A reflective 1-bit programmable metasurface unit

Abstract

The application discloses a reflective 1-bit programmable metasurface unit and belongs to the technical field of microwave and millimeter wave antennas.The application comprises a first dielectric substrate and a second dielectric substrate arranged in sequence from top to bottom, the upper surface of the first dielectric substrate is provided with a patch antenna unit, and the lower surface is provided with a metal ground plate; the lower surface of the second dielectric substrate is provided with a bias circuit; the periphery of the patch antenna unit is provided with a plurality of rectangular slots, one end of the patch antenna unit is etched with a hollow area, and a PIN diode is arranged in the hollow area and connected with the patch antenna unit; the bias circuit comprises a fan-shaped branch and an L-shaped branch connected in sequence; the patch antenna unit is respectively provided with a first metal via hole and a second metal via hole on the metal ground plate and the bias circuit.The application realizes dynamic regulation and control of the reflection phase of the metasurface unit, improves the performance of the metasurface antenna, achieves the purpose of low profile, and realizes the effect of miniaturization of the metasurface antenna.

Description

Technical Field

[0001] This invention belongs to the field of microwave and millimeter-wave antenna technology, specifically referring to a reflective 1-bit programmable metasurface unit. Background Technology

[0002] With the rapid development of modern wireless technology, phased array antennas, with their advantages of fast beam scanning speed, flexible pattern shaping, strong anti-interference capability, and high tracking accuracy, are widely used in airborne and shipborne radar systems. Easily integrated, scalable, and miniaturized phased array antenna modules are urgently needed for modern multi-functional radar systems. Reflector antennas, due to their mature technology, light weight, simple structure, and low cost, are currently the most widely used type of spaceborne communication antenna. However, under the background of low-cost construction and operation, the above antenna solutions, either due to their relatively large size, weight, and cross-section, or due to their high construction costs, pose challenges to the development of modern communications.

[0003] In recent years, electromagnetic metasurfaces have attracted widespread attention, with related research and applications flourishing. Subwavelength phase modulation structures exhibit excellent control over the phase of electromagnetic waves. By combining subwavelength phase modulation structures with existing feed antennas, dynamic control of electromagnetic beams can be achieved. Beam-scanning antennas based on metasurfaces are relatively low-cost, and with proper design, they can achieve multiple functions. Furthermore, they can be integrated with existing antennas, offering greater flexibility and promising to play a significant role in the future of antenna design. Summary of the Invention

[0004] In view of this, the present invention proposes a reflective 1-bit programmable metasurface unit that can realize low profile and miniaturization of antenna.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A reflective 1-bit programmable metasurface unit includes a first dielectric substrate 2 and a second dielectric substrate 4 arranged sequentially from top to bottom. The upper surface of the first dielectric substrate 2 is provided with a patch antenna unit 1, and the lower surface is provided with a metal ground plane 3. The lower surface of the second dielectric substrate 4 is provided with a bias circuit 5. The main body of the patch antenna unit 1 is an elliptical patch, which is divided into four regions by the major axis and the minor axis. Each region is etched with the same number of slots. The slots in adjacent regions are symmetrical about the major axis or the minor axis. A hollow area symmetrical about the major axis of the elliptical patch is etched on the elliptical patch. A PIN diode 1-1 is provided in the hollow area. The PIN diode 1-1 is connected to the elliptical patch through two connecting branches 1-2. The two connecting branches 1-2 coincide with the major axis of the elliptical patch.

[0007] The bias circuit 5 includes a fan-shaped branch 5-3 and an L-shaped branch 5-2. The fan-shaped branch 5-3 is located below the hollow area of ​​the elliptical patch. The long side of the L-shaped branch 5-2 coincides with the orthographic projection of the major axis of the elliptical patch. The vertex of the fan-shaped branch 5-3 coincides with the endpoint of the long side of the L-shaped branch 5-2. The short sides of the fan-shaped branch 5-3 and the L-shaped branch 5-2 are located on the left and right sides of the long side of the L-shaped branch 5-2.

[0008] A first metal via 1-3 is provided between the patch antenna unit 1 and the metal ground plane, and a second metal via 5-1 is provided between the patch antenna unit 1 and the bias circuit 5; the second metal via 5-1 is located at the end of one of the connecting branches 1-2.

[0009] Furthermore, the gaps in each region of the elliptical patch are rectangular gaps; the hollowed-out areas on the elliptical patch are elliptical hollowed-out areas, and the elliptical hollowed-out areas are close to one end of the major axis of the elliptical patch, and the two connecting branches 1-2 are rectangular branches of the same size.

[0010] Furthermore, the first metal via 1-3 is located at the center of the patch antenna unit 1.

[0011] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0012] 1. The metasurface antenna element provided by this invention uses an embedded control circuit to load a PIN diode, thereby achieving dynamic control of the reflection phase of the metasurface element and ultimately realizing a digital metasurface phased array antenna. Compared with traditional phased array antennas, it has the advantages of low cost, small size, light weight, and high efficiency.

[0013] 2. The metasurface unit structure used in this invention has low loss, and the working bandwidth of the metasurface unit is further improved. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a reflective 1-bit programmable metasurface unit in an embodiment of the present invention.

[0015] Figure 2 This is in the implementation of the present invention Figure 1 Top view.

[0016] Figure 3 This is in the implementation of the present invention Figure 1 Rear cross-sectional view.

[0017] Figure 4 This is in the implementation of the present invention Figure 1 Side view.

[0018] Figure 5This is a diagram showing the relationship between the reflection amplitude and the operating state of the PIN diode in the implementation of this invention.

[0019] Figure 6 This is a diagram showing the relationship between the reflection phase and the operating state of the PIN diode in an embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] A reflective 1-bit programmable metasurface unit, such as Figure 1 As shown, the device includes a first dielectric substrate 2 and a second dielectric substrate 4 arranged sequentially from top to bottom. The upper surface of the first dielectric substrate 2 is provided with a patch antenna unit 1, and the lower surface is provided with a metal ground plane 3. The lower surface of the second dielectric substrate 4 is provided with a bias circuit 5. Figure 2 As shown, the main body of the patch antenna unit 1 is an elliptical patch. The elliptical patch is divided into four regions by the major axis and the minor axis. Each region has the same number of slots etched on it. The slots in two adjacent regions are symmetrical about the major axis or the minor axis. A hollow area symmetrical about the major axis of the elliptical patch is etched on the elliptical patch. A PIN diode 1-1 is provided in the hollow area. The PIN diode 1-1 is connected to the elliptical patch through two connecting branches 1-2. The two connecting branches 1-2 coincide with the major axis of the elliptical patch.

[0022] like Figure 3 As shown, the bias circuit 5 includes a fan-shaped branch 5-3 and an L-shaped branch 5-2. The fan-shaped branch 5-3 is located below the hollow area of ​​the elliptical patch. The long side of the L-shaped branch 5-2 coincides with the orthographic projection of the long axis of the elliptical patch. The vertex of the fan-shaped branch 5-3 coincides with the endpoint of the long side of the L-shaped branch 5-2. The short sides of the fan-shaped branch 5-3 and the L-shaped branch 5-2 are located on the left and right sides of the long side of the L-shaped branch 5-2.

[0023] like Figure 4 As shown, a first metal via 1-3 is provided between the patch antenna unit 1 and the metal ground plane, and a second metal via 5-1 is provided between the patch antenna unit 1 and the bias circuit 5; the second metal via 5-1 is located at the end of one of the connecting branches 1-2.

[0024] Furthermore, the gaps in each region of the elliptical patch are rectangular gaps; the hollowed-out area on the elliptical patch is an elliptical hollowed-out area, the elliptical hollowed-out area is close to one of the endpoints of the major axis of the elliptical patch, and the two connecting branches 1-2 are rectangular branches of the same size.

[0025] Furthermore, the first metal via 1-3 is located at the center of the patch antenna unit 1.

[0026] Specifically, the elliptical patch has a major axis of 10mm and a minor axis of 8mm. Each of the four regions of the elliptical patch has a rectangular slot on its elliptical curve. The rectangular slot is 1.25mm long and 0.4mm wide, and the angle between the rectangular slot and the major axis of the elliptical patch is 45°. The elliptical hollow area has a major axis of 2.6mm and a minor axis of 2.08mm, and the distance between the center of the elliptical hollow area and the center of the elliptical patch is 3.5mm. The two connecting branches 1-2 have a long side of 0.9mm and a short side of 0.3mm. The first metal via 1-3 and the second metal via 5-1 have a diameter of 0.4mm, and their centers are located on the major axis of the elliptical patch. The first dielectric substrate 2, the metal ground plane 3, and the second dielectric substrate 4 all have square unit boundaries with the same side length of 11mm. The thickness of the first dielectric substrate 2 is 1.52mm, and the thickness of the second dielectric substrate 4 is 0.5mm. The first dielectric substrate 2 is made of Arlon AD255 material with a relative permittivity of 2.55, and the second dielectric substrate 4 is made of FR4 material with a relative permittivity of 4.4. The second metal via 5-1 is connected to the apex of the fan-shaped branch 5-3. The long side of the L-shaped branch 5-2 is 10 mm, the short side is 1.9 mm, and the width is 0.2 mm. The radius of the fan-shaped branch 5-3 is 3 mm, the opening angle is 68°, and the angle between the long side of the fan-shaped branch 5-3 and the long side of the L-shaped branch 5-2 is 41°.

[0027] Furthermore, the reflective 1-bit programmable metasurface unit can achieve a 180° change in the reflection phase of the unit by adjusting the on / off state of the PIN diode 1-1 through the bias circuit 5.

[0028] Simulation tests were performed on the above-mentioned metasurface antenna element. Figure 5 The graph shows the relationship between reflection amplitude and the operating state of the PIN diode. When the diode on the metasurface unit is turned on and off, the reflection amplitude of the metasurface antenna unit is within -3.5dB in the frequency range of 11.45-11.72GHz, and the loss is relatively small. Figure 6 The diagram shows the relationship between the reflection phase and the operating state of the PIN diode. When the PIN diode on the metasurface element is turned on and off, the metasurface antenna element can achieve a phase shift range of 180°±15° in the frequency band of 11.47-11.72GHz.

[0029] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the structure and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A reflective 1-bit programmable metasurface unit, comprising a first dielectric substrate (2) and a second dielectric substrate (4) arranged sequentially from top to bottom, wherein a patch antenna unit (1) is provided on the upper surface of the first dielectric substrate (2), and a metal ground plane (3) is provided on the lower surface; a bias circuit (5) is provided on the lower surface of the second dielectric substrate (4); characterized in that, The main body of the patch antenna unit (1) is an elliptical patch. The elliptical patch is divided into four regions by the major axis and the minor axis. Each region has the same number of slots etched on it. The slots in two adjacent regions are symmetrical about the major axis or the minor axis. The elliptical patch has a hollow area symmetrical about the major axis of the elliptical patch. A PIN diode (1-1) is provided at the center of the hollow area. The PIN diode (1-1) is connected to the elliptical patch through two connecting branches (1-2). The two connecting branches (1-2) coincide with the major axis of the elliptical patch. The bias circuit (5) includes a fan-shaped branch (5-3) and an L-shaped branch (5-2). The fan-shaped branch (5-3) is located below the hollow area of ​​the elliptical patch. The long side of the L-shaped branch (5-2) coincides with the orthographic projection of the major axis of the elliptical patch. The vertex of the fan-shaped branch (5-3) coincides with the endpoint of the long side of the L-shaped branch (5-2). The short sides of the fan-shaped branch (5-3) and the L-shaped branch (5-2) are located on the left and right sides of the long side of the L-shaped branch (5-2). A first metal via (1-3) is provided between the patch antenna unit (1) and the metal ground plane, and a second metal via (5-1) is provided between the patch antenna unit (1) and the bias circuit (5); the second metal via (5-1) is located at the end of one of the connecting branches (1-2).

2. The reflective 1-bit programmable metasurface unit according to claim 1, characterized in that, The gaps in each area of ​​the elliptical patch are rectangular gaps; the hollow areas on the elliptical patch are elliptical hollow areas, and the elliptical hollow areas are close to one end of the long axis of the elliptical patch. The two connecting branches (1-2) are rectangular branches of the same size.

3. The reflective 1-bit programmable metasurface unit according to claim 1, characterized in that, The first metal via (1-3) is located at the center of the patch antenna unit (1).

Images