Ultra-wideband frequency and directional diagram reconfigurable double-arm helical antenna based on liquid metal

Abstract

The invention discloses a liquid metal-based ultra-wideband frequency and directional diagram reconfigurable double-arm helical antenna, which comprises an antenna radiation unit, a circular metal reflection back cavity, a liquid metal injection and discharge port, a feed balun structure and liquid metal, and is characterized in that the antenna radiation unit is provided with two helical arm-shaped micro-channels for filling the liquid metal. The antenna radiator structure is changed by utilizing the characteristic that the liquid metal can flow at room temperature, and ultra-wideband frequency polarization reconfiguration within the range of 0.2-20GHz is realized. The length of the radiation arm of the helical antenna is controlled by the liquid metal, the frequency of the antenna is reconfigurable, the filling state of the two arms of the helical antenna is controlled by the liquid metal, the beam pointing switching of the antenna pattern can be realized, and the reconfigurable pattern is realized. Compared with a traditional antenna, the liquid metal antenna can realize continuous tuning in an ultra-wideband range; and secondly, due to the fact that the liquid metal has high viscosity, stability is high, and repeatability is high.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, specifically relating to an ultra-wideband frequency and pattern reconfigurable dual-arm helical antenna based on liquid metal. Background Technology

[0002] Currently, gallium-based liquid metals exhibit significant advantages in the field of radio frequency antennas. Their core characteristic is reconfigurability; for example, by electrochemically controlling the surface tension of the liquid metal, the antenna shape and operating frequency can be dynamically adjusted, achieving a much wider tunable range than traditional solid-state antennas (experiments show it can be more than twice as wide). They also possess self-healing capabilities, recovering function after physical damage, thus improving reliability. Furthermore, the high conductivity of liquid metals supports efficient signal transmission, and their environmental adaptability allows for stable operation in extreme temperatures or complex media. Reconfigurable antennas based on liquid metals have become a new research hotspot in the field of reconfigurable antennas in recent years.

[0003] Traditional reconfigurable antennas typically utilize varactor diodes, pin diodes, or similar methods to achieve reconfigurable antenna characteristics. However, these devices generate significant losses and nonlinear effects, degrading the antenna's transmit and receive capabilities, and also present the challenge of complex bias circuitry. Compared to traditional reconfigurable antennas, liquid metal-based reconfigurable antennas offer advantages such as low loss and no nonlinear effects, while also enabling continuous tuning over a wide range. The paper "A Wideband Frequency- and Polarization-Reconfigurable Liquid Metal-Based Spiral Antenna," published in *IEEE Antennas and Wireless Propagation Letters*, discloses a frequency-reconfigurable liquid metal spiral antenna. By filling the antenna with liquid metal to alter its spiral radiation structure, it achieves switching between right-hand circularly polarized waves from 0.6 GHz to 13.5 GHz and left-hand circularly polarized waves from 1 GHz to 2.5 GHz.

[0004] However, the feed structure of the existing liquid metal spiral antenna is separated from the antenna radiator, and the connection between the liquid metal and the feed structure is unstable. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides an ultra-wideband frequency and pattern reconfigurable dual-arm helical antenna based on liquid metal. The technical problem to be solved by this invention is achieved through the following technical solution: This invention provides an ultra-wideband frequency and pattern reconfigurable dual-arm helical antenna based on liquid metal. The reconfigurable helical antenna includes an antenna radiating element, a circular metal reflective cavity, a liquid metal injection and discharge port, and a feed balun structure; wherein, The antenna radiating element is used to generate electromagnetic waves. The antenna radiating element is provided with two spiral arm-shaped microchannels for filling liquid metal, so that the frequency and radiation pattern of the antenna can be reconfigured by controlling the filling state of the liquid metal in the two spiral arm-shaped microchannels. A circular metal reflective cavity is located below the antenna radiating element; the circular metal reflective cavity is used to reflect electromagnetic waves. The liquid metal injection and discharge port is located at the center of the antenna radiating element; the liquid metal injection and discharge port is used to inject liquid metal from the outside into the antenna radiating element; A feed balun structure is positioned between the antenna radiating element and the circular metal reflective cavity; the feed balun structure is used to provide excitation for the antenna radiating element.

[0006] In one embodiment of the present invention, the antenna radiating element includes a microfluidic dielectric substrate, a solid metal structure, a first helical arm-shaped microchannel, a second helical arm-shaped microchannel, and a first feed balun perforation structure; wherein... The solid metal structure and the first power feeding balun perforation structure are both located inside the microfluidic dielectric substrate at the center of the microfluidic dielectric substrate. Both the first spiral arm-shaped microchannel and the second spiral arm-shaped microchannel are located inside the microfluidic medium substrate, and both are spiral structure designs surrounding the solid metal structure. Through the first feeding balun perforated structure, the first spiral arm-shaped microchannel and the second spiral arm-shaped microchannel are connected to the feeding balun structure by a solid metal structure. Liquid metal (5) flows inside the first spiral arm-shaped microchannel and the second spiral arm-shaped microchannel, respectively; The first and second spiral arm-shaped microchannels are not directly connected to the circular metal reflective back cavity.

[0007] In one embodiment of the present invention, the linewidths of the first spiral arm-shaped microchannel and the second spiral arm-shaped microchannel are consistent, and the spacing between the first spiral arm-shaped microchannel and the second spiral arm-shaped microchannel is consistent.

[0008] In one embodiment of the present invention, the first spiral arm-shaped microchannel and the second spiral arm-shaped microchannel are any one of the following spirals: Archimedes function, equiangular spiral function, and sin function, or a composite spiral composed of several of them.

[0009] In one embodiment of the present invention, the circular metal reflective back cavity includes a supporting step and a second feeding balun perforation structure; wherein... The supporting steps are fixedly connected to the microfluidic dielectric substrate. The second feed balun perforation structure is located at the center of the circular metal reflective back cavity and is coaxial with the first feed balun perforation structure; the antenna radiating element is connected to the feed balun structure through the first feed balun perforation structure and the second feed balun perforation structure.

[0010] In one embodiment of the present invention, the liquid metal injection and discharge port includes a third fed balun perforated structure, a first microchannel interface, and a second microchannel interface; wherein... The third feed balun perforation structure is located at the center of the liquid metal injection outlet and is coaxial with the first feed balun perforation structure; the antenna radiating element is connected to the feed balun structure through the first feed balun perforation structure and the third feed balun perforation structure. The first microfluidic interface and the second microfluidic interface are respectively located at different positions on the microfluidic medium substrate; the first microfluidic interface and the second microfluidic interface respectively realize the physical isolation between the liquid metal inside the first spiral arm microfluidic channel and the air.

[0011] In one embodiment of the present invention, the third power supply balun perforation structure, the first microchannel interface, and the second microchannel interface all adopt Roller connectors.

[0012] In one embodiment of the present invention, the power supply balun structure is any one of a microstrip balun, a coaxial balun, or a transformer balun.

[0013] In one embodiment of the present invention, the liquid metal is a gallium indium tin alloy, which comprises 68.5% gallium, 21.5% indium, and 10% tin by mass.

[0014] In one embodiment of the present invention, a sodium hydroxide solution also flows within the spiral arm-shaped microchannel of the antenna radiating unit to physically isolate the liquid metal from the air.

[0015] The beneficial effects of this invention are: This invention proposes an ultra-wideband frequency and pattern reconfigurable dual-arm helical antenna based on liquid metal. It innovatively designs the antenna shape by controlling the size and shape of the antenna radiator by changing the filling length of the liquid metal, achieving frequency reconfigurability. This solves the problems of narrow reconfigurable frequency range and limited reconfigurable performance in existing antennas, thus meeting the diverse frequency and polarization requirements of various environments. Specifically, the proposed dual-arm helical antenna includes an antenna radiating element, a circular metal reflective cavity, a liquid metal injection and discharge port, a feed balun structure, and liquid metal. The antenna radiating element is designed with two helical arm-shaped microchannels for filling the liquid metal. By utilizing the flowability of liquid metal at room temperature to modify the antenna radiator structure, ultra-wideband frequency polarization reconfigurability is achieved in the 0.2GHz~20GHz range. Frequency reconfigurability is achieved by controlling the length of the radiating arms of the helical antenna using liquid metal, and pattern beam pointing can be switched by controlling the filling state of the dual arms using liquid metal, thus achieving pattern reconfigurability. Compared with traditional antennas, liquid metal antennas can achieve continuous tuning in the ultra-wideband range; secondly, due to the strong viscosity of liquid metal itself, they have strong stability and high repeatability.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal, provided in an embodiment of the present invention. Figure 2 This is provided by the embodiments of the present invention. Figure 1 A schematic diagram of the antenna radiating element in the structure shown. Figure 3 This is provided by the embodiments of the present invention. Figure 1 A schematic diagram of the specific structure of the circular metal reflective back cavity and the liquid metal injection and discharge port in the structure shown. Figure 4 This is provided by the embodiments of the present invention. Figure 1 A side view of the structure shown; Figure 5 This is a schematic diagram of a microchannel interface based on a Roller connector provided in an embodiment of the present invention; Figure 6 This is provided by the embodiments of the present invention. Figure 1 The diagram shows the front and back views of the feed balun structure in the structure shown. Figure 7 This is provided by the embodiments of the present invention. Figure 1 A schematic diagram showing the standing wave ratio of the structure under different liquid metal filling cycles in the range of 1 GHz to 8 GHz. Figure 8 This is provided by the embodiments of the present invention. Figure 1 A schematic diagram showing the standing wave ratio of the structure under different liquid metal filling cycles in the range of 0.2 GHz to 1 GHz; Figure 9 This is provided by the embodiments of the present invention. Figure 1 The structure shown has three states of E-plane radiation patterns when filled with liquid metal at a frequency of 1 GHz and with a period of 10.

[0018] Explanation of reference numerals in the attached figures: 1-Antenna radiating element; 101-Microfluidic dielectric substrate; 102-Solid metal structure; 103-First spiral arm-shaped microchannel; 104-Second spiral arm-shaped microchannel; 105-First feed balun perforation structure; 2-Circular metal reflective back cavity; 201-Supporting step; 202-Second feed balun perforation structure; 3-Liquid metal injection / discharge port; 301-Third feed balun perforation structure; 302-First microchannel interface; 303-Second microchannel interface; 304-Roll connector; 4-Feed balun structure; 401-Balon dielectric substrate; 402-Graded microstrip line; 5-Liquid metal. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0020] Current published papers and patents on liquid metal frequency reconfigurable antennas all suffer from problems such as the separation between the feed structure and the antenna radiator, and poor connection stability between the liquid metal and the feed structure. Achieving ultra-wideband frequency and polarization reconfigurability is of great significance in the field of communications. For solutions to this technical challenge, please refer to [link to relevant documentation / reference]. Figure 1 This invention provides an ultra-wideband frequency and pattern reconfigurable dual-arm helical antenna based on liquid metal. The reconfigurable helical antenna includes an antenna radiating element 1, a circular metal reflective cavity 2, a liquid metal injection and discharge port 3, and a feed balun structure 4; wherein, Antenna radiating element 1 is used to generate electromagnetic waves; antenna radiating element 1 is provided with two spiral arm-shaped microchannels for filling liquid metal 5, so that the frequency and radiation pattern of the antenna can be reconfigured by controlling the filling state of liquid metal 5 in the two spiral arm-shaped microchannels. A circular metal reflective cavity 2 is disposed below the antenna radiating element 1; the circular metal reflective cavity 2 is used to reflect electromagnetic waves. The liquid metal injection and discharge port 3 is located at the center of the antenna radiating element 1; the liquid metal injection and discharge port 3 is used to inject liquid metal 5 from the outside into the antenna radiating element 1; The feeding balun structure 4 is disposed between the antenna radiating element 1 and the circular metal reflective back cavity 2; the feeding balun structure 4 is used to provide excitation for the antenna radiating element 1.

[0021] Next, for Figure 1 Each part of the double-arm helical antenna shown will be described in detail.

[0022] Antenna radiating element 1 in this embodiment of the invention is as follows Figure 2 As shown, the system includes a microfluidic dielectric substrate 101, a solid metal structure 102, a first helical arm-shaped microchannel 103, a second helical arm-shaped microchannel 104, and a first power-feeding balun through-hole structure 105. The solid metal structure 102 and the first power-feeding balun through-hole structure 105 are both disposed inside the microfluidic dielectric substrate 101 at its center. The first helical arm-shaped microchannel 103 and the second helical arm-shaped microchannel 104 are both disposed inside the microfluidic dielectric substrate 101. All are spiral structures designed around the solid metal structure 102; the first spiral arm-shaped microchannel 103 and the second spiral arm-shaped microchannel 104 are connected to the feeding balun structure 4 through the first feeding balun perforation structure 105 and the solid metal structure 102 respectively; liquid metal 5 flows inside the first spiral arm-shaped microchannel 103 and the second spiral arm-shaped microchannel 104 respectively; the first spiral arm-shaped microchannel 103 and the second spiral arm-shaped microchannel 104 are not directly connected to the circular metal reflective back cavity 2.

[0023] In this embodiment of the invention, the linewidths of the first spiral arm-shaped microchannel 103 and the second spiral arm-shaped microchannel 104 are consistent, and the spacing between the first spiral arm-shaped microchannel 103 and the second spiral arm-shaped microchannel 104 is consistent.

[0024] In this embodiment of the invention, the first spiral arm-shaped microchannel 103 and the second spiral arm-shaped microchannel 104 are any one of the following spirals: Archimedes function, equiangular spiral function, and sin function, or a composite spiral composed of several of them.

[0025] In this embodiment of the invention, the solid metal structure 102 is made of copper, and the microfluidic dielectric substrate 101 is made of polymethyl methacrylate (PMMA).

[0026] This invention uses liquid metal 5 as the antenna radiator, utilizing the flowability of liquid metal 5 at room temperature to replace traditional solid metal, thus achieving flexible antenna characteristic reconfiguration. Compared with existing papers and patents on liquid metal reconfigurable antennas, this invention has advantages such as wide bandwidth, continuous reconfigurability, multiple reconfigurable states, and simple control.

[0027] This invention introduces a solid metal structure 102 into the microfluidic antenna structure. The solid metal structure 102 connects the antenna feed structure and the reconfigurable liquid metal radiator structure. That is, the solid metal structure 102 connects the feed balun structure 4 with the first spiral arm-shaped microchannel 103 and the second spiral arm-shaped microchannel 104, thus ensuring the stability of the antenna operation and realizing the integrated microfluidic antenna design.

[0028] Furthermore, in this embodiment of the invention, the circular metal reflective back cavity 2 is as follows: Figure 3 As shown, it includes a supporting step 201 and a second feeding balun perforation structure 202; wherein, the supporting step 201 is fixedly connected to the microfluidic dielectric substrate 101; the second feeding balun perforation structure 202 is disposed at the center of the circular metal reflective back cavity 2 and is coaxial with the first feeding balun perforation structure 105; the antenna radiating element 1 is connected to the feeding balun structure 4 through the first feeding balun perforation structure 105 and the second feeding balun perforation structure 202.

[0029] In this embodiment of the invention, the circular metal reflective back cavity 2 is made of conductive metal material such as copper, iron, steel, alloy, aluminum, or tin.

[0030] Furthermore, in this embodiment of the invention, the liquid metal injection and discharge port 3 is as follows: Figure 3 and Figure 4 As shown, it includes a third feed balun perforation structure 301, a first microfluidic channel interface 302, and a second microfluidic channel interface 303. The third feed balun perforation structure 301 is located at the center of the liquid metal injection outlet 3 and is coaxial with the first feed balun perforation structure 105. The antenna radiating element 1 and the feed balun structure 4 are connected through the first feed balun perforation structure 105 and the third feed balun perforation structure 301. The first microfluidic channel interface 302 and the second microfluidic channel interface 303 are respectively located at different positions on the microfluidic dielectric substrate 101. The first microfluidic channel interface 302 and the second microfluidic channel interface 303 respectively realize the physical isolation between the liquid metal 5 inside the first spiral arm-shaped microfluidic channel 103 and the second spiral arm-shaped microfluidic channel 104 and the air.

[0031] In this embodiment of the invention, the third power supply balun perforated structure 301, the first microchannel interface 302, and the second microchannel interface 303 all adopt a Roller connector 304. Figure 5 As shown, Figure 5 The left side shows a schematic diagram of the Roller connector 304 of the third power supply balun perforated structure 301. Figure 5The diagram on the right shows the Roller connector 304 of the first microfluidic interface 302, and the Roller connector 304 of the second microfluidic interface 303 has a similar structure. This invention designs a stable liquid metal filling structure based on the Roller connector 304 for the injection and discharge of liquid metal 5. The designed, stably installable spiral interface not only solves the problem of air entering the microfluidic channel and oxidizing the liquid metal, but also enables the integrability of multi-channel microfluidic liquid metal filling through the Roller connector interface.

[0032] In this embodiment of the invention, the liquid metal injection and discharge port 3 is made of polyetheretherketone (PEEK) material. The liquid metal injection and discharge module 3 is connected to the microfluidic dielectric substrate 101 of the antenna radiating unit 1 by thermal bonding.

[0033] Furthermore, in this embodiment of the invention, the feed balun structure 4 can be any one of a microstrip balun, a coaxial balun, or a transformer balun. The feed balun structure 4 and the solid metal structure 102 of the antenna radiating element 1 are smoothly connected through a first feed balun perforation structure 105 disposed on the microfluidic dielectric substrate 101. For example, the microstrip balun is composed of a balun dielectric substrate 401 and gradient microstrip lines 402 on both sides. Figure 6 As shown, Figure 6 The left side shows the front structure. Figure 6 The right side shows the reverse side. The balun dielectric substrate 401 is made of FR-4 epoxy glass cloth laminate.

[0034] Furthermore, in this embodiment of the invention, the liquid metal 5 is a gallium indium tin alloy, which comprises 68.5% gallium, 21.5% indium, and 10% tin by mass. A sodium hydroxide solution also flows within the spiral arm-shaped microchannel of the antenna radiating unit 1 to physically isolate the liquid metal 5 from air. For example, the gallium indium tin alloy serves as the radiator of the antenna radiating unit 1, and a 0.01 mol / L sodium hydroxide solution is used to isolate the gallium indium tin alloy from air. The gallium indium tin alloy and the 0.01 mol / L sodium hydroxide solution are jointly encapsulated within the first spiral arm microchannel 103 and the second spiral arm microchannel 104 of the antenna radiating unit 1.

[0035] In this embodiment of the invention, an opening is provided at the corresponding position of the antenna radiation unit 1 and the liquid metal injection outlet 3, and the microchannel is connected to the external driving device through the through hole.

[0036] In practical applications, the ultra-wideband frequency and pattern reconfigurable dual-arm helical antenna based on liquid metal provided in this invention, when it is necessary to increase the length of the liquid metal 5 in the first helical arm microchannel 103 and the second helical arm microchannel 104 of the antenna radiating element 1, is injected into the first helical arm microchannel 103 and the second helical arm microchannel 104 from one end of the liquid metal-filled microchannel 103 and the second helical arm microchannel 104 by driving control. At this time, 0.01 mol of liquid metal is stored in the microchannel. A 1 / L sodium hydroxide solution is discharged from the other end, thereby increasing the length of the liquid metal 5 in the microchannel. When it is necessary to reduce the length of the liquid metal 5 in the first spiral arm microchannel 103 and the second spiral arm microchannel 104 of the antenna radiating element 1, the liquid metal 5 is driven to flow in the opposite direction from the liquid metal filled in the first spiral arm microchannel 103 and the second spiral arm microchannel 104. At this time, the 0.01 mol / L sodium hydroxide solution stored in the microchannel is injected back into the microchannel under pressure. When it is necessary to reconstruct the antenna pattern, there are three injection states according to the antenna beam pointing requirements: injecting liquid metal 5 only into the first spiral arm microchannel 103 of the antenna radiating element 1, injecting liquid metal 5 only into the second spiral arm microchannel 104, and injecting liquid metal 5 into both the first spiral arm microchannel 103 and the second spiral arm microchannel 104, thereby realizing the polarization reconstruction of the antenna.

[0037] To verify the effectiveness of the ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal provided in this embodiment of the invention, the following experiments were conducted.

[0038] Figure 7 This is a schematic diagram illustrating the standing wave ratio (SWR) under different liquid metal charging cycles within the 1GHz to 8GHz range, provided by an embodiment of the present invention. Figure 7 The horizontal axis represents frequency, and the vertical axis represents standing wave ratio (VSWR). Figure 8 This is a schematic diagram illustrating the standing wave ratio (SWR) under different liquid metal charging periods within the range of 0.2 GHz to 1 GHz, provided by an embodiment of the present invention. Figure 8 The horizontal axis represents frequency, and the vertical axis represents standing wave ratio (SWR). Figure 7 and Figure 8 Together they demonstrated that when the number of liquid metal 5 filling turns inside the first spiral arm microchannel 103 and the second spiral arm microchannel 104 increased from 0.3 turns to 23 turns, the minimum operating frequency of the spiral antenna decreased from 5.2 GHz to 0.2 GHz, achieving a frequency reconstruction effect.

[0039] Figure 9 This is provided by the embodiments of the present invention. Figure 1The structure shown has three states of E-plane radiation patterns when filled with liquid metal at a frequency of 1 GHz with a period of 10. Specifically, when liquid metal 5 is selectively filled only in the first spiral arm microchannel 103 (left spiral arm), only in the second spiral arm microchannel 104 (right spiral arm), or simultaneously in the first spiral arm microchannel 103 and the second spiral arm microchannel 104, the E-plane radiation pattern of the spiral antenna changes direction, which is +30°, 0° and -30° respectively.

[0040] This invention enables reconfigurable ultra-wideband frequency polarization within the 0.2 GHz to 20 GHz range. The experiment only illustrates the reconfigurable ultra-wideband frequency polarization within the 0.2 GHz to 8 GHz range.

[0041] In summary, the ultra-wideband frequency and pattern reconfigurable dual-arm helical antenna based on liquid metal proposed in this invention innovatively designs the antenna shape. By changing the filling length of the liquid metal, the size and shape of the antenna radiator are controlled, achieving frequency reconfigurability. This solves the problems of narrow reconfigurable frequency range and limited reconfigurable performance in existing antennas, thus meeting the diverse requirements of different environments for antenna operating frequency and polarization. Specifically, the proposed dual-arm helical antenna includes an antenna radiating element, a circular metal reflective cavity, a liquid metal injection and discharge port, a feed balun structure, and liquid metal. The antenna radiating element is designed with two helical arm-shaped microchannels for filling the liquid metal. By utilizing the flowability of liquid metal at room temperature to modify the antenna radiating element structure, ultra-wideband frequency polarization reconfigurability is achieved in the range of 0.2 GHz to 20 GHz. By controlling the length of the radiating arms of the helical antenna with liquid metal, frequency reconfigurability is achieved. By controlling the filling state of the two arms of the helical antenna with liquid metal, the antenna pattern beam pointing can be switched, thus achieving pattern reconfigurability. Compared with traditional antennas, liquid metal antennas can achieve continuous tuning in the ultra-wideband range; secondly, due to the strong viscosity of liquid metal itself, they have strong stability and high repeatability.

[0042] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0043] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the specification and accompanying drawings, will understand and implement other variations of the disclosed embodiments in carrying out the claimed invention. In the specification, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. While certain measures are described in different embodiments, this does not mean that these measures cannot be combined to produce good results.

[0044] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A wideband frequency and pattern reconfigurable dual-arm helical antenna based on liquid metal, characterized in that, The reconfigurable helical antenna includes an antenna radiating element (1), a circular metal reflective cavity (2), a liquid metal injection and discharge port (3), and a feed balun structure (4); wherein, Antenna radiating unit (1) is used to generate electromagnetic waves; the antenna radiating unit (1) is provided with two spiral arm-shaped microchannels for filling liquid metal (5) so that the frequency and radiation pattern of the antenna can be reconfigured by controlling the filling state of liquid metal (5) in the two spiral arm-shaped microchannels. A circular metal reflective cavity (2) is disposed below the antenna radiating element (1); the circular metal reflective cavity (2) is used to reflect electromagnetic waves; A liquid metal injection outlet (3) is located at the center of the antenna radiating unit (1); the liquid metal injection outlet (3) is used to inject liquid metal (5) from the outside into the antenna radiating unit (1); A feeding balun structure (4) is disposed between the antenna radiating element (1) and the circular metal reflective back cavity (2); the feeding balun structure (4) is used to provide excitation for the antenna radiating element (1).

2. The ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal according to claim 1, characterized in that, The antenna radiating element (1) includes a microfluidic dielectric substrate (101), a solid metal structure (102), a first helical arm-shaped microchannel (103), a second helical arm-shaped microchannel (104), and a first feed balun perforation structure (105); wherein, The solid metal structure (102) and the first power-feeding balun perforation structure (105) are both disposed inside the microfluidic dielectric substrate (101) at the center position of the microfluidic dielectric substrate (101); The first spiral arm-shaped microchannel (103) and the second spiral arm-shaped microchannel (104) are both located inside the microfluidic medium substrate (101) and are both spiral structure designs surrounding the solid metal structure (102). The first spiral arm-shaped microchannel (103) and the second spiral arm-shaped microchannel (104) are connected to the feeding balun structure (4) by the first feeding balun perforated structure (105) and the solid metal structure (102). Liquid metal (5) flows inside the first spiral arm-shaped microchannel (103) and the second spiral arm-shaped microchannel (104); The first spiral arm-shaped microchannel (103) and the second spiral arm-shaped microchannel (104) are not directly connected to the circular metal reflective back cavity (2).

3. The ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal according to claim 2, characterized in that, The linewidths of the first spiral arm-shaped microchannel (103) and the second spiral arm-shaped microchannel (104) are consistent, and the spacing between the first spiral arm-shaped microchannel (103) and the second spiral arm-shaped microchannel (104) is consistent.

4. The ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal according to claim 2, characterized in that, The first spiral arm-shaped microchannel (103) and the second spiral arm-shaped microchannel (104) are any one of the following spirals: Archimedes function, equiangular spiral function, sin function, or a composite spiral composed of several of them.

5. The ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal according to claim 2, characterized in that, The circular metal reflective back cavity (2) includes a supporting step (201) and a second feeding balun perforated structure (202); wherein, The support step (201) is fixedly connected to the microfluidic dielectric substrate (101); The second feeding balun perforation structure (202) is located at the center of the circular metal reflective back cavity (2) and is coaxial with the first feeding balun perforation structure (105); the antenna radiating element (1) is connected to the feeding balun structure (4) through the first feeding balun perforation structure (105) and the second feeding balun perforation structure (202).

6. The ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal according to claim 2, characterized in that, The liquid metal injection and discharge port (3) includes a third fed balun perforated structure (301), a first microchannel interface (302), and a second microchannel interface (303); wherein, The third feed balun perforation structure (301) is located at the center of the liquid metal injection outlet (3) and is coaxial with the first feed balun perforation structure (105); the antenna radiating element (1) is connected to the feed balun structure (4) through the first feed balun perforation structure (105) and the third feed balun perforation structure (301). The first microfluidic interface (302) and the second microfluidic interface (303) are respectively disposed at different positions on the microfluidic medium substrate (101); the first microfluidic interface (302) and the second microfluidic interface (303) respectively realize the physical isolation between the liquid metal (5) inside the first spiral arm microfluidic channel (103) and the second spiral arm microfluidic channel (104) and the air.

7. The ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal according to claim 6, characterized in that, The third power supply balun perforated structure (301), the first microchannel interface (302), and the second microchannel interface (303) all adopt the Roll connector (304).

8. The ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal according to claim 1, characterized in that, The power supply balun structure (4) can be any one of the following: microstrip balun, coaxial balun, or transformer balun.

9. The ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal according to claim 1, characterized in that, The liquid metal (5) is a gallium-indium-tin alloy comprising 68.5% gallium, 21.5% indium, and 10% tin by mass.

10. The ultra-wideband frequency and pattern reconfigurable double-arm helical antenna based on liquid metal according to claim 1, characterized in that, Sodium hydroxide solution also flows in the spiral arm-shaped microchannel of the antenna radiating unit (1) to physically isolate the liquid metal (5) from the air.

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