Wide-beam series-fed microstrip antenna array and radar

Abstract

The application discloses a wide-beam series-fed microstrip antenna array and a radar. The wide-beam series-fed microstrip antenna array comprises a substrate, a feed line, an antenna array element group and a copper layer. The feed line is arranged on the top surface of the substrate. The feed line comprises a short section and a first long straight section and a second long straight section which are arranged in parallel from the two ends of the short section to one side. The length of the first long straight section is shorter than the length of the second long straight section. The antenna array element group is arranged on the top surface of the substrate and is located between the first long straight section and the second long straight section. The antenna array element group comprises a plurality of first antenna array elements connected to the first long straight section and a plurality of second antenna array elements connected to the second long straight section. The plurality of first antenna array elements and the plurality of second antenna array elements are arranged in a staggered manner along the longitudinal direction of the second long straight section. The copper layer is arranged on the bottom surface of the substrate. The wide-beam series-fed microstrip antenna array has low design difficulty and low cost, improves the beam stability and optimizes the wide-beam characteristics.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar, in particular to a wide-beam series-fed microstrip antenna array and radar. BACKGROUND

[0002] In the field of military, civilian wireless communication and radar detection, wide-beam series-fed microstrip antenna arrays have gradually begun to be used, especially in automotive radar, wide-beam series-fed microstrip antenna arrays have been widely used. At present, the beam widening method used by the wide-beam series-fed microstrip antenna array is to increase parasitic resonant units, increase metal walls and the like. These methods all use external structures to widen the beam, resulting in increased design difficulty and cost. SUMMARY

[0003] The main purpose of the present application is to provide a wide-beam series-fed microstrip antenna array and radar, which aims to solve the problem that the current wide-beam series-fed microstrip antenna array uses external structures to widen the beam, resulting in increased design difficulty and cost.

[0004] To achieve the above purpose, the present application provides a wide-beam series-fed microstrip antenna array, which comprises:

[0005] a substrate;

[0006] a feed line provided on the top surface of the substrate, the feed line comprising a short section and a first long straight section and a second long straight section extending in parallel from both ends of the short section to one side, the length of the first long straight section being shorter than the length of the second long straight section;

[0007] a set of antenna array elements provided on the top surface of the substrate and located between the first long straight section and the second long straight section, the set of antenna array elements comprising a plurality of first antenna array elements connected to the first long straight section and a plurality of second antenna array elements connected to the second long straight section, the plurality of first antenna array elements and the plurality of second antenna array elements being arranged in a staggered manner along the longitudinal direction of the second long straight section; and

[0008] a copper layer provided on the bottom surface of the substrate.

[0009] Optionally, the distance between two adjacent first antenna array elements is λ g , λ g is the wavelength of the transmission line guided wave; and / or,

[0010] the distance between two adjacent second antenna array elements is λ g , λ g is the wavelength of the transmission line guided wave.

[0011] Optionally, the distance between the first antenna array element and the second antenna array element is 0.5* λ g, λ g is a transmission line guided wave wavelength.

[0012] Optionally, the first antenna array element and / or the second antenna array element is / are arranged as a rectangular resonant unit.

[0013] Optionally, the length of the rectangular resonant unit is 0.5* λ g0 , λ g0 is an antenna resonant wavelength.

[0014] Optionally, the width of at least two of the plurality of first antenna array elements is different; and / or,

[0015] the width of at least two of the plurality of second antenna array elements is different.

[0016] Optionally, the longitudinal spacing between the first antenna array element and the second antenna array element is (0.15~0.3)* λ g , λ g is a transmission line guided wave wavelength.

[0017] Optionally, the wide-beam series-fed microstrip antenna array further comprises:

[0018] an outer transceiver feeder line arranged on the top surface of the substrate; and,

[0019] an impedance matching structure arranged on the top surface of the substrate and connected between the first long straight section and the outer transceiver feeder line.

[0020] Optionally, the length of the short section is (0.65~0.8)* λ g , λ g is a transmission line guided wave wavelength.

[0021] The present application also provides a radar comprising the wide-beam series-fed microstrip antenna array as described above.

[0022] In the technical solution of the present application, the short section, the first long straight section and the second long straight section of the feeder line form an "η" shape, the plurality of first antenna array elements and the plurality of second antenna array elements of the antenna array element group form two rows of array elements, the two rows of array elements form a triangular lattice array, and the feeder line and the antenna array element group together form an in-phase fed amplitude weighted array. The wide-beam series-fed microstrip antenna array realizes beam widening through the combination of the feeder line and the antenna array element group, without the need for additional structures, and has low design difficulty and cost. Moreover, the "η" shaped feeder line can make the signal flow directions at the feeding points of the two rows of array elements opposite, and the phase changes on the first long straight section and the second long straight section opposite, thereby improving the beam stability. In addition, the "η" shaped bending line of the feeder line itself radiates a wide-beam pattern, and the triangular lattice array pattern of the antenna array element group is multiplied, thereby optimizing the wide-beam characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the accompanying drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0024] Figure 1 Structure schematic diagram of a first embodiment of the wide-beam series-fed microstrip antenna array provided by the present application;

[0025] Figure 2 Structure schematic diagram of a second embodiment of the wide-beam series-fed microstrip antenna array provided by the present application; Figure 1 Cross-sectional view of the wide-beam series-fed microstrip antenna array;

[0026] Figure 3 Local schematic diagram of the feed line of the wide-beam series-fed microstrip antenna array; Figure 1 Cross-sectional view of the wide-beam series-fed microstrip antenna array;

[0027] Figure 4 Structure schematic diagram of a first embodiment of the wide-beam series-fed microstrip antenna array provided by the present application;

[0028] Figure 5 E-plane radiation pattern of the wide-beam series-fed microstrip antenna array of the first embodiment of the present application;

[0029] Figure 6 H-plane radiation pattern of the wide-beam series-fed microstrip antenna array of the first embodiment of the present application;

[0030] Figure 7 Voltage standing wave ratio result diagram of the wide-beam series-fed microstrip antenna array of the first embodiment of the present application;

[0031] Figure 8 E-plane radiation pattern of the wide-beam series-fed microstrip antenna array of the second embodiment of the present application;

[0032] Figure 9 H-plane radiation pattern of the wide-beam series-fed microstrip antenna array of the second embodiment of the present application;

[0033] Figure 10 Voltage standing wave ratio result diagram of the wide-beam series-fed microstrip antenna array of the second embodiment of the present application.

[0034] Explanation of the reference signs:

[0035] Reference Name Reference Name 100 Wide-beam series-fed microstrip antenna array 32 Second antenna array element 1 Substrate 4 Copper layer 2 Feed line 5 External transceiver feed line 21 Short segment 6 Impedance matching structure 22 First long straight segment 61 Rectangle one 23 Second long straight segment 62 Rectangle two 3 Antenna array element group 63 Rectangle three 31 First antenna array element

[0036] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0038] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0039] In addition, if the embodiments of the present application involve descriptions such as “first”, “second”, etc., the descriptions of “first”, “second”, etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first” and “second” can explicitly or implicitly include at least one of the features. In addition, the meaning of “and / or” appearing throughout the text includes three parallel solutions. Taking “A and / or B” as an example, it includes A solution, or B solution, or A and B solutions. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it. When the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope of the present application.

[0040] In radars, wide-beam series-fed microstrip antenna arrays have been widely used. At present, the beam widening methods used by the wide-beam series-fed microstrip antenna arrays are all to increase parasitic resonant units, increase metal walls and the like. These methods are all to widen the beam by using additional structures, which leads to increased design difficulty and cost.

[0041] In view of this, the present application provides a wide-beam series-fed microstrip antenna array, Figures 1 to 4 The embodiments of the wide-beam series-fed microstrip antenna array provided by the present application, Figure 1 The structure schematic diagram of the first embodiment of the wide-beam series-fed microstrip antenna array provided by the present application, Figure 2 The structure schematic diagram of the first embodiment of the wide-beam series-fed microstrip antenna array provided by the present application, Figure 1 The cross-sectional view of the wide-beam series-fed microstrip antenna array, Figure 3 The cross-sectional view of the wide-beam series-fed microstrip antenna array, Figure 1 The local schematic diagram of the feed line of the wide-beam series-fed microstrip antenna array, Figure 4A structural schematic diagram of a second embodiment of the wide-beam series-fed microstrip antenna array provided by the present application.

[0042] Please refer to Figures 1 to 4 , the wide-beam series-fed microstrip antenna array 100 comprises a substrate 1, a feed line 2, an antenna element group 3, and a copper layer 4, the feed line 2 is arranged on the top surface of the substrate 1, the feed line 2 comprises a short section 21 and a first long straight section 22 and a second long straight section 23 extending in parallel from both ends of the short section 21 to one side, the length of the first long straight section 22 is shorter than the length of the second long straight section 23, the antenna element group 3 is arranged on the top surface of the substrate 1 and located between the first long straight section 22 and the second long straight section 23, the antenna element group 3 comprises a plurality of first antenna elements 31 connected to the first long straight section 22 and a plurality of second antenna elements 32 connected to the second long straight section 23, the plurality of first antenna elements 31 and the plurality of second antenna elements 32 are arranged in a staggered manner along the longitudinal direction of the second long straight section 23, and the copper layer 4 is arranged on the bottom surface of the substrate 1.

[0043] In the technical scheme of the present application, the short section 21, the first long straight section 22, and the second long straight section 23 of the feed line 2 form an “η” shape, the plurality of first antenna elements 31 and the plurality of second antenna elements 32 of the antenna element group 3 form two rows of elements, the two rows of elements form a triangular lattice array, and the feed line 2 and the antenna element group 3 together form an in-phase fed amplitude weighted array. The wide-beam series-fed microstrip antenna array 100 realizes beam widening through the combination of the feed line 2 and the antenna element group 3, without the need for additional structures, and has low design difficulty and cost; and the “η” shaped feed line 2 can make the signal flow directions at the feed points of the two rows of elements opposite, the phase changes on the first long straight section 22 and the second long straight section 23 opposite, thereby improving the beam stability; in addition, the “η” shaped bending line of the feed line 2 itself radiates a wide-beam directional diagram, which is multiplied by the directional diagram of the triangular lattice array of the antenna element group 3, thereby optimizing the wide-beam characteristics.

[0044] Specifically, in the embodiment of the present application, the distance between two adjacent first antenna elements 31 is 0.5*λ g , and λ g is the transmission line guided wave length, so as to ensure the performance of the antenna array; the distance between two adjacent second antenna elements 32 is 0.5*λ g , and λ g is the transmission line guided wave length, so as to ensure the performance of the antenna array.

[0045] Specifically, in the embodiment of the present application, the distance between the first antenna element 31 and the second antenna element 32 is 0.5*λ g , and λ g is the transmission line guided wave length, so as to ensure the performance of the antenna array.

[0046] In the embodiments of the present application, the first antenna array element 31 is arranged as a rectangular resonant element, and / or the second antenna array element 32 is arranged as a rectangular resonant element, further improving the performance of the antenna array.

[0047] Specifically, the length of the rectangular resonant element is 0.5*λ g0 , λ g0 is the resonant wavelength of the antenna, and the width is adjusted according to the amplitude weighting requirements of the antenna array.

[0048] The width of at least two of the plurality of first antenna array elements 31 is different; and / or the width of at least two of the plurality of second antenna array elements 32 is different, so as to further optimize the performance of the antenna element group 3.

[0049] Further, the longitudinal spacing between the first antenna array element 31 and the second antenna array element 32 is (0.15-0.3)*λ g , λ g is the guided wave wavelength of the transmission line, so that the antenna element group 3 under the above longitudinal spacing is more conducive to realizing a wide beam in combination with the excitation phase provided by the "η" shaped feed line 2. It should be noted that the longitudinal spacing refers to the distance between the first antenna array element 31 close to one end of the second long straight section 23 and the second long straight section 23, or the distance between the second antenna array element 32 close to one end of the first long straight section 22 and the first long straight section 22.

[0050] Further, the wide-beam series-fed microstrip antenna array 100 further comprises an external transceiver feed line 5 and an impedance matching structure 6, the external transceiver feed line 5 is arranged on the top surface of the substrate 1, and the impedance matching structure 6 is arranged on the top surface of the substrate 1 and connected between the first long straight section 22 and the external transceiver feed line 5. The impedance matching structure 6 realizes impedance matching of the antenna array. Wherein, impedance matching is a conventional means in the art, therefore, the specific structure of the impedance matching structure 6 is not particularly described in the present application.

[0051] Further, the length of the short section 21 is (0.65-0.8)*λ g , λ g is the guided wave wavelength of the transmission line, so that the length of the part of the feed line 2 between the two antenna array elements closest to the short section 21 is 1.5*λ g .

[0052] The technical solutions of the present application will be further described in detail below in combination with the specific parameters and performance of the first and second embodiments of the wide-beam series-fed microstrip antenna array 100. It should be understood that the following embodiments are only used to explain the present application, and are not used to limit the present application.

[0053] First embodiment:

[0054] The material of the substrate 1 in the embodiment is selected as PTFE+ceramic composite material with a dielectric constant of 3.0, and the resonant frequency of each antenna element of the antenna element group 3 is 77 GHz. The H-plane of the wide-beam series-fed microstrip antenna array 100 in the embodiment is controlled by Taylor weighting to control the sidelobe, and the voltage standing wave ratio of the wide-beam series-fed microstrip antenna array 100 in the embodiment is less than 2 in the frequency band of 76 GHz-78.9 GHz by adjusting part of the feed line 2.

[0055] Continuing to refer to Figures 1 to 3 , the external receiver transmitter feed line 5 is connected to a 50-ohm transmitter port or a receiver port; the impedance matching structure 6 includes a rectangle one 61 and a rectangle two 62 connected in series, the length of the rectangle one 61 is 0.6 mm, and the width is 0.13 mm, the length of the rectangle two 62 is 0.45 mm, and the width is 0.28 mm; the line width of the feed line 2 is 0.2 mm, the length of the first long straight section 22 is 11.32 mm, the length of the short section 21 is 1.43 mm, and the length of the second long straight section 23 is 12.54 mm; the length of each first antenna element 31 and each second antenna element 32 is 1.1 mm, and the width of each antenna element from left to right is 0.154 mm, 0.282 mm, 0.455 mm, 0.609 mm, 0.7 mm, 0.7 mm, 0.609 mm, 0.455 mm, 0.282 mm, and 0.154 mm, respectively, the distance between two adjacent first antenna elements 31 is 2.6 mm, the distance between two adjacent second antenna elements 32 is 2.6 mm, the distance between the first antenna element 31 and the second antenna element 32 is 1.3 mm, and the longitudinal distance between the first antenna element 31 and the second antenna element 32 is 0.33 mm; the length of the substrate 1 is 20 mm, the width is 10 mm, and the thickness is 0.127 mm.

[0056] Referring to Figures 5 to 7 , Figure 5 is the E-plane radiation pattern of the wide-beam series-fed microstrip antenna array 100 in the first embodiment of the application, Figure 6 is the H-plane radiation pattern of the wide-beam series-fed microstrip antenna array 100 in the first embodiment of the application, Figure 7 is the voltage standing wave ratio result diagram of the wide-beam series-fed microstrip antenna array 100 in the first embodiment of the application; and Figure 5 It can be known that the wide-beam series-fed microstrip antenna array 100 in the embodiment realizes a matching of 2.9 GHz by using only two impedance transformation sections; and Figure 6 It can be known that the 10-dB beam width of the wide-beam series-fed microstrip antenna array 100 in the embodiment is greater than 160° in the matching bandwidth; and Figure 7 It can be known that the maximum value of the H-plane gain of the wide-beam series-fed microstrip antenna array 100 in the embodiment is all directed to 0°.

[0057] Second embodiment:

[0058] The wide-beam series-fed microstrip antenna array 100 of the present embodiment is a 24GHz-band antenna, the E-plane of which is a wide beam and the H-plane of which is a narrow beam.

[0059] In the present embodiment, the material of the substrate 1 is a ceramic+hydrocarbon+glass fiber composite material with a dielectric constant of 3.66, and the resonant frequency of each antenna element of the antenna element group 3 is 24GHz. The H-plane of the wide-beam series-fed microstrip antenna array 100 of the present embodiment adopts amplitude tapering control of sidelobes, and through adjustment of the feed line 2, the wide-beam series-fed microstrip antenna array 100 of the present embodiment has a voltage standing wave ratio of less than 2 in the frequency band of 23.5GHz-24.5GHz.

[0060] Continuing to refer to Figure 4 , the impedance matching structure 6 includes a rectangular three 63 with a length of 2.75mm and a width of 0.7mm; the feed line 2 has a line width of 0.3mm, the first long straight section 22 has a length of 18.6mm, the short section 21 has a length of 4.5mm, and the second long straight section 23 has a length of 22.05mm; each first antenna element 31 and each second antenna element 32 has a length of 3.15mm, and in the direction from left to right, the width of each antenna element is 1.1mm, 2mm, 2.4mm, 2.4mm, 2mm, and 1.1mm respectively, the distance between two adjacent first antenna elements 31 is 7.8mm, the distance between two adjacent second antenna elements 32 is 7.8mm, the distance between an adjacent first antenna element 31 and an adjacent second antenna element 32 is 3.9mm, and the longitudinal distance between the first antenna element 31 and the second antenna element 32 is 1.35mm; the substrate 1 has a length of 40mm, a width of 20mm, and a thickness of 0.508mm.

[0061] Referring to Figures 8 to 10 , Figure 8 is the E-plane radiation pattern of the wide-beam series-fed microstrip antenna array 100 of the second embodiment of the present application, Figure 9 is the H-plane radiation pattern of the wide-beam series-fed microstrip antenna array 100 of the second embodiment of the present application, Figure 10 is the voltage standing wave ratio result graph of the wide-beam series-fed microstrip antenna array 100 of the second embodiment of the present application; and Figure 8 It can be seen that the wide-beam series-fed microstrip antenna array 100 of the present embodiment achieves a matching of 1GHz only by using one impedance transformation section; and Figure 9 It can be seen that the 10dB beam width of the wide-beam series-fed microstrip antenna array 100 of the present embodiment in the matching bandwidth is greater than 160°; and Figure 10 It can be seen that the maximum value of the H-plane gain of the wide-beam series-fed microstrip antenna array 100 of the present embodiment is directed to 0°.

[0062] In conclusion, the wide-beam series-fed microstrip antenna array 100 provided by the application has low antenna matching difficulty, and can realize a bandwidth of more than 3.5% without a complex matching structure; within the impedance bandwidth, the 10dB power beam width in the directional diagram is greater than 160°; within the impedance bandwidth, the maximum beam pointing deviation of the directional diagram is less than 1°.

[0063] The application further provides a radar comprising the wide-beam series-fed microstrip antenna array 100 as described above. Since the radar adopts all the technical solutions of all the embodiments of the wide-beam series-fed microstrip antenna array 100 described above, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here. The radar can be a car radar.

[0064] The above only describes the preferred embodiments of the application, and does not limit the patent scope of the application, and any equivalent structural transformation made under the concept of the application, or direct / indirect application in other related technical fields, is included in the patent protection scope of the application.

Claims

1. A wide-beam series-fed microstrip antenna array, characterized by, The wide-beam series-fed microstrip antenna array comprises: a substrate; a feed line disposed on a top surface of the substrate, the feed line comprising a stub section and a first long straight section and a second long straight section extending in parallel from two ends of the stub section towards a side, the first long straight section having a length shorter than that of the second long straight section; a group of antenna elements disposed on the top surface of the substrate and located between the first long straight section and the second long straight section, the group of antenna elements comprising a plurality of first antenna elements connected to the first long straight section and a plurality of second antenna elements connected to the second long straight section, the plurality of first antenna elements and the plurality of second antenna elements being arranged in an interleaved manner along a longitudinal direction of the second long straight section; and a copper layer disposed on a bottom surface of the substrate. The wide-beam series-fed microstrip antenna array further comprises: an external transceiver feed line disposed on the top surface of the substrate; and an impedance matching structure disposed on the top surface of the substrate and connected between the first long straight section and the external transceiver feed line. The external transceiver feed line is connected to an end of the first long straight section away from the stub section.

2. The wide beam fed microstrip antenna array of claim 1, wherein, The interval between two adjacent first antenna elements is , is a wavelength of a guided wave on the transmission line; and / or, The interval between two adjacent second antenna elements is , is a wavelength of a guided wave on the transmission line.

3. The wide beam fed microstrip antenna array of claim 1, wherein, The distance between the adjacent first antenna array element and the second antenna array element is 0.5 , is a wavelength of a guided wave on the transmission line.

4. The wide beam fed microstrip antenna array of claim 1, wherein, The first antenna elements and / or the second antenna elements are arranged as rectangular resonant units.

5. The wide beam fed microstrip antenna array of claim 4, wherein, The length of the rectangular resonant unit is 0.5 , is the antenna resonant wavelength.

6. The wide beam fed microstrip antenna array of claim 5, wherein, At least two of the plurality of first antenna elements have different widths; and / or At least two of the plurality of second antenna elements have different widths.

7. The wide beam fed microstrip antenna array of claim 1, wherein, The longitudinal spacing between the first antenna array element and the second antenna array element is (0.15~0.3) , is a wavelength of a guided wave on the transmission line.

8. The wide beam fed microstrip antenna array of claim 1, wherein, The length of the short segment is (0.65~0.8) , is the wavelength of the guided wave of the transmission line.

9. A radar, characterized by The wide-beam series-fed microstrip antenna array as claimed in any one of claims 1 to 8.

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