Microfluidic antenna with reconfigurable frequency and directivity pattern

Abstract

Disclosed in the present invention is a microfluidic antenna with a reconfigurable frequency and directivity pattern. The microfluidic reconfigurable antenna consists of six parts, which are a metal floor, a metal radiation patch, a top reflector, a middle dielectric substrate, a coaxial feeder line penetrating the dielectric substrate, and an annular microfluidic channel packaged with a magnetic liquid metal column, respectively. Different modes can be excited by means of manipulating the length of the magnetic liquid metal column in the microfluidic channel, thus realizing the switching between radiation frequency bands; an antenna directivity pattern is reconfigured by means of manipulating the position of the magnetic liquid metal column; the microfluidic antenna involves main beam switching in a total of ten azimuthal planes within three bands of 5.98-6.10 GHz, 6.08-6.23 GHz and 6.85-7.47 GHz, and the maximum gain values in the states of the three bands are 8.5 dB, 7.4 dB and 8.1 dB, respectively; and the front-to-back ratios are 13 dB, 17 dB and 16 dB, respectively. The present invention has the characteristics of a simple structure, easy integration, a good performance, no introduction of extra distortion, low noise, a high-power operation capability and flexible application.

Description

A frequency and pattern reconfigurable microfluidic antenna Technical Field

[0001] The invention relates to a frequency and directional pattern reconfigurable microfluidic antenna, belonging to the technical field of communications. Background Art

[0002] In wireless communication systems, antennas transmit or receive electromagnetic waves. Proper antenna design is a key indicator of the quality of a wireless communication system. In everyday civilian applications, a range of wireless communication technologies have emerged, including mobile communications, navigation and satellite positioning, Wi-Fi, and Bluetooth. As wireless frequency bands increase, the radio wave propagation environment becomes more complex and dynamic. However, carrier platform space is limited. Integrating antennas with different operating modes not only increases the platform burden but also causes electromagnetic interference between antennas. Antenna technology faces the challenge of multifunctional integration. To address these thorny issues, reconfigurable antennas have emerged. The 6 GHz band (5925 MHz to 7125 MHz) is a key component of the intermediate frequency band (IF), combining the coverage advantages of low-frequency bands with the capacity advantages of high-frequency bands. It holds great promise for future wireless communication systems. Traditional reconfigurable antennas typically achieve reconfigurability using RF switches, such as varactor diodes, PIN diodes, or microelectromechanical systems. However, RF switches cannot withstand high microwave power and exhibit nonlinear effects. Loading active devices requires an external DC bias circuit, which adds complexity to the antenna structure. There are also methods to control the antenna radiation performance by using tunable materials, photoconductive switches or physical controllers for mechanical rotation, which will result in a short service life of the antenna and a bulky overall structure. Summary of the Invention

[0003] The purpose of the present invention is to address the defects and shortcomings of the above-mentioned existing technologies and provide a microfluidic antenna with reconfigurable frequency and radiation pattern. By using microfluidic driving technology to manipulate the length and position of the magnetic liquid metal column, the connection area and connection position of the circular patch and the parasitic patch group can be controlled, thereby achieving the purpose of reconfigurable antenna frequency and radiation pattern, integrating multiple functions into one.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a frequency and radiation pattern reconfigurable microfluidic antenna, the microfluidic antenna includes a top reflector 13, a middle dielectric substrate 5, a metal patch located on the upper surface of the dielectric substrate 5, an annular microchannel 4 encapsulated with a magnetic liquid metal column, and a metal floor 12 located on the lower surface of the dielectric substrate 5; the metal patch on the upper surface of the dielectric substrate 5 includes a middle circular patch 1 and a first parasitic patch group 6, a second parasitic patch group 7, a third parasitic patch group 8, a fourth parasitic patch group 9 and a fifth parasitic patch group 10 separated and placed in five directions, and the first parasitic patch group 6, the second parasitic patch group 7, the third parasitic patch group 8, The fourth parasitic patch group 9 and the fifth parasitic patch group 10 are connected to the circular patch 1 in the middle through the flowable magnetic liquid metal column in the annular microchannel 4. The first parasitic patch group 6, the second parasitic patch group 7, the third parasitic patch group 8, the fourth parasitic patch group 9 and the fifth parasitic patch group 10 are all composed of fan-shaped parasitic patches 2 and stepped parasitic patches 3. The first parasitic patch group 6, the second parasitic patch group 7, the third parasitic patch group 8, the fourth parasitic patch group 9 and the fifth parasitic patch group 10 are rotationally symmetrically placed in a ring. The metal floor 12 covers the lower surface of the dielectric substrate 5. The radius of the metal floor 12 is 35 mm. The microfluidic antenna is fed by a coaxial line running through the dielectric substrate 5.

[0005] Furthermore, the radius of the circular patch 1 is 5.5 mm, the inner and outer radii of the fan-shaped parasitic patch 2 are 6.5 mm and 10 mm respectively, and the stepped parasitic patch 3 includes four rectangular metal patches with length and width of 6 mm and 3.9 mm, 16 mm and 4 mm, 18 mm and 4 mm, and 20 mm and 4 mm respectively, wherein the long side of the rectangular metal patch partially connected to the fan-shaped parasitic patch 2 is cut into an arc shape.

[0006] Furthermore, the rotation angle between the adjacent first parasitic patch group 6 , second parasitic patch group 7 , third parasitic patch group 8 , fourth parasitic patch group 9 and fifth parasitic patch group 10 is 72°, and the interval between adjacent sector-shaped parasitic patches 2 is 1 mm.

[0007] Furthermore, the annular microchannel 4 is placed in the gap between the circular patch 1 and the fan-shaped parasitic patch 2. The inner and outer radii of the annular microchannel 4 are 5.5 mm and 6.5 mm respectively, the width is 1 mm, and the thickness is 0.5 mm. The inner and outer radii of the top reflector 13 are 30 mm and 33 mm respectively, the width is 3 mm, and the height is 10 mm.

[0008] Furthermore, the magnetic liquid metal column is a mixture of liquid metal and magnetic particles, has magnetic response characteristics, and the liquid metal is EGaln.

[0009] Furthermore, the length of the magnetic liquid metal column is controlled by injecting or extracting liquid through a syringe. Liquid metal columns of different lengths respectively connect the circular patch 1 to one group of parasitic patches, two groups of parasitic patches, or three groups of parasitic patches, thereby reconstructing the three frequency bands of the antenna. By moving a strong magnet above the annular microchannel 4, the magnetic liquid metal column can be driven to different positions, and then connected to the parasitic patch groups at different positions, thereby reconstructing the directional pattern of the antenna azimuth plane.

[0010] Furthermore, the present invention controls the length of the magnetic liquid metal column injected into the microchannel, controls the position of the magnetic liquid metal column by a strong magnet, and then connects parasitic patch groups of different numbers and positions to achieve dynamic regulation of the operating frequency band and radiation pattern. The microfluidic antenna of the present invention has three frequency band switching states, and the maximum beam pointing of the microfluidic antenna has ten switching states in the azimuth plane, including:

[0011] State 1: The middle circular patch 1 is connected to only one set of parasitic patches through the magnetic liquid metal column, as shown in Figure 4(a). At this time, the antenna operating frequency band is 5.98-6.10 GHz. The magnetic liquid metal column is driven to connect five sets of parasitic patches at different positions, and the main radiation direction changes in sequence. As shown in Figure 5, the main radiation direction has five reconstruction angles: θ = 52°, θ=52°, θ=52°, θ=52°, θ=52°,

[0012] State 2: The middle circular patch 1 is connected to two adjacent parasitic patches via a magnetic liquid metal column, as shown in Figure 6. At this time, the antenna operates in the 6.08-6.23 GHz frequency band. The magnetic liquid metal column is driven to connect two adjacent parasitic patch groups at different positions. The main radiation direction also has five reconstruction angles: θ = 54°, θ=54°, θ=54°, θ=54°, θ=54°,

[0013] State 3: The middle circular patch 1 is connected to three adjacent parasitic patches via a magnetic liquid metal column, as shown in Figure 7. At this time, the antenna operates in the frequency band of 6.85 to 7.47 GHz. The magnetic liquid metal column is driven to connect three adjacent parasitic patches at different positions. The main radiation direction has five reconstruction angles: θ = 52°, θ=52°, θ=52°, θ=52°, θ=52°,

[0014] Furthermore, the dielectric substrate 5 is a polytetrafluoroethylene plate with a dielectric constant of 2.55, and the top reflector 13 and the metal patch are both copper Cu.

[0015] Furthermore, the dielectric substrate 5 is a circle with a radius of 35 mm and a thickness of 2 mm. Beneficial effects:

[0016] 1. The present invention designs the antenna's radiating surface into a rotationally symmetrical pattern, effectively achieving the antenna's frequency characteristics and 360° beam steering. The antenna's operating frequency covers a wide range of the 6 GHz intermediate frequency band, promising broad application prospects in future wireless communication systems.

[0017] 2. The present invention combines microfluidic technology to achieve frequency reconstruction and pattern reconstruction of the antenna.

[0018] 3. Compared with semiconductor or MEMS reconfigurable antennas, the present invention has a simple structure, small size, easy integration, supports high power input, high peak gain, high front-to-back ratio, does not introduce additional distortion, and is multifunctional and flexible in application.

[0019] 4. The liquid metal used in the present invention has excellent electrical conductivity and flowability. Using microfluidic technology to drive the liquid metal can solve the problems of traditional RF control components, such as antenna nonlinear distortion caused by the need for a DC bias circuit, inability to operate at high power, complex structure, and low processing power. This provides a new approach for the multifunctional integrated integration of antennas in wireless communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic diagram of the upper surface structure of a medium substrate of a frequency and directional pattern reconfigurable microfluidic antenna according to the present invention.

[0021] Label description: 1-circular patch, 2-sector annular parasitic patch, 3-stepped parasitic patch, 4-annular microchannel, 5-dielectric substrate, 6-first parasitic patch group, 7-second parasitic patch group, 8-third parasitic patch group, 9-fourth parasitic patch group, 10-fifth parasitic patch group.

[0022] FIG2 is a schematic diagram of the lower surface structure of a medium substrate of a frequency and directional pattern reconfigurable microfluidic antenna according to the present invention.

[0023] Marking instructions: 11-feeding point, 12-metal floor.

[0024] FIG3 is a three-dimensional schematic diagram of the overall structure of a frequency and directional pattern reconfigurable microfluidic antenna according to the present invention.

[0025] Marking Description: 13-Top reflector.

[0026] FIG4 is a schematic diagram of the beam steering mechanism of a frequency and pattern reconfigurable microfluidic antenna in state 1 of the present invention.

[0027] 4(a), 4(b), 4(c), 4(d), and 4(e) are schematic diagrams of the middle circular patch being connected to only one set of parasitic patches in five radiation direction states.

[0028] Marking Description: 14-Magnetic liquid metal column.

[0029] FIG5 is a diagram showing five directional modes in the azimuth plane of a state 1 of a frequency and directional pattern reconfigurable microfluidic antenna according to the present invention.

[0030] FIG6 is a schematic diagram of the beam steering mechanism of a frequency and pattern reconfigurable microfluidic antenna in state 2 of the present invention.

[0031] 6(a), 6(b), 6(c), 6(d), and 6(e) are schematic diagrams of the middle circular patch connecting two adjacent groups of parasitic patches in five radiation direction states.

[0032] FIG7 is a schematic diagram of the beam steering mechanism of a frequency and pattern reconfigurable microfluidic antenna in state 3 of the present invention.

[0033] 7(a), 7(b), 7(c), 7(d), and 7(e) are schematic diagrams of the middle circular patch connecting three adjacent groups of parasitic patches in five radiation direction states.

[0034] FIG8 is a graph showing return loss of a frequency and pattern reconfigurable microfluidic antenna in operation in states 1, 2, and 3 according to the present invention.

[0035] FIG9 shows a microfluidic antenna with reconfigurable frequency and pattern in state 1 of the present invention, with the maximum radiation direction being θ=52°. Radiation pattern when .

[0036] FIG10 shows a microfluidic antenna with reconfigurable frequency and pattern in state 2 of the present invention, with a maximum radiation direction of θ=54°. Radiation pattern when .

[0037] FIG11 shows a microfluidic antenna with reconfigurable frequency and pattern in state 3 of the present invention, with the maximum radiation direction being θ=52°. Radiation pattern when . DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings.

[0039] As shown in Figures 1 to 3, the present invention provides a frequency and pattern reconfigurable microfluidic antenna, which includes a top reflector 13, a dielectric substrate 5 in the middle, a metal patch located on the upper surface of the dielectric substrate 5, an annular microchannel 4 encapsulated with a magnetic liquid metal column, and a circular metal floor 12 located on the lower surface of the dielectric substrate 5; the metal patch on the upper surface of the dielectric substrate 5 includes a central circular radiation patch 1 and a first parasitic patch group 6, a second parasitic patch group 7, a third parasitic patch group 8, a fourth parasitic patch group 9 and a fifth parasitic patch group 10 separated and placed in five directions, and the first parasitic patch group 6, the second parasitic patch group 7, the third parasitic patch group 8, the fourth parasitic patch group 9 and the fifth parasitic patch group 10 are arranged in a direction of rotation. The parasitic patch group 9 and the fifth parasitic patch group 10 are connected to the circular patch 1 in the middle through the flowable magnetic liquid metal column in the annular microchannel 4. The first parasitic patch group 6, the second parasitic patch group 7, the third parasitic patch group 8, the fourth parasitic patch group 9 and the fifth parasitic patch group 10 are all composed of fan-shaped parasitic patches 2 and stepped parasitic patches 3. The first parasitic patch group 6, the second parasitic patch group 7, the third parasitic patch group 8, the fourth parasitic patch group 9 and the fifth parasitic patch group 10 are rotationally symmetrically placed in a ring. The metal floor 12 covers the lower surface of the dielectric substrate 5. The radius of the metal floor 12 is 35 mm. The microfluidic antenna is fed by a coaxial line running through the dielectric substrate 5.

[0040] The radius of the circular patch 1 of the present invention is 5.5 mm, the inner and outer radii of the fan-shaped parasitic patch 2 are 6.5 mm and 10 mm respectively, and the stepped parasitic patch 3 includes four rectangular metal patches with length and width of 6 mm and 3.9 mm, 16 mm and 4 mm, 18 mm and 4 mm, and 20 mm and 4 mm respectively, wherein the long side of the rectangular metal patch partially connected to the fan-shaped parasitic patch 2 is cut into an arc shape.

[0041] The rotation angle between adjacent parasitic patch groups of the first parasitic patch group 6, the second parasitic patch group 7, the third parasitic patch group 8, the fourth parasitic patch group 9 and the fifth parasitic patch group 10 of the present invention is 72°, and the interval between adjacent sector-shaped parasitic patches 2 is 1 mm.

[0042] The annular microchannel 4 described in the present invention is placed in the gap between the circular patch 1 and the fan-shaped parasitic patch 2. The inner and outer radii of the annular microchannel 4 are 5.5 mm and 6.5 mm respectively, the width is 1 mm, and the thickness is 0.5 mm. The inner and outer radii of the top reflector 13 are 30 mm and 33 mm respectively, the width is 3 mm, and the height is 10 mm.

[0043] The magnetic liquid metal column of the present invention is a mixture of liquid metal (EGaln can be selected) and magnetic particles, and has magnetic response characteristics.

[0044] The length of the magnetic liquid metal column described in the present invention is controlled by injecting or extracting liquid through a syringe. Liquid metal columns of different lengths respectively connect the circular patch 1 to one group of parasitic patches, two groups of parasitic patches, or three groups of parasitic patches, thereby realizing the reconfiguration of the three frequency bands of the antenna; by moving a strong magnet above the annular microchannel 4, the magnetic liquid metal column can be driven to different positions, and then connected to the parasitic patch groups at different positions, thereby realizing the reconfiguration of the directional pattern of the antenna azimuth plane.

[0045] The dielectric substrate 5 of the present invention is a polytetrafluoroethylene plate with a dielectric constant of 2.55, and the top reflector 13 and the metal patch are both made of copper Cu.

[0046] The dielectric substrate 5 of the present invention is a circle with a radius of 35 mm and a thickness of 2 mm.

[0047] The present invention controls the length of the magnetic liquid metal column injected into the microchannel, and then controls the position of the magnetic liquid metal column through a strong magnet, thereby connecting different numbers and positions of parasitic patch groups to achieve dynamic control of the operating frequency band and radiation pattern. The antenna of the present invention has three reconfigurable frequency bands, and the maximum beam pointing of the antenna has ten reconfigurable directions in the azimuth plane, including:

[0048] State 1: The middle circular patch 1 is connected to only one set of parasitic patches through the magnetic liquid metal column, as shown in Figure 4. At this time, the antenna operating frequency band is 5.98-6.10 GHz. The magnetic liquid metal column is driven to connect to five sets of parasitic patches in different positions, and the main radiation direction changes in sequence. As shown in Figure 5, the main radiation direction has five reconstruction angles: θ = 52°, θ=52°, θ=52°, θ=52°, θ=52°,

[0049] State 2: The middle circular patch 1 is connected to two adjacent parasitic patches via a magnetic liquid metal column, as shown in Figure 6. At this time, the antenna operates in the 6.08-6.23 GHz frequency band. The magnetic liquid metal column is driven to connect two adjacent parasitic patch groups at different positions. The main radiation direction also has five reconstruction angles: θ = 54°, θ=54°, θ=54°, θ=54°, θ=54°,

[0050] State 3: The middle circular patch 1 is connected to three adjacent parasitic patches via a magnetic liquid metal column, as shown in Figure 7. At this time, the antenna operates in the frequency band of 6.85 to 7.47 GHz. The magnetic liquid metal column is driven to connect three adjacent parasitic patches at different positions. The main radiation direction has five reconstruction angles: θ = 52°, θ=52°, θ=52°, θ=52°, θ=52°,

[0051] Figure 8 shows the antenna's |S when operating in three frequency bands. 11 Simulation curves. When the antenna operates in state 1, the impedance bandwidth is 1.9% (5.98-6.10 GHz); when the antenna operates in state 2, the impedance bandwidth is 2.4% (6.08-6.23 GHz); and when the antenna operates in state 3, the impedance bandwidth is 8.6% (6.85-7.47 GHz).

[0052] Figures 9 to 11 show the directional radiation patterns of the antenna in state 1, state 2, and state 3, respectively. The maximum gain values ​​of the antenna in the three operating frequency bands are 8.5dB, 7.4dB, and 8.1dB, respectively; the front-to-back ratios are 13dB, 17dB, and 16dB, respectively. The present invention achieves good antenna frequency characteristics and beam steering characteristics within a 360° range through microfluidic technology. It covers a wide range of the intermediate frequency 6GHz band and has broad application prospects in future wireless communication systems. The present invention has a simple structure, is easy to integrate, has good performance, does not introduce additional distortion, has low noise, can operate at high power, and has flexible applications.

[0053] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. The specific embodiments and descriptions in the specification are merely intended to further illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A frequency and pattern reconfigurable microfluidic antenna, characterized in that: The microfluidic antenna comprises a top reflector (13), a dielectric substrate (5) in the middle, a metal patch located on the upper surface of the dielectric substrate (5), an annular microchannel (4) encapsulating a magnetic liquid metal column, and a metal floor (12) located on the lower surface of the dielectric substrate (5); the metal patch on the upper surface of the dielectric substrate (5) comprises a circular patch (1) in the middle and a first parasitic patch group (6), a second parasitic patch group (7), a third parasitic patch group (8), a fourth parasitic patch group (9) and a fifth parasitic patch group (10) arranged in five directions, and the first parasitic patch group (6), the second parasitic patch group (7), the third parasitic patch group (8), the fourth parasitic patch group (9) and the fifth parasitic patch group (10) are arranged in a manner that is consistent with the present invention. ) is connected to the circular patch (1) in the middle through the liquid metal that can flow in the annular microchannel (4); the first parasitic patch group (6), the second parasitic patch group (7), the third parasitic patch group (8), the fourth parasitic patch group (9) and the fifth parasitic patch group (10) are all composed of fan-shaped parasitic patches (2) and stepped parasitic patches (3); the first parasitic patch group (6), the second parasitic patch group (7), the third parasitic patch group (8), the fourth parasitic patch group (9) and the fifth parasitic patch group (10) are arranged in a rotationally symmetrical annular shape; the metal floor (12) covers the lower surface of the dielectric substrate (5); the radius of the metal floor (12) is 35 mm; and the microfluidic antenna is fed by a coaxial line that runs through the dielectric substrate (5); The length of the magnetic liquid metal column is controlled by injecting or extracting liquid through an injection tube. Liquid metal columns of different lengths respectively connect the circular patch (1) to one group of parasitic patches, two groups of parasitic patches or three groups of parasitic patches, thereby reconstructing three frequency bands of the antenna. The magnetic liquid metal column can be driven to different positions by moving a strong magnet above the annular microchannel (4), and then connected to the parasitic patch groups at different positions, thereby reconstructing the directional diagram of the antenna azimuth plane.

2. The frequency and pattern reconfigurable microfluidic antenna according to claim 1, characterized in that: The radius of the circular patch (1) is 5.5 mm, the inner and outer radii of the fan-shaped parasitic patch (2) are 6.5 mm and 10 mm respectively, and the stepped parasitic patch (3) comprises four rectangular metal patches with lengths and widths of 6 mm and 3.9 mm, 16 mm and 4 mm, 18 mm and 4 mm, and 20 mm and 4 mm respectively, wherein the long sides of the rectangular metal patches connected to the fan-shaped parasitic patches (2) are cut into arc shapes.

3. The frequency and pattern reconfigurable microfluidic antenna according to claim 1, characterized in that: The rotation angle between the adjacent first parasitic patch group (6), the second parasitic patch group (7), the third parasitic patch group (8), the fourth parasitic patch group (9) and the fifth parasitic patch group (10) is 72°, and the interval between the adjacent sector-shaped parasitic patches (2) is 1 mm.

4. The frequency and pattern reconfigurable microfluidic antenna according to claim 1, characterized in that: The annular microchannel (4) is placed in the gap between the circular patch (1) and the fan-shaped parasitic patch (2). The inner and outer radii of the annular microchannel (4) are 5.5 mm and 6.5 mm respectively, the width is 1 mm, and the thickness is 0.5 mm. The inner and outer radii of the top reflector (13) are 30 mm and 33 mm respectively, the width is 3 mm, and the height is 10 mm.

5. The frequency and pattern reconfigurable microfluidic antenna according to claim 1, characterized in that: The magnetic liquid metal column is a mixture of liquid metal and magnetic particles and has magnetic response characteristics. The liquid metal is EGaln.

6. The frequency and pattern reconfigurable microfluidic antenna according to claim 1, characterized in that: The dielectric substrate (5) is a polytetrafluoroethylene plate with a dielectric constant of 2.55, and the top reflector (13) and the metal patch are both copper Cu.

7. The frequency and pattern reconfigurable microfluidic antenna according to claim 1, characterized in that: The dielectric substrate (5) is a cylinder with a radius of 35 mm and a thickness of 2 mm.

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