Millimeter wave dual-band wideband 1-bit electronic scanning reflector unit

Abstract

The application discloses a millimeter wave dual-frequency broadband 1-bit electric scanning reflection unit, which comprises a surface metal structure, a dielectric core layer and a back metal ground layer arranged in a top-down stacking mode; the surface metal structure comprises a main radiation patch, a radio frequency switch and a parasitic patch, the main radiation patch is connected with the back metal ground layer through a metallized via, and the parasitic patch is coupled with the main radiation patch through an interdigital structure; the electric scanning reflection unit realizes phase switching in response to polarization by controlling the switching state of the radio frequency switch, and the working frequency covers at least two typical millimeter wave frequencies. The application covers a wider frequency band while keeping the surface topological structure unchanged. Through the improvement of the application, the limitation of the narrow band of the traditional electric scanning unit is overcome, and more design schemes are provided for the electric scanning type metasurface unit.

Description

Technical Field

[0001] This invention relates to electrically scanned reflective array antenna technology, and in particular to a novel ultra-wideband electrically scanned reflective unit covering the 5G millimeter-wave band. Background Technology

[0002] With the continuous development of 5G and future 6G networks, reconfigurable intelligent metasurfaces (RIS), as a novel wireless communication technology, have become a research hotspot due to their tunability, flexibility, and low cost. One of the main ways to realize RIS is through reconfigurable reflective array antennas (RRAs), because RRAs have simplified feeding systems, compact planar structures, and low production costs. Electrically scanned reconfigurable reflective array antennas achieve beam scanning and beamforming by changing the reflection phase of each element. The modulation of the reflection phase is controlled by various active devices and materials, such as microelectromechanical systems (MEMS) technology, liquid crystal materials, varactor diodes, and PIN diodes. Reflective arrays designed using unfed half-wavelength and sub-half-wavelength electromagnetic metasurface elements can achieve high gain, wide bandwidth, low sidelobes, and beam scanning without the need for large and complex feeding and phase-shifting circuits. This has significant advantages for improving antenna miniaturization and reducing design complexity. Compared to traditional mechanical rotating scanning antennas and the high-cost, complex phase-shifting channels used in traditional phased array antennas, beam scanning functionality achieved by controlling switches using digital systems such as FPGAs and microprocessors (MPUs) not only better meets the needs of high-speed systems but also significantly reduces manufacturing costs. By loading various active devices onto reflective patches, the phase-shifting circuit is moved from the rear end of the array to the front end of the array aperture. The resulting electromagnetic metasurface unit can more flexibly control electromagnetic waves without altering the surface structure, showing broad application prospects in areas such as absorption / reflection / transmission, polarization deflection / conversion, radar cross section (RCS) reduction, beam reconstruction, and the formation of orbital angular momentum (OAM) vortex electromagnetic fields.

[0003] In recent years, with the pursuit of full spectrum, full coverage, and full application in 5G and 6G communication systems, the demand for and use of spectrum have changed significantly. These systems require higher data rates, faster handover mechanisms, and wider operating bandwidth. To meet these needs, 5G has introduced higher frequency bands, especially millimeter-wave bands, thus providing abundant spectrum resources and significantly improving system capacity and transmission rates. However, there are few reported studies on RIS (Radio-Induced Surface Unit) structures for the 5G millimeter-wave band, and the reported RIS operating bandwidths are relatively narrow, covering only one or two adjacent frequency bands of the 5G millimeter-wave band, limiting the application scope and failing to fully utilize the abundant millimeter-wave spectrum resources. Therefore, researching broadband electromagnetic metasurface unit structures capable of covering multiple millimeter-wave bands can reduce the need for multiple independent antenna arrays and their control circuits, thereby significantly reducing the overall system cost and possessing significant application value. Summary of the Invention

[0004] Technical Problem: The purpose of this invention is to provide a novel ultra-wideband electrically scanned reflector unit structure covering multiple millimeter-wave frequency bands, further improving the operating bandwidth of metasurface units. Unlike traditional electrically scanned units, this invention achieves subwavelength miniaturization of the antenna unit, with a unit size smaller than half a wavelength. Simultaneously, an interdigital structure is introduced to replace the traditional coupling method between the main reflector and the parasitic patch, effectively broadening the bandwidth of the antenna unit. The proposed unit covers a wider frequency band while maintaining the same surface topology. This approach does not increase the number of RF board layers; it achieves this function solely by changing the topology of the PCB surface patches. Through the improvements of this invention, the narrow-band limitation of traditional electrically scanned units is overcome, and more design options are provided for electrically scanned metasurface units.

[0005] Technical solution:

[0006] To achieve the above objectives, this invention provides a millimeter-wave dual-band broadband 1-bit electrically scanned reflector unit, comprising a surface metal structure, a dielectric core layer, and a back metal ground layer stacked from top to bottom. The surface metal structure includes a main radiating patch, an RF switch, and a parasitic patch. The main radiating patch is connected to the back metal ground layer through a metallized via, and the parasitic patch is coupled to the main radiating patch through an interdigital structure. The electrically scanned reflector unit achieves phase switching of the response polarization by controlling the switching state of the RF switch, and the operating frequency covers at least two typical millimeter-wave frequencies. The state of the RF switch in the unit is defined as: 0 indicates the switch is off, and 1 indicates the switch is on. The switching on and off can generate a 180° reflection phase difference for the corresponding common-polarized wave.

[0007] Furthermore, the surface metal structure includes a pair of main radiating patches, which are the same size and symmetrical in shape, and are arranged in a mirror image with respect to the center of the unit.

[0008] Furthermore, the slot at the center of the electronically scanned reflective unit is the welding point for the RF switch.

[0009] Furthermore, the opening position of the metallized via is on the axis of symmetry of the main radiating patch, and each of the two main radiating patches has a metallized via connected to the back metal ground layer.

[0010] Furthermore, each of the four corners of the main radiating patch has a rectangular parasitic patch, which is coupled to the main radiating patch through an interdigital structure.

[0011] Furthermore, the feed structure of the electro-scanning reflective unit is located on the back of the dielectric core layer.

[0012] Furthermore, the electronically scanned reflective unit is manufactured using PCB technology.

[0013] Furthermore, the size of the electronically scanned reflective unit is less than half of its corresponding wavelength.

[0014] The present invention also provides a reconfigurable smart metasurface, which is composed of the above-mentioned electrically scanned reflective units.

[0015] Furthermore, the electronically scanned reflective units are tightly fitted together.

[0016] Beneficial Effects: Compared with existing technologies, the beneficial effects of this invention are as follows: This invention provides an ultra-wideband electrically scanned reflector unit with coverage of multiple millimeter-wave frequency bands. By improving the traditional reflector unit structure, it further broadens the operating frequency band of the 180° phase-response reflection and allows it to be controlled via a programmable logic gate (FPGA) chip. The proposed antenna structure is reasonable, meets current manufacturing processes, has excellent scalability, and has great application prospects in electrically scanned arrays. The proposed solution has high engineering practicality and innovation, meeting the needs of various application scenarios. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural view of the ultra-wideband electronic scanning unit;

[0018] Figure 2 This is a perspective view of the structure of the ultra-wideband electronic scanning unit;

[0019] Figure 3 This is a top view of the structure of the ultra-wideband electronic scanning unit;

[0020] Figure 4 This is a side view of the ultra-wideband electronic scanning unit;

[0021] Figure 5 The amplitude response of the ultra-wideband electronic scanning unit in two states during operation;

[0022] Figure 6 A comparison of the phase response of the ultra-wideband electronic scanning unit in two states during operation;

[0023] The numbers in the diagram represent:

[0024] 1- Schematic diagram of the main radiating patch on the surface metal layer; 2- Metallized via connecting the two poles of the RF switch to the metal ground layer; 3- Schematic diagram of the parasitic patches around the main radiating patch; 4- Dielectric core layer; 5- Metal ground layer located at the bottom of the cell. Detailed Implementation

[0025] The above description and other technical features of the present invention will be further explained below with reference to the accompanying drawings.

[0026] This specific embodiment discloses a broadband electrically scanned reflective unit that can be compactly arranged, such as... Figures 1 to 4 As shown, Figure 1 This is a three-dimensional structural view of the ultra-wideband electronic scanning unit; Figure 2 This is a perspective view of the structure of the ultra-wideband electronic scanning unit; Figure 3 This is a top view of the structure of the ultra-wideband electronic scanning unit; Figure 4 Side view of the ultra-wideband electronic scanning unit.

[0027] The broadband electrically scanned metasurface reflective unit of this invention, which can be compactly arranged, includes a surface metal structure, a dielectric core layer, and a back metal ground layer stacked from top to bottom. A pair of mirror-symmetrical main radiating patches on the surface each have a slot of a certain length in the middle for placing an RF switch.

[0028] Furthermore, firstly, a periodic structure of half-wavelength of the unit is selected based on the highest frequency point within the operating frequency band. In this embodiment, the period length of the unit is the same in both the x and y directions. A pair of vias on the axis of the main radiating patch are used to feed the RF switch at the center of the patch. It is worth noting that the patch shape, the corresponding via positions, and the number of PCB layers can all be modified according to actual application requirements.

[0029] Example

[0030] This embodiment provides an ultrawideband 1-bit reflective metasurface unit operating in the 25-40GHz range. The period length p of the unit in both the x and y directions is set to 3.5mm. The dielectric core board 4 adopts the Rogers RO4003C high-frequency board. The thickness of the copper cladding layer on the top and bottom of the core board is 0.018mm, and the diameter of the via is 0.26mm.

[0031] like Figure 1As shown, the copper-clad pattern on the surface of the upper dielectric core board is a pair of main radiating patches 1. Both patches are connected to the metal ground layer 5 through grounding vias 2. Four parasitic patches 3 are loaded around the main radiating patches and are coupled to the main radiating patches 1 through interdigital structures.

[0032] The 1-bit reflective metasurface unit in the implementation case, calculated using Floquet port periodic boundary simulation, exhibits the following amplitude response in both RF switch on and off states: Figure 5 As shown, the phase response is as follows Figure 6 As shown, it can be seen that by using the unit structure proposed in this invention, the unit achieves a phase response with a 180° phase difference between the two states in an ultra-wide bandwidth.

[0033] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. It should be noted that those skilled in the art can make various improvements, or even equivalents, without departing from the principles of the present invention, such as modifying the cell size or number of layers and fine-tuning the patches. However, all such improvements and modifications will be considered within the scope of protection of the present invention.

Claims

1. A millimeter-wave dual-frequency broadband 1-bit electrically scanned reflective unit, characterized in that, The device comprises a surface metal structure, a dielectric core layer, and a back metal ground layer stacked from top to bottom. The surface metal structure includes a main radiating patch, an RF switch, and a parasitic patch. The main radiating patch is connected to the back metal ground layer through a metallized via, and the parasitic patch is coupled to the main radiating patch through an interdigital structure. The electronically scanned reflector unit achieves phase switching of the response polarization by controlling the switching state of the RF switch, and the operating frequency covers at least two typical millimeter-wave frequencies. The surface metal structure includes a pair of main radiating patches. The two main radiating patches are the same size and symmetrical in shape, and are arranged in a mirror image with respect to the center of the unit. The main radiating patch has rectangular parasitic patches at its four corners, and the parasitic patches are coupled to the main radiating patch through interdigital structures. The size of the electroscanned reflective unit is less than half of its corresponding wavelength.

2. The millimeter-wave dual-frequency broadband 1-bit electrically scanned reflective unit according to claim 1, characterized in that, The slot at the center of the electronically scanned reflective unit is the welding point for the RF switch.

3. The millimeter-wave dual-frequency broadband 1-bit electrically scanned reflective unit according to claim 1, characterized in that, The opening position of the metallized via is on the axis of symmetry of the main radiating patch, and each of the two main radiating patches has a metallized via connected to the back metal ground layer.

4. The millimeter-wave dual-frequency broadband 1-bit electrically scanned reflective unit according to claim 1, characterized in that, The feed structure of the electro-scanning reflective unit is located on the back of the dielectric core layer.

5. The millimeter-wave dual-frequency broadband 1-bit electrically scanned reflective unit according to claim 1, characterized in that, The electroscanning reflective unit is manufactured using PCB technology.

6. A reconfigurable smart metasurface, characterized in that, It is composed of the electronically scanned reflective units described in any one of claims 1-5.

7. A reconfigurable smart metasurface according to claim 6, characterized in that, The electronically scanned reflective units are tightly fitted together.

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