Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a microminiaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber. The technical problem to be solved by the invention is realized by the following technical scheme:
the invention provides a microminiaturized 2.5-dimensional absorption-penetration integrated frequency-selective wave absorber which comprises a plurality of continuous periodically-arranged metamaterial units, wherein each metamaterial unit comprises a top layer resonance layer, a first dielectric layer, a second dielectric layer, a third dielectric layer and a bottom layer resonance layer which are sequentially stacked from top to bottom, each top layer resonance layer comprises a first metal patch unit, a thin film resistor and 4 second metal patch units, each top layer resonance layer comprises a first metal patch unit, a second metal patch unit and a second metal patch unit,
the first metal patch unit is square, the thin film resistor is of a cross structure, the thin film resistor divides the first metal patch unit into 4 triangular metal patches with the same size, and the thin film resistor and the 4 triangular metal patches form a square structure;
the second metal patch units are connected with the triangular metal patches in a one-to-one correspondence mode, 4 second metal patch units form a central symmetrical graph, and the symmetrical center of the central symmetrical graph is the center of the thin film resistor;
the second metal patch unit comprises a first folded metal strip, a first circular metal patch, a second folded metal strip and a second circular metal patch which are sequentially connected, one end of the first folded metal strip is connected with the middle point of the bottom edge of the triangular metal patch, and the circle centers of the first circular metal patch and the second circular metal patch are both positioned on the extension line of the symmetry axis of the triangular metal patch;
the bottom of the first medium layer is provided with 4 third metal patch units, the 4 third metal patch units are respectively arranged in parallel corresponding to the four edges of the bottom surface of the first medium layer, and each third metal patch unit is connected with the corresponding second metal patch unit through a metalized through hole penetrating through the first medium layer;
the bottom resonance layer is provided with a hollow structure, the hollow structure is square, and the middle parts of four sides of the square are sunken towards the center of the square to form a U-shaped sunken groove.
In one embodiment of the invention, the first folded metal strip comprises a first strip portion, a second strip portion, a third strip portion, a fourth strip portion and a fifth strip portion, wherein,
the first end of the first ribbon part is connected with the middle point of the bottom edge of the triangular metal patch, and the second end of the first ribbon part is vertically connected with the first end of the second ribbon part;
the second end of the second strip part is vertically connected with the first end of the third strip part, and the second end of the third strip part is close to the triangular metal patch;
a first end of the fourth strap portion is perpendicularly connected to a second end of the third strap portion, the second end of the fourth strap portion being proximate to the triangular metal patch;
the first end of the fifth strip part is vertically connected with the second end of the fourth strip part, the second end of the fifth strip part is far away from the triangular metal patch, and the second end of the fifth strip part is connected with the first circular metal patch.
In one embodiment of the invention, the second folded metal strip includes a sixth strip portion, a seventh strip portion, and an eighth strip portion, wherein,
the first end of the sixth strip part is connected with the first round metal patch, the first end of the sixth strip part is arranged opposite to the second end of the fifth strip part, and the second end of the sixth strip part is vertically connected with the first end of the seventh strip part;
a second end of the seventh strap portion distal from the triangular metal patch, the second end of the seventh strap portion being perpendicularly connected to the first end of the eighth strap portion;
the second end of the eighth strap portion is adjacent to the triangular metal patch, and the second end of the eighth strap portion is connected to the second circular metal patch.
In one embodiment of the present invention, the third metal patch unit includes a first rectangular metal patch and a second rectangular metal patch arranged in parallel, wherein,
the length of the first rectangular metal patch is smaller than that of the second rectangular metal patch;
the first rectangular metal patch is connected with the first round metal patch through a first metalized through hole;
the second rectangular metal patch is connected with the second round metal patch through a second metalized through hole;
the connection point of the first rectangular metal patch and the first metalized through hole is positioned at the center of the first rectangular metal patch;
the connection point of the second rectangular metal patch and the second metalized through hole is positioned at the center of the second rectangular metal patch.
In one embodiment of the invention, the included angle between the side edge and the bottom edge of the U-shaped concave groove is 90 degrees.
In one embodiment of the invention, the film resistor is a graphene resistor film, and the sheet resistance value range is 340Ohm/sq-400 Ohm/sq;
the thin film resistor and 4 triangular metal patches form a side length D of a square structure1Has a value range of 0.052 lambdat<D1<0.054λtFour arms of the cross-shaped structure are equal in length, and the arm length D is equal to the arm length D2Has a value range of 0.022 lambdat<D2<0.023λtThe arm width D of the cross-shaped structure3Has a value range of 0.0143 lambdat<D3<0.0146λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In one embodiment of the invention, the first folded metal strip has a width W1Has a value range of 0.0038 lambdat<D1<0.004λtLength l of said first strip portion1Is in the value range of 0.0103 lambdat<l1<0.0106λtLength l of said second strip portion2Has a value range of 0.068 lambdat<l2<0.070λtLength l of said third strip3Has a value range of 0.0195 lambdat<l3<0.0199λtLength l of said fourth strip portion4Has a value range of 0.0142 lambdat<l4<0.0147λtLength l of the fifth strip portion5Has a value range of 0.0205 lambdat<l5<0.0215λt;
The bandwidth W of the second folded metal strip2Has a value range of 0.0052 lambdat<W2<0.0054λtLength l of the sixth strip portion6Has a value range of 0.042 lambdat<l6<0.046λtLength l of said seventh strip portion7Is in the range of 0.0202 lambdat<l7<0.0211λtLength l of the eighth strap portion8Is in the range of 0.042 lambdat<l6<0.046λt;
The first circular metal patch and the second circular metal patch are equal in size and have a radius R1Has a value range of 0.0071 lambdat<R1<0.00715λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In one embodiment of the present invention, the first rectangular metal patch and the second rectangular metal patch have the same width, and the width W of the first rectangular metal patch and the second rectangular metal patch is equal3Has a value range of 0.014 lambdat<W3<0.015λtLength m of the first rectangular metal patch1Has a value range of 0.052 lambdat<m1<0.053λtLength m of the second rectangular metal patch2Has a value range of 0.1037 lambdat<m2<0.1046λtRadius R of the metallized via2Has a value range of 0.0039 lambdat<R2<0.0040λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In one embodiment of the invention, the first dielectric layer and the third dielectric layer are both made of F4B, and the second dielectric layer is an air layer;
the first mentionedA thickness h of a dielectric layer1Has a value range of 0.0523 lambdat<h1<0.0529λt;
Thickness h of the second dielectric layer2Is in the range of 0.155 lambdat<h2<0.159λt;
Thickness h of the third dielectric layer3Has a value range of 0.026 lambdat<h3<0.0264λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In one embodiment of the invention, the distance b between two opposite U-shaped concave grooves1Is in the range of 0.034 lambdat<b1<0.035λtThe groove width b of the U-shaped concave groove2Has a value range of 0.0155 lambdat<b2<0.016λtThe groove depth b of the U-shaped concave groove3Has a value range of 0.044 lambdat<b3<0.045λtAnd the distance b between the side wall of the U-shaped concave groove and the vertex of the square hollowed-out structure4Has a value range of 0.064 lambdat<b4<0.0648λt;
The hollow-out width W of the hollow-out structure4Has a value range of 0.0052 lambdat<W4<0.0054λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the microminiaturized 2.5-dimensional absorption-transmission integrated frequency-selective wave absorber, a thin-film resistor is adopted to replace a lumped resistor in each metamaterial unit, the thin-film resistor is a graphene resistive film, the effect of an omnidirectional resistor can be realized only through one graphene resistive film, a plurality of lumped resistors do not need to be welded, and the planar integration and the mass production are facilitated.
2. The microminiaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber provided by the invention realizes microminiaturization by utilizing the design of combining the folded metal strip and the through hole, so that the appearance of grating lobes is inhibited, the double-station RCS under oblique incidence is reduced, and the oblique incidence stealth performance is greatly improved.
3. The microminiaturized 2.5-dimensional absorption and penetration integrated frequency-selective wave absorber adopts the centrosymmetric pattern design in each layer of structure of the metamaterial unit, so that the frequency-selective wave absorber is insensitive to the polarization direction of incident electromagnetic waves.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.
Detailed Description
In order to further illustrate the technical means and effects of the present invention adopted to achieve the predetermined object, a subminiaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber according to the present invention will be described in detail below with reference to the accompanying drawings and the detailed description.
The foregoing and other technical matters, features and effects of the present invention will be apparent from the following detailed description of the embodiments, which is to be read in connection with the accompanying drawings. While the present invention has been described in connection with the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Example one
The embodiment provides a microminiaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber, which is characterized in that a wave transmission window is arranged at the high frequency of a wave absorption band, the structure is transparent to incident waves in a wave transmission frequency band, and electromagnetic waves can penetrate through the structure without reflection, so that an antenna system in the wave absorber can normally work and has good wave absorption stealth performance outside a working frequency band. Referring to fig. 1 to fig. 5, fig. 1 is a schematic perspective view of a subminiaturized 2.5-dimensional absorption-transmission integrated frequency-selective wave absorber according to an embodiment of the present invention; FIG. 2 is a schematic perspective view of a metamaterial unit provided in an embodiment of the present invention; fig. 3 is a schematic structural diagram of a top resonance layer provided in an embodiment of the present invention, fig. 4 is a schematic structural diagram of a thin film resistor provided in an embodiment of the present invention, and fig. 5 is a schematic structural diagram of a top resonance layer with a thin film resistor removed provided in an embodiment of the present invention. As shown in the figure, the microminiaturized 2.5-dimensional absorption-transmission integrated frequency-selective wave absorber of the present embodiment includes a plurality of metamaterial units 1 arranged continuously and periodically, and optionally, the metamaterial units 1 are arranged in a continuous matrix of m × n, where m is greater than or equal to 2, and n is greater than or equal to 2, as shown in fig. 1, in the present embodiment, the metamaterial units 1 are arranged in a continuous matrix of 3 × 3. In this embodiment, the unit period P of the metamaterial unit 1 is 6 mm.
As shown in fig. 2, the metamaterial unit 1 includes a top-layer resonance layer 10, a first dielectric layer 20, a second dielectric layer 30, a third dielectric layer 40, and a bottom-layer resonance layer 50, which are sequentially stacked from top to bottom.
Specifically, as shown in fig. 3, the top-layer resonance layer 10 includes a first metal patch unit, a thin- film resistor 101, and 4 second metal patch units 102. The first metal patch unit is square, the thin film resistor 101 is of a cross structure, the thin film resistor 101 divides the first metal patch unit into 4 triangular metal patches 103 with the same size, and the thin film resistor 101 and the 4 triangular metal patches 103 form a square structure. The second metal patch units 102 are connected with the triangular metal patches 103 in a one-to-one correspondence manner, and 4 second metal patch units 102 form a central symmetrical pattern, wherein the symmetrical center of the central symmetrical pattern is the center of the thin film resistor 101.
Optionally, the material of the first metal patch element and the second metal patch element 102 is copper, and the conductivity thereof is 5.8 × 109And (5) S/m. The thin film resistor 101 is a graphene resistive film, and the square resistance value range is 340Ohm/sq-400 Ohm/sq. As shown in FIG. 4, the thin film resistor 101 and the 4 triangular metal patches 103 form a side length D of a square structure1Has a value range of 0.052 lambdat<D1<0.054λtFour arms of the cross-shaped structure are equal in length, and the arm length D is equal to the arm length D2Has a value range of 0.022 lambdat<D2<0.023λtArm width D of cruciform structure3Has a value range of 0.0143 lambdat<D3<0.0146λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In this embodiment, the sheet resistance of the thin film resistor 101 is 360Ohm/sq, and the side length D of the square structure formed by the thin film resistor 101 and the 4 triangular metal patches 103 is a square12mm, the arm length of the cruciform configuration (i.e. the waist length of the triangular metal patch 103) D20.86mm, arm width D3The apex angle of the triangular metal patch 103 is 90 ° and the waist length is 0.86mm, which is 0.55 mm.
Further, the second metal patch unit 102 includes a first folded metal strip 1021, a first circular metal patch 1022, a second folded metal strip 1023, and a second circular metal patch 1024, which are connected in sequence, one end of the first folded metal strip 1021 is connected to a bottom edge midpoint of the triangular metal patch 103, and centers of the first circular metal patch 1022 and the second circular metal patch 1024 are located on an extension line of a symmetry axis of the triangular metal patch 103.
It should be noted that the centers of the first circular metal patch 1022 and the second circular metal patch 1024 are located on the extension line of the symmetry axis of the adjacent triangular metal patch 103 of the triangular metal patches 103 connected to the first circular metal patch and the second circular metal patch.
In each metamaterial unit of the microminiaturized 2.5-dimensional absorption-transmission integrated frequency-selection wave absorber, a thin film resistor is adopted to replace a lumped resistor, the thin film resistor is a graphene resistive film, the lumped resistor is a two-port device, the graphene resistive film is a resistive film with impedance characteristics, as long as the graphene resistive film is in contact with the resistive film, the capacitive coupling type optical fiber wave absorber can be regarded as having infinite ports, all the resistors are seen from each direction, the effect of the omnidirectional resistor can be realized only through one graphene resistive film in the implementation, a plurality of lumped resistors do not need to be welded, the price of the resistor or the complexity of the processed resistor is far higher than that of the lumped resistor, and the planar integration and the batch production are facilitated.
In the present embodiment, the first folded metal strip 1021 includes a first strip portion 10211, a second strip portion 10212, a third strip portion 10213, a fourth strip portion 10214 and a fifth strip portion 10215. Wherein, the first end of the first stripe portion 10211 is connected to the middle point of the bottom edge of the triangular metal patch 103, and the second end is connected to the first end of the second stripe portion 10212 perpendicularly; a second end of the second strap portion 10212 is perpendicularly connected to a first end of the third strap portion 10213, and a second end of the third strap portion 10213 is close to the triangular metal patch 103; a first end of the fourth strap portion 10214 is perpendicularly connected to a second end of the third strap portion 10213, the second end of the fourth strap portion 10214 being adjacent to the triangular metal patch 103; a first end of the fifth strap portion 10215 is connected perpendicularly to a second end of the fourth strap portion 10214, the second end of the fifth strap portion 10215 is distal from the triangular-shaped metal patch 103, and the second end of the fifth strap portion 10215 is connected to the first circular-shaped metal patch 1022.
Further, the second folded metal strip 1023 includes a sixth strip portion 10216, a seventh strip portion 10217 and an eighth strip portion 10218. Wherein a first end of the sixth strap 10216 is connected to the first circular metal patch 1022, a first end of the sixth strap 10216 is disposed opposite a second end of the fifth strap 10215, and the second end of the sixth strap 10216 is connected perpendicular to the first end of the seventh strap 10217; a second end of the seventh strap portion 10217 is distal from the triangular metal patch 103, and the second end of the seventh strap portion 10217 is perpendicularly connected to the first end of the eighth strap portion 10218; a second end of the eighth strap portion 10218 is adjacent to the triangular metal patch 103 and a second end of the eighth strap portion 10218 is connected to the second circular metal patch 1024.
Optionally, the bandwidth W of the first folded metal strip 10211Value range of (2) is 0.0038 lambdat<D1<0.004λtLength l of the first swath portion 102111Is in the value range of 0.0103 lambdat<l1<0.0106λtLength l of second strap portion 102122Has a value range of 0.068 lambdat<l2<0.070λtLength l of third strap 102133Has a value range of 0.0195 lambdat<l3<0.0199λtLength l of fourth strip portion 102144Has a value range of 0.0142 lambdat<l4<0.0147λtLength l of fifth strap part 102155Has a value range of 0.0205 lambdat<l5<0.0215λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In this embodiment, the first folded metal strip 1021 has a width W10.15mm, length l of the first strip portion 1021110.4mm, length l of the second strap part 1021222.65mm, length l of the third strap 1021330.75mm, length l of fourth strap portion 1021440.55mm, length l of the fifth strap portion 102155=0.75mm。
Optionally, the bandwidth W of the second folded metal strip 10232Has a value range of 0.0052 lambdat<W2<0.0054λtLength l of sixth strap portion 102166Is in the range of 0.042 lambdat<l6<0.046λtLength l of seventh strip portion 102177Is in the range of 0.0202 lambdat<l7<0.0211λtLength l of eighth strap portion 102188Has a value range of 0.042 lambdat<l6<0.046λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In this embodiment, the sixth strap portion 10216 has a length l61.7mm, length l of the seventh strip portion 1021770.7mm, length l of eighth strip 102188=1.7mm。
Optionally, the first circular metal patch 1022 and the second circular metal patch 1024 are equal in size and have a radius R1Has a value range of 0.0071 lambdat<R1<0.00715λtIn this embodiment, the radius R of the first circular metal patch 1022 and the second circular metal patch 10241=0.27mm。
Furthermore, 4 third metal patch units 201 are disposed at the bottom of the first dielectric layer 20, the 4 third metal patch units 201 are respectively disposed in parallel with the four corresponding edges of the bottom surface of the first dielectric layer 20, and each third metal patch unit 201 is connected to the corresponding second metal patch unit 102 through a metalized through hole 202 penetrating through the first dielectric layer 20.
Specifically, please refer to fig. 6, where fig. 6 is a schematic structural diagram of a third metal patch unit according to an embodiment of the present invention, and as shown in the drawing, the third metal patch unit 201 includes a first rectangular metal patch 2011 and a second rectangular metal patch 2012 which are arranged in parallel, where a length of the first rectangular metal patch 2011 is smaller than a length of the second rectangular metal patch 2012; the first rectangular metal patch 2011 is connected with the first circular metal patch 1022 through the first metallization through hole 2021; the second rectangular metal patch 2012 is connected to the second circular metal patch 1024 through a second metalized through hole 2022; the connection point of the first rectangular metal patch 2011 and the first metallized via 2021 is located at the center of the first rectangular metal patch 2011; the connection point of the second rectangular metal patch 2012 and the second metallized via 2022 is located at the center of the second rectangular metal patch 2012.
Optionally, the widths of the first rectangular metal patch 2011 and the second rectangular metal patch 2012 are equal, and the widths W thereof are W3Has a value range of 0.014 lambdat<W3<0.015λtLength m of first rectangular metal patch 20111Has a value range of 0.052 lambdat<m1<0.053λtLength m of second rectangular metal patch 20122Has a value range of 0.1037 lambdat<m2<0.1046λtRadius R of metallized via 2022Has a value range of 0.0039 lambdat<R2<0.0040λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In the present embodiment, the widths W of the first rectangular metal patch 2011 and the second rectangular metal patch 201230.54mm, length m of the first rectangular metal patch 201112mm, length m of the second rectangular metal patch 20122Radius R of the first 2021 and second 2022 metalized vias is 4mm2=0.15mm。
Further, referring to fig. 7, fig. 7 is a schematic structural diagram of the bottom-layer resonance layer according to the embodiment of the present invention, as shown in the figure, a hollow structure is disposed on the bottom-layer resonance layer 50, the hollow structure is square, and the middle of four sides of the square is recessed toward the center of the square to form a U-shaped recessed groove. In this embodiment, the angle between the side edge and the bottom edge of the U-shaped concave groove is 90 °.
Optionally, the distance b between two opposite U-shaped concave grooves1Is in the range of 0.034 lambdat<b1<0.035λtGroove width b of U-shaped concave groove2Has a value range of 0.0155 lambdat<b2<0.016λtDepth b of U-shaped concave groove3Has a value range of 0.044 lambdat<b3<0.045λtAnd the distance b between the side wall of the U-shaped concave groove and the vertex of the square hollowed-out structure4Has a value range of 0.064 lambdat<b4<0.0648λtHollow width W of hollow structure4Has a value range of 0.0052 lambdat<W4<0.0054λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In this embodiment, the distance b between two opposite U-shaped concave grooves11.3mm, groove width b of U-shaped concave groove20.6mm, groove depth b of U-shaped concave groove31.7mm, the distance b between the side wall of the U-shaped concave groove and the vertex of the square hollow structure42.45mm, hollow width W of hollow structure4=0.2mm。
Further, in the present embodiment, the materials of the first dielectric layer 20 and the third dielectric layer 40 are both F4B, which has a relative dielectric constant of 2.2, and the second dielectric layer 30 is an air layer, which has a relative dielectric constant of 1. Optionally, the thickness h of the first dielectric layer 201Has a value range of 0.0523 lambdat<h1<0.0529λt(ii) a Thickness h of the second dielectric layer 302Is in the range of 0.155 lambdat<h2<0.159λt(ii) a Thickness h of the third dielectric layer 403Has a value range of 0.026 lambdat<h3<0.0264λtWherein λ istIs the wavelength corresponding to the wave-transparent frequency.
In the present embodiment, the thickness h of the first dielectric layer 2012 mm; thickness h of the second dielectric layer 3026 mm; third mediumThickness h of layer 403=1mm。
For periodic structures, when the period is too large, the array factor under oblique incidence also has peaks except for the main lobe direction, and the peaks are called grating lobes which can cause the dual-station RCS to rise and increase the probability of being detected by the radar. The frequency of the grating lobes is inversely proportional to the period p of the structure, that is, the smaller the structure period p is, the higher the frequency point of the grating lobes is, in this embodiment, the design of combining the folded metal strips and the through holes is utilized to achieve microminiaturization, and the grating lobes are delayed by the miniaturized unit structure, so that no grating lobe appears in the working frequency band, thereby reducing the dual-station RCS under oblique incidence and greatly improving the oblique incidence stealth performance. Meanwhile, the microminiaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber of the embodiment has a wave transmission window at the high frequency of the wave absorbing band, the structure is transparent to incident waves in a wave transmission frequency band, and electromagnetic waves can penetrate through the structure without reflection, so that an antenna system in the wave absorber can normally work and has good wave absorption stealth performance outside the working frequency band.
In addition, the microminiaturized 2.5-dimensional absorption-penetration integrated frequency-selective wave absorber of the embodiment of the invention adopts the centrosymmetric pattern design in each layer of the metamaterial unit, so that the frequency-selective wave absorber is insensitive to the polarization direction of incident electromagnetic waves.
Example two
In this embodiment, the performance of the ultra-miniaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber of the first embodiment is verified and explained through a simulation experiment.
1. Simulation conditions are as follows:
in the microminiaturized 2.5-dimensional absorption-transmission integrated frequency-selective wave absorber of the embodiment, the metamaterial units 1 are arranged in a continuous matrix of m × n, m and n are infinite, and the transmission coefficient and the reflection coefficient of the frequency-selective wave absorber are simulated by commercial simulation software HFSS _ 19.2.
2. Simulation content and results:
simulation 1, performing electromagnetic simulation on the absorption-transmission integrated wave absorber by using TE polarization and TM polarization respectively under a vertical incidence condition to obtain a reflection coefficient curve thereof, as shown in fig. 8, fig. 8 is a reflection coefficient simulation curve diagram of the microminiaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber provided by the embodiment of the invention under different polarizations. As can be seen from fig. 8: the absorption band of the absorption and transmission integrated wave absorber is 2.47-8.81GHz, the reflection coefficients in the band are all smaller than-10 dB, the relative bandwidth is 112.4%, the transmission band is 7.52-8.40GHz, the transmission coefficients in the band are all smaller than-1 dB, and the insertion loss at the 8GHz frequency point is only-0.3 dB, which shows that the electromagnetic waves in the band can penetrate through the structure with lower insertion loss, and an antenna system in the antenna housing can perform normal transceiving work at the frequency band.
Simulation 2, when the incident angle is increased from 0 ° to 60 ° under TE polarization and TM polarization, respectively, the absorption-transmission integrated wave absorber is simulated to obtain a reflection coefficient curve, as shown in fig. 9, fig. 9 is a reflection coefficient simulation curve diagram corresponding to the microminiaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber provided by the embodiment of the present invention, in which the incident angle is increased from 0 degree to 60 degrees under different polarizations. In fig. 6, (a) is a graph showing a reflectance curve obtained in TE polarization, and (b) is a graph showing a reflectance curve obtained in TM polarization. As can be seen from the diagram (a): under TE polarization, when the incident angle range is 0 degrees < theta <30 degrees, the wave absorbing effect of the wave absorber is good, and the wave absorbing effect is still achieved under 45 degrees incidence, and the graph (b) shows that: under TM polarization, when the incident angle range is 0 degrees < theta <60 degrees, the wave absorbing effect of the wave absorber is basically kept good, and when the wave is incident at 60 degrees, a frequency band can absorb waves well, only the bandwidth is narrowed, which shows that the wave absorber has good polarization stability.
The simulation results show that the microminiaturized 2.5-dimensional absorption-transmission integrated frequency selective wave absorber effectively absorbs waves in a wide frequency band, the relative bandwidth reaches 112.4 percent, and due to the microminiaturized structure, the grating lobe is restrained, and the probability of detection by the dual-station RCS under oblique incidence is reduced; based on the centrosymmetric design of the structure, the structure has polarization stability; the 2.5-dimensional structural design of the wave absorber also ensures the wave absorbing stability under oblique incidence.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or device that comprises a list of elements does not include only those elements but may include other elements not expressly listed. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of additional like elements in the article or device comprising the element. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The directional or positional relationships indicated by "upper", "lower", "left", "right", etc., are based on the directional or positional relationships shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.