A low-profile, high-efficiency waveguide slot array antenna with data transmission suppression function

Abstract

The present invention discloses a low-profile high-efficiency waveguide slot array antenna with a data transmission suppression function, the antenna comprising a radiation part and a feeding part, N first radiation units are connected end to end in azimuth, N second radiation units are connected end to end in azimuth, and the tail end of the Nth first radiation unit is connected to the head end of the first second radiation unit; the first radiation unit and the second radiation unit each comprise two V-shaped inclined radiation slots distributed at equal intervals in azimuth; the feeding part comprises a power layer, a filter layer and a coaxial line running through the power layer and the filter layer, which are sequentially stacked under the radiation part. The present invention adds a waveguide filter layer to the feeding part, uses the cutoff wavelength of the waveguide to filter out interference from other noises, and gives the antenna the function of data transmission suppression, reduces the size of the waveguide, improves the radiation efficiency, and achieves a low-profile effect.

Description

Technical Field

[0001] The present invention belongs to the field of radar technology, and in particular relates to a low-profile and high-efficiency waveguide slot array antenna with a data transmission suppression function. Background Art

[0002] X-band antennas are widely used in airborne radar systems in military and civilian fields such as security and surveillance due to their high resolution and high precision. In these systems, low profile and high gain are important parameters for radar antennas, so high requirements are placed on the miniaturization and efficient resource utilization of such antennas. Waveguide slot array antennas have become ideal candidates for radar applications due to their advantages in weight, volume and radiation characteristics. These antennas are light in weight, small in volume, high in power capacity, high in gain, narrow in beam, and excellent in reliability. They can provide radar systems with directional transmit and receive electromagnetic wave radiation to detect and track targets. For the design of waveguide slot array antennas, ridge waveguides are usually used to overcome the limitations of rectangular waveguides in terms of size, layout and performance.

[0003] The existing technology usually uses a longitudinal slot on the wide side of the ridge waveguide to achieve the radiation of the waveguide slot array antenna. Compared with the traditional rectangular waveguide, this design method not only makes the antenna size more compact, but also expands the bandwidth to a certain extent. However, for the application in radar, it is still necessary to explore low-profile, small-size and high-efficiency waveguide slot array antennas. In addition, in order to suppress interference and improve signal quality, the existing technology will add special waveguide filters, which will inevitably increase the profile height and antenna complexity. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a low-profile high-efficiency waveguide slot array antenna with a data transmission suppression function. The antenna radiation unit is designed in the form of a single-ridge waveguide surrounded by a full metal outer wall, and a V-shaped slot is opened on the ridge edge of the single-ridge waveguide. The two double oblique slots of the V-shaped slot extend toward the inner side of the ridge and toward the side wall of the single-ridge waveguide surrounded by the full metal outer wall. In addition, the cutoff wavelength of the waveguide is used for filtering, and there is no need to add a special waveguide filter, which further reduces the profile height and complexity of the antenna and also enables the antenna to have a data transmission suppression function.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A low-profile, high-efficiency waveguide slot array antenna with a data transmission suppression function, the antenna comprising a radiation part and a feeding part, wherein:

[0007] The radiation part includes a first radiation unit and a second radiation unit, N first radiation units are connected end to end in the azimuth direction, N second radiation units are connected end to end in the azimuth direction, and the tail end of the Nth first radiation unit is connected to the head end of the first second radiation unit, and a total of 2N radiation units constitute a single-ridged waveguide surrounded by a concave-shaped all-metal outer wall with a top wall width greater than a side wall width; the first radiation unit and the second radiation unit each include two V-shaped inclined radiation slots distributed at equal intervals in the azimuth direction, each V-shaped inclined radiation slot includes two inclined radiation slots, one end of each inclined radiation slot extends toward the inner side of the single-ridged waveguide ridge along the distance direction, and the other end extends toward the outer side wall of the single-ridged waveguide along the distance direction;

[0008] The feeding part comprises a power layer, a filter layer and a coaxial line which penetrates the power layer and the filter layer and are sequentially stacked below the radiation part.

[0009] Furthermore, the first radiation unit includes left-open V-shaped inclined radiation slots and right-open V-shaped inclined radiation slots distributed at equal intervals along the azimuth direction, and the second radiation unit includes right-open V-shaped inclined radiation slots and left-open V-shaped inclined radiation slots distributed at equal intervals along the azimuth direction.

[0010] Furthermore, the power layer is formed of a metal plate, and two I-shaped gaps penetrating the metal plate are symmetrically loaded at both ends of the metal plate in the azimuth direction.

[0011] Furthermore, the middle area of ​​the filter layer is a complete third-order rectangular waveguide block, the top wall width of the third-order rectangular waveguide block gradually narrows inward along the distance, and the left and right ends of the complete third-order rectangular waveguide block in the middle area are both half third-order rectangular waveguide blocks.

[0012] Furthermore, the center positions of the power layer, the filter layer and the coaxial line in azimuth coincide with the center of the single-ridged waveguide.

[0013] Furthermore, the center points of the two I-shaped gaps are respectively on the same straight line with the center points of the rightmost end of the N / 2th radiation unit and the leftmost end of the 2Nth radiation unit in the radiation part in terms of distance upwards.

[0014] Furthermore, each first radiation unit and each second radiation unit maintain a fixed interval d in the azimuth direction:

[0015] ,

[0016] in, is the operating wavelength of the waveguide slot array antenna, is the preset maximum scanning angle of the waveguide slot array antenna.

[0017] The beneficial effects of the present invention are:

[0018] The present invention adopts a V-shaped slot extending from the ridge edge of a single-ridge waveguide surrounded by a full metal outer wall to design an antenna radiation unit. By extending the double oblique slots of the V-shaped slot, the equivalent radiation length and radiation aperture of the double oblique slots are increased, so that the slot size and the waveguide size are reduced and the radiation efficiency is improved; a waveguide filter layer is added to the feeding part, and the cutoff wavelength of the waveguide is used to filter out the interference of other noises, giving the antenna a function of data transmission suppression; the filter layer and the power layer of the feeding part are divided into half-height waveguides, which further achieve a low-profile effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of the radiation subunit of the waveguide slot array antenna of the present invention, wherein (a) is a top view, (b) is a side view, and (c) is a 3D view;

[0020] Figure 2 It is a schematic diagram of the structure of the power layering of the waveguide slot array antenna of the present invention;

[0021] Figure 3 It is a schematic diagram of the overall structure of the waveguide slot array antenna filter layer and the coaxial line of the present invention;

[0022] Figure 4 Schematic diagram of the overall structure of the waveguide slot array antenna of the present invention, wherein (a) is a top view, (b) is a side view, and (c) is a bottom view;

[0023] Figure 5 is the S parameter of the waveguide slot array antenna of the present invention;

[0024] Figure 6 is the normal far-field pattern of the waveguide slot array antenna of the present invention;

[0025] Figure 7 is the gain of the waveguide slot array antenna of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] The present invention discloses a low-profile, high-efficiency waveguide slot array antenna with a data transmission suppression function. The array antenna is formed by opening a V-shaped slot on a single-ridge waveguide surrounded by a full metal outer wall to form a radiation unit, and the bottom coaxial line passes through the filter layer and the power layer in sequence for central feeding. The waveguide slot array antenna proposed by the present invention has a low profile, high efficiency and a data transmission suppression function, and has extremely broad application prospects compared to similar designs.

[0028] Specifically, Figure 1As shown in (a)-(c) of the invention, the waveguide slot array antenna includes a radiating part and a feeding part. The radiating part includes a first radiating unit and a second radiating unit, N first radiating units are connected end to end in azimuth, N second radiating units are connected end to end in azimuth, and the tail end of the Nth first radiating unit is connected to the head end of the first second radiating unit, and a total of 2N radiating units form a top wall width greater than the side wall width (such as the top wall is Figure 1 The wall at the position marked a in the figure is Figure 1 A single ridge waveguide surrounded by a concave all-metal outer wall (the wall at the position marked b in the figure). Figure 2 In the embodiment, N is preferably 4, and the 4 first radiation units and the 4 second radiation units are arranged on the left and right sides along the midpoint of the azimuth direction. The first radiation unit and the second radiation unit each include two V-shaped inclined radiation slots distributed at equal intervals along the azimuth direction, and each V-shaped inclined radiation slot includes two inclined radiation slots, one end of each inclined radiation slot extends toward the inner side of the ridge of the single-ridge waveguide along the distance direction, and the other end extends toward the outer side wall of the single-ridge waveguide along the distance direction, that is, the cutting depth of each inclined radiation slot is the length from the top of each outer side wall of the concave single-ridge waveguide to the middle groove.

[0029] Further, such as Figure 1 As shown in (a), the first radiation unit includes a left-open V-shaped inclined radiation slot 1 and a right-open V-shaped inclined radiation slot 2 that are evenly spaced in the azimuth direction, and the second radiation unit includes a right-open V-shaped inclined radiation slot 2 and a left-open V-shaped inclined radiation slot 1 that are evenly spaced in the azimuth direction. Two extended V-shaped inclined radiation slots are symmetrically designed at the center axis of the waveguide top wall to increase the equivalent radiation length and radiation aperture area of ​​the two inclined radiation slots, and a waveguide side ridge is added at the center of the side wall to improve the radiation characteristics.

[0030] like Figure 2 As shown, the feeding part is composed of a power layer, a filter layer and a coaxial line stacked in sequence along the longitudinal direction and placed below the radiation part, and the coaxial line runs through the power layer and the filter layer. Figure 3 As shown, the power layer is formed by symmetrically loading two I-shaped gaps 3 and 4 penetrating the metal plate at both ends of a metal plate in the azimuth direction, so as to realize equal energy feeding.

[0031] like Figure 4As shown, the filter layer as a whole is an irregular rectangular waveguide block, and the middle area of ​​the filter layer is a complete third-order rectangular waveguide block 5. The top wall width of the three-order rectangular waveguide block gradually narrows inward along the distance. The left and right ends of the three-order rectangular waveguide block in the middle area are both half a third-order rectangular waveguide block 6 with the same structure. Filtering is performed by changing the size of the rectangular waveguide waveguide port and thus changing the cutoff frequency. No additional filtering structure is required, and the cutoff wavelength of the waveguide is used to filter out interference from other noises to achieve a low profile effect.

[0032] The coaxial line 7 at the bottom of the feeding part runs through the entire filter layer and the power layer, and the center positions of the power layer, the filter layer and the coaxial line 7 in the azimuth direction coincide with the center of the single-ridge waveguide. The radiating part has a total of 2N radiating units, of which there are N first radiating units and N second radiating units. The center points of the left and right I-shaped slots 3 and 4 on the power layer are respectively on the same straight line with the center points of the rightmost end of the N / 2 radiating unit and the leftmost end of the 2N radiating unit in the radiating part in the direction of the ridge side wall.

[0033] Figure 4 (a)- Figure 4 (c) shows a schematic diagram of the overall structure of a waveguide slot array antenna according to an embodiment of the present disclosure. Figure 4 (a)- Figure 4 As shown in (c), each radiating element of the waveguide slot array antenna has two V-shaped radiating slots in the azimuth direction. The fixed interval d maintained by the radiating element in the azimuth direction is calculated as follows:

[0034] ,

[0035] in, is the operating wavelength of the waveguide slot array antenna, is the preset maximum scanning angle of the waveguide slot array antenna. This formula is also called the grating lobe-free condition. The distance element spacing is designed to be as narrow as possible to avoid the generation of grating lobes within the scanning range.

[0036] Example

[0037] A specific implementation result of the present invention is given in combination with parameters.

[0038] Table 1 summarizes Figure 1 (a)- Figure 1(c) The values ​​of the parameters. a is the width of the radiation unit, b is the height of the radiation unit, l is the length of each radiation unit, a_j is the width of the added ridge, b_j is the depth of the added ridge, f_w is the width of the gap, q is the angle of the gap tilt (q is 20°), d is the spacing between the azimuth radiation units, f_h is the depth of the V-shaped radiation tilt gap extending to the inner side of the ridge and the side wall of the single-ridge waveguide surrounded by the all-metal outer wall; g_l is the length of the two long gaps in the I-shaped gap, g_w is the width of the two long gaps in the I-shaped gap, g_l1 is the length of a short gap in the I-shaped gap, g_ w1 is the width of a short slit in the I-shaped gap; l_w is the width of a third-order rectangular waveguide block in the middle area of ​​the filter layer, l_w1 is the width of half a third-order rectangular waveguide block at the upper and lower ends of the filter layer along the azimuth direction, l_h1, l_h2 and l_h3 are the heights of a third-order rectangular waveguide block in the middle area of ​​the filter layer, l1_h1, l1_h2 and l1_h3 are the heights of half a third-order rectangular waveguide block at the upper and lower ends of the filter layer along the azimuth direction, ll is the length of the entire filter layer; r1 and r2 are the inner and outer radii of the coaxial line respectively.

[0039] Table 1

[0040]

[0041] The simulation results of the above waveguide slot array are as follows:

[0042] Figure 5 The S parameters of the waveguide slot array antenna according to one embodiment of the present disclosure are shown. It can be seen from the figure that the transmission characteristics of the array antenna are good.

[0043] Figure 6 The radiation pattern of the waveguide slot array antenna according to one embodiment of the present disclosure is shown. It can be seen from the figure that the gain of the array antenna is 19dB, the first sidelobe level is 13.2dB, and the radiation characteristics are good.

[0044] Figure 7 The gain of the waveguide slot array antenna according to an embodiment of the present disclosure is shown. It can be seen from the figure that the gain of the array antenna is good within the working frequency band.

[0045] The above description is only a preferred embodiment of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present disclosure is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present disclosure (but not limited to) by each other.

Claims

1. A low-profile, high-efficiency waveguide slot array antenna with a data transmission suppression function, characterized in that: The antenna comprises a radiation part and a feeding part, wherein: The radiation part includes a first radiation unit and a second radiation unit, N first radiation units are connected end to end in the azimuth direction, N second radiation units are connected end to end in the azimuth direction, and the tail end of the Nth first radiation unit is connected to the head end of the first second radiation unit, and a total of 2N radiation units constitute a single-ridged waveguide surrounded by a concave-shaped all-metal outer wall with a top wall width greater than a side wall width; the first radiation unit and the second radiation unit each include two V-shaped inclined radiation slots distributed at equal intervals in the azimuth direction, each V-shaped inclined radiation slot includes two inclined radiation slots, one end of each inclined radiation slot extends toward the inner side of the single-ridged waveguide ridge along the distance direction, and the other end extends toward the outer side wall of the single-ridged waveguide along the distance direction; The feeding part comprises a power layer, a filter layer and a coaxial line which penetrates the power layer and the filter layer and are sequentially stacked below the radiation part; The middle area of ​​the filter layer is a complete third-order rectangular waveguide block, the top wall width of which gradually narrows inward along the distance, and the left and right ends of the complete third-order rectangular waveguide block in the middle area are both half third-order rectangular waveguide blocks.

2. A low-profile, high-efficiency waveguide slot array antenna with data transmission suppression function according to claim 1, characterized in that: The first radiation unit includes a left-open V-shaped inclined radiation slot and a right-open V-shaped inclined radiation slot distributed at equal intervals along the azimuth direction, and the second radiation unit includes a right-open V-shaped inclined radiation slot and a left-open V-shaped inclined radiation slot distributed at equal intervals along the azimuth direction.

3. The low-profile, high-efficiency waveguide slot array antenna with data transmission suppression function according to claim 1, characterized in that: The power layer is made of a metal plate, and two I-shaped gaps penetrating the metal plate are symmetrically loaded at both ends of the metal plate in the azimuth direction.

4. The low-profile, high-efficiency waveguide slot array antenna with data transmission suppression function according to claim 1, characterized in that: The center positions of the power layer, the filter layer and the coaxial line in azimuth coincide with the center of the single-ridge waveguide.

5. The low-profile, high-efficiency waveguide slot array antenna with data transmission suppression function according to claim 3, characterized in that: The center point of one of the I-shaped gaps is on the same straight line as the midpoint between the N / 2th radiation unit and the (N / 2+1)th radiation unit of the radiation part in terms of distance upward, and the center point of the other I-shaped gap is on the same straight line as the midpoint between the 3N / 2th radiation unit and the (3N / 2+1)th radiation unit of the radiation part in terms of distance upward.

6. The low-profile, high-efficiency waveguide slot array antenna with data transmission suppression function according to claim 1, characterized in that: A fixed interval d is maintained between each first radiation unit and each second radiation unit in the azimuth direction: ， in, is the operating wavelength of the waveguide slot array antenna, is the preset maximum scanning angle of the waveguide slot array antenna.

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