Magnetic dipole radiator, transmitting antenna and underwater active electromagnetic detection system

Abstract

A magnetic dipole radiator comprises a first coil winding and a third coil winding which are wound at the two ends of an iron core respectively, and the number of turns of the first coil winding and the number of turns of the third coil winding are the same; the second coil winding is wound on the middle section of the iron core, the second coil winding, the first coil winding and the third coil winding form a mutual inductance coupling double-tuning loop, the winding directions of the first coil winding, the second coil winding and the third coil winding are the same, and the number of turns of the second coil winding is multiple times that of the first coil winding; and the matching capacitor is connected in series with the second coil winding and is matched on the bandwidth center frequency. The utility model also provides a transmitting antenna comprising the magnetic dipole radiator. Three groups of coils are wound on the iron core, so that the broadband, high-power and small-size harmonic variable magnetic dipole radiator is formed, and a practical and convenient technical means is provided for electromagnetic detection and electromagnetic interference of underwater broadband emission and variable frequency emission.

Description

Technical Field

[0001] The utility model relates to the technical field of electromagnetic detection, in particular to a magnetic dipole radiator, a transmitting antenna and an underwater active electromagnetic detection system. Background Art

[0002] The transmitting antenna is an important part of the active electromagnetic detection system. In the underwater active electromagnetic detection system, a harmonic magnetic dipole radiator must be used to emit the source electromagnetic field. When performing active electromagnetic interference and countermeasure underwater, a broadband and high-power electromagnetic radiation source is required. The commonly used harmonic magnetic dipole radiator generally densely winds a single set of coils on an iron core with a certain shape and size. The harmonic magnetic dipole radiator, a tuning capacitor and a transmitting mechanism form a series-tuned transmitting circuit, which emits a detection electromagnetic field under the excitation of a signal source. The characteristic of this series-tuned transmitting circuit is that the harmonic magnetic dipole radiator obtains a certain current excitation under certain frequency conditions, so as to realize the rated radiation magnetic moment.

[0003] The above-mentioned harmonic magnetic dipole radiator adopts a simple single-winding mode, and the formed transmitting circuit can only be in a series-tuned mode. Its disadvantage is that the working bandwidth is too narrow, and the radiation magnetic moment will drop sharply when the frequency deviates from the resonance point, which cannot meet the actual needs of electromagnetic detection and electromagnetic interference in the wide frequency band range and variable frequency working mode. Although the traditional harmonic magnetic dipole radiator can be switched according to needs in the form of multiple series-tuned circuits to realize tuning at multiple frequency points and broaden the working frequency domain of the system, due to the limitations of the structure and working mechanism, its actual working bandwidth, real-time performance, continuity, uniformity, stability of the radiation electromagnetic field, etc. cannot meet the actual requirements of wide frequency band, high power, continuously adjustable, small volume, etc. Summary of the Utility Model

[0004] The technical problem solved by the utility model is to provide a magnetic dipole radiator, a transmitting antenna and an underwater active electromagnetic detection system, so as to solve the problems that the radiator with a single-winding mode has too narrow working bandwidth and the radiation magnetic moment drops sharply when the frequency deviates from the resonance point.

[0005] To solve the above technical problems, an embodiment of the utility model provides a magnetic dipole radiator, which includes: a first coil winding and a third coil winding, which are respectively wound at both ends of the iron core, and the number of turns of the first coil winding and the third coil winding is the same; a second coil winding, which is wound in the middle section of the iron core and forms a mutual inductance-coupled double-tuned circuit with the first coil winding and the third coil winding. The winding directions of the first coil winding, the second coil winding and the third coil winding are the same, and the number of turns of the second coil winding is several times that of the first coil winding; a tuning capacitor, which is connected in series with the second coil winding and is tuned at the center frequency of the bandwidth.

[0006] Optionally, the iron core is a sub-nanocrystalline iron core.

[0007] Optionally, the second coil winding and the tuning capacitor form one of the emission circuits resonating at the center frequency.

[0008] Optionally, the first coil winding and the third coil winding are tuned on both sides of the center frequency and together form a double-tuned broadband harmonic magnetic dipole radiator.

[0009] Optionally, the number of turns of the second coil winding is 4-8 times that of the first coil winding.

[0010] Optionally, the number of turns of the second coil winding is 6 times that of the first coil winding.

[0011] The present utility model further provides a transmitting antenna, including the above-mentioned magnetic dipole radiator, a first power amplifier, and a second power amplifier; wherein, one end of the first coil winding is connected to the first power amplifier, one end of the third coil winding is connected to the second power amplifier, a first capacitor is connected in parallel with the first coil winding and the third coil winding, and a first diode and a second diode are connected in series and then connected in parallel with the first capacitor.

[0012] The first power amplifier and the second power amplifier are alternately turned on under the drive of an excitation signal source. The first coil winding and the third coil winding generate a radiation electromagnetic field signal under the corresponding loop current, and the second coil winding synchronously generates a radiation electromagnetic field signal. The radiation electromagnetic field signals generated by the first coil winding, the second coil winding, and the third coil winding are combined into a broadband and high-power radiation electromagnetic field.

[0013] Optionally, the mathematical model of the radiation magnetic moment of the radiation electromagnetic field is:

[0014]

[0015] Wherein:

[0016]

[0017] η = KQ

[0018] M(ω) is the harmonic magnetic dipole radiation magnetic moment;

[0019] ω is the radiation electromagnetic field signal frequency;

[0020] μ0 is the vacuum magnetic permeability;

[0021] μ d is the magnetic permeability of the iron core of the electromagnetic radiator;

[0022] S is the cross-sectional area of the iron core of the electromagnetic radiator;

[0023] N1 and N3 are the number of turns of electromagnetic radiation coils L1 and L3;

[0024] N2 is the number of turns of electromagnetic radiation coil L2;

[0025] I1(ω) and I3(ω) are the excitation currents of electromagnetic radiation coils L1 and L3;

[0026] I2(ω) is the excitation current of electromagnetic radiation coil L2;

[0027] φ o (ω) is the initial phase of the radiated electromagnetic signal;

[0028] m is the mutual inductance;

[0029] L1, L2, and L3 are the inductance of the electromagnetic radiation coil windings;

[0030] U is the excitation power supply voltage;

[0031] η is the coupling factor;

[0032] ξ is the generalized detuning;

[0033] C is the tuning capacitor;

[0034] KK is the coupling coefficient, 0 ≤ K ≤ 1.

[0035] The present utility model also provides an underwater active electromagnetic detection system, including the above-mentioned transmitting antenna.

[0036] Compared with the prior art, the technical solution of the embodiment of the present utility model has the following beneficial effects:

[0037] The magnetic dipole radiator of the technical solution of the present utility model forms a broadband, high-power, and small-size harmonic magnetic dipole radiator by winding three groups of coils on the iron core, providing a practical and convenient technical means for underwater broadband emission, frequency conversion emission electromagnetic detection and electromagnetic interference.

[0038] When the first power amplifier and the second power amplifier are alternately turned on under the drive of the excitation signal source, the corresponding loop currents generate radiation electromagnetic field signals when passing through the first coil winding and the third coil winding respectively. At the same time, the second coil winding also generates a radiation electromagnetic field signal synchronously. Therefore, the first coil winding, the second coil winding, and the third coil winding synthesize to generate a radiation electromagnetic field with a certain frequency and a certain power, so that the frequency band width of the electromagnetic field signal radiated by the magnetic dipole radiator under the double-tuning condition is greatly increased compared with that of the conventional magnetic dipole radiator.

[0039] The underwater active electromagnetic detection system of the technical solution of the present utility model provides a practical and convenient technical means for underwater broadband emission, frequency conversion emission of electromagnetic detection and electromagnetic interference through a magnetic dipole radiator with three groups of coils wound on an iron core. Brief Description of the Drawings

[0040] Figure 1 is a schematic diagram of the principle structure of the magnetic dipole radiator provided by the present utility model;

[0041] Figure 2 is a schematic diagram of the principle structure of the transmitting antenna provided by the present utility model;

[0042] Figure 3 is a schematic diagram of the amplitude-frequency characteristic corresponding to the transmitting antenna provided by the present utility model. Detailed Embodiments

[0043] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the embodiments of the present utility model. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0044] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present utility model, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0045] In the embodiments of the present utility model, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "fixed" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or a communication; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to specific circumstances.

[0046] The following disclosure provides many different embodiments or examples for implementing different structures of the embodiments of the present utility model. To simplify the disclosure of the embodiments of the present utility model, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the embodiments of the present utility model. In addition, the embodiments of the present utility model may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0047] To better understand the purpose, structure, and function of the present utility model, the following further describes in detail a magnetic dipole radiator, a transmitting antenna, and an underwater active electromagnetic detection system of the present utility model with reference to the accompanying drawings.

[0048] Figure 1 is a schematic diagram of the principle structure of the magnetic dipole radiator provided by the present utility model. Referring to Figure 1 , the present utility model provides a magnetic dipole radiator, including: a first coil winding L1 and a third coil winding L3, which are respectively wound around both ends of an iron core, and the number of turns of the first coil winding L1 and the third coil winding L3 is the same; a second coil winding L2, which is wound around the middle section of the iron core and forms a mutually inductive coupling double-tuned circuit with the first coil winding L1 and the third coil winding L3. The winding directions of the first coil winding L1, the second coil winding L2, and the third coil winding L3 are the same, and the number of turns of the second coil winding L2 is several times that of the first coil winding L1; a tuning capacitor C, which is connected in series with the second coil winding L2 and is tuned at the center frequency of the bandwidth.

[0049] In the embodiment of the present utility model, the iron core is a sub-nanocrystalline iron core. The sub-nanocrystalline iron core is made of sub-nanocrystalline alloy strips. The sub-nanocrystalline alloy strips are sub-nanocrystalline high-permeability magnetic materials of the same size cut according to requirements. Multiple layers of sub-nanocrystalline alloy strips are neatly stacked into a sub-nanocrystalline iron rod of a certain size and shape. Among them, the sub-nanocrystalline alloy material has better magnetic permeability than the conventional silicon steel sheet material. Under the same size and winding process conditions, the radiation magnetic moment generated by the electromagnetic radiator made of the sub-nanocrystalline iron core is 5%-10% larger than that of the electromagnetic radiator made of the ordinary iron core.

[0050] In the embodiment of the present utility model, the second coil winding and the tuning capacitor form one of the transmitting circuits resonating at the center frequency. This transmitting circuit forms a resonant circuit by connecting the tuning capacitor and the electric energy transmitting coil in series; the first coil winding and the third coil winding are tuned on both sides of the center frequency and jointly form a double-tuned broadband harmonic magnetic dipole radiator.

[0051] Figure 2 is a schematic diagram of the principle structure of the transmitting antenna provided by the present utility model. Referring toFigure 2 , a power amplifier circuit, including the magnetic dipole radiator as described above. One end of the first coil winding L1 is connected to the first power amplifier T1, and one end of the third coil winding L3 is connected to the second power amplifier T2. The first capacitor C1 is connected in parallel with the first coil winding L1 and the third coil winding L3. The first diode D1 and the second diode D2 are connected in series and then connected in parallel with the first capacitor C1.

[0052] The first coil winding L1 and the third coil winding L3 are alternately excited by the signal source of push-pull power amplification. When the first power amplifier T1 and the second power amplifier T2 are alternately turned on under the drive of the excitation signal source, the corresponding loop currents I1(ω) and I3(ω) will generate radiation electromagnetic field signals when passing through the first coil winding L1 and the third coil winding L3 respectively. At the same time, the second coil winding L2 that forms a magnetic hinge with the first coil winding L1 and the third coil winding L3 will synchronously generate radiation electromagnetic field signals and generate an excitation current I2(ω). The first coil winding L1, the second coil winding L2, and the third coil winding L3 are combined into a broadband and high-power radiation electromagnetic field; and both the bandwidth of the radiation electromagnetic field and the value of the radiation magnetic moment are greatly improved compared with the single-winding coil mode. Among them, generally, when the working frequency band is not less than 10% of the center frequency, it is considered broadband. In addition, when the magnetic dipole radiation power reaches about 70, it is high power.

[0053] The mathematical model of the radiation magnetic moment generated by the above broadband harmonic magnetic dipole radiator is:

[0054]

[0055] Among them,

[0056]

[0057] m is the mutual inductance, η = KQ ; M(ω) is the harmonic magnetic dipole radiation magnetic moment; ω is the frequency of the radiation electromagnetic field signal; μ0 is the vacuum magnetic permeability; μ d is the magnetic permeability of the iron core of the electromagnetic radiator; S is the cross-sectional area of the iron core of the electromagnetic radiator; N1 and N3 are the number of turns of the first coil winding L1 and the third coil winding L3 respectively; N2 is the number of turns of the second coil winding L2; I1(ω) and I3(ω) are the excitation currents of the first coil winding L1 and the third coil winding L3 respectively; I2(ω) is the excitation current of the second coil winding L2; φ o(ω) is the initial phase of the radiated electromagnetic signal; L1, L2, and L3 are the inductances of the first coil winding L1, the second coil winding L2, and the third coil winding L3, respectively; U is the excitation power supply voltage; η is the coupling factor; ξ is the generalized detuning; C is the tuning capacitor; K is the coupling coefficient, where 0 ≤ K ≤ 1.

[0058] Figure 3 It is a schematic diagram of the amplitude-frequency characteristic corresponding to the transmitting antenna provided by the present invention. In the embodiment of the present invention, the cross-sectional area of the iron core S = 30 × 30 mm 2 , the number of turns N1 = N3 = 120 turns, N2 = 720 turns, the winding resistance r1 = r3 = 0.8 Ω, r2 = 4.2 Ω, the winding inductance L1 = L3 = 2.5 mH, L2 = 95 mH, the working voltage U = 27 V. Referring to Figure 3 , under the double-tuning condition, the bandwidth of the electromagnetic field signal radiated by the magnetic dipole radiator is greatly increased compared with that of the conventional magnetic dipole radiator. The working bandwidth of the magnetic dipole radiator under the double-tuning condition ≥ 15F0%, and the magnetic moment ≥ 80 Am 2 , the radiated magnetic moment will not show a sudden drop when the frequency deviates from the resonant point. Compared with the conventional magnetic dipole radiator under the same scale condition, the bandwidth is increased by more than 10 times, the radiated magnetic moment is larger by (5 - 10)%, and the controllability, real-time performance, and stability are all significantly superior. The underwater active electromagnetic detection system provided by the present invention includes the above-mentioned transmitting antenna, providing a practical and convenient technical means for underwater broadband transmission, frequency conversion transmission, electromagnetic detection, and electromagnetic interference.

[0059] It can be understood that the present invention is described through the above embodiments. Those skilled in the art know that without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. In addition, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. A magnetic dipole radiator, characterized in that, Comprising: A first coil winding and a third coil winding, respectively wound around both ends of an iron core, and the number of turns of the first coil winding and the third coil winding is the same; A second coil winding, wound around the middle section of the iron core, and forms a mutual inductance-coupled double-tuned circuit with the first coil winding and the third coil winding. The winding directions of the first coil winding, the second coil winding, and the third coil winding are the same, and the number of turns of the second coil winding is several times that of the first coil winding; A tuning capacitor, connected in series with the second coil winding and tuned at the center frequency of the bandwidth.

2. The magnetic dipole radiator according to claim 1, wherein The iron core is a sub-nanocrystalline iron core.

3. The magnetic dipole radiator according to claim 1, characterized in that, The second coil winding and the tuning capacitor form one of the emission circuits resonating at the center frequency.

4. The magnetic dipole radiator according to claim 3, characterized in that, The first coil winding and the third coil winding are tuned on both sides of the center frequency and jointly form a double-tuned broadband harmonic magnetic dipole radiator.

5. The magnetic dipole radiator according to any one of claims 1-4, characterized in that, The number of turns of the second coil winding is 4 - 8 times that of the first coil winding.

6. The magnetic dipole radiator according to claim 5, wherein, The number of turns of the second coil winding is 6 times that of the first coil winding.

7. An emission antenna, characterized in that, Comprising the magnetic dipole radiator according to any one of claims 1 - 6, a first power amplifier, and a second power amplifier; wherein, one end of the first coil winding is connected to the first power amplifier, one end of the third coil winding is connected to the second power amplifier, a first capacitor is connected in parallel with the first coil winding and the third coil winding, and a first diode and a second diode are connected in series and then connected in parallel with the first capacitor.

8. The transmitting antenna according to claim 7, wherein The first power amplifier and the second power amplifier are alternately turned on under the drive of an excitation signal source. The first coil winding and the third coil winding generate a radiation electromagnetic field signal under the corresponding loop current, and the second coil winding synchronously generates a radiation electromagnetic field signal. The radiation electromagnetic field signals generated by the first coil winding, the second coil winding, and the third coil winding are synthesized into a broadband and high-power radiation electromagnetic field.

9. The transmitting antenna according to claim 8, wherein The mathematical model of the radiation magnetic moment of the radiation electromagnetic field is: Wherein: ； ； ； =KQ is the harmonic magnetic dipole radiation magnetic moment; is the frequency of the radiated electromagnetic field signal; is the permeability of free space; is the magnetic permeability of the iron core of the electromagnetic radiator; is the cross-sectional area of the iron core of the electromagnetic radiator; are the number of turns of the electromagnetic radiation coils L1 and L3; is the number of turns of the electromagnetic radiation coil L2; are the exciting currents of the electromagnetic radiation coils L1 and L3; is the exciting current of the electromagnetic radiation coil L2; is the initial phase of the radiated electromagnetic signal; is mutual inductance; is the inductance of the electromagnetic radiation coil winding; is the excitation power supply voltage; is the coupling factor; is the generalized detuning; is the tuning capacitor; is the coupling coefficient, 0 ≤ K ≤ 1.

10. An underwater active electromagnetic detection system, characterized in that, Comprising the transmitting antenna according to any one of claims 7 - 9.

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