A shortwave miniaturized antenna based on electromagnetic super-metamaterial resonance mechanism

Abstract

The application discloses a shortwave miniaturized antenna based on electromagnetic super-metamaterial resonance mechanism and belongs to the technical field of wireless communication and antenna. The antenna comprises a main radiator, a plurality of electromagnetic super-metamaterial resonance units and a feeding structure, wherein the physical length of the main radiator is far less than the working wavelength; the super-metamaterial resonance units are arranged in the near-field region of the main radiator and are strongly coupled with the main radiator, magnetic resonance or electric resonance is generated at a target shortwave frequency point, a frequency splitting effect is generated, the resonance frequency of the antenna is greatly reduced, and deep miniaturization is realized; and the feeding structure is used for coupling radio frequency energy. The application can reduce the size of the shortwave antenna to less than 1 / 5 of the size of a conventional antenna, meanwhile, a relatively high radiation efficiency is maintained, frequency electric tuning can be realized through integrated adjustable elements, and the application is suitable for shortwave communication occasions with limited space, such as mobile platforms and portable devices.

Description

Technical Field

[0001] This invention relates to the field of radio communication and antenna technology, specifically to a miniaturized shortwave antenna based on the electromagnetic metamedia resonance mechanism, and particularly to a high-performance shortwave antenna that utilizes the resonance mechanism of an artificial electromagnetic metamedia to achieve physical miniaturization. Background Technology

[0002] Shortwave communication, with its unique advantage of enabling over-the-horizon communication over distances of hundreds to thousands of kilometers through ionospheric reflection, holds an irreplaceable position in military command, emergency rescue, ocean navigation, and broadcasting communications. However, the relatively long wavelength of shortwave (10 to 100 meters) results in exceptionally large physical dimensions for traditional resonant antennas, typically requiring tens of meters of installation space. This severely limits the application of shortwave communication equipment on mobile platforms and portable equipment for individual soldiers.

[0003] To reduce antenna size, existing technologies mainly employ passive loading and structural meandering methods. Passive loading technology cancels the antenna's own reactance by connecting lumped inductors and capacitors in series or parallel on the radiator, thereby achieving resonance in a smaller size. However, this method typically introduces large ohmic losses, significantly reducing antenna radiation efficiency and resulting in an extremely narrow operating bandwidth. Structural meandering increases the electrical length by adding current paths, but excessive meandering can degrade radiation performance and increase cross-polarization.

[0004] Electromagnetic metamedia are novel composite materials composed of periodically arranged subwavelength-scale artificial structural units, exhibiting unique electromagnetic properties not found in naturally occurring materials, such as negative refractive index and near-zero parameters. Among them, metamedia based on resonant units can generate strong electromagnetic resonances and field localization near specific frequencies. Combining these resonant units with electrically small antennas, utilizing the strong coupling between their resonant fields and the antenna's near-field, can effectively reduce the antenna's resonant frequency, representing a new approach to overcoming traditional size limitations. However, designing structurally sound and efficiently coupled metamedia resonant units for low-frequency, long-wavelength short-wavelength bands, and co-designing them with the main radiator to achieve deep miniaturization while ensuring usable radiation efficiency and bandwidth, remains a current technical challenge. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing shortwave antennas, such as their large size and low efficiency due to traditional miniaturization techniques, by providing a miniaturized shortwave antenna based on the electromagnetic metamaterial resonance mechanism. This antenna achieves a significant reduction in physical size by combining a specially designed metamaterial resonant element with the main radiator, utilizing the strong resonance effect of the metamaterial while maintaining superior radiation performance compared to conventional loaded antennas.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism includes:

[0008] The physical length L of the main radiator is much smaller than the working wavelength λ0;

[0009] At least one electromagnetic meta-medium resonant unit is arranged in the near-field region of the main radiator and is electromagnetically coupled to the main radiator.

[0010] A power feeding structure is used to couple radio frequency signal energy to the integrated body composed of the main radiator and the electromagnetic metamaterial resonant unit;

[0011] The electromagnetic metamaterial resonant unit is configured to generate magnetic or electrical resonance at the target shortwave frequency, thereby causing a frequency splitting effect, reducing the resonant frequency of the entire antenna, and realizing the miniaturization of the antenna's physical size.

[0012] Furthermore, the physical length L of the main radiator is ≤ λ0 / 5.

[0013] Furthermore, the main radiator is a ring structure made of metal wires, and the ring structure has an opening.

[0014] Furthermore, the power supply structure is a closed resonant ring made of metal wires, which transfers energy to the main radiator through mutual inductance coupling. There is no direct electrical contact between the power supply structure and the main radiator. The closed resonant ring and the main radiator are arranged concentrically and coplanarly to maximize the coupling coefficient.

[0015] Furthermore, the main radiator and the electromagnetic metamaterial resonant unit are coupled through near-field inductive coupling or direct electrical connection.

[0016] Furthermore, the electromagnetic metamaterial resonant unit is a subwavelength artificial microstructure, and its unit feature size is less than 1 / 5 of the operating wavelength.

[0017] Furthermore, the electromagnetic metamaterial resonant unit is an open-ended resonant ring, and the opening direction of the open-ended resonant ring is consistent with the opening direction of the main radiator.

[0018] Furthermore, the plurality of said open-ended resonant rings are arranged in a periodic array, and tuning capacitors are connected between adjacent open-ended resonant rings and between the open-ended resonant rings and the main radiator in parallel or series.

[0019] Furthermore, the electromagnetic metamaterial resonant unit integrates an adjustable element, which is used to change the effective capacitance or inductance of the metamaterial resonant unit, thereby continuously adjusting the operating frequency of the antenna.

[0020] Furthermore, the adjustable element is a varactor diode, which is connected at the opening of the open resonant ring and its junction capacitance is controlled by an external bias voltage.

[0021] The physical length L of the main radiator is much smaller than its free-space operating wavelength λ0, typically satisfying L≤λ0 / 5, which falls into the category of a typical electrically small antenna. The main radiator can be a simple wire, a metal patch, or other compact form.

[0022] The electromagnetic metamaterial resonant unit is the core of this invention, composed of subwavelength artificial microstructures with characteristic dimensions much smaller than the operating wavelength. This unit is precisely arranged in the near-field region of the main radiator and strongly electromagnetically coupled to the main radiator through near-field induction or direct connection. This metamaterial unit is specifically designed to induce magnetic or electrical resonance near the target shortwave frequency. This resonance effect produces two key benefits: first, it creates a strong local field enhancement, significantly altering the field distribution around the main radiator; second, it forms a strong near-field coupling effect with the main radiator, thereby drastically reducing the resonant frequency of the entire antenna system. This allows the antenna to achieve effective radiation at frequencies much lower than its inherent resonant frequency corresponding to its physical size, thus achieving deep miniaturization.

[0023] The feeding structure is used to couple the radio frequency signal energy of the transmitter to the aforementioned integrated structure. The electromagnetic metamaterial resonant unit can be a periodically arranged array of open resonant rings placed on a three-dimensional antenna frame to achieve stronger coupling and lower resonant frequency within a limited volume. Furthermore, adjustable components (such as varactor diodes) can be integrated into the metamaterial unit. By changing the effective capacitance of the unit through an external bias voltage, the resonant frequency of the metamaterial can be continuously adjusted, ultimately achieving electrical tuning of the antenna's operating frequency band, greatly enhancing its environmental adaptability and functionality.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] This invention employs frequency splitting via multiple open resonant rings to reduce efficiency loss; the more rings, the higher the efficiency. Utilizing the subwavelength resonance characteristics of the metamaterial, the physical height / length of the shortwave antenna can be reduced to 1 / 5 or even less of a traditional half-wave dipole antenna, solving the fundamental problem of deploying shortwave antennas on space-constrained platforms. Compared to single lumped element loading, this invention achieves parameter modulation through distributed structural resonance, resulting in lower loss and higher radiation efficiency within the same size. The structure and arrangement of the metamaterial units are flexible and diverse, allowing for precise control of antenna performance through parametric design. Integration of adjustable components enables frequency agility, meeting the multi-band communication needs in complex electromagnetic environments. Attached Figure Description

[0026] Figure 1This is a schematic diagram of the overall structure provided in Embodiment 1 of the present invention.

[0027] Figure 2 The simulation results show the S11 amplitude response of the antenna under different numbers of open resonant rings.

[0028] Figure 3 The image shows the S11 amplitude response diagram of the antenna of Embodiment 1 of the present invention at the target frequency, obtained through simulation.

[0029] Figure 4 The image shows the radiation efficiency of the antenna in Embodiment 1 of the present invention at the target frequency, obtained through simulation.

[0030] Figure 5 The image shows the radiation efficiency of the antenna at the target frequency in Embodiment 2 of the present invention, obtained through simulation.

[0031] Figure 6 The image shows the radiation efficiency of the antenna in Embodiment 3 of the present invention at the target frequency, obtained through simulation.

[0032] The diagram is labeled as follows: 1. Main radiator; 2. Electromagnetic metamaterial resonant unit; 3. Adjustable element; 4. Feeding structure. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] Example 1:

[0035] This embodiment provides a shortwave antenna suitable for portable devices.

[0036] like Figure 1As shown, the shortwave miniaturized antenna based on the electromagnetic metamaterial resonant mechanism provided by this invention includes a main radiator 1 consisting of two metal wires of length L1 meters wound into a ring structure (one end open and directly connected to a coaxial feed line, the other end with an opening spacing of G1). On both sides of the main radiator 1, two sets of periodic open-ring resonant arrays are symmetrically arranged as electromagnetic metamaterial resonant units 2. Each array consists of multiple single-ring resonators (SRRs) arranged parallel to the main radiator periodically (adjacent spacing of G2), with the opening direction consistent with the opening direction of the main radiator 1. The ring size, linewidth, and opening spacing of the SRRs are the same as those of the main radiator 1, ensuring that the magnetic resonant frequency of a single-ring resonator is highly consistent with the magnetic resonant frequency of the main radiator 1. The main radiator 1 and the multiple single-ring resonators are connected in parallel at the openings, and a capacitor C1 is added at the openings to adjust the overall resonant frequency. The feed structure 4 is a closed-ring resonator formed by winding a metal wire of length L1 meters, with an AC feed line connected to the closed-ring resonator. Furthermore, an adjustable element 3 is integrated into the electromagnetic metamaterial resonant unit 2. In this embodiment, a varactor diode is used to change the effective capacitance of the unit by means of an external bias voltage.

[0037] The feed structure 4 does not have a direct electrical connection with the main radiator 1. Specifically, the feed structure 4 employs a closed resonant ring, which is concentrically positioned with the main radiator, meaning the geometric center of the closed resonant ring essentially coincides with the geometric center of the main radiator, and they are coplanar. Both ends of the closed resonant ring are connected to a radio frequency (RF) signal source, transferring RF energy to the main radiator via mutual inductance coupling. Experiments and simulations show that when the feed structure 4 and the main radiator 1 are concentric and coplanar, the mutual inductance coefficient between them is maximized, resulting in the highest energy transfer efficiency.

[0038] In this embodiment, the metal wire wound into the main radiator 1 is enameled wire with a diameter of 1.2 mm and a length L1 of 3 m. The opening spacing G1 is predetermined to be 20 mm. The spacing G2 between adjacent rings is predetermined to be 20 mm, and the main radiator is connected in parallel with forty single-opening resonant rings at the openings. The cathodes of forty-one varactor diodes are welded to one end of the opening, and the anodes are welded to the other end of the opening.

[0039] Antenna radiation efficiency when only the main radiator 1 is used:

[0040]

[0041] Where R r R is the radiation resistance of a single open-loop resonant ring. o The ohmic resistance of a single open-loop resonant ring.

[0042] Regarding the antenna radiation efficiency when N specially designed electromagnetic metamaterial resonant units 2 are integrated with the main radiator 1:

[0043]

[0044] Electromagnetic simulation was performed on Example 1. The target center frequency was 3MHz. With only the main radiator, the antenna had a severe input impedance mismatch at this frequency, resulting in almost no radiation. After integrating and optimizing the SRR array, as shown... Figure 3 As shown, the antenna resonates perfectly at 3MHz, and the -10dB impedance bandwidth meets the requirements for human communication. Figure 4 The radiation efficiency is shown to be much higher than that of traditional loaded antennas.

[0045] Example 2:

[0046] In this embodiment, the metal wire wound into the main radiator 1 is an enameled wire with a diameter of 1.2 mm and a length L1 of 3 m. The opening spacing G1 is predetermined to be 20 mm. The spacing G2 between adjacent rings is predetermined to be 20 mm, and the main radiator is connected in parallel with twenty single-opening resonant rings at the openings. The cathodes of twenty-one varactor diodes are welded to one end of the opening, and the anodes are welded to the other end of the opening.

[0047] Electromagnetic simulation was performed on Example 2, with a target center frequency of 3MHz. Figure 5 The radiation efficiency is lower than that of the antenna in Example 1.

[0048] Example 3:

[0049] In this embodiment, the metal wire wound into the main radiator 1 is enameled wire with a diameter of 1.2 mm and a length L1 of 3 m. The opening spacing G1 is predetermined to be 20 mm. The spacing G2 between adjacent rings is predetermined to be 20 mm, and the main radiator is connected in parallel with ten single-opening resonant rings at the openings. The cathodes of eleven varactor diodes are welded to one end of the opening, and the anodes are welded to the other end of the opening.

[0050] Electromagnetic simulation was performed on Example 3, with a target center frequency of 3MHz. Figure 6 The radiation efficiency is lower than that of the antenna in Example 2.

Claims

1. A shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism, characterized in that, include: The physical length L of the main radiator is much smaller than the working wavelength λ0; At least one electromagnetic meta-medium resonant unit is arranged in the near-field region of the main radiator and is electromagnetically coupled to the main radiator. A power feeding structure is used to couple radio frequency signal energy to the integrated body composed of the main radiator and the electromagnetic metamaterial resonant unit; The electromagnetic metamaterial resonant unit is configured to generate magnetic or electrical resonance at the target shortwave frequency, thereby causing a frequency splitting effect, reducing the resonant frequency of the entire antenna, and realizing the miniaturization of the antenna's physical size.

2. The shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism according to claim 1, characterized in that, The physical length L of the main radiator is ≤ λ0 / 5.

3. The shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism according to claim 2, characterized in that, The main radiator is a ring structure made of metal wires, and the ring structure has an opening.

4. The shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism according to claim 3, characterized in that, The power supply structure is a closed resonant ring made of metal wires. There is no direct electrical contact between the power supply structure and the main radiator. Energy is transferred to the main radiator through mutual inductance coupling.

5. The shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism according to claim 1, characterized in that, The main radiator and the electromagnetic metamaterial resonant unit are coupled through near-field inductive coupling or direct electrical connection.

6. The shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism according to claim 5, characterized in that, The electromagnetic metamaterial resonant unit is a subwavelength artificial microstructure, and its unit feature size is... Less than 1 / 5 of the working wavelength.

7. The shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism according to claim 6, characterized in that, The electromagnetic metamaterial resonant unit is an open-ended resonant ring, and the opening direction of the open-ended resonant ring is consistent with the opening direction of the main radiator.

8. The shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism according to claim 7, characterized in that, The plurality of said open resonant rings are arranged in a periodic array, and tuning capacitors are connected between adjacent open resonant rings and between the open resonant rings and the main radiator in parallel or series.

9. The shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism according to claim 8, characterized in that, The electromagnetic metamaterial resonant unit integrates an adjustable element, which is used to change the effective capacitance or inductance of the metamaterial resonant unit, thereby continuously adjusting the operating frequency of the antenna.

10. The shortwave miniaturized antenna based on the electromagnetic metamaterial resonance mechanism according to claim 9, characterized in that, The adjustable element is a varactor diode, which is connected at the opening of the open resonant ring and its junction capacitance is controlled by an external bias voltage.

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