Two-dimensional frequency scanning leaky wave antenna array and two-dimensional frequency scanning method

Abstract

The present invention provides a two-dimensional frequency-scanning leaky-wave antenna array and a two-dimensional frequency-scanning method, belonging to the field of electronic communications technology. The array comprises a top metal layer, an upper dielectric layer, an intermediate metal layer, a lower dielectric layer, and a bottom metal layer, arranged in sequence; the top metal layer is etched with an array of slots; both the upper and lower dielectric layers are provided with arrays of metallized through-holes; the upper dielectric layer, the top metal layer, and the intermediate metal layer etched with coupling slots together form an upper leaky-wave antenna array based on a substrate-integrated waveguide; and the lower dielectric layer, the intermediate metal layer, and the bottom metal layer together form an energy-circulating phase-shifting feeding network based on the substrate-integrated waveguide. The present invention has a compact structure, simple power feeding, and is easy to process and mass-produce. The scanning angle of the beam in two dimensions can be adjusted simply by changing the frequency, thus offering improved practicality.

Description

Technical Field

[0001] The present invention relates to the field of electronic communication technology, and in particular to a two-dimensional frequency scanning leaky wave antenna array and a two-dimensional frequency scanning method. Background Art

[0002] Currently, many fields and technologies require the antenna beam to have the ability to scan in two dimensions, such as electromagnetic imaging, radar systems, and MIMO technology in mobile communications. In recent years, researchers have proposed a variety of methods to achieve two-dimensional beam scanning, such as the fully electronic control method, the multi-beam method, and a combination of the above methods. However, the electronic control method requires the introduction of a DC bias network, which not only increases the complexity of the structure, but also increases the energy consumption of the antenna, thereby reducing the antenna efficiency. The multi-beam method requires complex switching circuits, which also increases the complexity of the antenna. In addition, due to the number of feed ports of the multi-beam antenna, the beam scanning range of the two-dimensional scanning antenna based on the multi-beam method is limited.

[0003] Furthermore, researchers have proposed a two-dimensional frequency-sweeping leaky-wave antenna, combining the frequency-sweeping characteristics of leaky-wave antennas. This involves connecting a phase-shifting network composed of unequal-length transmission lines with frequency-dependent phase differences in front of the leaky-wave antenna array. This phase-shifting network provides one-dimensional frequency sweep, while the frequency-sweeping characteristics of the leaky-wave antenna provide another. However, this approach still requires a bulky phase-shifting network, resulting in a complex design and a less compact and concise overall structure. Summary of the Invention

[0004] The object of the present invention is to provide a two-dimensional frequency scanning leaky wave antenna array and a two-dimensional frequency scanning method with a simple and compact structure and a larger scanning range, so as to solve at least one technical problem existing in the above-mentioned background technology.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In one aspect, the present invention provides a two-dimensional frequency scanning leaky wave antenna array, comprising:

[0007] It includes a top metal layer, an upper dielectric layer, an intermediate metal layer, a lower dielectric layer, and a bottom metal layer arranged in sequence;

[0008] The top metal layer is etched with gaps arranged in an array;

[0009] The upper dielectric layer and the lower dielectric layer are both provided with metallized through-hole arrays;

[0010] The upper dielectric layer, the top metal layer, and the intermediate metal layer with the coupling gaps etched therein together constitute an upper leaky wave antenna array based on a substrate integrated waveguide;

[0011] The lower dielectric layer, the middle metal layer and the bottom metal layer together form an energy circulation phase-shift feeding network based on a substrate integrated waveguide.

[0012] Preferably, the gaps etched in the top metal layer are sinusoidally periodically modulated gaps.

[0013] Preferably, the sinusoidal periodic modulated gaps etched in the top metal layer are used to suppress the open stop band.

[0014] Preferably, a first metal via is provided next to the metallized through hole array provided on the upper dielectric layer for impedance matching.

[0015] Preferably, S-shaped phase shifters arranged in sequence are provided on the lower dielectric layer to form an energy circulation phase shift feeding network.

[0016] Preferably, a second metal via is provided at the bend of the S-shaped phase shifter for impedance matching.

[0017] Preferably, a first gradient microstrip line and a second gradient microstrip line are provided on the top metal layer.

[0018] In a second aspect, the present invention provides a two-dimensional frequency scanning method using the two-dimensional frequency scanning leaky wave antenna array as described above, wherein electromagnetic wave energy is fed into the upper leaky wave antenna array from the input port, enters the energy cycle phase shift feeding network through coupling, and is fed into the upper leaky wave antenna array again through coupling. After several identical energy cycle feedings, all antennas of the upper leaky wave antenna array are fed; in this process, a phase difference that varies with frequency is formed between the leaky wave antenna array elements, causing the beam angle to be scanned in the azimuth plane, and combined with the frequency scanning characteristics of the leaky wave antenna in the pitch plane, two-dimensional frequency scanning is achieved.

[0019] The present invention has the following beneficial effects: compact structure, simple power feeding, easy processing and mass production, and the scanning angle of the beam in two-dimensional space can be adjusted only by changing the frequency, thereby having better practicality.

[0020] Additional aspects and advantages of the present invention will be set forth in part in the following description, will become apparent from the following description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1Schematic diagram of energy flow in the two-dimensional frequency scanning method according to an embodiment of the present invention.

[0023] Figure 2 Schematic diagram of the layered structure of the two-dimensional frequency scanning leaky wave antenna array according to an embodiment of the present invention.

[0024] Figure 3 A schematic diagram of the S parameters of the two-dimensional frequency-scanning leaky-wave antenna array according to an embodiment of the present invention.

[0025] Figure 4 This is the 3D radiation pattern of the two-dimensional frequency scanning leaky wave antenna array at 14.2 GHz according to an embodiment of the present invention.

[0026] Figure 5 This is the 3D radiation pattern of the two-dimensional frequency scanning leaky wave antenna array at 15.5 GHz according to an embodiment of the present invention.

[0027] Figure 6 This is the 3D radiation pattern of the two-dimensional frequency scanning leaky wave antenna array at 16.1 GHz according to an embodiment of the present invention.

[0028] Figure 7 This is the beam scanning pattern of the two-dimensional frequency scanning leaky wave antenna array on the xoz plane according to an embodiment of the present invention.

[0029] Figure 8 This is the beam scanning pattern of the two-dimensional frequency scanning leaky wave antenna array on the yoz plane according to an embodiment of the present invention.

[0030] Figure 9 This is a two-dimensional 3dB contour pattern of the two-dimensional frequency scanning leaky wave antenna array according to an embodiment of the present invention.

[0031] Figure 10 This is a graph showing the gain and efficiency of the two-dimensional frequency-scanning leaky-wave antenna array according to an embodiment of the present invention.

[0032] Among them: 5-top metal layer; 6-upper dielectric layer; 7-middle metal layer; 8-lower dielectric layer; 9-bottom metal layer; 10-gap; 12-metallized through-hole array; 13-coupling gap; 11-first metal via; 17-S-shaped phase shifter; 14-second metal via; 15-first gradient microstrip line; 16-second gradient microstrip line; 1-upper leaky wave antenna array; 2-first coupling structure; 3-phase shifting structure; 4-second coupling structure. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention.

[0034] Those skilled in the art will understand that unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs.

[0035] It should also be understood that terms, such as those defined in commonly used dictionaries, should be understood to have a meaning consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless as defined herein.

[0036] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a," "an," "said," and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0037] In the description of this specification, reference to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and integrate different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless otherwise inconsistent.

[0038] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0039] In the description of this specification, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present technology and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting the present technology.

[0040] Unless otherwise specified or limited, the terms "installed," "connected," "connected," and "disposed" should be understood broadly. For example, they may refer to fixed connection or disposition, detachable connection or disposition, or integral connection or disposition. Those skilled in the art will understand the specific meanings of these terms in this technology based on specific circumstances.

[0041] To facilitate understanding of the present invention, the present invention is further explained below with reference to specific embodiments in conjunction with the accompanying drawings, and the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0042] Those skilled in the art should understand that the drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily necessary for implementing the present invention.

[0043] Example

[0044] like Figure 2 As shown, in this embodiment, a two-dimensional frequency scanning leaky wave antenna array is first provided, whose structure includes: a top metal layer 5, an upper dielectric layer 6, an intermediate metal layer 7, a lower dielectric layer 8, and a bottom metal layer 9 arranged in sequence; the top metal layer 5 is etched with an array of slots 10; the upper dielectric layer 6 and the lower dielectric layer 8 are both provided with a metallized through-hole array 12; the upper dielectric layer 6, the top metal layer 5, and the intermediate metal layer 7 with etched coupling slots 13 together constitute an upper leaky wave antenna array 1 based on a substrate integrated waveguide; the lower dielectric layer 8, the intermediate metal layer 7, and the bottom metal layer 9 together constitute an energy circulation phase shift feeding network 3 based on a substrate integrated waveguide. The dielectric constant of the dielectric substrate of the upper dielectric layer and the lower dielectric layer is ε r =3, the height of the dielectric plate is 1.524 mm, and the overall structural dimensions of the antenna are 126 mm × 94.5 mm × 3.048 mm.

[0045] The slits 10 etched in the top metal layer 5 are sinusoidally periodically modulated slits. These sinusoidally periodically modulated slits serve to suppress the open-stop band. A first metal via 11 is provided adjacent to the metallized through-hole array 12 provided on the upper dielectric layer 6 for impedance matching. S-shaped phase shifters 17 are arranged in sequence on the lower dielectric layer 8 to form an energy-circulating phase-shifting feed network. Second metal vias 14 are provided at the bends of the S-shaped phase shifters 17 for impedance matching. A first gradient microstrip line 15 and a second gradient microstrip line 16 are provided on the top metal layer 5.

[0046] In this embodiment, a two-dimensional frequency scanning method can be implemented using the above antenna array. Figure 1 A schematic diagram showing the energy flow in the two-dimensional frequency scanning method is shown in FIG. Figure 1 As shown, in the two-dimensional frequency scanning method, the electromagnetic wave energy enters the upper leaky wave antenna array 1 of the upper plate (that is, abstractly composed of the upper dielectric layer, the top metal layer, and the intermediate metal layer with the coupling slot etched therein) from the left waveguide, enters the energy circulation phase shift feeding network 3 of the lower plate (that is, abstractly composed of the lower dielectric layer 8, the intermediate metal layer 7, and the bottom metal layer 9) through the first coupling structure 2 (that is, abstractly composed of the coupling slot 13, the first metal via 11, and the metal via 21), and enters the upper leaky wave antenna array 1 again through the second coupling structure 4 (that is, abstractly composed of the coupling slot 18, the metal via 19, and the metal via 20) and feeds it. After several identical energy cycles, all antennas in the upper leaky wave antenna array 1 are fed. When the overall antenna structure is fixed, the energy transmission path difference between adjacent leaky-wave antenna elements is constant. However, for dispersive waveguides, their transmission constant varies with frequency. Therefore, the phase difference between adjacent leaky-wave antennas also varies with frequency. According to antenna array theory, the change in phase difference will cause the beam angle to scan in the xoz plane. Combined with the frequency scanning characteristics of the leaky-wave antenna in the yoz plane, the antenna can achieve two-dimensional frequency scanning.

[0047] After the energy is fed into the first element of the leaky wave antenna array through the first tapered microstrip line 15, it enters the energy circulation phase-shift feeding network and feeds the second element through it. After several identical cycles, all the leaky wave antenna elements are fed, and the remaining energy is absorbed by the matching load connected to the second tapered microstrip line 16.

[0048] Figure 3 Shows the S parameters of the antenna, from Figure 3It can be seen from the figure that the simulated operating frequency band of the antenna is 13.6GHz-16.9GHz, and the measured operating frequency band is 13.1GHz-17.7GHz. Within the working frequency band of the antenna, both the simulated and measured |S11| are less than -10dB, the simulated |S21| is less than -10dB, and the measured |S21| is less than -20dB.

[0049] Figure 4 、 Figure 5 、 Figure 6 The 3D radiation patterns of the antenna at 14.2 GHz, 15.5 GHz, and 16.1 GHz are shown respectively. As can be seen from the figure, as the frequency changes from low to high, the projection of the antenna main beam on the xoz plane and yoz plane both scans from negative to positive.

[0050] Figure 7 、 Figure 8 The directional patterns of the antenna beams on the xoz and yoz planes are shown respectively. Figure 6 It can be seen that the beam on the xoz plane scans from -60° to 30° in the frequency range of 15.3GHz-15.7GHz. Figure 7 It can be seen that the beam located on the yoz plane scans from -17° to 17° in the frequency band of 14.4GHz-16.8GHz.

[0051] Figure 9 The two-dimensional 3dB contour pattern of the antenna array is shown. It can be seen from the figure that in the frequency range of 14GHz-16.8GHz, the scanning range of the antenna is 120°×180° (theta×phi).

[0052] Figure 10 The gain and efficiency of the antenna are shown. As can be seen from the figure, the gain of the antenna is basically around 15dBi. In addition, because the antenna structure adopts an energy circulation phase shift feeding network, the antenna has a high radiation efficiency of about 70%.

[0053] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solutions disclosed in the present invention without the need for creative work should be included in the scope of protection of the present invention.

Claims

1. A two-dimensional frequency scanning leaky wave antenna array, characterized in that include: It comprises a top metal layer (5), an upper dielectric layer (6), an intermediate metal layer (7), a lower dielectric layer (8), and a bottom metal layer (9) which are arranged in sequence; The top metal layer (5) is etched with array-arranged slits (10); The upper dielectric layer (6) and the lower dielectric layer (8) are both provided with a metallized through-hole array (12); The upper dielectric layer (6), the top metal layer (5), and the intermediate metal layer (7) with the etched coupling gap (13) together form an upper leaky wave antenna array (1) based on a substrate integrated waveguide; The lower dielectric layer (8), the intermediate metal layer (7), and the bottom metal layer (9) together form an energy circulation phase-shift feeding network (3) based on a substrate integrated waveguide; The slits (10) etched on the top metal layer (5) are sinusoidal periodic modulation slits; the sinusoidal periodic modulation slits etched on the top metal layer (5) are used to suppress the open resistance band; a first metal via (11) is provided next to the metallized through-hole array (12) provided on the upper dielectric layer (6) for impedance matching; S-shaped phase shifters (17) arranged in sequence are provided on the lower dielectric layer (8) to form an energy circulation phase shift feeding network; a second metal via (14) is provided at the bend of the S-shaped phase shifter (17) for impedance matching; Electromagnetic wave energy is fed into the upper leaky wave antenna array (1) from the input port, enters the energy circulation phase shift feeding network (3) through coupling, and is fed into the upper leaky wave antenna array (1) again through coupling. After several identical energy circulation feedings, all antennas of the upper leaky wave antenna array (1) are fed. In this process, a phase difference that varies with frequency is formed between the leaky wave antenna elements, causing the beam angle to scan in the azimuth plane. Combined with the frequency scanning characteristics of the leaky wave antenna in the elevation plane, two-dimensional frequency scanning is achieved.

2. The two-dimensional frequency scanning leaky wave antenna array according to claim 1, characterized in that: A first gradient microstrip line (15) and a second gradient microstrip line (16) are provided on the top metal layer (5).

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