A microstrip line-fed ionic liquid antenna

Abstract

The present application relates to an ionic liquid antenna fed by a microstrip line, comprising: a base and a dielectric resonator arranged on the base; the base comprises a floor and a dielectric plate arranged in a stacked manner, the dielectric resonator being arranged on the floor; a coupling slot is arranged on the base at a position corresponding to the dielectric resonator, the coupling slot passes through the floor and the dielectric plate; a microstrip line is arranged at the bottom of the dielectric plate, the microstrip line intersects with the coupling slot; the dielectric resonator is a cylindrical structure with an open top and a sealed bottom and a hollow accommodating cavity inside; an ionic liquid is arranged in the accommodating cavity to form a radiation source; and further comprising: a coaxial probe; the inner conductor of the coaxial probe extends into the ionic liquid after passing through the base, and the outer conductor of the coaxial probe passes through the dielectric plate and is connected to the floor. The present application can realize microstrip line feeding of non-metallic liquid antennas.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a microstrip line-fed ionic liquid antenna. Background Art

[0002] With the vigorous development of wireless communication systems, antennas, as the "eyes" of wireless communication systems, play a vital role in wireless communication systems.

[0003] Liquid antenna is a new type of antenna that uses liquid material instead of traditional metal material as the radiator. Since it contains no metal parts except the feeding device, there is almost no conductor loss that often restricts the efficiency of the antenna. This has attracted the interest of many researchers in the production of high-efficiency antennas.

[0004] According to the different research objects and focuses, liquid antennas are currently divided into liquid metal antennas and non-metallic liquid antennas. The main material used in liquid metal antennas is mercury, which essentially uses its high conductivity, similar to the radiation mechanism of traditional metal antennas; however, mercury is toxic, which limits its widespread use. Non-metallic liquid antennas mainly use water (distilled water, pure water, tap water, seawater), oil, etc. as radiation materials. Non-metallic liquids have great advantages in terms of antenna cost, reconfigurability, and miniaturization due to their easy availability, flexible structure, environmental friendliness, and high dielectric constant. In recent years, research results on water antennas have continued to emerge at home and abroad.

[0005] However, existing non-metallic liquid antennas all use coaxial feeding, which requires manual welding operations, and the feeding method is relatively complicated and has low production efficiency. Summary of the invention

[0006] Based on this, it is necessary to provide a microstrip line-fed ionic liquid antenna to address the above technical problems, so as to realize the microstrip line feeding of the non-metallic liquid antenna.

[0007] A microstrip line-fed ionic liquid antenna comprises: a base and a dielectric resonator arranged on the base;

[0008] The base comprises a floor and a dielectric plate which are stacked one on another, and the dielectric resonator is arranged on the floor; a coupling slot is arranged on the base at a position corresponding to the dielectric resonator, and the coupling slot penetrates the floor and the dielectric plate; a microstrip line is arranged at the bottom of the dielectric plate, and the microstrip line intersects with the coupling slot;

[0009] The dielectric resonator is a cylindrical structure with an open top and a sealed bottom and a hollow containing cavity inside; an ionic liquid is arranged in the containing cavity to form a radiation source.

[0010] In one embodiment, it further comprises: a coaxial probe;

[0011] The inner conductor of the coaxial probe passes through the base and then extends into the ionic liquid, and the outer conductor of the coaxial probe passes through the dielectric plate and then connects to the floor.

[0012] In one embodiment, the dielectric resonator is a cylindrical structure, the base is a square structure, and the coupling slot and the microstrip line are both rectangular structures;

[0013] The centers of the base, the dielectric resonator, the coupling slot, and the microstrip line coincide with each other.

[0014] In one embodiment, the center of the coaxial probe is arranged on a diagonal line of the base.

[0015] In one embodiment, the inner conductor of the coaxial probe abuts against the inner wall of the dielectric resonator.

[0016] In one embodiment, the microstrip line is perpendicular to the coupling slot, and the microstrip line is perpendicular to one side of the base.

[0017] In one embodiment, one end of the microstrip line coincides with an edge of the dielectric plate, and the length of the microstrip line is greater than half of the side length of the base.

[0018] In one embodiment, an absolute value of a difference between the dielectric constants of the ionic liquid and the dielectric resonator is less than or equal to 1.

[0019] In one embodiment, the ionic liquid is trihexyltetradecylphosphonium chloride.

[0020] In one embodiment, the dielectric resonator is made of photosensitive resin.

[0021] The above-mentioned microstrip line-fed ionic liquid antenna is provided with a floor, a dielectric plate, a coupling slot and a microstrip line to form a slot-coupled feeding, and an ionic liquid is selected as a radiation source, thereby realizing a microstrip line slot-coupled ionic liquid antenna, that is, it is possible to realize microstrip line feeding for non-metallic liquid antennas. This application is a new type of liquid antenna with broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the three-dimensional structure of a microstrip line-fed ionic liquid antenna in one embodiment;

[0023] Figure 2 A front view of the structure of an ionic liquid antenna fed by a microstrip line in one embodiment;

[0024] Figure 3 A top view of the structure of a microstrip line-fed ionic liquid antenna in one embodiment;

[0025] Figure 4 is a bandwidth curve diagram of TM01 mode S11 operating in the wimax frequency band in one embodiment;

[0026] Figure 5 It is a bandwidth curve diagram of HEM11 mode S11 working in 5G wifi frequency band in one embodiment;

[0027] Figure 6 is a TM01 mode XoZ plane radiation pattern operating in the WiMAX frequency band in an embodiment;

[0028] Figure 7 is a TM01 mode XoY plane radiation pattern operating in the WiMAX frequency band in an embodiment;

[0029] Figure 8 It is a XoZ plane radiation pattern of HEM11 mode working in 5G wifi frequency band in one embodiment;

[0030] Fig. 9 This is a XoY plane radiation pattern of the HEM11 mode operating in the 5G wifi frequency band in an embodiment. Description of the drawings:

[0032] Base 1, floor 11, dielectric plate 12, coupling slot 13, microstrip line 14, dielectric resonator 2, ionic liquid 21, inner conductor 22, outer conductor 23. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] like Figures 1 to 3 As shown, a microstrip line-fed ionic liquid antenna provided in the present application, in one embodiment, comprises: a base 1 and a dielectric resonator 2 arranged on the base 1;

[0035] The base 1 includes a floor 11 and a dielectric plate 12 which are stacked, and a dielectric resonator 2 is arranged on the floor 1; a coupling slot 13 is arranged on the base 1 at a position corresponding to the dielectric resonator 2, and the coupling slot 13 runs through the floor 11 and the dielectric plate 12; a microstrip line 14 is arranged at the bottom of the dielectric plate 12, and the microstrip line 14 intersects with the coupling slot 13;

[0036] The dielectric resonator 2 is a cylindrical structure with an open top and a sealed bottom and a hollow containing cavity inside; an ionic liquid 21 is arranged in the containing cavity to form a radiation source.

[0037] This embodiment does not limit the shapes and sizes of the base and the dielectric resonator 2, and they can be specifically designed according to actual needs.

[0038] The shape and size of the floor 11 and the dielectric plate 12 are completely consistent, and the floor 11 is arranged above the dielectric plate 12. The floor 11 is made of metal material, and the dielectric plate 12 is made of non-metallic material, such as FR4. Preferably, the material of the dielectric plate is Rogers 5880, which has a small dielectric loss and is conducive to improving the gain of the antenna.

[0039] The coupling slot 13 can be regarded as a through hole penetrating the base, and preferably, the through hole is rectangular.

[0040] Preferably, the dielectric resonator 2 is also provided with an upper cover to prevent the ionic liquid from overflowing.

[0041] Ionic liquids are used as radiation materials for liquid antennas, and trihexyltetradecyl phosphonium chloride (TPC), 1-ethyl-3-methyldicyanamide, ethyl acetate, acetone, acetonitrile or oil can be selected.

[0042] Ionic liquids have a large liquid working range, which makes their working performance insensitive to temperature changes; they have very low conductivity and can be perfectly equivalent to a medium, making them ideal materials for generating dielectric resonance modes; their loss tangent value is very small, and has a small fluctuation range with temperature and frequency changes, and their radiation efficiency is also high when working in high-frequency bands. The performance of ionic liquids is very stable, and they are radiation materials that can replace water antennas. They effectively avoid the shortcomings of conventional water antennas, which have a sharp increase in loss and a decrease in antenna radiation efficiency when working in high-frequency bands, allowing the antenna to maintain a high radiation efficiency in high-frequency bands.

[0043] Preferably, the ionic liquid is TPC, which has a liquid working range of -69.8°C to 350°C, a relative dielectric constant of about 3 at room temperature and remains stable with frequency, a conductivity of about 0.00025S / m, a loss tangent of about 0.002, and almost no conductivity. It is an ideal material for generating dielectric resonance, has a large liquid working range, and has a strong ability to adapt to the environment. As the frequency increases, the dielectric loss is almost unaffected and remains at a low value, which is conducive to achieving higher antenna efficiency. It is also transparent, which is conducive to achieving antenna stealth.

[0044] The antenna is essentially a field-to-path converter. Its working principle is to collect electromagnetic wave energy in space, convert it into guided waves, and then transmit it to the wireless communication system for processing through RF cables, or vice versa.

[0045] The working principle of this embodiment is: the floor, dielectric plate, coupling slot and microstrip line together form a slot coupling feed, the electromagnetic wave is transmitted by the microstrip line and propagates along the microstrip line, the floor resonates between the microstrip line and the floor, and then leaks the generated resonant electromagnetic energy into the dielectric resonator through the coupling slot, the dielectric resonator resonates, thereby generating radiation, and finally radiates the electromagnetic wave into the atmosphere. In addition, the floor also reflects the radiation generated by the dielectric resonator, ensuring that the radiation generated by the dielectric resonator is not transmitted downward, but reflected upward; the dielectric substrate separates the microstrip line from the floor to avoid the situation where short circuit cannot generate resonance.

[0046] The above-mentioned microstrip line-fed ionic liquid antenna is provided with a floor, a dielectric plate, a coupling slot and a microstrip line to form a slot-coupled feeding, and an ionic liquid is selected as a radiation source, thereby realizing a microstrip line slot-coupled ionic liquid antenna, that is, it is possible to realize microstrip line feeding for non-metallic liquid antennas. This application is a new type of liquid antenna with broad application prospects.

[0047] In one embodiment, it further includes: a coaxial probe; an inner conductor 22 of the coaxial probe passes through the base and extends into the ionic liquid 21 , and an outer conductor 23 of the coaxial probe passes through the dielectric plate 12 and is connected to the floor 11 .

[0048] In this embodiment, an ionic liquid antenna that can be simultaneously fed by microstrip lines and fed by coaxial lines can be realized, and a dual-feed excited dielectric resonator operation is realized using an antenna structure, thereby solving the technical problem in the prior art that an antenna has only one function, achieving dual use of an antenna and saving production costs.

[0049] Preferably, the dielectric resonator 2 is a cylindrical structure, the base is a square structure, the coupling slot and the microstrip line are both rectangular structures; the centers of the base, the dielectric resonator, the coupling slot and the microstrip line coincide.

[0050] In this embodiment, the antenna adopts a dual-feed excitation dielectric resonator, wherein the microstrip line feeding is used to excite the TM01 mode of the dielectric resonator, which works in the Wimax frequency band (2.5-2.7GHz), and the coaxial feeding is used to excite the HEM11 mode of the dielectric resonator, which works in the WiFi frequency band (5.15-5.25GHz, 5.25-5.35GHz, 5.47-5.525GHz). Since the two feeding methods correspond to the two modes of the antenna respectively, the mode can be reconfigured; since the two modes correspond to two different working frequency bands, the frequency can be reconfigured; and since the far-field radiation patterns corresponding to the two modes are different, the radiation pattern can be reconfigured; thus, the dual-feed method is finally used to realize an ionic liquid antenna with reconfigurable mode, frequency, and radiation pattern, and it can be switched in the WiFi / Wimax frequency band, realizing dual-use of one antenna, which is conducive to cost saving and can be widely used in communication equipment such as base stations, mobile phones, and routers.

[0051] Further preferably, the center of the coaxial probe is arranged on the diagonal line of the base 1, which can improve the isolation between the two ports.

[0052] More preferably, the inner conductor 22 of the coaxial probe abuts against the inner wall of the dielectric resonator 2, so that the distance between the two feeding ports (microstrip line and coaxial probe) is relatively large, thereby further effectively improving the isolation between the two ports.

[0053] In one embodiment, the microstrip line 14 is perpendicular to the coupling slot 13 and is perpendicular to one side of the base 1 , which is beneficial to microstrip line feeding and can well feed electromagnetic energy into the dielectric resonator 2 above.

[0054] In one embodiment, one end of the microstrip line 14 coincides with the edge of the dielectric plate 12, and the length of the microstrip line 14 is greater than half of the side length of the base, which is beneficial to feeding the microstrip line 14. The electromagnetic on the microstrip line 14 can pass through the coupling slot 13 and be transmitted into the dielectric resonator 2 above.

[0055] In one embodiment, the absolute value of the difference between the dielectric constants of the ionic liquid 21 and the dielectric resonator 2 is less than or equal to 1.

[0056] The above arrangement can minimize adverse effects such as distortion of the directional pattern caused by the electromagnetic waves reflecting and refracting back and forth between different media due to the large difference in relative dielectric constant between the radiation medium (ionic liquid) and the container (medium) in which it is contained.

[0057] The smaller the difference in dielectric constant is, the better. The dielectric constants of the ionic liquid and the dielectric resonator can be set according to actual conditions.

[0058] Preferably, the ionic liquid 21 is trihexyltetradecylphosphine chloride, and the material of the dielectric resonator is photosensitive resin. The relative dielectric constant of the ionic liquid is about 3, and the relative dielectric constant of the photosensitive resin is about 3.2, and the dielectric constants of the two are close.

[0059] In one embodiment, the material of the dielectric resonator 2 is photosensitive resin.

[0060] The dielectric loss of photosensitive resin is relatively small, about 0.02, which is acceptable as a material for designing antennas. Photosensitive resin is formed by 3D printing technology and is also transparent, which is conducive to further realizing the stealth of the antenna.

[0061] In a specific embodiment, the base, floor and dielectric plate are all square structures with a side length of 50 mm, the thickness of the floor is 0.035 mm, and the thickness of the dielectric plate is 1.575 mm; the coupling slot and microstrip line are all rectangular structures, the length of the coupling slot is 29 mm, the width is 2 mm, the length of the microstrip line is 55 mm, the width is 4.85 mm, and the thickness is 0.035 mm; the dielectric resonator is a cylindrical structure with a radius of 30 mm, a height of 50 mm, and a wall thickness of 1.2 mm; the coaxial probe is 50 ohms, the distance from the center of the floor is 28.7 mm, the radius of the inner conductor is 1.2 mm, the length is 50 mm, the radius of the outer conductor is 4.2 mm, and the length is 9 mm; the centers of the base, coupling slot, microstrip line and dielectric resonator coincide, the material of the dielectric resonator is photosensitive resin, and the ionic liquid is trihexyltetradecylphosphine chloride.

[0062] This application uses the electromagnetic full-wave simulation software CST to simulate, analyze and optimize the microstrip line-fed ionic liquid antenna, and studies and verifies its performance.

[0063] like Figure 4 The bandwidth diagram of TM01 mode S11 in the wimax band is shown. The horizontal axis is frequency (unit GHz) and the vertical axis is S parameter (unit dB). It can be seen that the bandwidth of TM01 mode working in the wimax band (2.5-2.7GHz) is 2.47-2.70GHz, covering the entire wimax band.

[0064] like Figure 5 The bandwidth diagram of the HEM11 mode S11 in the 5G wifi frequency band is shown. The horizontal axis is the frequency (unit GHz) and the vertical axis is the S parameter (unit dB). It can be seen that the bandwidth of the HEM11 mode working in the 5G wifi frequency band (5.15-5.525GHz) is 4.21-6.35GHz, covering the entire 5G wifi frequency band.

[0065] like Figures 6 to 9The XoZ and XoY radiation patterns of the TM01 mode and HEM11 mode are shown. It can be seen from the figure that the antenna radiation beam is wide, and the maximum gain is 6.645dBi@2.6GHz and 10.05dBi@5.2GHz respectively.

[0066] Figure 6 In the example, the frequency is 2.6GHz, the main lobe amplitude is 6.44dBi, the main lobe direction is 2°, the 3dB beamwidth is 69.6°, and the side lobe level is -8.4dB.

[0067] Figure 7 In the example, the frequency is 2.6GHz, the main lobe amplitude is -2.14dBi, the main lobe direction is 86°, the 3dB beamwidth is 101.4°, and the side lobe level is -1.0dB.

[0068] Figure 8 In the example, the frequency is 5.2GHz, the main lobe amplitude is 4.15dBi, the main lobe direction is 68°, the 3dB beamwidth is 47.3°, and the side lobe level is -4.4dB.

[0069] Fig. 9 In the example, the frequency is 5.2GHz, the main lobe amplitude is 5.97dBi, the main lobe direction is 225°, the 3dB beamwidth is 26.9°, and the side lobe level is -3.8dB.

[0070] The ionic liquid antenna in this application achieves the following performance:

[0071] 1. Bandwidth

[0072] 1. The TM01 module bandwidth operating in the WiMAX frequency band (2.5-2.7GHz) is 2.47-2.70GHz, covering the entire WiMAX frequency band.

[0073] 2. The HEM11 module bandwidth operating in the 5G wifi frequency band (5.15-5.525GHz) is 4.21-6.35GHz, covering the entire 5G wifi frequency band.

[0074] 2. Gain and Efficiency

[0075] 1. The TM01 mode gain working in the WiMAX frequency band (2.5-2.7GHz) is 6.645dBi@2.6GHz, and the antenna efficiency is 93.8%.

[0076] 2. The HEM11 mode gain operating in the 5G wifi frequency band (5.15-5.525 GHz) is 10.05 dBi @ 5.2 GHz, and the antenna efficiency is 95.9%.

[0077] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A microstrip line-fed ionic liquid antenna, characterized in that: include: A base and a dielectric resonator arranged on the base; The base comprises a floor and a dielectric plate which are stacked together, and the dielectric resonator is arranged on the floor; A coupling slot is provided on the base at a position corresponding to the dielectric resonator, and the coupling slot penetrates the floor and the dielectric plate; a microstrip line is provided at the bottom of the dielectric plate, and the microstrip line intersects with the coupling slot; The centers of the base, the dielectric resonator, the coupling slot and the microstrip line coincide with each other; The dielectric resonator is a cylindrical structure with an open top and a sealed bottom and a hollow accommodating cavity inside; an ionic liquid is arranged in the accommodating cavity to form a radiation source; It also includes: a coaxial probe; the inner conductor of the coaxial probe passes through the base and then extends into the ionic liquid, and the outer conductor of the coaxial probe passes through the dielectric plate and then connects to the floor; the coaxial probe and the microstrip line and the coupling slot are all arranged at intervals; the center of the coaxial probe is arranged on the diagonal line of the base; the inner conductor of the coaxial probe abuts against the inner wall of the dielectric resonator; The antenna works by dual-feeding excited dielectric resonator, where microstrip line feeding is used to excite the TM01 mode of the dielectric resonator, and coaxial feeding is used to excite the HEM11 mode of the dielectric resonator; the two feeding methods correspond to the two modes of the antenna, thereby realizing mode reconfiguration; the two modes correspond to two different working frequency bands, thereby realizing frequency reconfiguration; the far-field radiation patterns corresponding to the two modes are different, thereby realizing radiation pattern reconfiguration; finally, the dual-feed method is used to realize an ionic liquid antenna with reconfigurable mode, frequency, and radiation pattern.

2. The ionic liquid antenna according to claim 1, characterized in that: The dielectric resonator is a cylindrical structure, the base is a square structure, and the coupling slot and the microstrip line are both rectangular structures.

3. The ionic liquid antenna according to claim 1 or 2, characterized in that: The microstrip line is perpendicular to the coupling slot, and the microstrip line is perpendicular to one side of the base.

4. The ionic liquid antenna according to claim 1 or 2, characterized in that: One end of the microstrip line coincides with the edge of the dielectric plate, and the length of the microstrip line is greater than half of the side length of the base.

5. The ionic liquid antenna according to claim 1 or 2, characterized in that: An absolute value of a difference between the dielectric constants of the ionic liquid and the dielectric resonator is less than or equal to 1.

6. The ionic liquid antenna according to claim 5, characterized in that: The ionic liquid is trihexyltetradecylphosphonium chloride.

7. The ionic liquid antenna according to claim 6, characterized in that: The material of the dielectric resonator is photosensitive resin.

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