A high-pass, steep-cutoff frequency selective structure with wide incident angles

Abstract

The present invention discloses a high-pass and steep-cutoff wide incident angle frequency selection structure. The structure includes first and second selection components arranged perpendicularly and interspersed with each other. Both the first and second selection components include a dielectric substrate with slits, and meandered conductive geometries and C-shaped conductive geometries on two surfaces of the dielectric substrate. The conductive geometries are interconnected through conductive metal vias. The present invention can achieve a high-pass filtering function for spatial electromagnetic waves within a range of below 5 GHz, any polarization direction, and a wide incident angle range of 0 to 60 degrees, and the transition band between the passband and the stopband is very narrow, having a steep cutoff effect. The present invention also solves the limitations in the prior art of narrow passband bandwidth, wide transition bandwidth between the passband and the stopband, and narrow incident angle range, and is easy to process and manufacture, and can be widely applied to radomes of platforms such as communication base stations, radars, satellite communications, and aircraft.

Description

Technical Field

[0001] The present invention relates to an angular frequency selection structure, which relates to the fields of spatial filtering technology and antenna technology, and specifically relates to a wide incident angle frequency selection structure with high-pass and steep cut-off characteristics. Background Art

[0002] As a spatial filter, a frequency selection structure can select and regulate spatial electromagnetic waves according to the operating frequency, polarization mode, incident angle, energy, etc. of the electromagnetic waves. Different from traditional filters, a frequency selection structure is a passive array, and its excitation source is not a voltage or current signal source, but electromagnetic waves in space. A frequency selection structure is usually an artificial electromagnetic structure periodic array composed of metal patches (or slotted apertures on a metal screen) and dielectric materials designed according to certain rules, and it exhibits the characteristics of total reflection or total transmission of spatial electromagnetic waves near the resonant frequency. Thanks to this unique electromagnetic wave selection and regulation ability, frequency selection structures have a wide range of applications in the fields of electromagnetic compatibility, electromagnetic interference suppression, antenna system performance improvement, and radar cross-section reduction.

[0003] Generally, in modern communication systems, multi-band antennas are integrated to increase the capacity of the communication system, which poses a great challenge to the performance of the frequency selection structure. It is required not only to have a frequency selection structure with an ultra-wide passband to cover the operating bands of all antennas, but also to have a fast cut-off rate and stopband suppression to suppress out-of-band interference. Existing research results are difficult to simultaneously achieve the performance of an ultra-wide passband, steep cut-off in the low-frequency stopband, and wide incident angle. Therefore, how to realize a frequency selection structure with an ultra-wide passband, steep cut-off, and wide incident angle is an urgent problem to be solved. Summary of the Invention

[0004] In order to solve the problems in the background art, the present invention provides a wide incident angle frequency selection structure with high-pass and steep cut-off characteristics, so as to simultaneously achieve the performance of an ultra-wide passband, steep cut-off in the low-frequency stopband, and wide incident angle. The present invention can filter spatial electromagnetic waves with frequencies below 5 GHz, any polarization direction, and within a wide incident angle range of 0 to 60 degrees. The transition band between the passband and the stopband is very narrow, with a steep cut-off effect, and it has great application value in the fields of modern communication, radar, and national defense.

[0005] The technical solution adopted by the present invention is:

[0006] The high-pass, steep-cutoff wide incident angle frequency selection structure of the present invention includes a number of first selection components in the form of rectangular plates arranged in parallel at uniform intervals and a number of second selection components in the form of rectangular plates arranged in parallel at uniform intervals. Each of the first selection components and each of the second selection components are orthogonal to each other and arranged in a vertically intersecting manner to form a mortise and tenon fitting structure; both side surfaces of each first selection component are divided into a number of rectangular first conductive geometric structure printing areas along the length direction of the first selection component itself, and the same first conductive geometric structure is printed on each first conductive geometric structure printing area; both side surfaces of each second selection component are divided into a number of rectangular second conductive geometric structure printing areas along the length direction of the second selection component itself, and the same second conductive geometric structure is printed on each second conductive geometric structure printing area; each first conductive geometric structure printing area is interposed between two adjacent second selection components, and each second conductive geometric structure area is interposed between two adjacent first selection components.

[0007] The first selection component is a first dielectric substrate with a number of first slots arranged at intervals. The first slots are strip-shaped through slots penetrating the plate surface of the first dielectric substrate and parallel to the width direction of the first dielectric substrate. A first slot is provided in each first conductive geometric structure printing area located on the first dielectric substrate, and each first slot is located between two adjacent first conductive geometric structures. The length direction of the first conductive geometric structure printing area is parallel to the width direction of the first dielectric substrate. Each first slot is opened from one of the short-side vertices of the first conductive geometric structure printing area to the center of the long side of the first conductive geometric structure printing area. Each first conductive geometric structure on one side surface of the first dielectric substrate coincides with the first conductive geometric structure on the opposite side surface after being flipped half a turn along the central axis in the length direction of the first conductive geometric structure printing area where it is located; the first conductive geometric structures and the first slots in each first conductive geometric structure printing area are arranged periodically along the length direction of the first dielectric substrate on both side surfaces of the first dielectric substrate.

[0008] The second selection component described above is a second dielectric substrate with a number of second slits arranged at intervals. The second slits are strip-shaped through slits penetrating the plate surface of the second dielectric substrate and parallel to the width direction of the second dielectric substrate. One second slit is provided in each second conductive geometric structure printing area located on the second dielectric substrate. Each second slit is located between two adjacent second conductive geometric structures. The length direction of the second conductive geometric structure printing area is parallel to the width direction of the second dielectric substrate. Each second slit is opened from one short-side vertex angle of the second conductive geometric structure printing area to the center of the long side of the second conductive geometric structure printing area. Each second conductive geometric structure on one side of the second dielectric substrate coincides with the second conductive geometric structure on the opposite side after being flipped half a turn along the central axis in the length direction of the second conductive geometric structure printing area where it is located; the second conductive geometric structures and the second slits in each second conductive geometric structure printing area are arranged periodically along the length direction of the second dielectric substrate on both sides of the second dielectric substrate.

[0009] When each first selection component and each second selection component are orthogonal to each other, each of the first slits on each first selection component is sequentially and perpendicularly inserted into one of the second slits on each second selection component. When each second selection component and each first selection component are orthogonal to each other, each of the second slits on each second selection component is sequentially and perpendicularly inserted into one of the first slits on each first selection component.

[0010] The first conductive geometric structure includes a meandering spiral conductive geometric structure and a C-shaped conductive geometric structure. The first conductive geometric structure printing areas on both sides of the first dielectric substrate face each other in pairs. The first meandering spiral conductive geometric structure and the first C-shaped conductive geometric structure are printed on the first conductive geometric structure printing area on one side of the first dielectric substrate, and the second meandering spiral conductive geometric structure and the second C-shaped conductive geometric structure are printed on the first conductive geometric structure printing area on the other side of the first dielectric substrate.

[0011] The C-shaped conductive geometric structure is integrally formed by a rectangular sheet-shaped conductive structure with wider sides and a rectangular strip-shaped conductive structure with a narrower middle, thus forming a three-segment right-angled bent C-shaped structure. The width direction of the rectangular sheet-shaped conductive structures on both sides of the C-shaped conductive geometric structure and the length direction of the rectangular strip-shaped conductive structure in the middle are both parallel to the length direction of the first conductive geometric structure printing area. The rectangular strip-shaped conductive structure is close to one long side of the first conductive geometric structure printing area and is located on the side away from the first cut groove in the first conductive geometric structure printing area where it is located. Right-angled bent serpentine slots are provided on the rectangular sheet-shaped conductive structures on both sides of the C-shaped conductive geometric structure. The two ends of the right-angled bent serpentine slots are both located on the symmetry axis of the length direction of the first conductive geometric structure printing area. The four top corners of the C-shaped conductive geometric structure are connected to form a rectangle and are successively provided with conductive metal vias penetrating the plate surface of the first dielectric substrate. The fifth conductive metal via and the sixth conductive metal via are located between two adjacent first cut grooves. The C-shaped conductive geometric structures on both sides of the first dielectric substrate are connected through the conductive metal vias.

[0012] The meandering spiral conductive geometric structure is located in the middle of the C-shaped conductive geometric structure. One end of the meandering spiral conductive geometric structure is located on the central axis of the length direction of the first cut groove in the first conductive geometric structure printing area where it is located and is close to the first cut groove. The other end of the meandering spiral conductive geometric structure is located at the center of the first conductive geometric structure printing area. One end of the meandering spiral conductive geometric structure is first printed along the width direction of the first conductive geometric structure printing area and then is right-angled bent in the direction close to the first cut groove, and then is printed in a right-angled spiral shape to the other end. Conductive metal vias penetrating the plate surface of the first dielectric substrate are respectively provided at both ends of the meandering spiral conductive geometric structure. The first conductive metal via is located at the center of the first conductive geometric structure printing area. The meandering spiral conductive geometric structures on both sides of the first dielectric substrate are connected through the first conductive metal via. The second conductive metal via is close to the first cut groove. The first meandering spiral conductive geometric structure on one side of the first dielectric substrate and a second meandering spiral conductive geometric structure on the other side of the first dielectric substrate that is not directly opposite but adjacent to it are connected through the second conductive metal via.

[0013] The second conductive geometric structure described above includes a meandering spiral conductive geometric structure and a C-shaped conductive geometric structure. The second conductive geometric structure printing areas on both sides of the second dielectric substrate are pairwise opposite. A third meandering spiral conductive geometric structure and a third C-shaped conductive geometric structure are printed on the second conductive geometric structure printing area on one side of the second dielectric substrate. A fourth meandering spiral conductive geometric structure and a fourth C-shaped conductive geometric structure are printed on the second conductive geometric structure printing area on the other side of the second dielectric substrate.

[0014] The C-shaped conductive geometric structure is integrally formed by a rectangular sheet-shaped conductive structure with a wider width on both sides and a rectangular strip-shaped conductive structure with a narrower width in the middle, thus forming a three-segment right-angled bent C-shaped structure. The width direction of the rectangular sheet-shaped conductive structures on both sides of the C-shaped conductive geometric structure and the length direction of the rectangular strip-shaped conductive structure in the middle are both parallel to the length direction of the second conductive geometric structure printing area. The long side of the rectangular strip-shaped conductive structure close to one side of the second conductive geometric structure printing area is located on the side away from the second cut groove in its own second conductive geometric structure printing area; Right-angled bent serpentine slots are opened on both of the rectangular sheet-shaped conductive structures on both sides of the C-shaped conductive geometric structure. The openings at both ends of the right-angled bent serpentine slots are both located on the symmetry axis of the length direction of the second conductive geometric structure printing area. The four top corners of the C-shaped conductive geometric structure are connected to form a rectangle, and conductive metal vias penetrating the plate surface of the second dielectric substrate are sequentially opened. The ninth conductive metal via and the tenth conductive metal via are located between two adjacent second cut grooves. The C-shaped conductive geometric structures on both sides of the second dielectric substrate are connected through the conductive metal vias.

[0015] The meandering spiral conductive geometric structure is located in the middle of the C-shaped conductive geometric structure. One end of the meandering spiral conductive geometric structure is located on the central axis of the length direction of the second cut groove in its own second conductive geometric structure printing area and is close to the second cut groove. The other end of the meandering spiral conductive geometric structure is located at the center of the second conductive geometric structure printing area. One end of the meandering spiral conductive geometric structure is first printed along the width direction of the second conductive geometric structure printing area and then bent at a right angle towards the direction close to the second cut groove, and then printed in a right-angled spiral shape to the other end. Conductive metal vias penetrating the plate surface of the second dielectric substrate are respectively opened at both ends of the meandering spiral conductive geometric structure. The seventh conductive metal via is located at the center of the second conductive geometric structure printing area. The meandering spiral conductive geometric structures on both sides of the second dielectric substrate are connected through the seventh conductive metal via. The eighth conductive metal via is close to the second cut groove. The third meandering spiral conductive geometric structure on one side of the second dielectric substrate and a fourth meandering spiral conductive geometric structure on the other side of the second dielectric substrate that is not directly opposite but adjacent to it are connected through the eighth conductive metal via.

[0016] When the first cut groove of the first dielectric substrate and the second cut groove of the second dielectric substrate are interpenetrated, the second conductive metal via on the first dielectric substrate and the eighth conductive metal via on the second dielectric substrate are respectively located on both sides of the center point of the width side of the dielectric substrate.

[0017] The lengths of the first cut groove of the first dielectric substrate and the second cut groove of the second dielectric substrate are 1 / 2 of the total width of the dielectric substrate. The widths of the first cut groove and the second cut groove are slightly wider than the thickness of the dielectric substrate.

[0018] The number of turns of the spiral of the described meandering spiral conductive geometric structure is 1.25 turns to 1.5 turns.

[0019] The number of bends of the serpentine slots of the described C-shaped conductive geometric structure is 2 times.

[0020] Application of the high-pass, steep-cutoff wide incident angle frequency selection structure of the present invention: The application of the high-pass, steep-cutoff wide incident angle frequency selection structure in a radome.

[0021] Application of the high-pass, steep-cutoff wide incident angle frequency selection structure of the present invention: The application of the high-pass, steep-cutoff wide incident angle frequency selection structure in a device for improving the isolation between antennas in an antenna system.

[0022] The beneficial effects of the present invention are:

[0023] The present invention can achieve a high-pass filtering function for spatial electromagnetic waves within the range of frequencies below 5 GHz, any polarization direction, and a wide incident angle range of 0 to 60 degrees. Moreover, the transition band between the passband and the stopband is very narrow. The relative fractional bandwidth of the passband is as high as 93.3% under the condition of less than 2 dB insertion loss, and the transition band between the passband and the stopband is only 0.13 GHz under the condition of 13 dB suppression ratio, having a steep cutoff effect. The present invention also solves the limitations of narrow passband bandwidth, wide transition bandwidth between the passband and the stopband, and narrow incident angle range in the prior art, and is easy to process and manufacture, and can be widely applied to radomes of platforms such as communication base stations, radars, satellite communications, and aircraft. Brief Description of the Drawings

[0024] Figure 1 It is a three-dimensional schematic diagram of the high-pass, steep-cutoff wide incident angle frequency selection structure provided by the present invention;

[0025] Figure 2 It is a partial structural schematic diagram of the A surface of the first selection component in the high-pass, steep-cutoff wide incident angle frequency selection structure;

[0026] Figure 3 It is a partial structural schematic diagram of the B surface of the first selection component in the high-pass, steep-cutoff wide incident angle frequency selection structure;

[0027] Figure 4 It is a partial structural schematic diagram of the A surface of the second selection component in the high-pass, steep-cutoff wide incident angle frequency selection structure;

[0028] Figure 5 It is a partial structural schematic diagram of the B surface of the second selection component in the high-pass, steep-cutoff wide incident angle frequency selection structure;

[0029] Figure 6Schematic diagram of the transmission coefficient in the transverse electric (TE) mode of the preferred embodiment of the high-pass, steep-cutoff wide incident angle frequency selection structure at electromagnetic wave incident angles of 0°, 30°, and 60°;

[0030] Figure 7 Schematic diagram of the transmission coefficient in the transverse magnetic (TM) mode of the preferred embodiment of the high-pass, steep-cutoff wide incident angle frequency selection structure at electromagnetic wave incident angles of 0°, 30°, and 60°;

[0031] In the figure: the first selection component 10, the first dielectric substrate 11, the first meandering spiral conductive geometry 1A2, the second meandering spiral conductive geometry 1B2, the first C-shaped conductive geometry 1A3, the second C-shaped conductive geometry 1B3, the first conductive metal via 14, the second conductive metal via 15, the third conductive metal via 16, the fourth conductive metal via 17, the fifth conductive metal via 18, the sixth conductive metal via 19, the second selection component 20, the second dielectric substrate 21, the third meandering spiral conductive geometry 2A2, the fourth meandering spiral conductive geometry 2B2, the third C-shaped conductive geometry 2A3, the fourth C-shaped conductive geometry 2B3, the seventh conductive metal via 24, the eighth conductive metal via 25, the ninth conductive metal via 26, the tenth conductive metal via 27, the eleventh conductive metal via 28, the twelfth conductive metal via 29. Detailed implementation manners

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] As Figure 1 shown, the high-pass, steep-cutoff wide incident angle frequency selection structure of the present invention includes a plurality of rectangular plate-shaped first selection components 10 arranged in parallel at equal intervals and a plurality of rectangular plate-shaped second selection components 20 arranged in parallel at equal intervals. Each of the first selection components 10 and each of the second selection components 20 are orthogonal to each other and are arranged perpendicularly and interpenetratingly to form a mortise and tenon fitting structure; both side surfaces of each first selection component 10 are divided into a plurality of rectangular first conductive geometry printing areas along the length direction of the first selection component 10, and the same first conductive geometry is printed on each first conductive geometry printing area; both side surfaces of each second selection component 20 are divided into a plurality of rectangular second conductive geometry printing areas along the length direction of the second selection component 20, and the same second conductive geometry is printed on each second conductive geometry printing area; each first conductive geometry printing area is interposed between two adjacent second selection components 20, and each second conductive geometry area is interposed between two adjacent first selection components 10.

[0034] The first selection component 10 is a first dielectric substrate 11 with a number of first slots arranged at intervals. The first slots are strip-shaped through slots penetrating the plate surface of the first dielectric substrate 11 and parallel to the width direction of the first dielectric substrate 11. One first slot is provided in each first conductive geometric structure printing area located on the first dielectric substrate 11. Each first slot is located between two adjacent first conductive geometric structures. The length direction of the first conductive geometric structure printing area is parallel to the width direction of the first dielectric substrate 11. Each first slot is opened from one short-side vertex angle of the first conductive geometric structure printing area to the center of the long side of the first conductive geometric structure printing area. Each first conductive geometric structure on one side surface of the first dielectric substrate 11 coincides with the first conductive geometric structure on the opposite side surface after being flipped half a turn along the central axis in the length direction of its own first conductive geometric structure printing area; the first conductive geometric structures and the first slots in each first conductive geometric structure printing area are arranged periodically along the length direction of the first dielectric substrate 11 on both side surfaces of the first dielectric substrate 11.

[0035] The second selection component 20 is a second dielectric substrate 21 with a number of second slots arranged at intervals. The second slots are strip-shaped through slots penetrating the plate surface of the second dielectric substrate 21 and parallel to the width direction of the second dielectric substrate 21. One second slot is provided in each second conductive geometric structure printing area located on the second dielectric substrate 21. Each second slot is located between two adjacent second conductive geometric structures. The length direction of the second conductive geometric structure printing area is parallel to the width direction of the second dielectric substrate 21. Each second slot is opened from one short-side vertex angle of the second conductive geometric structure printing area to the center of the long side of the second conductive geometric structure printing area. Each second conductive geometric structure on one side surface of the second dielectric substrate 21 coincides with the second conductive geometric structure on the opposite side surface after being flipped half a turn along the central axis in the length direction of its own second conductive geometric structure printing area; the second conductive geometric structures and the second slots in each second conductive geometric structure printing area are arranged periodically along the length direction of the second dielectric substrate 21 on both side surfaces of the second dielectric substrate 21.

[0036] When each first selection component 10 and each second selection component 20 are orthogonal to each other, each first slot on each first selection component 10 is sequentially and perpendicularly inserted into one second slot on each second selection component 20. When each second selection component 20 and each first selection component 10 are orthogonal to each other, each second slot on each second selection component 20 is sequentially and perpendicularly inserted into one first slot on each first selection component 10.

[0037] Such as Figure 2 And Figure 3As shown, the first conductive geometric structure includes meandering spiral conductive geometric structures 1A2 and 1B2, and C-shaped conductive geometric structures 1A3 and 1B3. The first conductive geometric structure printing areas on the two side surfaces of the first dielectric substrate 11 face each other in pairs. The first meandering spiral conductive geometric structure 1A2 and the first C-shaped conductive geometric structure 1A3 are printed on the first conductive geometric structure printing area on one side surface of the first dielectric substrate 11, and the second meandering spiral conductive geometric structure 1B2 and the second C-shaped conductive geometric structure 1B3 are printed on the first conductive geometric structure printing area on the other side surface of the first dielectric substrate 11.

[0038] The C-shaped conductive geometric structures 1A3 and 1B3 are integrally formed by two relatively wide rectangular sheet-like conductive structures on both sides and a relatively narrow rectangular strip-like conductive structure in the middle to form a three-segment right-angle bent C-shaped structure. The width direction of the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structures 1A3 and 1B3 and the length direction of the rectangular strip-like conductive structure in the middle are both parallel to the length direction of the first conductive geometric structure printing area. The long side of the rectangular strip-like conductive structure close to one side of the first conductive geometric structure printing area is located on the side away from the first cut groove in the first conductive geometric structure printing area where it is located; right-angle bent serpentine slots are provided on the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structures 1A3 and 1B3. The two ends of the right-angle bent serpentine slots are both located on the symmetry axis of the length direction of the first conductive geometric structure printing area. The four top corners of the C-shaped conductive geometric structures 1A3 and 1B3 are connected to form a rectangle, and conductive metal vias 16, 17, 18, and 19 that penetrate the plate surface of the first dielectric substrate 11 are sequentially provided. The fifth conductive metal via 18 and the sixth conductive metal via 19 are located between two adjacent first cut grooves. The C-shaped conductive geometric structures 1A3 and 1B3 on the two side surfaces of the first dielectric substrate 11 are connected through the conductive metal vias 16, 17, 18, and 19.

[0039] The spiral conductive geometric structures 1A2 and 1B2 are located in the middle of the C-shaped conductive geometric structures 1A3 and 1B3. One end of the spiral conductive geometric structures 1A2 and 1B2 is located on the central axis of the length direction of the first cut groove in the first conductive geometric structure printing area where they are located and is close to the first cut groove, and the other end of the spiral conductive geometric structures 1A2 and 1B2 is located at the center of the first conductive geometric structure printing area. One end of the spiral conductive geometric structures 1A2 and 1B2 is first printed along the width direction of the first conductive geometric structure printing area and then bent at a right angle towards the direction close to the first cut groove, and then printed in a right-angled spiral shape to the other end. Conductive metal vias 14 and 15 that penetrate the plate surface of the first dielectric substrate 11 are respectively provided at both ends of the spiral conductive geometric structures 1A2 and 1B2. The first conductive metal via 14 is located at the center of the first conductive geometric structure printing area. The spiral conductive geometric structures 1A2 and 1B2 on both side surfaces of the first dielectric substrate 11 are connected through the first conductive metal via 14. The second conductive metal via 15 is close to the first cut groove. The first spiral conductive geometric structure 1A2 on one side surface of the first dielectric substrate 11 and a second spiral conductive geometric structure 1B2 on the other side surface of the first dielectric substrate 11 that is not directly opposite but adjacent to it are connected through the second conductive metal via 15.

[0040] As Figure 4 and Figure 5 shown, the second conductive geometric structure includes spiral conductive geometric structures 2A2 and 2B2 and C-shaped conductive geometric structures 2A3 and 2B3. The second conductive geometric structure printing areas on both side surfaces of the second dielectric substrate 21 are pairwise directly opposite. A third spiral conductive geometric structure 2A2 and a third C-shaped conductive geometric structure 2A3 are printed on the second conductive geometric structure printing area on one side surface of the second dielectric substrate 21, and a fourth spiral conductive geometric structure 2B2 and a fourth C-shaped conductive geometric structure 2B3 are printed on the second conductive geometric structure printing area on the other side surface of the second dielectric substrate 21.

[0041] The C-shaped conductive geometric structures 2A3 and 2B3 are integrally formed by a rectangular sheet-shaped conductive structure that is wider on both sides and a rectangular strip-shaped conductive structure that is narrower in the middle, thereby forming a three-segment right-angled bent C-shaped structure. The width direction of the rectangular sheet-shaped conductive structures on both sides of the C-shaped conductive geometric structures 2A3 and 2B3 and the length direction of the rectangular strip-shaped conductive structure in the middle are both parallel to the length direction of the second conductive geometric structure printing area. The long side of the rectangular strip-shaped conductive structure close to one side of the second conductive geometric structure printing area is located on the side away from the second cut groove in the second conductive geometric structure printing area where it is located. Right-angled bent serpentine slots are provided on the rectangular sheet-shaped conductive structures on both sides of the C-shaped conductive geometric structures 2A3 and 2B3. The openings at both ends of the right-angled bent serpentine slots are both located on the symmetry axis of the length direction of the second conductive geometric structure printing area. The four top corners of the C-shaped conductive geometric structures 2A3 and 2B3 are connected to form a rectangle, and conductive metal vias 26, 27, 28, and 29 that penetrate the plate surface of the second dielectric substrate 21 are sequentially provided. The ninth conductive metal via 26 and the tenth conductive metal via 27 are located between two adjacent second cut grooves. The C-shaped conductive geometric structures 2A3 and 2B3 on both sides of the second dielectric substrate 21 are connected through the conductive metal vias 26, 27, 28, and 29.

[0042] The meandering spiral conductive geometric structures 2A2 and 2B2 are located in the middle of the C-shaped conductive geometric structures 2A3 and 2B3. One end of the meandering spiral conductive geometric structures 2A2 and 2B2 is located on the central axis of the length direction of the second cut groove in the second conductive geometric structure printing area where it is located and is close to the second cut groove. The other end of the meandering spiral conductive geometric structures 2A2 and 2B2 is located at the center of the second conductive geometric structure printing area. One end of the meandering spiral conductive geometric structures 2A2 and 2B2 is first printed in the width direction of the second conductive geometric structure printing area and then bent at a right angle toward the direction close to the second cut groove, and then printed in a right-angled spiral shape to the other end. Conductive metal vias 24 and 25 that penetrate the plate surface of the second dielectric substrate 21 are respectively provided at both ends of the meandering spiral conductive geometric structures 2A2 and 2B2. The seventh conductive metal via 24 is located at the center of the second conductive geometric structure printing area. The meandering spiral conductive geometric structures 2A2 on both sides of the second dielectric substrate 21 are connected through the seventh conductive metal via 24. The eighth conductive metal via 25 is close to the second cut groove. The third meandering spiral conductive geometric structure 2A2 on one side of the second dielectric substrate 21 and a fourth meandering spiral conductive geometric structure 2B2 on the other side of the second dielectric substrate 21 that is not directly opposite but adjacent to it are connected through the eighth conductive metal via 25.

[0043] When the first cut groove of the first dielectric substrate 11 and the second cut groove of the second dielectric substrate 21 are interpenetrated, the second conductive metal via 15 on the first dielectric substrate 11 and the eighth conductive metal via 25 on the second dielectric substrate 21 are respectively located on both sides of the center points of the width sides of the dielectric substrates 11 and 21.

[0044] The lengths of the first cut groove of the first dielectric substrate 11 and the second cut groove of the second dielectric substrate 21 are 1 / 2 of the total widths of the dielectric substrates 11 and 21, and the widths of the first cut groove and the second cut groove are slightly wider than the thicknesses of the dielectric substrates 11 and 21.

[0045] The number of turns of the spiral loops of the meandering spiral conductive geometries 1A2, 1B2, 2A2, and 2B2 is 1.25 turns to 1.5 turns.

[0046] The number of bends of the serpentine slits of the C-shaped conductive geometries 1A3, 1B3, 2A3, and 2B3 is 2 times.

[0047] The specific embodiments of the present invention are as follows:

[0048] In the first selection component 10 and the second selection component 20 of the high-pass, steep cut-off wide incident angle frequency selection structure provided in this embodiment, the cut grooves on the dielectric substrates 11 and 21 and the conductive geometries on the two surfaces of the dielectric substrates 11 and 21 are both arranged in a periodic manner, and the period is 4 mm.

[0049] In the first selection component 10 and the second selection component 20 of the high-pass, steep cut-off wide incident angle frequency selection structure provided in this embodiment, the total widths of the dielectric substrates 11 and 21 are 30 mm, the thicknesses of the dielectric substrates 11 and 21 are 0.2 mm, the lengths of the cut grooves are 1 / 2 of the total widths of the dielectric substrates 11 and 21, that is, 15 mm, the widths of the cut grooves are slightly wider than the thicknesses of the dielectric substrates 11 and 21, which are 0.2 mm to 0.22 mm, and specifically 0.22 mm can be adopted. The dielectric constants of the dielectric substrates 11 and 21 are 3.1, and the loss tangent is 0.0028.

[0050] In the high-pass, steep cut-off wide incident angle frequency selection structure provided in this embodiment, the number of turns of the spiral loops of the meandering spiral conductive geometries 1A2, 1B2, 2A2, and 2B2 on the two surfaces of the dielectric substrates 11 and 21 is 1.25 turns to 1.5 turns, and specifically 1.25 turns can be adopted. The line widths of the meandering spiral conductive geometries 1A2, 1B2, 2A2, and 2B2 are 0.2 mm, and the spacing between the spiral loops is 0.4 mm.

[0051] The C-shaped conductive geometries 1A3, 1B3, 2A3, and 2B3 on the two surfaces of the dielectric substrates 11 and 21 of the high-pass, steep-cutoff, wide incident angle frequency selection structure provided in this embodiment have serpentine slots on the conductive metal patches on both sides. The number of bends of the serpentine slots is 2. The line width of the horizontal conductive metal structure of the C-shaped conductive geometries 1A3, 1B3, 2A3, and 2B3 is 0.2 mm. The line width of the relatively wide vertical conductive metal structures on both sides of the C-shaped conductive geometries 1A3, 1B3, 2A3, and 2B3 is 1.0 mm. The width of the serpentine slots on the relatively wide vertical conductive metal structures on both sides of the C-shaped conductive geometries 1A3, 1B3, 2A3, and 2B3 is 0.2 mm.

[0052] The meandering spiral conductive geometries 1A2, 1B2, 2A2, and 2B2 on the two surfaces of the dielectric substrates 11 and 21 of the high-pass, steep-cutoff, wide incident angle frequency selection structure provided in this embodiment are connected at the spiral center positions through conductive metal vias 14 and 24. Conductive metal arms extend from the outermost sides of the meandering spiral conductive geometries 1A2, 1B2, 2A2, and 2B2 to the periodic edges, and are connected to the conductive metal arms extended from the meandering spiral conductive geometries 1A2, 1B2, 2A2, and 2B2 of adjacent periods through conductive metal vias 15 and 25 at the periodic edges. The diameters of the conductive metal vias 14, 15, 24, and 25 are 0.2 mm.

[0053] The C-shaped conductive geometries 1A3, 1B3, 2A3, and 2B3 on the two surfaces of the dielectric substrates 11 and 21 of the high-pass, steep-cutoff, wide incident angle frequency selection structure provided in this embodiment have opposite opening directions, and are connected at the four corners through conductive metal vias 16, 17, 18, 19, 26, 27, 28, and 29. The diameters of the conductive metal vias 16, 17, 18, 19, 26, 27, 28, and 29 are 0.2 mm.

[0054] The intervals between multiple first selection components 10 and between multiple second selection components 20 of the high-pass, steep-cutoff, wide incident angle frequency selection structure provided in this embodiment are 4 mm. The strip-shaped through slots of the first selection components 10 are inserted into the opposite sides of the strip-shaped through slots of the second selection components 20 to form a mortise and tenon fit structure, and the first selection components 10 and the second selection components 20 are arranged in an orthogonal and perpendicular interpenetrating manner to form the final embodiment.

[0055] The results obtained by the full-wave simulation software for the high-pass, steep-cutoff, wide incident angle frequency selection structure provided in this embodiment are as Figure 6 and Figure 7As shown: This embodiment can achieve the high-pass filtering function of spatial electromagnetic waves within the range of frequencies below 5 GHz, any polarization direction, and wide incident angles from 0 to 60 degrees. The relative fractional bandwidth of the passband is as high as 93.3% under the condition of an insertion loss less than 2 dB. The transition band between the passband and the stopband is only 0.13 GHz under the condition of a suppression level of 13 dB, showing a sharp cut-off effect.

[0056] According to one aspect of the present invention, a specific implementation provides a radome, which includes the high-pass and sharp-cutoff wide-incident-angle frequency selection structure in the above embodiment. Through this radome, electromagnetic waves in non-operating frequency bands can be effectively suppressed, thereby reducing interference outside the operating frequency band.

[0057] According to another aspect of the present invention, a specific implementation provides a device for improving the isolation between antennas in an antenna system. By setting this device in the antenna system, electromagnetic waves in non-operating frequency bands can be effectively suppressed, the isolation between antennas in different frequency bands can be improved, and the performance of the antenna system can be enhanced.

[0058] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-pass, steep-cutoff wide-angle-of-incidence frequency selection structure, characterized in that: It includes a number of first selection components (10) in the form of rectangular plates arranged in parallel at equal intervals and a number of second selection components (20) in the form of rectangular plates arranged in parallel at equal intervals. Each of the first selection components (10) and each of the second selection components (20) are orthogonal to each other and arranged perpendicularly and alternately; both side surfaces of each first selection component (10) are divided into a number of rectangular first conductive geometric structure printing areas along the length direction of itself, and the same first conductive geometric structure is printed on each first conductive geometric structure printing area; both side surfaces of each second selection component (20) are divided into a number of rectangular second conductive geometric structure printing areas along the length direction of itself, and the same second conductive geometric structure is printed on each second conductive geometric structure printing area; each first conductive geometric structure printing area is interspersed between two adjacent second selection components (20), and each second conductive geometric structure area is interspersed between two adjacent first selection components (10); The first selection component (10) is a first dielectric substrate (11) with a number of first slots arranged at intervals, and the second selection component (20) is a second dielectric substrate (21) with a number of second slots arranged at intervals; The first conductive geometric structure includes a meandering spiral conductive geometric structure (1A2, 1B2) and a C-shaped conductive geometric structure (1A3, 1B3). The four top corners of the C-shaped conductive geometric structure (1A3, 1B3) are connected to form a rectangle and are successively provided with conductive metal vias (16, 17, 18, 19) penetrating through the plate surface of the first dielectric substrate (11). The fifth conductive metal via (18) and the sixth conductive metal via (19) are located between two adjacent first slots. The C-shaped conductive geometric structures (1A3, 1B3) on both side surfaces of the first dielectric substrate (11) are connected through the conductive metal vias (16, 17, 18, 19); both ends of the meandering spiral conductive geometric structure (1A2, 1B2) are respectively provided with conductive metal vias (14, 15) penetrating through the plate surface of the first dielectric substrate (11). The first conductive metal via (14) is located at the center of the first conductive geometric structure printing area. The meandering spiral conductive geometric structures (1A2, 1B2) on both side surfaces of the first dielectric substrate (11) are connected through the first conductive metal via (14). The second conductive metal via (15) is close to the first slot. The first meandering spiral conductive geometric structure (1A2) on one side surface of the first dielectric substrate (11) and a second meandering spiral conductive geometric structure (1B2) on the other side surface of the first dielectric substrate (11) that is not directly opposite but adjacent to it are connected through the second conductive metal via (15); The second conductive geometric structure includes a meandering spiral conductive geometric structure (2A2, 2B2) and a C-shaped conductive geometric structure (2A3, 2B3). The four top corners of the C-shaped conductive geometric structure (2A3, 2B3) are connected to form a rectangle, and conductive metal vias (26, 27, 28, 29) that penetrate the plate surface of the second dielectric substrate (21) are successively provided. The ninth conductive metal via (26) and the tenth conductive metal via (27) are located between two adjacent second cut grooves. The C-shaped conductive geometric structures (2A3, 2B3) on both side surfaces of the second dielectric substrate (21) are connected through the conductive metal vias (26, 27, 28, 29). Conductive metal vias (24, 25) that penetrate the plate surface of the second dielectric substrate (21) are respectively provided at both ends of the meandering spiral conductive geometric structure (2A2, 2B2). The seventh conductive metal via (24) is located at the center of the second conductive geometric structure printing area. The meandering spiral conductive geometric structures (2A2, 2B2) on both side surfaces of the second dielectric substrate (21) are connected through the seventh conductive metal via (24). The eighth conductive metal via (25) is close to the second cut groove. The third meandering spiral conductive geometric structure (2A2) on one side surface of the second dielectric substrate (21) and a fourth meandering spiral conductive geometric structure (2B2) that is not directly opposite but adjacent to it on the other side surface of the second dielectric substrate (21) are connected through the eighth conductive metal via (25).

2. The high-pass and sharp-cutoff wide incident angle frequency selection structure according to claim 1, wherein: The first cut groove is a strip-shaped through groove that penetrates the plate surface of the first dielectric substrate (11) and is parallel to the width direction of the first dielectric substrate (11). A first cut groove is provided in each first conductive geometric structure printing area located on the first dielectric substrate (11). Each first cut groove is located between two adjacent first conductive geometric structures. The length direction of the first conductive geometric structure printing area is parallel to the width direction of the first dielectric substrate (11). Each first cut groove is opened from one short-side top corner of the first conductive geometric structure printing area to the center of the long side of the first conductive geometric structure printing area. Each first conductive geometric structure on one side surface of the first dielectric substrate (11) coincides with the first conductive geometric structure on the opposite side surface after being flipped half a turn along the central axis in the length direction of its own first conductive geometric structure printing area; The second cut groove is a strip through groove penetrating the plate surface of the second dielectric substrate (21) and parallel to the width direction of the second dielectric substrate (21). A second cut groove is provided in each second conductive geometric structure printing area located on the second dielectric substrate (21). Each second cut groove is located between two adjacent second conductive geometric structures. The length direction of the second conductive geometric structure printing area is parallel to the width direction of the second dielectric substrate (21). Each second cut groove is opened from one short side vertex angle of the second conductive geometric structure printing area to the center of the long side of the second conductive geometric structure printing area. Each second conductive geometric structure on one side surface of the second dielectric substrate (21) coincides with the second conductive geometric structure on the opposite side surface after being flipped half a turn along the central axis in the length direction of the second conductive geometric structure printing area where it is located; When each first selection component (10) and each second selection component (20) are orthogonal to each other, each first cut groove on each first selection component (10) is sequentially and perpendicularly inserted into a second cut groove on each second selection component (20). When each second selection component (20) and each first selection component (10) are orthogonal to each other, each second cut groove on each second selection component (20) is sequentially and perpendicularly inserted into a first cut groove on each first selection component (10).

3. The wide incident angle frequency selection structure with high pass and steep cut-off according to claim 1, characterized in that: The first conductive geometric structure printing areas on both side surfaces of the first dielectric substrate (11) are pairwise opposite. The first conductive geometric structure printing area on one side surface of the first dielectric substrate (11) is printed with a first meandering spiral conductive geometric structure (1A2) and a first C-shaped conductive geometric structure (1A3). The first conductive geometric structure printing area on the other side surface of the first dielectric substrate (11) is printed with a second meandering spiral conductive geometric structure (1B2) and a second C-shaped conductive geometric structure (1B3); The C-shaped conductive geometric structures (1A3, 1B3) are integrally formed by two relatively wide rectangular sheet-like conductive structures on both sides and a relatively narrow rectangular strip-like conductive structure in the middle to form a three-segment right-angled bent C-shaped structure. The width direction of the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structures (1A3, 1B3) and the length direction of the rectangular strip-like conductive structure in the middle are both parallel to the length direction of the first conductive geometric structure printing area. The rectangular strip-like conductive structure is close to one long side of the first conductive geometric structure printing area and is located on the side away from the first cut groove in the first conductive geometric structure printing area where it is located; Right-angled bent serpentine slots are provided on both of the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structures (1A3, 1B3). Both ends of the right-angled bent serpentine slots are opened on the symmetry axis line in the length direction of the first conductive geometric structure printing area; The meandering spiral conductive geometric structure (1A2, 1B2) is located in the middle of the C-shaped conductive geometric structure (1A3, 1B3). One end of the meandering spiral conductive geometric structure (1A2, 1B2) is located on the central axis of the length direction of the first cut groove in the first conductive geometric structure printing area where it is located and is close to the first cut groove. The other end of the meandering spiral conductive geometric structure (1A2, 1B2) is located at the center of the first conductive geometric structure printing area. One end of the meandering spiral conductive geometric structure (1A2, 1B2) is first printed along the width direction of the first conductive geometric structure printing area and then bent at a right angle towards the direction close to the first cut groove, and then printed in a right-angled spiral shape to the other end.

4. The wide incident angle frequency selection structure with high pass and steep cut-off according to claim 1, characterized in that: The second conductive geometric structure printing areas on both sides of the second dielectric substrate (21) face each other in pairs. The third meandering spiral conductive geometric structure (2A2) and the third C-shaped conductive geometric structure (2A3) are printed on the second conductive geometric structure printing area on one side of the second dielectric substrate (21), and the fourth meandering spiral conductive geometric structure (2B2) and the fourth C-shaped conductive geometric structure (2B3) are printed on the second conductive geometric structure printing area on the other side of the second dielectric substrate (21); The C-shaped conductive geometric structure (2A3, 2B3) is integrally formed by two relatively wide rectangular sheet-like conductive structures on both sides and a relatively narrow rectangular strip-like conductive structure in the middle to form a three-segment right-angled bent C-shaped structure. The width direction of the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structure (2A3, 2B3) and the length direction of the rectangular strip-like conductive structure in the middle are both parallel to the length direction of the second conductive geometric structure printing area. The rectangular strip-like conductive structure is close to one long side of the second conductive geometric structure printing area and is located on the side away from the second cut groove in the second conductive geometric structure printing area where it is located; Right-angled bent serpentine slots are provided on both of the rectangular sheet-like conductive structures on both sides of the C-shaped conductive geometric structure (2A3, 2B3), and both ends of the right-angled bent serpentine slots are open on the axis of symmetry of the length direction of the second conductive geometric structure printing area; The meandering spiral conductive geometric structure (2A2, 2B2) is located in the middle of the C-shaped conductive geometric structure (2A3, 2B3). One end of the meandering spiral conductive geometric structure (2A2, 2B2) is located on the central axis of the length direction of the second cut groove in the second conductive geometric structure printing area where it is located and is close to the second cut groove. The other end of the meandering spiral conductive geometric structure (2A2, 2B2) is located at the center of the second conductive geometric structure printing area. One end of the meandering spiral conductive geometric structure (2A2, 2B2) is first printed along the width direction of the second conductive geometric structure printing area and then bent at a right angle towards the direction close to the second cut groove, and then printed in a right-angled spiral shape to the other end.

5. The wide incident angle frequency selection structure with high pass and steep cut-off according to claim 1, characterized in that: When the first cut groove of the first dielectric substrate (11) and the second cut groove of the second dielectric substrate (21) are interpenetrated, the second conductive metal via hole (15) on the first dielectric substrate (11) and the eighth conductive metal via hole (25) on the second dielectric substrate (21) are respectively located on both sides of the center point of the width side of the dielectric substrates (11, 21).

6. The wide incident angle frequency selection structure with high pass and steep cut-off according to claim 1, characterized in that: The lengths of the first cut groove of the first dielectric substrate (11) and the second cut groove of the second dielectric substrate (21) are 1 / 2 of the total width of the dielectric substrates (11, 21), and the widths of the first cut groove and the second cut groove are wider than the thicknesses of the dielectric substrates (11, 21).

7. The wide incident angle frequency selection structure with high pass and steep cut-off according to claim 1, characterized in that: The number of turns of the meandering spiral conductive geometric structures (1A2, 1B2, 2A2, 2B2) is 1.25 turns to 1.5 turns.

8. The wide-incidence-angle frequency selection structure with high-pass and steep cut-off according to claim 1, characterized in that: The number of bends of the serpentine slots of the C-shaped conductive geometric structures (1A3, 1B3, 2A3, 2B3) is 2 times.

9. Application of the high-pass, steep-cutoff wide incident angle frequency selection structure according to any one of claims 1-8, characterized in that: Application of the high-pass, steep cut-off wide incident angle frequency selective structure in a radome.

10. Application of the high-pass, steep-cutoff wide incident angle frequency selection structure according to any one of claims 1-8, characterized in that: Application of the high-pass, steep cut-off wide incident angle frequency selective structure in a device for improving the isolation between antennas in an antenna system.

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