Polarization reconfigurable broadband cross dipole antenna based on liquid metal

Abstract

The invention discloses a polarization reconfigurable broadband cross dipole antenna based on liquid metal, which comprises a cross dipole, a parasitic patch structure and a metal reflection cavity structure, four first fluid channels are loaded at the cross dipole, and different first fluid channels in the four first fluid channels are filled with liquid metal, so that the polarization reconfigurable broadband cross dipole antenna is formed. Left-hand circular polarization or right-hand circular polarization of the broadband cross dipole antenna can be achieved, the parasitic patch structure and the cross dipole generate coupling, a current path on the cross dipole is prolonged, a new resonance point is excited to broaden the bandwidth, and the metal reflection cavity structure is provided with eight second fluid channels. The eight second fluid channels are filled with liquid metal to form a vertical reflecting plate, and the vertical reflecting plate and the crossed dipoles generate a coupling effect; the antenna has the advantages that polarization reconfiguration is achieved, and meanwhile the antenna has large bandwidth and high gain.

Description

Technical Field

[0001] The invention relates to a cross dipole antenna, in particular to a polarization reconfigurable broadband cross dipole antenna based on liquid metal. Background Art

[0002] In the field of contemporary wireless communications, antennas are a key technology whose performance directly affects the communication efficiency and reliability of the entire wireless communication system. With the vigorous development of wireless communication technology, higher performance requirements are placed on antennas, especially broadband and multifunctionality. In this context, broadband circularly polarized antennas have become the focus of research due to their advantages in polarization matching and multipath effects.

[0003] The cross-dipole antenna has become an ideal choice in the design of broadband circularly polarized antennas due to its good circular polarization performance. Through the clever design of the quarter-wavelength phase delay line and the antenna structure, the cross-dipole antenna can generate stable circularly polarized waves in multiple frequency bands. The original cross-dipole antenna was proposed in the document "Baik JW, Lee KJ, Yoon WS, et al. Circularly Polarised Printed Crossed Dipole Antennas with Broadband Axial Ratio [J]. Electronics Letters, 2008, 44 (13): 785-786." The cross-dipole antenna achieves circular polarization through a pair of orthogonally placed dipoles. However, its axial ratio bandwidth is 15.6%, the bandwidth is narrow, and it has fixed performance and structure, which is relatively limited in the increasingly dynamic communication environment. Therefore, in order to expand the circular polarization bandwidth of the cross-dipole antenna and improve the antenna performance, researchers have proposed a series of design schemes and structural improvements.

[0004] At present, there are three main ways to expand the circular polarization bandwidth of cross-dipole antennas, namely, adding parasitic units to the cross-dipole antenna design, using a broadband planar dipole structure, and combining the antenna design with improved dipole and parasitic unit technology. However, the cross-dipole antennas implemented by the above three methods can only achieve broadband circular polarization, cannot achieve polarization reconfiguration, and have low gain.

[0005] In addition, there are some studies that use the switching state of PIN diodes to realize single parameter reconfigurable cross-dipole antennas with polarization, frequency and directional pattern. The document "J. Row, Y. Wei. Wideband Reconfigurable Crossed-Dipole Antenna With Quad-Polarization Diversity [J]. IEEE Transactions on Antennas and Propagation, 2018, 66 (4): 2090-2094" proposes a cross-dipole antenna. Although the cross-dipole antenna can realize polarization reconfiguration through the feeding network, its bandwidth is narrow and the gain is low. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a polarization reconfigurable broadband cross-dipole antenna based on liquid metal, which has a larger bandwidth and a higher gain while realizing polarization reconfiguration.

[0007] The technical solution adopted by the present invention to solve the above technical problems is: a polarization reconfigurable broadband cross-dipole antenna based on liquid metal, comprising a cross dipole, a parasitic patch structure and a metal reflection cavity structure, wherein four first fluid channels are loaded at the cross dipole, and by filling different first fluid channels among the four first fluid channels with liquid metal, the left-hand circular polarization or right-hand circular polarization of the broadband cross-dipole antenna can be achieved, the parasitic patch structure is used to couple with the cross dipole, so that the current path on the cross dipole is extended, thereby exciting a new resonance point to widen the bandwidth, and the metal reflection cavity structure has eight second fluid channels, and a vertical reflection plate is formed by filling the eight second fluid channels with liquid metal, which produces a coupling effect with the cross dipole, so that the bandwidth of the broadband cross-dipole antenna is biased towards a lower frequency band, the impedance bandwidth and axial ratio bandwidth of the broadband cross-dipole antenna are expanded, and the directional radiation capability of the broadband cross-dipole antenna is improved, thereby significantly improving the gain performance of the broadband cross-dipole antenna.

[0008] The polarization reconfigurable broadband cross-dipole antenna based on liquid metal also includes a first dielectric substrate, which is in the shape of a rectangular parallelepiped. The length direction of the first dielectric substrate is taken as the left-right direction, the width direction is taken as the front-to-back direction, and the thickness direction is taken as the up-down direction. The length of the first dielectric substrate is equal to its width; the straight line where the center line of the first dielectric substrate in the up-down direction is located is called the first center line, the plane that makes the first dielectric substrate front-to-back symmetrical is called the first symmetry plane, and the plane that makes the first dielectric substrate left-to-right symmetrical is called the second symmetry plane; the cross-dipole includes 4 metal radiation patches, 2 annular metal sheets and 4 metal connecting sheets, the 4 metal radiation patches are respectively called the first radiation patch, the second radiation patch, the third radiation patch and the fourth radiation patch, the 2 annular metal sheets are respectively called the first annular sheet and the second annular sheet, and the 4 metal connecting sheets are respectively called the first connecting sheet, the second connecting sheet, the third connecting sheet and the fourth connecting sheet; the first annular sheet is attached to the upper surface of the first dielectric substrate, and its center is located on the first center line. The radiation patch and the second radiation patch are both attached to the upper surface of the first dielectric substrate, and if the first radiation patch is rotated 90° clockwise with the first center line as the axis, it will completely overlap with the second radiation patch; the first radiation patch includes an isosceles trapezoidal metal patch and two metal filling sheets, the upper base and the lower base of the isosceles trapezoidal metal patch both extend in the front-to-back direction, and its upper base is located on the right side of its lower base, the upper base of the isosceles trapezoidal metal patch is circumscribed with the outer circumference of the first annular sheet, and the two metal filling sheets are located in the Between the upper base of the isosceles trapezoidal metal patch and the first circular ring piece, and distributed on the front and rear sides of the tangent point between the upper base of the isosceles trapezoidal metal patch and the first circular ring piece, if the two waists of the isosceles trapezoidal metal patch extend toward the first circular ring piece until they intersect with the first circular ring piece, at this time, the extended sections of the two waists of the isosceles trapezoidal metal patch, the upper base of the isosceles trapezoidal metal patch and the outer circumference of the first circular ring piece will enclose two areas, and the two metal filling sheets are located in the two areas in a one-to-one correspondence, and the two areas are completely filled;The first radiation patch is symmetrical front-to-back with respect to the first symmetry plane, and the second radiation patch is symmetrical left-to-right with respect to the second symmetry plane. The waist of the isosceles trapezoidal metal patch of the first radiation patch located on the front side of the first symmetry plane is called its front waist, and the waist of the isosceles trapezoidal metal patch of the second radiation patch located on the left side of the second symmetry plane is called its left waist. If the front waist of the isosceles trapezoidal metal patch of the first radiation patch extends toward the first circular ring piece and intersects with the first circular ring piece, the intersection is called the first intersection. The left waist of the isosceles trapezoidal metal patch of the second radiation patch extends toward the first circular ring piece. The extension will intersect with the first circular ring piece, and the intersection is called the second intersection. The first circular ring piece starts from the first intersection and is intercepted in a clockwise direction to a part of the second intersection to form a first notch; the third radiation patch and the fourth radiation patch are both attached to the lower surface of the first dielectric substrate. If the first radiation patch is rotated 180° clockwise with the first center line as the axis and then mapped to the lower surface of the first dielectric substrate, it will completely overlap with the third radiation patch. If the third radiation patch is rotated 90° clockwise with the first center line as the axis, it will overlap with the fourth radiation patch. The second annular sheet is attached to the lower surface of the first dielectric substrate. If the first annular sheet is mapped to the lower surface of the first dielectric substrate, it will completely overlap with the second annular sheet. A second notch is opened on the second annular sheet. If the first notch is rotated 180° clockwise with the first center line as the axis and then mapped to the lower surface of the first dielectric substrate, it will completely overlap with the second notch. The first connecting sheet and the second connecting sheet are both attached to the upper surface of the first dielectric substrate and are located inside the first annular sheet. The first connecting sheet is square and its center is aligned with the first annular sheet. The centers of the ring pieces coincide, one of the two adjacent sides of the first connecting piece extends in the left-right direction and the other in the front-back direction, the side length of the first connecting piece is equal to the upper base length of the isosceles trapezoidal metal patch of the first radiation patch, and the second connecting piece is located on the left side of the first connecting piece. If the two opposite sides of the first connecting piece extending in the left-right direction are extended to the left to intersect with the first circular ring piece, then the extension lines of the two opposite sides of the first connecting piece extending in the left-right direction, the inner circumference of the first circular ring piece and the left side of the first connecting piece will enclose an area, and the second connecting piece is located inside the area and completely fills the area;The third connecting piece and the fourth connecting piece are both attached to the lower surface of the first dielectric substrate. If the first connecting piece is mapped to the lower surface of the first dielectric substrate, it will completely overlap with the third connecting piece. If the second connecting piece is rotated 180° clockwise with the first center line as the axis and then mapped to the lower surface of the first dielectric substrate, it will completely overlap with the fourth connecting piece. ;

[0009] The parasitic patch structure includes three groups of metal patches, which are respectively referred to as the first group of metal patches, the second group of metal patches and the third group of metal patches; the first group of metal patches includes 8 metal patches, all of which are isosceles trapezoidal in shape, and the 8 metal patches are respectively referred to as the first patch, the second patch, the third patch, the fourth patch, the fifth patch, the sixth patch, the seventh patch and the eighth patch, the first patch, the second patch, the third patch and the fourth patch are attached to the upper surface of the first dielectric substrate, the fifth patch, the sixth patch, the seventh patch and the eighth patch are attached to the lower surface of the first dielectric substrate, the first patch is located on the left side of the first radiation patch, and its upper base and lower base both extend in the front-to-back direction, the lower base of the first patch is located on the right side of its upper base, and there is a section between the two. A distance is provided between the upper bottom of the first patch and the plane where the left end surface of the first dielectric substrate is located. The first patch is front-to-back symmetrical about the first symmetry plane. If the first patch is rotated 90° in a clockwise direction with the first center line as the axis, it will completely overlap with the second patch. If the first patch is rotated 180° in a clockwise direction with the first center line as the axis, it will completely overlap with the third patch. If the first patch is rotated 270° in a clockwise direction with the first center line as the axis, it will completely overlap with the fourth patch. If the first patch, the second patch, the third patch and the fourth patch are all mapped to the lower surface of the first dielectric substrate, they will overlap with the fifth patch, the sixth patch, the seventh patch and the eighth patch one by one.The second group of metal patches includes 8 metal patches, all of which are isosceles trapezoidal in shape. The 8 metal patches are respectively referred to as the ninth patch, the tenth patch, the eleventh patch, the twelfth patch, the thirteenth patch, the fourteenth patch, the fifteenth patch and the sixteenth patch. The ninth patch, the tenth patch, the eleventh patch and the twelfth patch are all attached to the upper surface of the first dielectric substrate. The thirteenth patch, the fourteenth patch, the fifteenth patch and the sixteenth patch are all attached to the lower surface of the first dielectric substrate. The ninth patch is located between the first radiation patch and the second radiation patch and is not in contact with the first radiation patch and the second radiation patch. The ninth patch is formed from the left front corner to the right rear corner of the first dielectric substrate. The diagonal surface is symmetrical about the plane where the ninth patch is located, the upper base of the ninth patch is close to the first annular patch relative to its lower base, if the ninth patch is rotated 90° in the clockwise direction with the first center line as the axis, it will completely overlap with the tenth patch, if the ninth patch is rotated 180° in the clockwise direction with the first center line as the axis, it will completely overlap with the eleventh patch, if the ninth patch is rotated 270° in the clockwise direction with the first center line as the axis, it will completely overlap with the twelfth patch, if the ninth patch, the tenth patch, the eleventh patch and the twelfth patch are all mapped to the lower surface of the first dielectric substrate, they will overlap with the thirteenth patch, the fourteenth patch, the fifteenth patch and the sixteenth patch one by one;The third group of metal patches includes 8 metal patches, all of which are rectangular in shape. The 8 metal patches are respectively called the 17th patch, the 18th patch, the 19th patch, the 20th patch, the 21st patch, the 22nd patch, the 23rd patch and the 24th patch. The 17th patch, the 18th patch, the 19th patch and the 20th patch are all attached to the upper surface of the first dielectric substrate. The 21st patch, the 22nd patch, the 23rd patch and the 24th patch are all attached to the lower surface of the first dielectric substrate. The 17th patch is located on the outside of the 9th patch, and one side of it completely overlaps with the bottom of the 9th patch. The 17th patch is at the left front corner of the first dielectric substrate. The plane of the diagonal surface formed by the right rear corner is symmetrical. If the 17th patch is rotated 90° clockwise with the first center line as the axis, it will completely overlap with the 18th patch. If the 17th patch is rotated 180° clockwise with the first center line as the axis, it will completely overlap with the 19th patch. If the 17th patch is rotated 270° clockwise with the first center line as the axis, it will completely overlap with the 20th patch. If the 17th patch, the 18th patch, the 19th patch and the 20th patch are all mapped to the lower surface of the first dielectric substrate, they will overlap with the 21st patch, the 22nd patch, the 23rd patch and the 24th patch one by one. ;

[0010] The metal reflection cavity structure includes a metal reflection wall, four first metal reflection plates and four second metal reflection plates. The metal reflection wall is formed by opening a rectangular cavity penetrating from top to bottom on a metal rectangular block. The metal rectangular block is called a first metal rectangular block. The length direction of the first metal rectangular block is along the left-right direction, the width direction is along the front-back direction, the thickness direction is along the up-down direction, and its length is equal to its width. The length direction of the rectangular cavity is along the left-right direction, the width direction is along the front-back direction, the thickness direction is along the up-down direction, and its length is equal to its width. The rectangular cavity The center line of the chamber along the up-down direction coincides with the center line of the first metal cuboid block along the up-down direction, the length of the cuboid chamber is less than the length of the first metal cuboid block, and the thickness of the cuboid chamber is equal to the thickness of the first metal cuboid block; the first metal cuboid block is located below the first dielectric substrate, the center line of the first metal cuboid block along the up-down direction coincides with the first center line, the length of the first dielectric substrate is less than the length of the cuboid chamber, and the width of the first dielectric substrate is less than the width of the cuboid chamber;Each first metal reflector is in the shape of a cuboid, and its length direction is along the left-right direction, its width direction is along the front-back direction, and its thickness direction is along the up-down direction. The length of each first metal reflector is equal to its width, and its thickness is less than the thickness of the cuboid chamber, and twice its length is less than the length of the cuboid chamber. The four first metal reflectors are fixedly arranged inside the cuboid chamber, the front end face of the first first metal reflector is in the same plane as the front end face of the cuboid chamber, the left end face of the first first metal reflector is in the same plane as the left end face of the cuboid chamber, and the first The lower end surface of the first metal reflector is located in the same plane as the lower end surface of the rectangular chamber, the first first metal reflector and the second first metal reflector are symmetrical about the second symmetry plane, the second first metal reflector and the third first metal reflector are symmetrical about the first symmetry plane, the first first metal reflector and the fourth first metal reflector are symmetrical about the first symmetry plane, each second metal reflector is in the shape of a rectangular parallelepiped, the four second metal reflectors are fixedly arranged inside the rectangular chamber, the first second metal reflector is located above the first first metal reflector. The first metal reflector is between the first metal reflector and the second first metal reflector, the length direction of the first second metal reflector is along the front-to-back direction, the width direction is along the left-right direction, and the thickness direction is along the up-down direction. The front end face of the first second metal reflector is in the same plane as the front end face of the rectangular chamber, the rear end face of the first second metal reflector is in the same plane as the rear end face of the first first metal reflector, the upper end face of the first second metal reflector is in the same plane as the upper end face of the first first metal reflector, the lower end face of the first second metal reflector is in the same plane as the lower end face of the first first metal reflector, and the first The second metal reflector is bilaterally symmetrical about the second symmetry plane, the sum of the width of the first second metal reflector and twice the length of the first first metal reflector is less than the length of the rectangular chamber, if the first second metal reflector is rotated 90 degrees clockwise around the first center line, it will completely overlap with the second second metal reflector, if the first second metal reflector is rotated 90 degrees counterclockwise around the first center line, it will completely overlap with the fourth second metal reflector, and the first second metal reflector and the third second metal reflector are front-to-back symmetrical about the first symmetry plane;The first second fluid channel is fixedly arranged in the gap between the first first metal reflector and the first second metal reflector. The first second fluid channel is realized by opening a cavity for filling liquid metal inside a rectangular block made of Watershed material. The rectangular block is called the first rectangular block. The length direction of the first rectangular block is along the front-to-back direction, the width direction is along the left-to-right direction, and the thickness direction is along the up-down direction. The front end face of the first rectangular block and the front end face of the rectangular chamber are located in the same plane, the upper end face of the first rectangular block and the upper end face of the rectangular chamber are located in the same plane, the lower end face of the first rectangular block and the lower end face of the rectangular chamber are located in the same plane, and the left end face of the first rectangular block is located at the right end face of the first first metal reflector. The end faces are in a fitted state, the right end face of the first rectangular block is in a fitted state with the left end face of the first second metal reflector, the length of the first rectangular block is less than the length of the first first metal reflector, a second second fluid channel is fixedly provided in the gap between the first second metal reflector and the second first metal reflector, the second second fluid channel is realized by providing an outer layer made of Watershed material on the outside of a rectangular metal block, the rectangular metal block is called the second rectangular metal block, the first rectangular block can completely overlap with the second rectangular metal block after being translated to the right, the outer layer wraps the part of the second rectangular metal block located above the plane where the upper end face of the second first metal reflector is located, and a gap for filling liquid metal is formed between the two;A third second fluid channel is arranged at the gap between the second first metal reflector and the second second metal reflector, a fourth second fluid channel is arranged at the gap between the second second metal reflector and the third first metal reflector, a fifth second fluid channel is arranged at the gap between the third first metal reflector and the third second metal reflector, a sixth second fluid channel is arranged at the gap between the third second metal reflector and the fourth first metal reflector, a seventh second fluid channel is arranged at the gap between the fourth second metal reflector and the fourth first metal reflector, an eighth second fluid channel is arranged at the gap between the first first metal reflector and the fourth second metal reflector, the first second metal reflector, the first second fluid channel and the second second fluid channel are taken as the first combined structure, the second second metal reflector, The third second fluid channel and the fourth second fluid channel are used as the second combination structure, the third second metal reflector, the fifth second fluid channel and the sixth second fluid channel are used as the third combination structure, and the fourth second metal reflector, the seventh second fluid channel and the eighth second fluid channel are used as the fourth combination structure. If the first combination structure is rotated 90 degrees clockwise around the first center line, it will completely overlap with the second combination structure. If the first combination structure is rotated 90 degrees counterclockwise around the first center line, it will completely overlap with the fourth combination structure. If the first combination structure is rotated 180 degrees clockwise around the first center line, it will completely overlap with the third combination structure. The lower end surface of the first dielectric substrate is fixed on the upper end surfaces of the eight second fluid channels, and the first dielectric substrate is supported by the eight second fluid channels. ;

[0011] The polarization reconfigurable broadband cross-dipole antenna based on liquid metal also includes a second dielectric substrate, which is located below the metal reflection cavity structure. The length direction of the second dielectric substrate is along the left-right direction, the width direction is along the front-back direction, and the thickness direction is along the up-down direction. The front end face of the second dielectric substrate is located in the same plane as the front end face of the first dielectric substrate, the rear end face of the second dielectric substrate is located in the same plane as the rear end face of the first dielectric substrate, the left end face of the second dielectric substrate is located in the same plane as the left end face of the first dielectric substrate, and the right end face of the second dielectric substrate is located in the same plane as the right end face of the first dielectric substrate. The upper end face of the second dielectric substrate is printed with a metal ground, the metal ground completely covers the upper surface of the second dielectric substrate, and the metal ground is bonded to the lower end face of the first metal rectangular block.

[0012] The liquid metal-based polarization reconfigurable broadband cross-dipole antenna also includes a coaxial cable, which sequentially passes through the center of the first dielectric substrate, the center of the second dielectric substrate, the center of the first connecting piece, and the center of the third connecting piece. The inner conductor of the coaxial cable is connected to the first circular ring piece, and the outer conductor of the coaxial cable is connected to the second circular ring piece. At the same time, the outer conductor of the coaxial cable is welded to the second dielectric substrate.

[0013] The first first fluid channel is realized by arranging an outer layer on the outer side of the second connecting piece, the outer layer material is Watershed, and a gap for filling liquid metal is formed between the outer layer and the second connecting piece; the second first fluid channel is arranged inside the first annular piece, and is formed by opening a cavity for filling liquid metal inside a sheet body made of Watershed material. If the second connecting piece is rotated 90 degrees clockwise around the first center line, it will completely overlap with the sheet body. The third first fluid channel is realized by arranging an outer layer on the outer side of the fourth connecting piece, the outer layer material is Watershed, and a gap for filling liquid metal is formed between the outer layer and the fourth connecting piece; the fourth first fluid channel is arranged inside the second annular piece, and is formed by opening a cavity for filling liquid metal inside a sheet body made of Watershed material. If the fourth connecting piece is rotated 90 degrees clockwise around the first center line, it will completely overlap with the sheet body.

[0014] Compared with the prior art, the present invention has the advantages of forming a broadband cross-dipole antenna through a cross-dipole, a parasitic patch structure and a metal reflection cavity structure, four first fluid channels are loaded at the cross-dipole, and by filling different first fluid channels among the four first fluid channels with liquid metal, left-hand circular polarization or right-hand circular polarization of the broadband cross-dipole antenna can be achieved, the parasitic patch structure can couple with the cross-dipole, so that the current path on the cross-dipole is extended, thereby exciting a new resonance point to widen the bandwidth, and the metal reflection cavity structure has eight second fluid channels, and a vertical reflection plate is formed by filling the eight second fluid channels with liquid metal, which produces a coupling effect with the cross-dipole, so that the bandwidth of the broadband cross-dipole antenna is biased towards a lower frequency band, the impedance bandwidth and axial ratio bandwidth of the broadband cross-dipole antenna are expanded, and the directional radiation capability of the broadband cross-dipole antenna is improved, so that the gain performance of the broadband cross-dipole antenna is significantly improved, so that the present invention has a larger bandwidth and a higher gain while realizing polarization reconfiguration. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1An exploded diagram of the polarization reconfigurable broadband cross-dipole antenna based on liquid metal of the present invention;

[0016] Figure 2 A three-dimensional diagram of the polarization reconfigurable broadband cross-dipole antenna based on liquid metal of the present invention;

[0017] Figure 3 A side view of the polarization reconfigurable broadband cross-dipole antenna based on liquid metal of the present invention;

[0018] Figure 4 A top view of a cross dipole of the polarization reconfigurable broadband cross dipole antenna based on liquid metal of the present invention;

[0019] Figure 5 A top view of a metal reflection cavity structure of a polarization reconfigurable broadband cross-dipole antenna based on liquid metal according to the present invention;

[0020] Figure 6 The invention relates to a broadband cross-dipole antenna with reconfigurable polarization based on liquid metal. 11 |And axis ratio simulation diagram;

[0021] Figure 7 This is a simulation diagram of the efficiency and gain of the liquid metal-based polarization reconfigurable broadband cross-dipole antenna of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to the accompanying drawings.

[0023] Embodiment 1: Figures 1 to 3 As shown, a polarization reconfigurable broadband cross-dipole antenna based on liquid metal includes a cross-dipole 1, a parasitic patch structure 2 and a metal reflection cavity structure 3. Four first fluid channels are loaded at the cross-dipole 1. By filling different first fluid channels among the four first fluid channels with liquid metal, left-hand circular polarization or right-hand circular polarization of the broadband cross-dipole antenna can be achieved. The parasitic patch structure 2 is used to couple with the cross-dipole 1 to extend the current path on the cross-dipole 1, thereby exciting a new resonance point to broaden the bandwidth. The metal reflection cavity structure 3 has eight second fluid channels. A vertical reflection plate is formed by filling the eight second fluid channels with liquid metal, which produces a coupling effect with the cross-dipole 1, so that the bandwidth of the broadband cross-dipole antenna is biased toward a lower frequency band, the impedance bandwidth and axial ratio bandwidth of the broadband cross-dipole antenna are expanded, and the directional radiation capability of the broadband cross-dipole antenna is improved, thereby significantly improving the gain performance of the broadband cross-dipole antenna.

[0024] Embodiment 2: This embodiment is basically the same as Embodiment 1, except that: Figure 4As shown, in this embodiment, the polarization reconfigurable broadband cross dipole antenna based on liquid metal further includes a first dielectric substrate 4, the first dielectric substrate 4 is in a rectangular shape, the length direction of the first dielectric substrate 4 is taken as the left-right direction, the width direction is taken as the front-back direction, the thickness direction is taken as the up-down direction, and the length of the first dielectric substrate 4 is equal to its width; the straight line where the center line of the first dielectric substrate 4 along the up-down direction is located is called the first center line, the plane that makes the first dielectric substrate 4 front-to-back symmetrical is called the first symmetry plane, and the first dielectric substrate 4 is made left-right symmetrical. The plane is called the second symmetry plane; the cross dipole 1 includes 4 metal radiation patches, 2 annular metal sheets and 4 metal connecting sheets, the 4 metal radiation patches are respectively called the first radiation patch 5, the second radiation patch 6, the third radiation patch 7 and the fourth radiation patch 8, the 2 annular metal sheets are respectively called the first annular sheet 9 and the second annular sheet, and the 4 metal connecting sheets are respectively called the first connecting sheet 10, the second connecting sheet 11, the third connecting sheet and the fourth connecting sheet 13; the first annular sheet 9 is attached to the upper surface of the first dielectric substrate 4, and its center is located at the first dielectric substrate 4. On a center line, the first radiation patch 5 and the second radiation patch 6 are both attached to the upper surface of the first dielectric substrate 4, and if the first radiation patch 5 is rotated 90° clockwise with the first center line as the axis, it will completely overlap with the second radiation patch 6; the first radiation patch 5 includes an isosceles trapezoidal metal patch 51 and two metal filling sheets 52, the upper base and the lower base of the isosceles trapezoidal metal patch 51 both extend in the front-to-back direction, and its upper base is located on the right side of its lower base, the upper base of the isosceles trapezoidal metal patch 51 is circumscribed with the outer circumference of the first annular sheet 9, and the two metal filling sheets 52 are connected to the first dielectric substrate 4. 2 is located between the upper base of the isosceles trapezoidal metal patch 51 and the first circular ring piece 9, and is distributed on both sides of the front and rear of the tangent point between the upper base of the isosceles trapezoidal metal patch 51 and the first circular ring piece 9. If the two waists of the isosceles trapezoidal metal patch 51 extend toward the first circular ring piece 9 until they intersect with the first circular ring piece 9, then, the extended sections of the two waists of the isosceles trapezoidal metal patch 51, the upper base of the isosceles trapezoidal metal patch 51 and the outer circumference of the first circular ring piece 9 will enclose two areas, and the two metal filling sheets 52 are located in the two areas in a one-to-one correspondence and completely fill the two areas;The first radiation patch 5 is front-to-back symmetrical about the first symmetry plane, and the second radiation patch 6 is left-to-right symmetrical about the second symmetry plane. A waist of the isosceles trapezoidal metal patch 51 of the first radiation patch 5 located on the front side of the first symmetry plane is called its front waist 511, and a waist of the isosceles trapezoidal metal patch 61 of the second radiation patch 6 located on the left side of the second symmetry plane is called its left waist 611. If the front waist 511 of the isosceles trapezoidal metal patch 51 of the first radiation patch 5 extends toward the first circular ring piece 9, it will intersect with the first circular ring piece 9, and the intersection is called the first intersection. If the left waist 611 of the isosceles trapezoidal metal patch 61 of the second radiation patch 6 extends toward the first circular ring piece 9, it will intersect with the first circular ring piece 9, and the intersection is called At the second intersection, a portion of the first annular sheet 9 is cut off from the first intersection in a clockwise direction to the second intersection, forming a first notch 14; the third radiation patch 7 and the fourth radiation patch 8 are both attached to the lower surface of the first dielectric substrate 4. If the first radiation patch 5 is rotated 180° in a clockwise direction with the first center line as the axis and then mapped to the lower surface of the first dielectric substrate 4, it will completely overlap with the third radiation patch 7. If the third radiation patch 7 is rotated 90° in a clockwise direction with the first center line as the axis, it will completely overlap with the fourth radiation patch 8. The second annular sheet is attached to the lower surface of the first dielectric substrate 4. If the first annular sheet 9 is mapped to the lower surface of the first dielectric substrate 4, it will completely overlap with the second annular sheet , a second notch is provided on the second annular sheet. If the first notch 14 is rotated 180° clockwise with the first center line as the axis and then mapped to the lower surface of the first dielectric substrate 4, it will completely overlap with the second notch; the first connecting sheet 10 and the second connecting sheet 11 are both attached to the upper surface of the first dielectric substrate 4 and are located inside the first annular sheet 9. The first connecting sheet 10 is a square, and its center coincides with the center of the first annular sheet 9. Two adjacent sides of the first connecting sheet 10 extend one in the left-right direction and one in the front-back direction. The side length of the first connecting sheet 10 is equal to the upper bottom length of the isosceles trapezoidal metal patch of the first radiation patch 5. The second connecting sheet 11 is located on the left side of the first connecting sheet 10. If the first connecting sheet 1 0 The two opposite sides extending in the left-right direction are both extended to the left to intersect with the first circular ring piece 9. At this time, the extension lines of the two opposite sides extending in the left-right direction of the first connecting piece 10, the inner circumference of the first circular ring piece 9 and the left side of the first connecting piece 10 will enclose an area, and the second connecting piece 11 is located inside the area and completely fills the area; the third connecting piece and the fourth connecting piece 13 are both attached to the lower surface of the first dielectric substrate 4. If the first connecting piece 10 is mapped to the lower surface of the first dielectric substrate 4, it will completely overlap with the third connecting piece. If the second connecting piece 11 is rotated 180° clockwise with the first center line as the axis and then mapped to the lower surface of the first dielectric substrate 4, it will completely overlap with the fourth connecting piece 13. ;

[0025] Embodiment 3: This embodiment is basically the same as Embodiment 2, except that: Figure 4As shown, in this embodiment, the parasitic patch structure 2 includes three groups of metal patches, which are respectively referred to as the first group of metal patches, the second group of metal patches and the third group of metal patches; the first group of metal patches includes 8 metal patches, all of which are isosceles trapezoidal in shape, and the 8 metal patches are respectively referred to as the first patch 15, the second patch 16, the third patch 17, the fourth patch 18, the fifth patch, the sixth patch, the seventh patch and the eighth patch. The first patch 15, the second patch 16, the third patch 17 and the fourth patch 18 are attached to the upper surface of the first dielectric substrate 4, and the fifth patch, the sixth patch, the seventh patch and the eighth patch are attached to the lower surface of the first dielectric substrate 4. The first patch 15 is located on the left side of the first radiation patch 5, and its upper bottom and lower bottom both extend in the front-to-back direction. The lower bottom of the first patch 15 is located on it. The first patch 15 is on the right side of the bottom, and there is a distance between the two. There is a distance between the upper bottom of the first patch 15 and the plane where the left end surface of the first dielectric substrate 4 is located. The first patch 15 is front-to-back symmetrical about the first symmetry plane. If the first patch 15 is rotated 90° in the clockwise direction with the first center line as the axis, it will completely overlap with the second patch 16. If the first patch 15 is rotated 180° in the clockwise direction with the first center line as the axis, it will completely overlap with the third patch 17. If the first patch 15 is rotated 270° in the clockwise direction with the first center line as the axis, it will completely overlap with the fourth patch 18. If the first patch 15, the second patch 16, the third patch 17 and the fourth patch 18 are all mapped to the lower surface of the first dielectric substrate 4, they will overlap with the fifth patch, the sixth patch, the seventh patch and the eighth patch one by one.The second group of metal patches includes 8 metal patches, all of which are isosceles trapezoidal in shape. The 8 metal patches are respectively called the ninth patch 19, the tenth patch 20, the eleventh patch 21, the twelfth patch 22, the thirteenth patch, the fourteenth patch, the fifteenth patch and the sixteenth patch. The ninth patch 19, the tenth patch 20, the eleventh patch 21 and the twelfth patch 22 are all attached to the upper surface of the first dielectric substrate 4, the thirteenth patch, the fourteenth patch, the fifteenth patch and the sixteenth patch are all attached to the lower surface of the first dielectric substrate 4, the ninth patch 19 is located between the first radiation patch 5 and the second radiation patch 6, and is not in contact with the first radiation patch 5 and the second radiation patch 6. The ninth patch 19 is about the left front of the first dielectric substrate 4. The upper base of the ninth patch 19 is close to the first annular sheet 9 relative to its lower base. If the ninth patch 19 is rotated 90° in the clockwise direction with the first center line as the axis, it will completely overlap with the tenth patch 20. If the ninth patch 19 is rotated 180° in the clockwise direction with the first center line as the axis, it will completely overlap with the eleventh patch 21. If the ninth patch 19 is rotated 270° in the clockwise direction with the first center line as the axis, it will completely overlap with the twelfth patch 22. If the ninth patch 19, the tenth patch 20, the eleventh patch 21 and the twelfth patch 22 are all mapped to the lower surface of the first dielectric substrate 4, they will overlap with the thirteenth patch, the fourteenth patch, the fifteenth patch and the sixteenth patch. The third group of metal patches includes 8 metal patches, all of which are rectangular in shape. The 8 metal patches are respectively called the 17th patch 23, the 18th patch 24, the 19th patch 25, the 20th patch 26, the 21st patch, the 22nd patch, the 23rd patch and the 24th patch. The 17th patch 23, the 18th patch 24, the 19th patch 25 and the 20th patch 26 are all attached to the upper surface of the first dielectric substrate 4, the 21st patch, the 22nd patch, the 23rd patch and the 24th patch are all attached to the lower surface of the first dielectric substrate 4, the 17th patch 23 is located on the outer side of the 9th patch 19, and one side thereof completely overlaps with the lower bottom of the 9th patch 19, and the 17th patch 23 is about the first The diagonal surface formed by the left front corner to the right rear corner of the dielectric substrate 4 is symmetrical in the plane. If the seventeenth patch 23 is rotated 90° in the clockwise direction with the first center line as the axis, it will completely overlap with the eighteenth patch 24. If the seventeenth patch 23 is rotated 180° in the clockwise direction with the first center line as the axis, it will completely overlap with the nineteenth patch 25. If the seventeenth patch 23 is rotated 270° in the clockwise direction with the first center line as the axis, it will completely overlap with the twentieth patch 26. If the seventeenth patch 23, the eighteenth patch 24, the nineteenth patch 25 and the twentieth patch 26 are all mapped to the lower surface of the first dielectric substrate 4, they will overlap with the twenty-first patch, the twenty-second patch, the twenty-third patch and the twenty-fourth patch one by one. ;

[0026] Embodiment 4: This embodiment is basically the same as Embodiment 3, except that: Figure 5As shown, in this embodiment, the metal reflection cavity structure 3 includes a metal reflection wall, four first metal reflection plates and four second metal reflection plates. The metal reflection wall is formed by opening a rectangular cavity 28 that penetrates from top to bottom on a metal rectangular block. The metal rectangular block is called a first metal rectangular block 27. The length direction of the first metal rectangular block 27 is along the left-right direction, the width direction is along the front-to-back direction, the thickness direction is along the up-down direction, and its length is equal to its width. The length direction of the rectangular cavity 28 is along the left-right direction, the width direction is along the front-to-back direction, the thickness direction is along the up-down direction, and its length is equal to its width. The length of the rectangular chamber 28 is equal to its width, the center line of the rectangular chamber 28 along the up-down direction coincides with the center line of the first metal rectangular block 27 along the up-down direction, the length of the rectangular chamber 28 is less than the length of the first metal rectangular block 27, and the thickness of the rectangular chamber 28 is equal to the thickness of the first metal rectangular block 27; the first metal rectangular block 27 is located below the first dielectric substrate 4, the center line of the first metal rectangular block 27 along the up-down direction coincides with the first center line, the length of the first dielectric substrate 4 is less than the length of the rectangular chamber 28, and the width of the first dielectric substrate 4 is less than the width of the rectangular chamber 28;Each first metal reflector is in the shape of a cuboid, and its length direction is along the left-right direction, its width direction is along the front-back direction, and its thickness direction is along the up-down direction. The length of each first metal reflector is equal to its width, and its thickness is less than the thickness of the cuboid chamber 28, and twice its length is less than the length of the cuboid chamber 28. The four first metal reflectors are fixedly arranged inside the cuboid chamber 28. The front end face of the first first metal reflector 29 is located in the same plane as the front end face of the cuboid chamber 28, the left end face of the first first metal reflector 29 is located in the same plane as the left end face of the cuboid chamber 28, and the first first metal reflector 2 The lower end surface of 9 is located in the same plane as the lower end surface of the rectangular chamber 28, the first first metal reflector 29 and the second first metal reflector 30 are symmetrical about the second symmetry plane, the second first metal reflector 30 and the third first metal reflector 31 are symmetrical about the first symmetry plane, the first first metal reflector 29 and the fourth first metal reflector 32 are symmetrical about the first symmetry plane, each second metal reflector is in the shape of a rectangular parallelepiped, the four second metal reflectors are fixedly arranged inside the rectangular chamber 28, the first second metal reflector 33 is located between the first first metal reflector 29 and the second Between the first metal reflection plates 30, the length direction of the first second metal reflection plate 33 is along the front-to-back direction, the width direction is along the left-to-right direction, and the thickness direction is along the up-down direction. The front end face of the first second metal reflection plate 33 and the front end face of the rectangular chamber 28 are located in the same plane, the rear end face of the first second metal reflection plate 33 and the rear end face of the first first metal reflection plate 29 are located in the same plane, the upper end face of the first second metal reflection plate 33 and the upper end face of the first first metal reflection plate 29 are located in the same plane, the lower end face of the first second metal reflection plate 33 and the lower end face of the first first metal reflection plate 29 are located in the same plane, and the The first second metal reflector 33 is bilaterally symmetrical about the second symmetry plane, the sum of the width of the first second metal reflector 33 and twice the length of the first first metal reflector 29 is less than the length of the rectangular chamber 28, if the first second metal reflector 33 is rotated 90 degrees clockwise around the first center line, it will completely overlap with the second second metal reflector 34, if the first second metal reflector 33 is rotated 90 degrees counterclockwise around the first center line, it will completely overlap with the fourth second metal reflector 36, the first second metal reflector 33 and the third second metal reflector 35 are front-to-back symmetrical about the first symmetry plane;The first second fluid channel 37 is fixedly arranged in the gap between the first first metal reflector 29 and the first second metal reflector 33. The first second fluid channel 37 is realized by opening a cavity for filling liquid metal inside a rectangular block made of Watershed material. The rectangular block is called the first rectangular block. The length direction of the first rectangular block is along the front-to-back direction, the width direction is along the left-to-right direction, and the thickness direction is along the up-down direction. The front end face of the first rectangular block is in the same plane as the front end face of the rectangular chamber 28, the upper end face of the first rectangular block is in the same plane as the upper end face of the rectangular chamber 28, the lower end face of the first rectangular block is in the same plane as the lower end face of the rectangular chamber 28, and the left end face of the first rectangular block is in the same plane as the right end face of the first first metal reflector 29. The first rectangular block is in a fitted state, the right end face of the first rectangular block is in a fitted state with the left end face of the first second metal reflector 33, the length of the first rectangular block is less than the length of the first first metal reflector 29, a second second fluid channel 38 is fixedly provided in the gap between the first second metal reflector 33 and the second first metal reflector 30, the second second fluid channel 38 is realized by providing an outer layer of a Watershed material on the outside of a rectangular metal block, the rectangular metal block is called the second rectangular metal block, the first rectangular block can be completely overlapped with the second rectangular metal block after being translated to the right, the outer layer wraps the part of the second rectangular metal block located above the plane where the upper end face of the second first metal reflector 30 is located, and a gap for filling liquid metal is formed between the two;A third second fluid channel 39 is provided in the gap between the second first metal reflecting plate 30 and the second second metal reflecting plate 34, a fourth second fluid channel 40 is provided in the gap between the second second metal reflecting plate 34 and the third first metal reflecting plate 31, a fifth second fluid channel 41 is provided in the gap between the third first metal reflecting plate 31 and the third second metal reflecting plate 35, a sixth second fluid channel 42 is provided in the gap between the third second metal reflecting plate 35 and the fourth first metal reflecting plate 32, a seventh second fluid channel 43 is provided in the gap between the fourth second metal reflecting plate 36 and the fourth first metal reflecting plate 32, an eighth second fluid channel 44 is provided in the gap between the first first metal reflecting plate 29 and the fourth second metal reflecting plate 36, and the first second metal reflecting plate 33, the first second fluid channel 37 and the second second fluid channel 38 are used as the first A combined structure, wherein the second second metal reflector 34, the third second fluid channel 39 and the fourth second fluid channel 40 are used as the second combined structure, the third second metal reflector 35, the fifth second fluid channel 41 and the sixth second fluid channel 42 are used as the third combined structure, and the fourth second metal reflector 36, the seventh second fluid channel 43 and the eighth second fluid channel 44 are used as the fourth combined structure. If the first combined structure is rotated 90 degrees clockwise around the first center line, it will completely overlap with the second combined structure. If the first combined structure is rotated 90 degrees counterclockwise around the first center line, it will completely overlap with the fourth combined structure. If the first combined structure is rotated 180 degrees clockwise around the first center line, it will completely overlap with the third combined structure. The lower end surface of the first dielectric substrate 4 is fixed on the upper end surfaces of the eight second fluid channels, and the first dielectric substrate 4 is supported by the eight second fluid channels. ;

[0027] In this embodiment, the polarization reconfigurable broadband cross dipole antenna based on liquid metal further includes a second dielectric substrate 45, which is located below the metal reflection cavity structure 3. The length direction of the second dielectric substrate 45 is along the left-right direction, the width direction is along the front-back direction, and the thickness direction is along the up-down direction. The front end face of the second dielectric substrate 45 is located in the same plane as the front end face of the first dielectric substrate 4, the rear end face of the second dielectric substrate 45 is located in the same plane as the rear end face of the first dielectric substrate 4, the left end face of the second dielectric substrate 45 is located in the same plane as the left end face of the first dielectric substrate 4, and the right end face of the second dielectric substrate 45 is located in the same plane as the right end face of the first dielectric substrate 4. The upper end face of the second dielectric substrate 45 is printed with a metal ground 46, and the metal ground 46 completely covers the upper surface of the second dielectric substrate 45. The metal ground 46 is bonded to the lower end face of the first metal cuboid block 27.

[0028] In this embodiment, the polarization reconfigurable broadband cross-dipole antenna based on liquid metal also includes a coaxial cable 47, which runs through the center of the first dielectric substrate 4, the center of the second dielectric substrate 45, the center of the first connecting plate 10 and the center of the third connecting plate in sequence. The inner conductor of the coaxial cable 47 is connected to the first circular ring plate 9, and the outer conductor of the coaxial cable 47 is connected to the second circular ring plate. At the same time, the outer conductor of the coaxial cable 47 is welded to the second dielectric substrate 45.

[0029] In this embodiment, the first first fluid channel K1 is realized by setting an outer layer on the outer side of the second connecting piece 11, and the outer layer material is Watershed, and a gap for filling liquid metal is formed between the second connecting piece 11; the second first fluid channel K2 is set inside the first annular piece 9, and is formed by opening a cavity for filling liquid metal inside a sheet body made of Watershed material. If the second connecting piece 11 is rotated 90 degrees clockwise around the first center line, it will completely overlap with the sheet body. The third first fluid channel K3 is realized by setting an outer layer on the outer side of the fourth connecting piece 13, and the outer layer material is Watershed, and a gap for filling liquid metal is formed between the fourth connecting piece 13; the fourth first fluid channel K4 is set inside the second annular piece, and is formed by opening a cavity for filling liquid metal inside a sheet body made of Watershed material. If the fourth connecting piece 13 is rotated 90 degrees clockwise around the first center line, it will completely overlap with the sheet body.

[0030] In this embodiment, the first dielectric substrate 4 and the second dielectric substrate 45 are both made of FR4_epoxy sheet with a dielectric constant of 4.4, and the size (length×width×thickness) is 100mm×100mm×0.8mm. The size (length×width×thickness) of the first metal rectangular block 27 is 160mm×160mm×36.78mm. The size (upper base×lower base×height×thickness) of the isosceles trapezoidal metal patch of the first radiation patch 5 is 2.6mm×15mm×19.7mm×0.035mm. The inner circle radius of the first annular piece 9 is 4.4mm, and the outer circle radius is 4.8mm. The length of the first connecting piece 10 is 2.6mm, the width is 2.6mm, and the thickness is 0.035mm. The upper base of the first patch 15 is 10mm, the lower base is 18mm, the height is 12mm, and the thickness is 0.035mm. The upper base of the ninth patch 19 is 1mm, the lower base is 19mm, the two sides are 21mm, and the thickness is 0.035mm. The seventeenth patch 23 is 19mm long, 16mm wide, and 0.035mm thick. The dimensions (length×width×thickness) of the rectangular chamber 28 are 150mm×150mm×28.782mm. The dimensions (length×width×thickness) of each first metal reflector are 50mm×50mm×8mm. The dimensions (length×width×thickness) of each second metal reflector are 40mm×50mm×8mm. The dimensions (length×width×thickness) of the second fluid channel 37, the second fluid channel 39, the second fluid channel 41, and the second fluid channel 43 are 30mm×5mm×36.782mm.

[0031] In this embodiment, the polarization reconfigurable broadband cross-dipole antenna based on liquid metal is excited by coaxial feeding through a coaxial cable 47, and a 90° phase difference is achieved between a portion of the structure of the cross dipole 1 located on the upper end surface of the first dielectric substrate 4 and a portion of the structure located on the lower end surface of the first dielectric substrate 4, thereby achieving circular polarization. When liquid metal is filled inside the first first fluid channel K1 and the third first fluid channel K3, the surface current of the broadband cross-dipole antenna flows in a counterclockwise direction, that is, right-hand circular polarization. When inside the second first fluid channel K2 and the fourth first fluid channel K4, the surface current of the broadband cross-dipole antenna flows in a clockwise direction, that is, left-hand circular polarization. The eight second fluid channels are divided into two groups, the first second fluid channel 37, the third second fluid channel 39, the fifth second fluid channel 41 and the seventh second fluid channel 43 are the first group of second fluid channels, the second second fluid channel 38, the fourth second fluid channel 40, the sixth second fluid channel 42 and the eighth second fluid channel 44 are the second group of second fluid channels. When the first group of second fluid channels are filled with liquid metal, the first group of second fluid channels acts as a vertical reflector and produces a coupling effect with the cross dipole 1, and the broadband cross dipole antenna operates in the LHCP state. When the second group of second fluid channels are filled with liquid metal, the second group of second fluid channels acts as a vertical reflector and produces a coupling effect with the cross dipole 1, and the broadband cross dipole antenna operates in the RHCP state.

[0032] In order to verify the performance of the polarization reconfigurable broadband cross-dipole antenna based on liquid metal of the present invention, the software HFSS is used to design and simulate the polarization reconfigurable broadband cross-dipole antenna based on liquid metal of the present invention, wherein the polarization reconfigurable broadband cross-dipole antenna based on liquid metal of the present invention is |S| 11 | and the axis ratio simulation results are shown in the figure Figure 6 As shown, the simulation results of the efficiency and gain of the polarization reconfigurable broadband cross dipole antenna based on liquid metal in the LHCP state and the RHCP state of the present invention are as follows: Figure 7 Analysis Figure 6 and Figure 7It can be seen that the impedance bandwidth of the polarization reconfigurable broadband cross dipole antenna based on liquid metal of the present invention when working in the LHCP state is 77.45% (1.25-2.83GHz), the axial ratio bandwidth is 63.48% (1.43-2.76GHz), and the gain peak is 12.19dBic; the impedance bandwidth of the polarization reconfigurable broadband cross dipole antenna based on liquid metal of the present invention when working in the RHCP state is 78.34% (1.25-2.86GHz), the axial ratio bandwidth is 63.18% (1.44-2.77GHz), and the gain peak is 12.19dBic. It can be seen that under different polarization states, the polarization reconfigurable broadband cross dipole based on liquid metal of the present invention has a larger bandwidth and higher gain.

[0033] In summary, the liquid metal-based polarization reconfigurable broadband cross-dipole antenna of the present invention utilizes liquid metal to achieve polarization reconfiguration and has good circular polarization characteristics, which not only successfully expands its impedance bandwidth and axial ratio bandwidth, but also ensures broadband and high gain performance.

Claims

1. A polarization reconfigurable broadband cross-dipole antenna based on liquid metal, characterized in that The invention comprises a cross dipole, a parasitic patch structure and a metal reflection cavity structure. The cross dipole is loaded with four first fluid channels. By filling different first fluid channels among the four first fluid channels with liquid metal, the left-hand circular polarization or right-hand circular polarization of the broadband cross dipole antenna can be achieved. The parasitic patch structure is used to couple with the cross dipole to extend the current path on the cross dipole, thereby exciting a new resonance point to widen the bandwidth. The metal reflection cavity structure has eight second fluid channels. By filling the eight second fluid channels with liquid metal to form a vertical reflection plate, a coupling effect is generated with the cross dipole, so that the bandwidth of the broadband cross dipole antenna is biased toward a lower frequency band, the impedance bandwidth and axial ratio bandwidth of the broadband cross dipole antenna are expanded, and the directional radiation capability of the broadband cross dipole antenna is improved, thereby significantly improving the gain performance of the broadband cross dipole antenna.

2. The polarization reconfigurable broadband cross-dipole antenna based on liquid metal according to claim 1, characterized in that The invention also includes a first dielectric substrate, which is in the shape of a rectangular parallelepiped. The length direction of the first dielectric substrate is taken as the left-right direction, the width direction is taken as the front-back direction, and the thickness direction is taken as the up-down direction. The length of the first dielectric substrate is equal to its width. The straight line where the center line of the first dielectric substrate in the up-down direction is located is called the first center line. The plane that makes the first dielectric substrate front-back symmetrical is called the first symmetry plane. The plane that makes the first dielectric substrate left-right symmetrical is called the second symmetry plane. The cross dipole includes 4 metal radiation patches, 2 annular metal sheets and 4 metal connecting sheets. The 4 metal radiation patches are respectively called the first radiation patch, the second radiation patch, the third radiation patch and the fourth radiation patch. The 2 annular metal sheets are respectively called the first annular sheet and the second annular sheet. The 4 metal connecting sheets are respectively called the first connecting sheet, the second connecting sheet, the third connecting sheet and the fourth connecting sheet. The first annular sheet is attached to the upper surface of the first dielectric substrate, and its center is located on the first center line. The first radiation patch and the second radiation patch are The first radiating patch is attached to the upper surface of the first dielectric substrate, and if the first radiating patch is rotated 90° in the clockwise direction with the first center line as the axis, it will completely overlap with the second radiating patch; the first radiating patch includes an isosceles trapezoidal metal patch and two metal filling sheets, the upper and lower bases of the isosceles trapezoidal metal patch both extend in the front-to-back direction, and the upper base is located on the right side of the lower base, the upper base of the isosceles trapezoidal metal patch is circumscribed with the outer circumference of the first annular sheet, and the two metal filling sheets are located on the isosceles trapezoidal metal patch. Between the upper base of the patch and the first circular ring piece, and distributed on the front and rear sides of the tangent point between the upper base of the isosceles trapezoidal metal patch and the first circular ring piece, if the two waists of the isosceles trapezoidal metal patch extend toward the first circular ring piece until they intersect with the first circular ring piece, at this time, the extended sections of the two waists of the isosceles trapezoidal metal patch, the upper base of the isosceles trapezoidal metal patch and the outer circumference of the first circular ring piece will enclose two areas, and the two metal filling sheets are located in the two areas one by one, and the two areas are completely filled;The first radiation patch is front-to-back symmetrical about the first symmetry plane, and the second radiation patch is left-to-right symmetrical about the second symmetry plane. A waist of the isosceles trapezoidal metal patch of the first radiation patch located on the front side of the first symmetry plane is called its front waist, and a waist of the isosceles trapezoidal metal patch of the second radiation patch located on the left side of the second symmetry plane is called its left waist. If the front waist of the isosceles trapezoidal metal patch of the first radiation patch extends toward the first circular ring piece, it will intersect with the first circular ring piece, and the intersection is called the first intersection. The left waist of the isosceles trapezoidal metal patch of the second radiation patch extends toward the first circular ring piece and intersects with the first circular ring piece, and the intersection is called the second intersection. Starting from the first intersection, a part of the first circular ring piece is cut off in the clockwise direction to the second intersection to form a first notch; The third radiation patch and the fourth radiation patch are both attached to the lower surface of the first dielectric substrate. If the first radiation patch is rotated 180° in the clockwise direction with the first center line as the axis and then mapped to the lower surface of the first dielectric substrate, it will completely overlap with the third radiation patch. If the third radiation patch is rotated 90° in the clockwise direction with the first center line as the axis, it will completely overlap with the fourth radiation patch. The second annular sheet is attached to the lower surface of the first dielectric substrate. If the first annular sheet is mapped to the lower surface of the first dielectric substrate, it will completely overlap with the second annular sheet. A second notch is provided on the second annular sheet. If the first notch is rotated 180° in the clockwise direction with the first center line as the axis and then mapped to the lower surface of the first dielectric substrate, it will completely overlap with the second notch. The first connecting sheet and the second connecting sheet are both attached to the upper surface of the first dielectric substrate and are located inside the first annular sheet. The first connecting sheet is square and its center is aligned with the first connecting sheet. The center of a circular ring piece coincides, one of the two adjacent sides of the first connecting piece extends in the left-right direction and the other extends in the front-back direction, the side length of the first connecting piece is equal to the upper base length of the isosceles trapezoidal metal patch of the first radiation patch, and the second connecting piece is located on the left side of the first connecting piece. If the two opposite sides of the first connecting piece extending in the left-right direction are both extended to the left to intersect with the first circular ring piece, at this time, the extension lines of the two opposite sides of the first connecting piece extending in the left-right direction, the inner circumference of the first circular ring piece and the left side of the first connecting piece will enclose an area, and the second connecting piece is located inside the area and completely fills the area; the third connecting piece and the fourth connecting piece are both attached to the lower surface of the first dielectric substrate. If the first connecting piece is mapped to the lower surface of the first dielectric substrate, it will completely overlap with the third connecting piece. If the second connecting piece is rotated 180° clockwise with the first center line as the axis and then mapped to the lower surface of the first dielectric substrate, it will completely overlap with the fourth connecting piece.

3. The polarization reconfigurable broadband cross-dipole antenna based on liquid metal according to claim 2, characterized in that The parasitic patch structure includes three groups of metal patches, which are respectively referred to as the first group of metal patches, the second group of metal patches and the third group of metal patches; the first group of metal patches includes 8 metal patches, all of which are isosceles trapezoidal in shape, and the 8 metal patches are respectively referred to as the first patch, the second patch, the third patch, the fourth patch, the fifth patch, the sixth patch, the seventh patch and the eighth patch, the first patch, the second patch, the third patch and the fourth patch are attached to the upper surface of the first dielectric substrate, the fifth patch, the sixth patch, the seventh patch and the eighth patch are attached to the lower surface of the first dielectric substrate, the first patch is located on the left side of the first radiation patch, and its upper base and lower base both extend in the front-to-back direction, the lower base of the first patch is located on the right side of its upper base, and there is a section between the two. A distance is provided between the upper bottom of the first patch and the plane where the left end surface of the first dielectric substrate is located. The first patch is front-to-back symmetrical about the first symmetry plane. If the first patch is rotated 90° in a clockwise direction with the first center line as the axis, it will completely overlap with the second patch. If the first patch is rotated 180° in a clockwise direction with the first center line as the axis, it will completely overlap with the third patch. If the first patch is rotated 270° in a clockwise direction with the first center line as the axis, it will completely overlap with the fourth patch. If the first patch, the second patch, the third patch and the fourth patch are all mapped to the lower surface of the first dielectric substrate, they will overlap with the fifth patch, the sixth patch, the seventh patch and the eighth patch one by one.The second group of metal patches includes 8 metal patches, all of which are isosceles trapezoidal in shape. The 8 metal patches are respectively referred to as the ninth patch, the tenth patch, the eleventh patch, the twelfth patch, the thirteenth patch, the fourteenth patch, the fifteenth patch and the sixteenth patch. The ninth patch, the tenth patch, the eleventh patch and the twelfth patch are all attached to the upper surface of the first dielectric substrate. The thirteenth patch, the fourteenth patch, the fifteenth patch and the sixteenth patch are all attached to the lower surface of the first dielectric substrate. The ninth patch is located between the first radiation patch and the second radiation patch and is not in contact with the first radiation patch and the second radiation patch. The ninth patch is formed from the left front corner to the right rear corner of the first dielectric substrate. The diagonal surface is symmetrical about the plane where the ninth patch is located, the upper base of the ninth patch is close to the first annular patch relative to its lower base, if the ninth patch is rotated 90° in the clockwise direction with the first center line as the axis, it will completely overlap with the tenth patch, if the ninth patch is rotated 180° in the clockwise direction with the first center line as the axis, it will completely overlap with the eleventh patch, if the ninth patch is rotated 270° in the clockwise direction with the first center line as the axis, it will completely overlap with the twelfth patch, if the ninth patch, the tenth patch, the eleventh patch and the twelfth patch are all mapped to the lower surface of the first dielectric substrate, they will overlap with the thirteenth patch, the fourteenth patch, the fifteenth patch and the sixteenth patch one by one;The third group of metal patches includes 8 metal patches, all of which are rectangular in shape. The 8 metal patches are respectively called the 17th patch, the 18th patch, the 19th patch, the 20th patch, the 21st patch, the 22nd patch, the 23rd patch and the 24th patch. The 17th patch, the 18th patch, the 19th patch and the 20th patch are all attached to the upper surface of the first dielectric substrate. The 21st patch, the 22nd patch, the 23rd patch and the 24th patch are all attached to the lower surface of the first dielectric substrate. The 17th patch is located on the outside of the 9th patch, and one side of it completely overlaps with the bottom of the 9th patch. The 17th patch is at the left front corner of the first dielectric substrate. The plane of the diagonal surface formed by the right rear corner is symmetrical. If the 17th patch is rotated 90° clockwise with the first center line as the axis, it will completely overlap with the 18th patch. If the 17th patch is rotated 180° clockwise with the first center line as the axis, it will completely overlap with the 19th patch. If the 17th patch is rotated 270° clockwise with the first center line as the axis, it will completely overlap with the 20th patch. If the 17th patch, the 18th patch, the 19th patch and the 20th patch are all mapped to the lower surface of the first dielectric substrate, they will overlap with the 21st patch, the 22nd patch, the 23rd patch and the 24th patch one by one. ; 4. The polarization reconfigurable broadband cross-dipole antenna based on liquid metal according to claim 2, characterized in that The metal reflection cavity structure includes a metal reflection wall, four first metal reflection plates and four second metal reflection plates. The metal reflection wall is formed by opening a rectangular cavity penetrating from top to bottom on a metal rectangular block. The metal rectangular block is called a first metal rectangular block. The length direction of the first metal rectangular block is along the left-right direction, the width direction is along the front-back direction, the thickness direction is along the up-down direction, and its length is equal to its width. The length direction of the rectangular cavity is along the left-right direction, the width direction is along the front-back direction, the thickness direction is along the up-down direction, and its length is equal to its width. The rectangular cavity The center line of the chamber along the up-down direction coincides with the center line of the first metal cuboid block along the up-down direction, the length of the cuboid chamber is less than the length of the first metal cuboid block, and the thickness of the cuboid chamber is equal to the thickness of the first metal cuboid block; the first metal cuboid block is located below the first dielectric substrate, the center line of the first metal cuboid block along the up-down direction coincides with the first center line, the length of the first dielectric substrate is less than the length of the cuboid chamber, and the width of the first dielectric substrate is less than the width of the cuboid chamber;Each first metal reflector is in the shape of a cuboid, and its length direction is along the left-right direction, its width direction is along the front-back direction, and its thickness direction is along the up-down direction. The length of each first metal reflector is equal to its width, and its thickness is less than the thickness of the cuboid chamber, and twice its length is less than the length of the cuboid chamber. The four first metal reflectors are fixedly arranged inside the cuboid chamber, the front end face of the first first metal reflector is in the same plane as the front end face of the cuboid chamber, the left end face of the first first metal reflector is in the same plane as the left end face of the cuboid chamber, and the first The lower end surface of the first metal reflector is located in the same plane as the lower end surface of the rectangular chamber, the first first metal reflector and the second first metal reflector are symmetrical about the second symmetry plane, the second first metal reflector and the third first metal reflector are symmetrical about the first symmetry plane, the first first metal reflector and the fourth first metal reflector are symmetrical about the first symmetry plane, each second metal reflector is in the shape of a rectangular parallelepiped, the four second metal reflectors are fixedly arranged inside the rectangular chamber, the first second metal reflector is located above the first first metal reflector. The first metal reflector is between the first metal reflector and the second first metal reflector, the length direction of the first second metal reflector is along the front-to-back direction, the width direction is along the left-right direction, and the thickness direction is along the up-down direction. The front end face of the first second metal reflector is in the same plane as the front end face of the rectangular chamber, the rear end face of the first second metal reflector is in the same plane as the rear end face of the first first metal reflector, the upper end face of the first second metal reflector is in the same plane as the upper end face of the first first metal reflector, the lower end face of the first second metal reflector is in the same plane as the lower end face of the first first metal reflector, and the first The second metal reflector is bilaterally symmetrical about the second symmetry plane, the sum of the width of the first second metal reflector and twice the length of the first first metal reflector is less than the length of the rectangular chamber, if the first second metal reflector is rotated 90 degrees clockwise around the first center line, it will completely overlap with the second second metal reflector, if the first second metal reflector is rotated 90 degrees counterclockwise around the first center line, it will completely overlap with the fourth second metal reflector, and the first second metal reflector and the third second metal reflector are front-to-back symmetrical about the first symmetry plane;The first second fluid channel is fixedly arranged in the gap between the first first metal reflector and the first second metal reflector. The first second fluid channel is realized by opening a cavity for filling liquid metal inside a rectangular block made of Watershed material. The rectangular block is called the first rectangular block. The length direction of the first rectangular block is along the front-to-back direction, the width direction is along the left-to-right direction, and the thickness direction is along the up-down direction. The front end face of the first rectangular block and the front end face of the rectangular chamber are located in the same plane, the upper end face of the first rectangular block and the upper end face of the rectangular chamber are located in the same plane, the lower end face of the first rectangular block and the lower end face of the rectangular chamber are located in the same plane, and the left end face of the first rectangular block is located at the right end face of the first first metal reflector. The end faces are in a fitted state, the right end face of the first rectangular block is in a fitted state with the left end face of the first second metal reflector, the length of the first rectangular block is less than the length of the first first metal reflector, a second second fluid channel is fixedly provided in the gap between the first second metal reflector and the second first metal reflector, the second second fluid channel is realized by providing an outer layer made of Watershed material on the outside of a rectangular metal block, the rectangular metal block is called the second rectangular metal block, the first rectangular block can completely overlap with the second rectangular metal block after being translated to the right, the outer layer wraps the part of the second rectangular metal block located above the plane where the upper end face of the second first metal reflector is located, and a gap for filling liquid metal is formed between the two;A third second fluid channel is arranged at the gap between the second first metal reflector and the second second metal reflector, a fourth second fluid channel is arranged at the gap between the second second metal reflector and the third first metal reflector, a fifth second fluid channel is arranged at the gap between the third first metal reflector and the third second metal reflector, a sixth second fluid channel is arranged at the gap between the third second metal reflector and the fourth first metal reflector, a seventh second fluid channel is arranged at the gap between the fourth second metal reflector and the fourth first metal reflector, an eighth second fluid channel is arranged at the gap between the first first metal reflector and the fourth second metal reflector, the first second metal reflector, the first second fluid channel and the second second fluid channel are taken as the first combined structure, the second second metal reflector, The third second fluid channel and the fourth second fluid channel are used as the second combination structure, the third second metal reflector, the fifth second fluid channel and the sixth second fluid channel are used as the third combination structure, and the fourth second metal reflector, the seventh second fluid channel and the eighth second fluid channel are used as the fourth combination structure. If the first combination structure is rotated 90 degrees clockwise around the first center line, it will completely overlap with the second combination structure. If the first combination structure is rotated 90 degrees counterclockwise around the first center line, it will completely overlap with the fourth combination structure. If the first combination structure is rotated 180 degrees clockwise around the first center line, it will completely overlap with the third combination structure. The lower end surface of the first dielectric substrate is fixed on the upper end surfaces of the eight second fluid channels, and the first dielectric substrate is supported by the eight second fluid channels. ; 5. The polarization reconfigurable broadband cross-dipole antenna based on liquid metal according to claim 4, characterized in that The invention also includes a second dielectric substrate, which is located below the metal reflective cavity structure. The length direction of the second dielectric substrate is along the left-right direction, the width direction is along the front-back direction, and the thickness direction is along the up-down direction. The front end face of the second dielectric substrate is located in the same plane as the front end face of the first dielectric substrate, the rear end face of the second dielectric substrate is located in the same plane as the rear end face of the first dielectric substrate, the left end face of the second dielectric substrate is located in the same plane as the left end face of the first dielectric substrate, and the right end face of the second dielectric substrate is located in the same plane as the right end face of the first dielectric substrate. The upper end face of the second dielectric substrate is printed with a metal ground, the metal ground completely covers the upper surface of the second dielectric substrate, and the metal ground is bonded to the lower end face of the first metal rectangular block.

6. The polarization reconfigurable broadband cross-dipole antenna based on liquid metal according to claim 5, characterized in that It also includes a coaxial cable, which passes through the center of the first dielectric substrate, the center of the second dielectric substrate, the center of the first connecting piece and the center of the third connecting piece in sequence, the inner conductor of the coaxial cable is connected to the first circular ring piece, the outer conductor of the coaxial cable is connected to the second circular ring piece, and the outer conductor of the coaxial cable is welded to the second dielectric substrate.

7. The polarization reconfigurable broadband cross-dipole antenna based on liquid metal according to claim 2, characterized in that The first first fluid channel is realized by arranging an outer layer on the outer side of the second connecting piece, the outer layer material is Watershed, and a gap for filling liquid metal is formed between the outer layer and the second connecting piece; the second first fluid channel is arranged inside the first annular piece, and is formed by opening a cavity for filling liquid metal inside a sheet body made of Watershed material. If the second connecting piece is rotated 90 degrees clockwise around the first center line, it will completely overlap with the sheet body. The third first fluid channel is realized by arranging an outer layer on the outer side of the fourth connecting piece, the outer layer material is Watershed, and a gap for filling liquid metal is formed between the outer layer and the fourth connecting piece; the fourth first fluid channel is arranged inside the second annular piece, and is formed by opening a cavity for filling liquid metal inside a sheet body made of Watershed material. If the fourth connecting piece is rotated 90 degrees clockwise around the first center line, it will completely overlap with the sheet body.

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