A substrate integrated circularly polarized electromagnetic radiation structure and array

Abstract

The present invention discloses a substrate integrated circularly polarized electromagnetic radiation structure, in which there are a plurality of connection points between the upper metal radiation structure and the lower metal backplane; the upper metal radiation structure is composed of a metal ring and two metal branches arranged inside the metal ring; the metal branches are bent structures, the metal ring is a rectangular ring structure, and the two metal branches are rotationally symmetrically arranged at 180 degrees with respect to the center of the feeding part. The serpentine structure formed by the two metal branches enables circular polarization (including left-handed circular polarization and right-handed circular polarization) to be achieved within a wide band and beam directivity to be realized.

Description

Technical Field

[0001] The present invention relates to the field of antennas, and particularly to a substrate integrated circularly polarized electromagnetic radiation structure and array. Background Art

[0002] For satellite communication and remote sensing systems, to effectively transmit information and overcome the polarization distortion caused by the ionospheric Faraday rotation effect, the antenna is required to have circular polarization performance, and the same antenna array works simultaneously in the receiving and transmitting modes, which requires the antenna to have the working capabilities of left-handed circular polarization and right-handed circular polarization. Militarily, in the field of space target warning, circularly polarized antennas are generally used as basic radiation units in various countries. Therefore, circular polarization technology has been widely applied in both military and civilian fields. The polarization of an antenna characterizes the characteristic that the orientation of the electric field strength vector at a given point in space changes with time during antenna radiation, and is described by the trajectory of the end point of the electric field strength vector changing with time. The polarization of an antenna is divided into three forms: linear polarization, circular polarization, and elliptical polarization. When a linearly polarized antenna is used as the receiving end, polarization mismatch is likely to occur, thus affecting the antenna receiving and transmitting quality. The circularly polarized antenna has the following advantages: the circularly polarized antenna can receive incoming waves of any linear polarization, and the circularly polarized wave radiated by the circularly polarized antenna can also be received by an antenna of any polarization; the circularly polarized antenna has the orthogonality of the rotation direction. If the antenna radiates a right-handed circularly polarized wave, it only receives the right-handed circularly polarized wave and does not receive the left-handed circularly polarized wave, and vice versa; the ideal polarization isolation can be achieved by using the orthogonality of the rotation direction; when a circularly polarized wave is incident on a symmetric target, the reflected wave changes the rotation direction, etc. It is precisely because of these characteristics that the circularly polarized antenna has strong anti-interference ability and has been widely applied in fields such as electronic reconnaissance and interference, polarization diversity operation of communication and radar, and electronic countermeasures.

[0003] Xue-Xia Yang et al. designed a polarization reconfigurable square microstrip antenna in the literature [A Polarization Reconfigurable Patch Antenna With Loop Slots on the Ground Plane, IEEE Antennas and Wireless Propagation Letters, 2012, 11(2): 69-72]. This antenna has a slot respectively opened on the ground metal plates corresponding to two corners on the same side of the square radiation patch, and a switching diode is respectively placed in the two slots. The polarization reconfiguration is realized by controlling the on and off states of the switches. However, the bandwidth of this antenna is too narrow and it has no advantage in performance. Summary of the Invention

[0004] The object of the present invention is to solve the problem of narrow bandwidth of the polarized reconfigurable antenna in the prior art. The present invention provides a substrate integrated circularly polarized electromagnetic radiation structure and array, which can achieve circular polarization (including left-handed circular polarization and right-handed circular polarization) within a wide bandwidth and achieve beam directivity.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A substrate integrated circularly polarized electromagnetic radiation structure includes an upper metal radiation structure, a lower metal backplane and a feeding part; there are a plurality of connection points between the upper metal radiation structure and the lower metal backplane;

[0007] The upper metal radiation structure includes a metal ring and two metal branches arranged inside the metal ring; the metal branches are bent structures, and the two metal branches are centrosymmetrically arranged with respect to the center of the feeding part; the metal ring is a rectangular ring structure.

[0008] The snake-shaped structure composed of two metal branches enables it to achieve circular polarization (including left-handed circular polarization and right-handed circular polarization) within a wide bandwidth and achieve beam directivity.

[0009] Preferably, a middle layer dielectric substrate is provided between the upper metal radiation structure and the lower metal backplane, and vias are arranged on the middle layer substrate at positions corresponding to the connection points between the upper metal radiation structure and the lower metal backplane.

[0010] Preferably, the metal branch is a bent structure in the shape of an L bent by 90 degrees.

[0011] Preferably, the range of the length and width of the metal ring is between 0.2 times the wavelength and 1.5 times the wavelength of the lowest operating frequency of the antenna.

[0012] Preferably, the upper metal radiation structure includes multiple concentric metal rings with different sizes.

[0013] Preferably, there is at least one notch on the metal ring.

[0014] Preferably, the feeding part includes a probe connected to one of the metal branches, and the probe passes through the via of the middle layer dielectric substrate.

[0015] Preferably, the feeding part includes a probe, the probe is located in the area between the two metal branches and has a distance from both metal branches, and the probe passes through the via of the middle layer dielectric substrate.

[0016] A substrate integrated circularly polarized electromagnetic radiation structure array is composed of a plurality of substrate integrated circularly polarized electromagnetic radiation structures as described in any one of the above; the array includes a left-handed substrate integrated circularly polarized electromagnetic radiation structure and a right-handed substrate integrated circularly polarized electromagnetic radiation structure.

[0017] Preferably, when the left-handed substrate integrated circularly polarized electromagnetic radiation structure is used to emit left-handed circularly polarized waves, the left-handed circularly polarized waves irradiate the object to be measured and reflect back right-handed circularly polarized waves, and the right-handed substrate integrated circularly polarized electromagnetic radiation structure is used to receive the right-handed circularly polarized waves;

[0018] When the right-handed substrate integrated circularly polarized electromagnetic radiation structure is used to emit right-handed circularly polarized waves, the right-handed circularly polarized waves irradiate the object to be measured and reflect back left-handed circularly polarized waves, and the left-handed substrate integrated circularly polarized electromagnetic radiation structure is used to receive the left-handed circularly polarized waves.

[0019] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

[0020] A substrate integrated circularly polarized electromagnetic radiation structure of the present invention has a plurality of connection points between the upper metal radiation structure and the lower metal backplane; the upper metal radiation structure is composed of a metal ring and two metal branches arranged inside the metal ring; the metal branches are bent structures, the metal ring is a rectangular ring structure, and the two metal branches are rotationally symmetrically arranged at 180 degrees with respect to the center of the feeding part. The snake-shaped structure formed by the two metal branches enables it to achieve circular polarization (including left-handed circular polarization and right-handed circular polarization) within a wide band and achieve beam directivity. Description of the Drawings

[0021] Figure 1 It is a schematic diagram of a left-handed substrate integrated circularly polarized electromagnetic radiation structure.

[0022] Figure 2 It is a schematic diagram of a right-handed substrate integrated circularly polarized electromagnetic radiation structure.

[0023] Figure 3 It is a three-dimensional view of a substrate integrated circularly polarized electromagnetic radiation structure.

[0024] Figure 4 (a), Figure 4 (b) is a schematic diagram of a substrate integrated circularly polarized electromagnetic radiation structure with a discontinuous metal ring; Figure 4 (c) is a schematic diagram of a substrate integrated circularly polarized electromagnetic radiation structure with multiple metal rings.

[0025] Figure 5 (a) is a schematic diagram of an array of substrate integrated circularly polarized electromagnetic radiation structures arranged in a dense array; Figure 5 (b) is a schematic diagram of an array of substrate integrated circularly polarized electromagnetic radiation structures arranged in a sparse array. Figure 6 It is a schematic diagram of an array of substrate integrated circularly polarized electromagnetic radiation structures of Example 4.

[0026] Figure 7(a)Schematic diagram of a substrate integrated circularly polarized electromagnetic radiation structure with direct probe feeding; Figure 7 (b)Schematic diagram of a substrate integrated circularly polarized electromagnetic radiation structure with probe-coupled feeding.

[0027] Markings in the figure: 1 - upper layer metal radiation structure, 11 - metal ring, 12 - metal branch, 2 - lower layer metal backplane, 3 - feeding part, 31 - probe, 4 - connection point. Detailed implementation manners

[0028] The present invention will be described in detail below with reference to the accompanying drawings.

[0029] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Embodiment 1

[0031] As Figure 1 shown, a substrate integrated circularly polarized electromagnetic radiation structure includes an upper layer metal radiation structure 1, a lower layer metal backplane 2 and a feeding part 3;

[0032] The upper layer metal radiation structure includes a metal ring 11 and two metal branches 12 arranged inside the metal ring; the metal branches 12 are bent structures, and the two metal branches 12 are rotationally symmetrically arranged at 180 degrees with respect to the center of the feeding part 3; the metal ring 11 is a rectangular ring structure.

[0033] As Figure 3 shown, there are multiple connection points 4 between the upper layer metal radiation structure and the lower layer metal backplane; the middle layer between the upper layer metal radiation structure and the lower layer metal backplane is a dielectric substrate, and vias are arranged at positions corresponding to the connection points between the upper layer metal radiation structure and the lower layer metal backplane on the middle layer substrate. The metal branch 12 is a bent structure bent by 90 degrees. The advantage of such connection is that it can achieve feeding balance, circular polarization and high gain.

[0034] The part surrounded by the upper layer metal ring 11 is the main radiation part of the antenna, and this part can work independently or multiple parts can form an array radiation. The size of the upper layer metal radiation structure 1 is between 0.2 times the wavelength and 1.5 times the wavelength of the lowest operating frequency of the antenna (for example, between 1 mm and 7.5 mm at 60 GHz, and between 0.76 mm and 5.77 mm at 78 GHz).

[0035] The lower metal back plate 2 mainly plays a reflective role, and its size characteristics include the upper metal part, that is, the lower metal plate includes the upper metal part (including the metal branch 12 and the metal ring 11) projected onto the lower metal plate 2. Circularly polarized waves can be divided into left-handed circular polarization and right-handed circular polarization according to the direction of electric field rotation, such as Figure 1 The figure shows the left-hand circular polarization form of the circularly polarized antenna. Figure 2 The right-hand circular polarization is shown. The two circular polarization forms of the antenna are mirror-symmetric.

[0036] Example 2

[0037] The antenna can be a circularly polarized antenna, and the upper metal radiation structure is a plurality of rotationally symmetrical metal branches 12. A structure surrounding the metal branches 12 can be arranged outside, which can be a ring structure or a ring structure with a gap. The basic feature of the metal ring 11 is that it is outside the two metal branches, and its specific shape has many forms, such as a discontinuous metal ring form (such as Figure 4 (a) Figure 4 (b), an opening on the metal ring 11) and a multi-ring metal ring form (such as Figure 4 (c)). In addition, when the antenna units are arranged in an array with small spacing (such as Figure 5 As shown in (a), the metal rings 11 may also be adjacent to each other.

[0038] Example 3

[0039] Antennas can be formed into arrays. An array can include antennas with different rotation directions, one for transmitting and the other for receiving. Figure 5 Show the specific structure of the array. Two array layout methods: one is a close array arrangement, such as Figure 5 (a) The array spacing is small, and the top metal of adjacent units will be connected; the other is a sparse array method, such as Figure 5 (b) The array spacing is large, and the top metal layers of adjacent cells are not connected.

[0040] Example 4

[0041] When the antenna is used for radar detection, it can adopt different polarization of transmission and reception to resist multipath interference, such as Figure 6 As shown. The principle of anti-multipath interference is (taking the transmission as left-hand circular polarization as an example): the radar's transmitting antenna emits a left-hand circular polarization wave, which is irradiated to the object under test and reflected back as a right-hand circular polarization wave, which is received by the receiving antenna. The wave reflected twice turns back into a left-hand circular polarization wave, which cannot be received by the receiving antenna. The energy of the wave reflected more than twice is already very weak and basically has no effect on reception.

[0042] Example 5

[0043] The feeding of the antenna can be achieved by direct connection of a probe or by coupling. The probe 31 is realized by a metal via. When the metal via is connected to one of the top metal branches 12, it is the direct connection mode of the probe, as shown in Figure 7 (a); while when the metal via is not connected to either of the two top metals, it is the feeding mode of probe coupling, as shown in Figure 7 (b).

[0044] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A substrate integrated circularly polarized electromagnetic radiation structure, characterized in that, It includes an upper-layer metal radiation structure, a lower-layer metal backplane, and a feeding part; there are multiple connection points between the upper-layer metal radiation structure and the lower-layer metal backplane; the upper-layer metal radiation structure includes a metal ring, and two metal branches are arranged inside the metal ring; the metal branches are bent structures in an L shape bent at 90 degrees, and the two metal branches are connected end to end to form a serpentine structure, and the two metal branches are centrosymmetrically arranged with respect to the center of the feeding part; the metal ring is a rectangular ring structure.

2. The substrate integrated circularly polarized electromagnetic radiation structure according to claim 1, characterized in that, A middle-layer dielectric substrate is provided between the upper-layer metal radiation structure and the lower-layer metal backplane, and vias are arranged on the middle-layer dielectric substrate at positions corresponding to the connection points between the upper-layer metal radiation structure and the lower-layer metal backplane.

3. A substrate integrated circularly polarized electromagnetic radiation structure according to claim 1, characterized in that, The range of the length and width of the metal ring is between 0.2 times the wavelength and 1.5 times the wavelength of the lowest operating frequency of the antenna.

4. A substrate integrated circularly polarized electromagnetic radiation structure according to claim 1, wherein The upper-layer metal radiation structure includes multiple concentric metal rings with different sizes.

5. The substrate integrated circularly polarized electromagnetic radiation structure according to claim 1, wherein There is at least one notch on the metal ring.

6. The substrate integrated circularly polarized electromagnetic radiation structure according to claim 1, wherein The feeding part includes a probe connected to one of the metal branches, and the probe passes through the via of the middle-layer dielectric substrate.

7. A substrate integrated circularly polarized electromagnetic radiation structure according to claim 1, characterized in that The feeding part includes a probe, the probe is located in the area between the two metal branches, and has a spacing from both metal branches, and the probe passes through the via of the middle-layer dielectric substrate.

8. A substrate integrated circularly polarized electromagnetic radiation structure array, characterized in that, The array is composed of multiple substrate integrated circularly polarized electromagnetic radiation structures as described in any one of claims 1-7; the array includes a left-handed substrate integrated circularly polarized electromagnetic radiation structure and a right-handed substrate integrated circularly polarized electromagnetic radiation structure.

9. The substrate integrated circularly polarized electromagnetic radiation structure array according to claim 8, characterized in that: When the left-handed substrate integrated circularly polarized electromagnetic radiation structure is used to emit left-handed circularly polarized waves, the left-handed circularly polarized waves irradiate the object to be measured and reflect back right-handed circularly polarized waves, and the right-handed substrate integrated circularly polarized electromagnetic radiation structure is used to receive the right-handed circularly polarized waves; when the right-handed substrate integrated circularly polarized electromagnetic radiation structure is used to emit right-handed circularly polarized waves, the right-handed circularly polarized waves irradiate the object to be measured and reflect back left-handed circularly polarized waves, and the left-handed substrate integrated circularly polarized electromagnetic radiation structure is used to receive the left-handed circularly polarized waves.

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