阅读说明：本技术 加载电流环的紧耦合阵列天线及天线单元 (Tightly coupled array antenna loaded with current loop and antenna unit ) 是由 谢佳玲 乔汉青 易超龙 方旭 石一平 樊亚军 夏文锋 朱郁丰 石磊 卢彦雷 张兴 于 2021-08-19 设计创作，主要内容包括：本发明公开了一种加载电流环的紧耦合阵列天线及天线单元。该阵列天线包括按照阵列排布的若干个天线单元,每相邻两个天线单元的E面之间形成紧耦合机制,确保两个相邻天线单元的电流幅度趋于恒定,相位趋于平滑渐变,相当于借用了邻近单元结构扩展了本单元的电长度,使阵列天线在低频段具有良好的匹配特性,实现以小尺寸辐射低频,同时每个天线单元的辐射主体部分与地板之间通过接地带连接,从而构成电流环,电流环将未通过口面辐射出去的电流利用起来形成磁振子,与天线本身的电振子构成互补,不仅能消除发射,而且能进一步增强辐射能力。(The invention discloses a tightly coupled array antenna loaded with a current loop and an antenna unit. The array antenna comprises a plurality of antenna units which are arranged according to an array, a tight coupling mechanism is formed between E surfaces of every two adjacent antenna units, the fact that the current amplitude of the two adjacent antenna units tends to be constant and the phase tends to be smoothly and gradually changed is guaranteed, namely the electric length of the antenna unit is expanded by means of the structure of the adjacent unit, the array antenna has good matching characteristics in a low-frequency band, low-frequency radiation with small size is achieved, meanwhile, the radiation main part of each antenna unit is connected with the floor through a grounding band, a current loop is formed, the current which is not radiated out through the mouth surface is utilized by the current loop to form a magnetic oscillator, the current loop and the electric oscillator of the antenna are complementary, emission can be eliminated, and the radiation capacity can be further enhanced.)

1. The utility model provides a load current loop's close coupling array antenna, includes a plurality of antenna element who arranges according to the array which characterized in that:

a tight coupling mechanism is formed between the E surfaces of every two adjacent antenna units, so that the current amplitude of the two adjacent antenna units tends to be constant, and the phase tends to be smoothly and gradually changed;

the radiation main part of each antenna unit is connected with the floor through a grounding strip, so that a current loop is formed.

2. A current-loop loaded tightly coupled array antenna as in claim 1, wherein: the tight coupling mechanism is that the E surfaces between two adjacent antenna units have a distance, or the E surfaces of two adjacent antenna units are mutually interdigitated, or the E surfaces of two adjacent antenna units are mutually overlapped.

3. A current-loop loaded tightly coupled array antenna as in claim 1, wherein: the radiating body part is in the form of a Vivaldi antenna or in the form of a dipole antenna.

4. An antenna element for forming an array antenna according to any of claims 1-3, the antenna element comprising: a radiation main body part made of conductive metal, a balun and a floor; the radiation main body part and the floor are vertical to each other;

a grounding band and a balun are arranged between the radiation main body part and the floor; the radiating body portion, the ground plane and the ground strip form a current loop.

5. The antenna unit of claim 4, wherein: the radiating body part is in the form of a Vivaldi antenna or in the form of a dipole antenna.

6. The antenna unit of claim 4, wherein: the balun adopts a structure in a gradual change parallel double-line form.

7. The antenna unit of claim 4, wherein: the conductive metal is copper.

8. An antenna element for forming an array antenna according to any of claims 1-3, the antenna element comprising: a radiation main body part made of conductive metal, a balun and a floor; the radiation main body part is parallel to the floor;

the radiation main body part is in a dipole antenna form;

a grounding band and a balun are vertically connected between the radiation main body part and the floor; the radiating body portion, the ground plane and the ground strip form a current loop.

9. The antenna unit of claim 8, wherein: the balun adopts a structure in a gradual change parallel double-line form.

10. The antenna unit of claim 8, wherein: the conductive metal is copper.

Technical Field

The invention relates to an ultra-wide spectrum pulse radiation antenna, in particular to a tightly coupled array antenna loaded with a current loop and an antenna unit.

Background

Ultra-wide spectrum electromagnetic pulses typically refer to pulse fronts or pulse widths in sub-nanoseconds (10)^-10s) magnitude and spectrum range from tens of MHz to several GHz, and is widely applied in target detection, target identification, electromagnetic compatibility, biomedicine and other fields. The ultra-wideband array antenna is an ultra-wideband electromagnetic pulse systemThe core component of the system is used for radiating the ultra-wide spectrum pulse generated by the pulse source to a specified area with a certain beam width.

Miniaturization of ultra-wideband array antennas is a problem that must be solved for practical application of ultra-wideband electromagnetic pulse systems. Because the ultra-wide spectrum pulse has abundant frequency components, the size of the array antenna adopted at present is large in order to effectively radiate out the low-frequency components of the pulse, but the factor becomes a main bottleneck problem limiting the miniaturization of the ultra-wide band antenna.

Disclosure of Invention

In order to solve the problem that the size of an array antenna used by the existing ultra-wideband array antenna is large in order to effectively radiate pulse low-frequency components, the invention provides a tightly-coupled array antenna loaded with a current loop, and also provides an antenna unit for forming the array antenna.

The specific technical scheme of the invention is as follows:

a tightly coupled array antenna loaded with a current loop comprises a plurality of antenna units which are arranged according to an array, wherein a tightly coupled mechanism is formed between E surfaces of every two adjacent antenna units, so that the current amplitude of the two adjacent antenna units tends to be constant, and the phase tends to be smoothly and gradually changed;

the radiation main part of each antenna unit is connected with the floor through a grounding strip, so that a current loop is formed.

Further, the tight coupling mechanism is that the E surfaces between two adjacent antenna units have a distance, or the E surfaces of two adjacent antenna units are interdigitated with each other, or the E surfaces of two adjacent antenna units are overlapped with each other.

Further, the radiation main body part is in a Vivaldi antenna form or a dipole antenna form.

Meanwhile, the invention also provides two antenna units for forming the array antenna;

the first antenna unit includes: a radiation main body part made of conductive metal, a balun and a floor; the radiation main body part and the floor are vertical to each other;

a grounding band and a balun are arranged between the radiation main body part and the floor; the radiating body portion, the ground plane and the ground strip form a current loop.

The radiating body part of the antenna element takes the form of a Vivaldi antenna or a dipole antenna.

The second antenna unit includes: a radiation main body part made of conductive metal, a balun and a floor; the radiation main body part is parallel to the floor;

the radiation main body part is in a dipole antenna form;

a grounding band and a balun are vertically connected between the radiation main body part and the floor; the radiating body portion, the ground plane and the ground strip form a current loop.

Furthermore, the balun in the two antenna units adopts a gradual change parallel double line structure.

Furthermore, the conductive metal in the two antenna units is copper metal.

The invention has the beneficial effects that:

1. according to the array antenna, the adjacent antenna units are closely arranged in the array in a tight coupling mode, so that the current amplitude of the adjacent antenna units in the array tends to be constant, the phase tends to be smoothly and gradually changed, namely the electric length of the array antenna is expanded by means of the structure of the adjacent unit, the array antenna has good matching characteristics in a low frequency band, and low-frequency radiation in a small size is realized.

2. The antenna unit forming the array antenna is additionally provided with a grounding zone at the edge of a feed arm of the antenna unit, forms a current loop with the ground, utilizes the current which is not radiated out through the mouth surface to form a magnetic oscillator, and is complementary with the electric oscillator of the antenna, so that the radiation can be eliminated, and the radiation capability can be further enhanced.

3. According to the invention, the low-frequency radiation capability of two adjacent antenna units is enhanced in a tight coupling array mode, and meanwhile, the magnetic oscillator formed by the loading current loop and the electric oscillator of the radiation main body part form complementary radiation, so that the radiation capability is further enhanced.

Drawings

Fig. 1 is a schematic diagram of a conventional non-tightly coupled antenna array.

Fig. 2(a) the effect of antenna element length L on standing wave ratio.

Fig. 2(b) shows the effect of the array spacing Harray of the antenna elements in the H-plane direction on the standing wave ratio.

Fig. 2(C) the effect of antenna element width W on standing wave ratio.

Fig. 3(a) is a schematic diagram of the close-coupled mode in the close-spaced mode.

FIG. 3(b) is a schematic diagram of the tight coupling mode being inter-digitated.

Fig. 3(c) is a schematic diagram when the tight coupling mode is the overlapping mode.

Fig. 4 is a schematic diagram of current distribution in a tightly coupled array antenna.

Fig. 5 is a schematic diagram of a first antenna unit structure, in which (a) is a front view and (b) is a rear view.

Fig. 6 is a schematic diagram of a second antenna unit structure, in which (a) is a front view and (b) is a rear view.

Fig. 7 is a schematic diagram of a third antenna unit structure, in which (a) is a front view and (b) is a rear view.

Fig. 8 is a comparison graph of standing wave ratios for different antenna configurations.

The reference numbers are as follows:

1-printed circuit board, 2-floor, 3-radiating body part, 4-balun, 5-grounding band.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The existing array antenna structure is shown in fig. 1, the standing-wave ratio of which has a resonance point, and through simulation analysis, as shown in fig. 2(a), (b) and (c), the frequency of the resonance point has a small correlation with the length L of the antenna unit, and has a large correlation with the array spacing Harray and the width W of the antenna unit in the H-plane direction, that is, a part of the current reaches the edge of the antenna unit and continues to propagate in the H-plane direction, and is reflected by the adjacent antenna unit in the direction to cause the resonance point.

In order to solve the above problems of the existing array antenna, the invention provides a tightly coupled array antenna loaded with a current loop, and the structure of the array antenna is as follows:

the antenna comprises a plurality of antenna units arranged according to an array, wherein a tight coupling mechanism is formed between E surfaces of every two adjacent antenna units, (the tight coupling mechanism is divided into a mode of close spacing, interdigital and partial overlapping), and the three modes are respectively shown in a figure 3(a), a figure 3(b) and a figure 3(c), so that the current amplitude of the adjacent antenna units in the array antenna tends to be constant, and the phase tends to be smoothly and gradually changed, as shown in a figure 4, the electrical length of the antenna units is enlarged, the antenna also has good matching characteristics in a low frequency range, and small-size radiation low frequency can be realized.

The close distance is actually the distance between the E surfaces of two adjacent antenna units, so that a coupling capacitor is formed between the adjacent antenna units;

the interdigital is actually an E-plane interdigital of two adjacent antenna units;

the overlap is actually the portion of the E-faces of two adjacent antenna elements that overlap each other.

Meanwhile, the radiation main body part of each antenna unit is connected with the floor through a grounding band, so that a current loop is formed, the current loop utilizes the current which is not radiated out through the mouth surface to form a magnetic oscillator, the current loop is complementary with the magnetic oscillator formed by the radiation main body part, the phase shift of the electric current and the magnetic current is adjusted through optimally designing the current loop, the electric dipole moment and the magnetic dipole moment reach a balance condition, the generated low-frequency radiation is synthesized in the main beam direction of the antenna radiation and is cancelled in the backward direction of the main beam, and the low-frequency radiation capability of the antenna is enhanced. Meanwhile, for the independent electric oscillator or magnetic oscillator, the near-region electric field energy and the magnetic field energy are different, the difference value of the near-region electric field energy and the magnetic field energy cannot participate in energy exchange to form radiation waves, and the electric oscillator and the magnetic oscillator are combined to enable the energy difference of the electric oscillator and the magnetic oscillator to change along with the phase change such as frequency and the like, so that the radiation energy flux density of the antenna is increased, the complementary radiation of the electromagnetic oscillator is realized, the radiation bandwidth is further expanded, and the radiation capability is enhanced.

For a more clear description of the structure of the array antenna, three different forms of antenna elements will now be described with reference to the accompanying drawings:

first structural form

As shown in fig. 5, the antenna unit includes a printed circuit board 1 and a floor 2 vertically and fixedly connected to the printed circuit board 1, wherein the floor 2 is made of a metal material with good electrical conductivity, the printed circuit board 1 is a dielectric board with less attenuation of high-frequency electromagnetic waves, a radiation main body portion 3 and a balun 4 are plated on the front surface and the back surface of the dielectric board, the radiation main body portion 3 adopts a Vivaldi antenna form, and the balun 4 adopts a gradual change parallel double-line structure; a grounding belt 5 is arranged between the front radiation main body part 3 and the floor 2; the radiation main body part 3, the floor 2 and the grounding band 5 form a current loop, the current loop utilizes the current which is not radiated out through the mouth surface to form a magnetic oscillator, and the current loop and the electric oscillator formed by the radiation main body part form complementation, so that the radiation bandwidth is further expanded, and the radiation capacity is enhanced. The size of the current loop can be realized by adjusting the width of the grounding strip.

Second structural form

As shown in fig. 6, the antenna unit includes a printed circuit board 1 and a floor 2 vertically and fixedly connected to the printed circuit board 1, wherein the floor 2 is made of a metal material with good electrical conductivity, the printed circuit board 1 is a dielectric plate with small attenuation of high-frequency electromagnetic waves, a radiation main body portion is coated on both the front surface and the back surface of the dielectric plate, the radiation main body portion 3 adopts a dipole antenna form, and the balun 4 adopts a gradual change parallel double-line form structure; a grounding belt 5 is arranged between the front radiation main body part 3 and the floor 2; the radiation main body part 3, the floor 2 and the grounding band 5 form a current loop, the current loop utilizes the current which is not radiated out through the mouth surface to form a magnetic oscillator, and the current loop and the electric oscillator formed by the radiation main body part form complementation, so that the radiation bandwidth is further expanded, and the radiation capacity is enhanced. The size of the current loop can be realized by adjusting the width of the grounding strip.

Third structural form

As shown in fig. 7, the antenna unit includes a printed circuit board 1 and a floor 2 disposed in parallel with the printed circuit board 1; the floor 2 is made of metal with good electric conductivity, the printed circuit board 1 is a dielectric plate with small high-frequency electromagnetic wave attenuation, the upper surface and the lower surface of the dielectric plate are respectively coated with a radiation main body part, and the radiation main body part 3 is in a dipole antenna form; a grounding belt 5 and a balun 4 are vertically connected between the radiation main body part 3 of the lower surface and the floor 2; the balun 4 adopts a structure in a gradual change parallel double-line form; the radiation main body part 3, the floor 2 and the grounding band 5 form a current loop, the current loop utilizes the current which is not radiated out through the mouth surface to form a magnetic oscillator, and the current loop and the electric oscillator formed by the radiation main body part form complementation, so that the radiation bandwidth is further expanded, and the radiation capacity is enhanced. The size of the current loop can be realized by adjusting the diameter of the grounding strip.

In order to further verify the effect of the array antenna, the following standing-wave ratio comparison simulation tests of four different array antennas are provided;

the four different array antennas are:

a: antenna structure with tightly coupled current loop

B: tightly coupled antenna structure without current loop

C: antenna structure combining non-tight coupling with current loop

D: antenna structure of non-tight coupling no current loop

As shown in fig. 8, when the antenna of the a structure works, because the unit antennas are tightly coupled, the current amplitudes of the adjacent units in the array tend to be constant, and the phases tend to be smoothly and gradually changed, thereby the electrical length of the unit antennas is enlarged, the antenna has a good matching characteristic in a low frequency band, and because a current loop exists, one part of the ultra-wide spectrum electromagnetic pulse passes through the radiation main body part, and the other part passes through the current loop, which is equivalent to a magnetic oscillator, and is complementary with the electric oscillator of the radiation main body part, thereby not only eliminating the emission, but also further enhancing the radiation capability.

When the antenna with the structure B works, current which is not radiated out through the mouth surface reaches the edge of the antenna unit, most of the current is coupled to the adjacent antenna unit, a small part of the current is transmitted along the direction of the H surface, and is reflected by the adjacent antenna unit in the direction to form a resonance point, and the frequency of the resonance point is related to the array spacing in the direction of the H surface.

When the antenna with the structure C works, the current which is not radiated out through the opening surface reaches the edge of the antenna unit, and because the units are mutually independent, the current is totally reflected back and flows into the floor through the grounding band to form a current loop. However, due to lack of tight coupling between the unit antennas, the low-frequency radiation capability of the radiating main body electric oscillator is limited, and the radiating main body electric oscillator cannot form effective complementary radiation with the current loop magnetic oscillator, that is, the low-frequency radiation performance of the antenna cannot be improved.

When the antenna with the structure D works, the current which is not radiated out through the mouth surface reaches the edge of the antenna unit, and the current is totally reflected back due to the mutual independence among the units, so that electromagnetic waves, particularly low-frequency electromagnetic waves, can not be radiated.

Therefore, compared with the B, C, D structure, the structure A has the advantages that the current loop is loaded on the antenna units and the adjacent antenna units are in the tight coupling layout, so that the low-frequency radiation bandwidth can be effectively expanded, the radiation capability is improved, and the performance of the antenna structure is optimal.