An ultra-wideband tightly coupled wide-angle scanning transmissive array antenna

Abstract

The application discloses an ultra-wideband tightly-coupled wide-angle scanning transmission array antenna, which comprises a transmission array and a feed antenna, and the transmission array is composed of a plurality of transmission units arranged periodically; the transmission unit comprises two parallel and opposite wide-angle impedance matching layers, an intermediate floor is arranged between the two wide-angle impedance matching layers, one tightly-coupled dipole antenna is arranged on each wide-angle impedance matching layer, a phase shift line and a metal coupling short column are connected between the two tightly-coupled dipole antennas; the two tightly-coupled dipole antennas and the intermediate floor constitute a receiving layer and a transmitting layer of the transmission unit; the phase center of the feed antenna is located at the focal point of the transmission array, and the transmission array converts the spherical electromagnetic wave emitted by the feed antenna into a plane electromagnetic wave; the feed displacement technology is adopted, the feed antenna is rotated along an arc-shaped track, and wide-angle beam scanning is realized; and the application has the advantages of ultra-wideband, low cost, wide-angle scanning range and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antenna in wireless communication system, and particularly relates to a super wideband tightly coupled wide-angle scanning transmissive array antenna. BACKGROUND

[0002] In application scenarios such as satellite communication, radar detection, deep space communication and ground point-to-point communication, high-gain antennas can provide stronger signal strength in the process of receiving and transmitting wireless signals, so high-gain antennas with directional beams have important application value. In addition, wideband wide-angle scanning array antennas are widely used in wireless communication systems, automotive radars and high-resolution imaging systems, and beam scanning transmissive array antennas have attracted much attention in the industry due to their high-gain beam scanning capability.

[0003] Current beam scanning transmissive array antennas mainly include electrically controlled beam scanning and mechanically scanned beam scanning. Electrically controlled beam scanning transmissive array antennas have the advantages of fast beam switching speed, accurate beam pointing and large scanning range, but they often need to integrate a large number of active devices on the transmissive array surface, which greatly increases the cost of the antenna. Mechanical beam scanning antennas have the advantages of simple engineering implementation and low manufacturing cost, but they have the disadvantages of inaccurate beam pointing and limited scanning range. Both types of beam scanning transmissive array antennas have the inherent defect of narrow working bandwidth, which limits their large-scale application. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a super wideband tightly coupled wide-angle scanning transmissive array antenna. The transmissive unit with high angle stability is designed by utilizing the wideband working effect of the tightly coupled array antenna. The beam scanning of ±40° is realized by the feed source displacement technology. The proposed transmissive array antenna has the characteristics of super wideband, wide angle and low cost.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0006] A super wideband tightly coupled wide-angle scanning transmissive array antenna, comprising a transmissive array and a feed antenna.

[0007] The transmissive array is composed of a plurality of transmissive units arranged periodically. The transmissive unit comprises two parallel and opposite wide-angle impedance matching layers, a middle floor is arranged between the two wide-angle impedance matching layers, and a tightly coupled dipole antenna is arranged on each wide-angle impedance matching layer. A phase shift line and a metal coupling short column are connected between the two tightly coupled dipole antennas. The two tightly coupled dipole antennas and the middle floor constitute the receiving layer and the transmitting layer of the transmissive unit.

[0008] The phase center of the feed antenna is located at the focal point of the transmission array, which converts the spherical electromagnetic wave emitted by the feed antenna into a planar electromagnetic wave; a feed displacement technique is adopted to realize wide-angle beam scanning by rotating the feed antenna along an arc-shaped track.

[0009] In one embodiment, the wide-angle impedance matching layer comprises a first dielectric substrate and a plurality of periodic cross-shaped metal patches printed on the outer side of the first dielectric substrate; the tightly coupled dipole antenna comprises a second dielectric substrate and tightly coupled dipoles printed on the outer side of the second dielectric substrate; the tightly coupled dipole is a structure in which a rectangular metal patch is cut into dipole arms in the middle; the first dielectric substrate is arranged on the outer side of the second dielectric substrate and is parallel to the second dielectric substrate.

[0010] In one embodiment, the phase shift line is printed on a third dielectric substrate, which is connected between the inner sides of the two second dielectric substrates and is perpendicular to the second dielectric substrates, and the dipole arms of the same tightly coupled dipole are symmetrical about the third dielectric substrate.

[0011] In one embodiment, the phase shift line is a bent parallel double line structure printed on both sides of the third dielectric substrate, and the two phase shift lines are respectively connected to the two tightly coupled dipoles on both sides of the third dielectric substrate.

[0012] In one embodiment, the metal coupling short column is C-shaped, and there are two of them, which are symmetrically placed between the two tightly coupled dipoles about the third dielectric substrate.

[0013] In one embodiment, the intermediate floor comprises two metal sheets passing through the third dielectric substrate, which are perpendicular to the third dielectric substrate, and the projection of the metal sheet on the second dielectric substrate does not overlap with the two tightly coupled dipoles.

[0014] In one embodiment, the profile of the transmission array is rectangular or circular, and the pitch of the transmission units is the side length of the second dielectric substrate.

[0015] The feed antenna adopts a corner or conical horn antenna, and the radiation direction of the feed antenna is directed towards the center of the transmission array.

[0016] In one embodiment, the transmission units realize the regulation of the transmission phase by changing the length l of the phase shift bending area, the amplitude parameter of the transmission unit is above -2dB, and the phase parameter satisfies 360°.

[0017] In one embodiment, two feed antennas are selected according to the working frequency to irradiate the array surface, and beam scanning is realized by rotating the feed antenna along an arc-shaped track.

[0018] In one embodiment, the ultra-wideband tightly coupled wide-angle scanning transmissive array antenna has a stable radiation pattern operating bandwidth of 3 times the frequency, i.e. 2GHz-6GHz, and a beam coverage range of 80°.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] The transmissive array used in the transmissive array antenna of the present application is composed of a wide-angle impedance matching layer, a metal coupling shorting post and a tightly coupled transceiving antenna combined with a phase shift line. Compared with other transmissive arrays, the transmissive array has an ultra-wideband operating capability, and the transmissive unit has higher angular stability. In terms of realizing the phase shift function of the transmissive unit, the designed unit realizes phase modulation with true time delay characteristics by changing the length of the bending area of the phase shift line. The designed transmissive array antenna has a wide frequency band range corresponding to a stable radiation pattern.

[0021] This antenna has the advantages of wide frequency band, large angle, low cost, etc., and is suitable for use in the fields of microwave relay stations, satellite communication, radar detection, etc. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings described herein are used to provide further understanding of the present application, constitute a part of the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 The figure is a structure diagram of the ultra-wideband tightly coupled wide-angle scanning transmissive array antenna in the specific embodiment of the present application.

[0024] Figure 2 The figure is a perspective structure diagram of the transmissive unit in the specific embodiment of the present application.

[0025] Figure 3 The figure is a top view of the wide-angle impedance matching layer of the transmissive unit, i.e. a related structure and parameter diagram in the specific embodiment of the present application.

[0026] Figure 4 The figure is a top view of the tightly coupled dipole of the transmissive unit, i.e. a related structure and parameter diagram in the specific embodiment of the present application.

[0027] Figure 5 The figure is a front view of the phase shift line of the transmissive unit, i.e. a related structure and parameter diagram in the specific embodiment of the present application.

[0028] Figure 6 The figure is a diagram showing the variation of the transmission parameters of the transmissive unit with frequency in the specific embodiment of the present application.

[0029] Figure 7 The figure is a diagram showing the transmission parameters of the transmissive unit when the unit is irradiated by a TE polarized electromagnetic wave at different angles in the specific embodiment of the present application.

[0030] Figure 8 The transmission parameters of the transmission unit in a specific embodiment of the present invention are the transmission parameters of the unit when it is obliquely irradiated by TM polarized electromagnetic waves at different angles.

[0031] Figure 9 This is the scanning pattern of an ultra-wideband tightly coupled wide-angle scanning transmission array antenna operating at 4 GHz in a specific embodiment of the present invention.

[0032] Figure 10 This is a simulation curve of the gain of the ultra-wideband tightly coupled wide-angle scanning transmission array antenna as a function of frequency in a specific embodiment of the present invention.

[0033] In the figure: 1. Transmission array; 2. Transmission element; 3. Feed antenna; 101. Cross-shaped metal patch; 102. First dielectric substrate; 103. Second dielectric substrate; 104. Tightly coupled dipole; 105. Third dielectric substrate; 106. Phase shift line; 107. Metal coupling short-circuit post; 108. Middle ground plane. Detailed Implementation

[0034] To make the objectives, features and advantages of the present invention more apparent and understandable, the invention will be further described in detail below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the invention in any way.

[0035] like Figure 1 The diagram shown is a structural schematic of the ultra-wideband tightly coupled wide-angle scanning transmission array antenna of the present invention. In this embodiment of the invention, the ultra-wideband tightly coupled wide-angle scanning transmission array antenna mainly includes a transmission array 1 and a feed antenna 3.

[0036] The phase center of the feed antenna 3 is located at the focal point of the transmission array 1. The transmission array 1 converts the spherical electromagnetic waves emitted by the feed antenna 3 into planar electromagnetic waves and radiates them outward; by using feed displacement technology, wide-angle beam scanning is achieved by rotating the feed antenna along an arc track.

[0037] The transmission array 1 of the present invention is composed of a plurality of transmission elements 2 arranged periodically, as shown in the reference. Figure 2 The transmission unit 2 includes two parallel, opposite wide-angle impedance matching layers, two tightly coupled dipole antennas, two intermediate ground planes 108, two phase shift lines 106, and two metal-coupled short-circuit posts 107. The two intermediate ground planes 108 are disposed between the two wide-angle impedance matching layers; they may be located on the same plane but are not connected. One tightly coupled dipole antenna is disposed on each wide-angle impedance matching layer, and the two tightly coupled dipole antennas are connected by the two phase shift lines 106. The two metal-coupled short-circuit posts 107 are also disposed between the two tightly coupled dipole antennas. Thus, the two tightly coupled dipole antennas and the two intermediate ground planes 108 constitute the receiving and transmitting layers of the transmission unit 2.

[0038] Obviously, in a transmission unit 2, the close-coupled dipole antennas close to the feed antenna 3 act as receiving antennas, and together with the two intermediate ground plates 108 form a receiving layer, while the close-coupled dipole antennas far from the feed antenna 3 act as transmitting antennas, and together with the two intermediate ground plates 108 form a transmitting layer.

[0039] With the above structure, the spherical electromagnetic wave generated by the feed antenna 3 is received by the receiving dipole antennas in the transmission array 1, i.e. the receiving layer, and is converted into a plane wave by the transmitting dipole antennas, i.e. the transmitting layer, by the phase adjustment of the phase shift line 106.

[0040] In an embodiment of the present application, referring again to Figure 2 , the wide-angle impedance matching layer comprises a first dielectric substrate 102 and a plurality of periodic cross-shaped metal patches 101 printed on the outer side of the first dielectric substrate 102. The close-coupled dipole antenna comprises a second dielectric substrate 103 and a close-coupled dipole 104 printed on the outer side of the second dielectric substrate 103. The first dielectric substrate 102 is arranged on the outer side of the second dielectric substrate 103 and parallel to the second dielectric substrate 103. If the feed antenna 3 is defined as being directly below the transmission array 1, the close-coupled dipole antennas close to the feed antenna 3 are located below, and the close-coupled dipole antennas far from the feed antenna 3 are located above, then the outer sides of the first dielectric substrate 102 and the second dielectric substrate 103 above refer to their upper surfaces, and the outer sides of the first dielectric substrate 102 and the second dielectric substrate 103 below refer to their lower surfaces. The inner side of the first dielectric substrate 102 is arranged opposite to the outer side of the second dielectric substrate 103, which can be in close contact or have a gap.

[0041] The plan view of the wide-angle impedance matching layer is shown in Figure 3 , and the cross-shaped metal patch 101 has a periodic structure. In this embodiment, there are 18 cross-shaped metal patches 101 in a unit period, and the period p, width w and pitch d of the cross-shaped metal patch 101 in the unit play a role in improving the angular stability of the unit.

[0042] The plan view of the close-coupled dipole 104 is shown in Figure 4 , which is a structure similar to a "bow tie" formed by cutting a rectangular metal patch in the middle to form dipole arms. The width and length of the dipole are a and b, respectively, and it is responsible for receiving and transmitting electromagnetic waves as a transceiving antenna. In the transmission array 1, the pitch of the transmission unit 2 is the side length of the second dielectric substrate 103, which is dx and dy, respectively.

[0043] The front view of the phase shift line 106 is shown in Figure 5As shown, phase shift lines 106 are printed on a third dielectric substrate 105, which is connected between the inner sides of two second dielectric substrates 103 and perpendicular to them. Further, the phase shift lines 106 are bent parallel double-line structures printed on both sides of the third dielectric substrate 105. The dipole arms of the same tightly coupled dipole 104 are symmetrical about the third dielectric substrate 105, and the two phase shift lines 106 connect two tightly coupled dipoles 104 on both sides of the third dielectric substrate 105 respectively. By changing the length l of the phase shift bending region, the transmission phase is changed, thus achieving phase modulation. The height of the dielectric substrate 105 is h. Based on the above upper and lower settings, the third dielectric substrate 105 can be described as being connected between the upper and lower second dielectric substrates 103, with an "I"-shaped cross-section.

[0044] The metal coupling short-circuit post 107 is C-shaped, and there are two of them. They are placed symmetrically and mirror-imagely with respect to the third dielectric substrate 105 between the two tightly coupled dipoles 104. The metal coupling short-circuit post 107 is located inside the printed dipole second dielectric substrate 103, supporting the upper and lower second dielectric substrates 103 between the upper and lower dipoles, and is connected to the intermediate ground plane 108. It plays a role in improving the unit angle stability and increasing the electromagnetic coupling between units to improve the impedance bandwidth.

[0045] The intermediate ground plane 108 is a metal sheet, and the two intermediate ground planes 108 are two metal sheets. The two metal sheets pass through the third dielectric substrate 105, are located on the same horizontal plane, and are perpendicular to the third dielectric substrate 105. The two metal sheets are not connected, and their projections on the second dielectric substrate 103 do not overlap with the two tightly coupled dipoles 104.

[0046] In one embodiment of the present invention, the transmission array 1 consists of 16×32 transmission elements 2, which are periodically distributed. The outline of the transmission array is rectangular or circular.

[0047] The feed antenna 3 is a pyramidal horn antenna or a conical horn antenna, with the radiation direction facing the center of the transmission array.

[0048] In one embodiment of the present invention, the dielectric substrates 102, 103, and 105 are all made of Rogers 4350 with a thickness of 0.508 mm and a relative permittivity of 3.66; the phase shift line 106 has a width of 0.5 mm; the metal coupling short-circuit post 107 has a thickness of 1 mm; and the gap between the ground planes 108 is 4 mm.

[0049] The specific dimensions of the transmission unit are shown in Table 1.

[0050] Table 1

[0051] Parameter dx dy a b Value (mm) 12 24 5 3 Parameter p w d h Value (mm) 4 0.6 0.8 29.016

[0052] In one embodiment of the present application, the feed antenna 3 adopts a corner horn antenna, according to the operating frequency band of the unit, two feed antennas 3 are selected to irradiate the array surface, in this embodiment, the two feed antennas 3 cover 2GHz-3.5GHz and 3.5GHz-6GHz respectively. The radiation direction of the feed antenna 3 is towards the center of the transmission array. According to the operating frequency, the beam scanning is realized by rotating the feed antenna 3 along the arc track.

[0053] As shown in Figure 6 , it is a curve diagram of the transmission performance of the transmission unit 1 changing with the length l of the phase shift bending area under the irradiation of the normally incident electromagnetic wave, the insertion loss of the transmission unit 2 is less than 2dB at 2GHz-6GHz, and the phase shift range covers 360°.

[0054] As shown in Figure 7 , it is a curve diagram of the transmission performance of the transmission unit under the irradiation of the TE polarized electromagnetic wave at different angles, it can be seen that the transmission performance of the unit remains stable as the angle of the incident electromagnetic wave increases, and has high angle stability.

[0055] As shown in Figure 8 , it is a curve diagram of the transmission performance of the transmission unit under the irradiation of the TM polarized electromagnetic wave at different angles, it can be seen that the transmission performance of the unit remains stable as the angle of the incident electromagnetic wave increases, and has high angle stability.

[0056] As shown in Figure 9 , it is a beam scanning pattern of the transmission array antenna at 4GHz in the range of 0°-40°, the pattern has a stable beam pointing direction. Due to the symmetry of the transmission surface, it still has a stable beam pointing direction at the mirror angle -40°-0°, that is, the transmission array antenna can realize a beam coverage range of 80°.

[0057] As shown in Figure 10 , it is a gain simulation curve diagram of the ultra-wideband tight coupling wide-angle scanning transmission array antenna, the gain of the antenna changes stably at 2GHz-6GHz, which indicates that the transmission array antenna has a stable pattern operating bandwidth of 3 times the frequency, and the change range of the edge radiation gain is 15.6-25.3dBi.

[0058] The above describes in detail the ultra-wideband tightly-coupled wide-angle scanning transmission array antenna provided by the present application, and the principle and implementation manner of the present application are described and implemented by using detailed structure design parameters. The above description of the embodiments is only used to help understand the method of the present application and its core idea. It should be pointed out that: for those skilled in the art, some improvements and refinements can be made without departing from the principle of the present application, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. An ultra-wideband tightly coupled wide-angle scanning transmission array antenna, characterized in that, It includes a transmission array (1) and a feed antenna (3); The transmission array (1) is composed of a number of transmission units (2) arranged in a periodic manner; the transmission unit (2) includes two parallel and opposite wide-angle impedance matching layers, and a middle ground plane (108) is provided between the two wide-angle impedance matching layers. Each wide-angle impedance matching layer is provided with a tightly coupled dipole antenna, and a phase shift line (106) and a metal coupling short-circuit post (107) are connected between the two tightly coupled dipole antennas; the two tightly coupled dipole antennas and the middle ground plane (108) constitute the receiving layer and the transmitting layer of the transmission unit (2); The phase center of the feed antenna (3) is located at the focal point of the transmission array (1). The transmission array (1) converts the spherical electromagnetic wave emitted by the feed antenna (3) into a planar electromagnetic wave. By using feed displacement technology, wide-angle beam scanning is achieved by rotating the feed antenna along an arc track. The wide-angle impedance matching layer includes a first dielectric substrate (102) and a plurality of periodic cross-shaped metal patches (101) printed on the outside of the first dielectric substrate (102); the tightly coupled dipole antenna includes a second dielectric substrate (103) and a tightly coupled dipole (104) printed on the outside of the second dielectric substrate (103); the tightly coupled dipole (104) is a structure formed by cutting a rectangular metal patch at the middle corner to form a dipole arm; the first dielectric substrate (102) is disposed on the outside of the second dielectric substrate (103) and parallel to the second dielectric substrate (103); The phase shift line (106) is printed on the third dielectric substrate (105). The metal coupling short-circuit post (107) is C-shaped and there are two of them. They are placed symmetrically and mirror-imagely with respect to the third dielectric substrate (105) between the two tightly coupled dipoles (104). The metal coupling short-circuit post (107) is located inside the printed dipole second dielectric substrate (103), supporting the upper and lower second dielectric substrates (103) between the upper and lower dipoles, and is connected to the middle ground plate (108). It plays a role in improving the unit angle stability and increasing the electromagnetic coupling between units to improve the impedance bandwidth.

2. The ultra-wideband tightly coupled wide-angle scanning transmission array antenna according to claim 1, characterized in that, The third dielectric substrate (105) is connected between the inner sides of the two second dielectric substrates (103) and is perpendicular to the second dielectric substrates (103). The dipole arms of the same tightly coupled dipole (104) are symmetrical about the third dielectric substrate (105).

3. The ultra-wideband tightly coupled wide-angle scanning transmission array antenna according to claim 2, characterized in that, The phase shift line (106) is a bent parallel double line structure printed on both sides of the third dielectric substrate (105), and the two phase shift lines (106) connect two tightly coupled dipoles (104) on both sides of the third dielectric substrate (105).

4. The ultra-wideband tightly coupled wide-angle scanning transmission array antenna according to claim 2, characterized in that, The intermediate floor (108) includes two metal strips passing through the third dielectric substrate (105), the two metal strips being perpendicular to the third dielectric substrate (105), and the projection of the metal strips onto the second dielectric substrate (103) not overlapping with the two tightly coupled dipoles (104).

5. The ultra-wideband tightly coupled wide-angle scanning transmission array antenna according to claim 2, characterized in that, The outline of the transmission array (1) is rectangular or circular, and the spacing of the transmission units (2) is the side length of the second dielectric substrate (103); the feed antenna (3) adopts a pyramidal or conical horn antenna, and the radiation direction of the feed antenna (3) is oriented towards the center of the transmission array.

6. The ultra-wideband tightly coupled wide-angle scanning transmission array antenna according to claim 1, characterized in that, The transmission unit (2) changes the length of the phase-shift bending region. l To achieve the control of the transmission phase, the amplitude parameter of the transmission unit (2) is above -2dB, and the phase parameter satisfies 360°.

7. The ultra-wideband tightly coupled wide-angle scanning transmission array antenna according to claim 1, characterized in that, Two feed antennas (3) are selected according to the operating frequency to illuminate the surface, and beam scanning is achieved by rotating the feed antennas (3) along the arc track.

8. The ultra-wideband tightly coupled wide-angle scanning transmission array antenna according to claim 1, characterized in that, The ultra-wideband tightly coupled wide-angle scanning transmission array antenna has a stable radiation pattern with a working bandwidth of 3 times the frequency, i.e., 2GHz-6GHz, and a beam coverage range of 80°.

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