar waveguide feed structure of the first metal layer and is perpendicular to the waveguide feed structure.

[0021] As a further optimization scheme of the utility model, the medium substrate adopts Rogers 4003C material, and the dielectric constant is 3.55.

[0022] As a further optimization scheme of the utility model, the length of the medium substrate is designed as 25.8mm, the width is 18mm, the thickness is 0.812mm, the HMSIW cavity length is 10mm, and the width is 12.75mm.

[0023] As a further optimization scheme of the utility model, the second metal layer is completely coincident with the size of the medium substrate, the first metal layer rectangular patch length is 10.8mm, the leftmost side of the patch is 5.2mm away from the left end of the medium substrate, and the cavity width is 12.75mm.

[0024] Beneficial effects:

[0025] Firstly, the utility model successfully widens the bandwidth of the HMSIW filtering antenna by opening the back groove (i.e. the rectangular groove of the second metal layer) of the HMSIW resonant cavity and coupling the excitation super surface array on the right side of the cavity, realizes the test bandwidth of 12.2%, and significantly improves the broadband performance.

[0026] Secondly, the utility model realizes the dual-port radiation mode by cutting the cavity through the metal short-circuit pin introduced at the opening end of the HMSIW cavity, effectively improves the filtering antenna gain, and reaches the peak value of 9.69dBi.

[0027] Thirdly, the separate design of the radiation zero point (the cavity and the super surface respectively affect the high and low frequency radiation zero points) realizes the adjustable radiation zero point, i.e. the flexible adjustment of the high frequency zero point is realized by adjusting the size or position of the back groove, and the adjustment of the low frequency radiation zero point is realized by the flexible adjustment of the size of the CSRRs.

[0028] Fourthly, the finally designed HMSIW filtering antenna of the utility model realizes the front-back symmetry in structure, the H-plane cross polarization is lower than -30dB, fully reflects the excellent low cross polarization performance, and the single-layer HMSIW cavity realizes the low profile and miniaturization of the antenna. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical scheme of the utility model embodiment, the drawings needed to be used in the embodiment will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained according to these drawings without creative labor for those skilled in the art.

[0030] Figure 1 It is the side view of the utility model.

[0031] Figure 2 is a medium substrate upper surface schematic diagram in the utility model.

[0032] Figure 3 is a medium substrate lower surface schematic diagram in the utility model.

[0033] Figure 4 is the simulation and test S parameter diagram of the embodiment of the utility model.

[0034] Figure 5 is the simulation and test gain diagram of the embodiment of the utility model.

[0035] Figure 6 is the normalized simulation and test result directional diagram of the embodiment of the utility model at 15.5GHz frequency.

[0036] Wherein, 1-first metal layer, 2-medium substrate, 3-second metal layer, 4-metal through hole, 5-metal short-circuit pin, 6-coplanar waveguide feed structure, 7-rectangular metal patch, 8-super surface array, 9-super surface array embedded with CSRR, 10-rectangular slot. DETAILED DESCRIPTION

[0037] The embodiments of the utility model will be described in detail below with reference to the drawings.

[0038] It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict; and based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present disclosure.

[0039] It should be noted that the various aspects of the embodiments described below are within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms and that any specific structure and / or function described herein is merely illustrative. Based on the disclosure, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, an apparatus and / or method can be implemented using any number of the aspects described herein. In addition, this apparatus and / or method can be implemented using other structures and / or functionality in addition to or other than one or more of the aspects described herein.

[0040] The embodiment of the application provides a high-gain broadband half-mode SIW filtering antenna based on a super surface, and the structural schematic diagram is as shown in Figures 1 to 3 Wherein Figure 1is a side view of the structure, comprising a dielectric substrate 2, a first metal layer 1 and a second metal layer 3; wherein the first metal layer 1 is attached to the upper surface of the dielectric substrate 2, and the second metal layer 3 is attached to the lower surface of the dielectric substrate 2;

[0041] The first metal layer comprises, from one end to the other, a co-planar waveguide feed structure 6, a rectangular metal patch 7, a metasurface metal patch array 8 column, and a metasurface array 9 embedded with CSRRs;

[0042] The dielectric substrate is provided with periodic metalized through holes 4 to form an HMSIW resonant cavity, the metalized through holes penetrate through the dielectric substrate and connect the first metal layer and the second metal layer, and the HMSIW resonant cavity is provided with N metalized shorting pins 5 in the middle of the opening end on the right side; the second metal layer is provided with a rectangular slot 10.

[0043] The specific process of the embodiment will be described in detail below

[0044] The dielectric substrate 1 adopts Rogers 4003C material, the dielectric constant is 3.55, the length of the dielectric substrate 1 is designed to be 25.8 mm, the width is 18 mm, and the thickness is 0.812 mm.

[0045] In order to design an HMSIW cavity working in the Ku band, the size of the cavity must be accurately designed, and a rectangular SIW cavity size can be obtained according to formula (1):

[0046]

[0047] Wherein, m and n represent the wave mode working in the SIW resonant cavity, when both are 1, the TE110 mode is the main mode; W is the width of the cavity, L is the length of the cavity, μ is the relative magnetic permeability of the SIW medium, ε is the relative dielectric constant of the SIW medium, c is the speed of light in vacuum, f mn0 is the main mode frequency of the cavity resonating at this size.

[0048] Subsequently, through transverse cutting, the length of the SIW is reduced by nearly half. In addition, the width of the SIW can determine the cutoff frequency of the SIW, so by adjusting the size of the HMSIW, the size reduction and filtering characteristics of the antenna can be realized. The entire HMSIW cavity is 10 mm long and 12.75 mm wide. The above-mentioned half-cavity cutting of the SIW cavity while maintaining a single-layer board structure realizes the miniaturization of the antenna while ensuring good performance.

[0049] At the same time, in order to avoid electromagnetic wave leakage from the gap of the metalized through hole, the diameter D and the pitch S of the metalized through hole constituting the HMSIW cavity need to satisfy formula (2):

[0050] D < 0.2λ, S < 2D (2)

[0051] where λ is the wavelength of the electromagnetic wave.

[0052] The diameter of the metal via 4 in the dielectric substrate 2 is finally determined to be 0.45 mm, and the spacing between adjacent vias is 0.75 mm. In order to realize the dual-port radiation mode, three metal shorting pins 5 are introduced at the middle of the dielectric substrate 2, i.e. the opening end of the HMSIW cavity, the diameter of the shorting pin 5 is 0.45 mm, the spacing is 0.75 mm, and the center of the leftmost shorting pin is 14 mm away from the leftmost end of the dielectric substrate 2. The position of the shorting pin at the opening end of the cavity is optimized for the cavity mode to achieve the shift of the resonant frequency, and finally the rightmost metalized shorting pin is determined to be 0.275 mm away from the right edge of the first metal layer rectangular patch.

[0053] Figure 2 The structure and arrangement of the first metal layer 1 are shown, and the first metal layer 1 has a total of four parts from left to right, including a co-planar waveguide feed structure 6, a rectangular metal patch 7, a metasurface metal patch array 8, and a metasurface array 9 embedded with CSRRs. The size of the HMSIW cavity is accurately designed according to the high-frequency filtering characteristics that can be achieved, and finally the first metal layer rectangular patch is 10.8 mm long, and the leftmost side of the patch is 5.2 mm away from the left end of the dielectric substrate, and the cavity width is 12.75 mm.

[0054] The length of the feed line is 10.8 mm, and the width is 0.5 mm. In order to optimize the impedance matching, a rectangular slot with a width of 0.92 mm is excavated on both sides of the junction of the feed line 6 and the rectangular metal patch 7, which realizes good impedance matching, and the input impedance is 50 Ω. The rectangular metal patch is coincident with the front and back directions of the dielectric substrate. The length of the rectangular metal patch 7 is 10.8 mm, and the width is 18 mm. The right side of the rectangular metal patch 7 is 0.31 mm away from the super surface metal patch array 8. Each rectangular patch has a length of 3.25 mm and a width of 2.76 mm. The size and arrangement spacing of the super surface unit are accurately designed according to the optimization of impedance matching and the best broadband effect. The coupling spacing between the patches is 0.21 mm, and the array arrangement satisfies the 2x4 form. The super surface array 9 embedded with complementary metal split ring resonators (CSRRs) is 0.31 mm away from the right side of the super surface metal patch array 1-3. Each patch has a length of 3.15 mm and a width of 2.76 mm. The CSRRs are nested on the patch by excavating a slot with a width of 0.1 mm. The outer ring has a length of 2 mm and a width of 1.6 mm, the inner ring has a length of 1.2 mm and a width of 0.8 mm, and the gap is 0.2 mm. In order to match the double-port radiation mode of the HMSIW cavity, the spacing between the upper and lower groups of patches in the metal patch array 8 and the super surface array 9 embedded with CSRRs is 0.6 mm. The total length of the outer resonant ring of the CSRRs unit is 7 mm, and the opening width is 0.2 mm. The geometric parameters are optimized and designed according to the low-frequency sideband roll-off characteristics.

[0055] Figure 3 The structure and arrangement form of the second metal layer 3 are shown. The length and width of the second metal layer 3 are consistent with the dielectric substrate 1. A rectangular slot 10 is excavated 0.9 mm below the feed structure 1-1 of the first metal layer 1. The opening has a length of 0.5 mm and a width of 5.7 mm, so that the lower surface of the dielectric substrate is exposed at the opening to introduce additional resonance.

[0056] The simulation and test results of the embodiment are as follows Figures 4 to 6As shown, the simulation bandwidth of the antenna reflection coefficient less than -10dB is 14.46GHz to 16.46GHz (bandwidth ratio 12.9%), and the test bandwidth is 14.72GHz to 16.64GHz (bandwidth ratio 12.2%). Compared with the simulation results, the test results are slightly narrower and offset by about 1.3% to the high frequency direction, but still exhibit excellent wideband characteristics. Within the operating bandwidth, the antenna gain is always greater than 6.5dBi, and the peak gain reaches 9.69dBi, which is significantly improved compared with the traditional HMSIW filter antenna, and exhibits excellent high gain performance. In addition, the cross-polarization level of the antenna H-plane is reduced by more than 30dB compared with the main polarization, fully embodying its excellent low cross-polarization performance. The size of the antenna is 1.29λ0x0.9λ0x0.04λ0, realizing the low profile structure of the filter antenna, further illustrating that the design still has good radiation performance while maintaining the low profile and miniaturization of the HMSIW filter antenna, meeting the design requirements of wideband and high gain.

[0057] The working principle of the utility model is as follows:

[0058] The metalized via penetrates the dielectric substrate, and is connected with the first metal layer and the second metal layer at both ends respectively, forming a SIW resonant cavity, so as to realize the low profile of the antenna; the cavity is cut, only part of the metalized via is reserved, and the geometric size of the cavity is adjusted, forming an HMSIW resonant cavity with a high-frequency radiation zero point, so as to realize the miniaturization and high-performance filtering characteristics of the antenna; three short-circuit pins are introduced in the middle of the opening end of the HMSIW resonant cavity, forming a dual-port radiation mode, so as to effectively improve the filtering performance and increase the antenna gain; a back groove is etched on the second metal layer, the additional resonance introduced combines with the basic resonance to realize bandwidth expansion, and in addition, the size of the back groove can be adjusted to realize the movement of the high-frequency radiation zero point; finally, the metasurface array containing complementary split ring resonators (CSRRs) is adopted, which significantly optimizes the impedance matching and introduces a controllable low-frequency radiation zero point to further improve the low-frequency filtering performance.

[0059] The antenna feeds the resonant cavity through the coplanar waveguide structure of the first metal layer, the resonant cavity is coupled to the metasurface through the right opening end, and the metasurface is excited to produce radiation, so as to realize excellent radiation performance. Through testing of the antenna, the whole working bandwidth is 14.72to 16.64GHz (12.2%), the gain in the passband is greater than 6.5dBi, and the peak gain is 9.69dBi, which is less than 6.5% of the bandwidth and lower than 7dBi of the gain compared with the traditional SIW filter antenna, achieving the purpose of wideband and high gain.

[0060] Prior Art One: K. Xu, J. Shi, X. Qing and Z. N. Chen, “A Substrate Integrated Cavity Backed Filtering Slot Antenna Stacked With a Patch for Frequency Selectivity Enhancement,” IEEE Antennas Wireless Propag. Lett., vol. 17, no. 10, pp. 1910-1914, Oct. 2018.

[0061] Prior Art Two: J.-Y. Yin et al., “Wideband Single-Layer Substrate Integrated Waveguide Filtering Antenna With U-Shaped Slots,” IEEE Antennas Wireless Propag. Lett., vol. 20, no. 9, pp. 1726-1730, Sept. 2021.

[0062] Prior Art Three: K.-Z. Hu, B.-C. Guo, S.-Y. Pan, D. Yan, M.-C. Tang and P. Wang, “Low-Profile Single-Layer Half-Mode SIW Filtering Antenna With Shorted Parasitic Patch and Defected Ground Structure,” IEEE Trans. Circuits Syst. II, Exp. Briefs, vol. 70, no. 1, pp. 91-95, Jan. 2023.

[0063] Detailed comparison results are as follows:

[0064]

[0065]

[0066] Compared with Prior Arts One to Three, the utility model realizes the effects of wideband and high gain while ensuring low profile and miniaturization.

[0067] To sum up, the above is only the preferred embodiment of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high-gain wideband half-mode SIW filtering antenna based on metasurface, characterized in that, The medium substrate, the first metal layer and the second metal layer are included; wherein the first metal layer is attached to the upper surface of the medium substrate, and the second metal layer is attached to the lower surface of the medium substrate; The first metal layer includes, from one end to the other end, a co-planar waveguide feed structure, a rectangular metal patch, a metasurface metal patch array, and a metasurface array embedded with CSRRs; The medium substrate is provided with a periodic metalized via hole to form an HMSIW resonant cavity, the metalized via hole penetrates the medium substrate and connects the first metal layer and the second metal layer, and the HMSIW resonant cavity is provided with N metalized short circuit pins in the middle of the right side opening end. The second metal layer is provided with a rectangular slot.

2. The high-gain wideband half-mode SIW filtered antenna based on metasurface of claim 1, wherein, The rectangular metal patch is provided with a rectangular groove towards one end of the waveguide feed structure, and the waveguide feed structure extends into the rectangular groove and is connected with the metal patch.

3. The high-gain wideband half-mode SIW filtered antenna based on metasurface of claim 1, wherein, The metasurface metal patch array is composed of 1x4 metal patch units.

4. The high-gain wideband half-mode SIW filtered antenna based on metasurface of claim 3, wherein, The metasurface array embedded with CSRRs is composed of 1x4 CSRR patch units.

5. The high-gain wideband half-mode SIW filtered antenna based on metasurface of claim 1, wherein, The diameter D and the pitch S of the metalized via hole constituting the HMSIW cavity need to satisfy the following formula: D≤0.2λ,S≤2D Wherein, λ is the wavelength of electromagnetic wave.

6. The high-gain wideband half-mode SIW filtered antenna based on metasurface of claim 1, wherein, The HMSIW resonant cavity is provided with 3 metalized short circuit pins in the middle of the right side opening end.

7. The high-gain wideband half-mode SIW filtered antenna based on metasurface of claim 1, wherein, The rectangular slot on the second metal layer is located below the co-planar waveguide feed structure of the first metal layer and is perpendicular to the waveguide feed structure.

8. The high-gain wideband half-mode SIW filtered antenna based on metasurface of claim 1, wherein, The medium substrate adopts Rogers 4003C material with a dielectric constant of 3.

55.

9. The high-gain wideband half-mode SIW filtered antenna based on metasurface of claim 8, wherein, The length of the medium substrate is designed to be 25.8mm, the width is 18mm, the thickness is 0.812mm, the length of the HMSIW cavity is 10mm, and the width is 12.75mm.

10. The high-gain wideband half-mode SIW filtered antenna based on metasurface of claim 9, wherein, The second metal layer and the medium substrate are completely coincident in size; the first metal layer rectangular patch is 10.8mm long, the leftmost side of the patch is 5.2mm away from the left end of the medium substrate, and the cavity width is 12.75mm.

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