Metasurface planar lens-type radar and beamforming antenna for communication capable of adjusting electromagnetic beam steering angle by selecting electromagnetic wave source without chipset active phase shifter

Abstract

Current beamforming antennas use an active phase shifter chipset attached to each radiating element to steer a beam, and this active phase shifter chipset consisting of a variable amplifier and a variable phase shifter is expensive due to the costs associated with semiconductor processing, amplifier bias, and control. The number of active phase shifter chipsets increases with RF power consumption, DC power consumption, and array size, thereby posing significant drawbacks in terms of development and operational resource investment. To address and improve these issues of existing beam streering antennas, presented is an operation method of the parts, entirety, and switches of a device in which a primary device that changes the steering angle of a beam through a metamaterial planar lens by changing the position of a radiating source, which is a purely passive component, and a series of patches are arranged for each position of the radiating source, without the need for a power divider, electromagnetic waves are incident onto the metamaterial lens through a simple selection of an RF switch, and a necessary phase compensation value at each point of the metamaterial lens is implemented through a combined structure of metal circular patches inside a metal ring, which more flexibly makes robust and sensitive resonance characteristics less susceptible to negative effects caused by changes in frequency signals or process errors even when the direction of incidence changes.

Description

Metasurface flat lens radar and communication beamforming antenna capable of controlling electromagnetic beam angle by electromagnetic source selection without requiring a chipset active phase shifter

[0001] The present invention relates to array antenna technology for radar systems, array antenna technology for satellites, millimeter wave band array antenna technology for 5G mobile communication repeaters, sub-terahertz band array antenna technology for 6G mobile communication repeaters, array antenna technology for high-frequency transceivers for autonomous vehicles, high-frequency transceiver array antenna technology for V2X, and high-frequency wireless power transmission array antenna technology, and more particularly, to a metasurface flat lens type radar and communication beamforming antenna capable of controlling an electromagnetic wave beam directivity angle by electromagnetic wave source selection that does not require a chipset active phase shifter.

[0002] Beamforming and beam steering antenna technologies are the core of radar, which is essential for following a moving receiver without stopping, connecting wireless communication devices, and preventing collisions with objects in the path of vehicles and UAVs and UAM aerial vehicles.

[0003] Beamforming technology, which is often discussed alongside the promotion of 5G communication services, is a function that forms and controls beams. It refers to the angle control of the main beam of electromagnetic waves through the combination of antenna radio wave radiation, long-distance constructive interference, and RF elements and digital signal processing control blocks. In a beamforming array antenna, the change in the direction of the main beam occurs due to the difference in the phases supplied to the radiating elements (array elements), and the output of the RF phase shifter for each radiating element is determined.

[0004] Most beamforming antennas, including fighter jet AESA radars and 5G beamforming transceivers, are in the form of semiconductor chips (chip sets) and combine expensive active phase shifters with each radiating element. As requirements for electromagnetic wave radiation gain and beam width increase, the number of active phase shifters increases rapidly along with the array size and the number of radiating elements, which raises many questions about the economic feasibility due to the enormous investment required. Furthermore, since the elements are active, large power consumption is unavoidable for operation. Not only are phase shifters active elements in the semiconductor process, but they are also required as many as the radiating elements.

[0005] The problem to be solved by the present invention is that, while existing beamforming antennas or beam steering antennas have high development and operation costs, high power consumption, and weight because active phase shifters are connected to each radiating element, and phase shifters are required in the square of the number of radiating elements when active phase shifters are attached to each radiating element, the present invention provides a metasurface flat lens type radar and communication beamforming antenna capable of controlling the electromagnetic wave directivity angle by selecting an electromagnetic wave source that does not require a chipset active phase shifter, which can significantly reduce the manufacturing cost and the operating power consumption while enabling steering of highly directive electromagnetic wave energy required for radar and 5G and 6G mobile communications to follow a moving object, and in addition to such practical value, it can provide a new technology that selects only one of an array of radiating sources instead of the existing method of simultaneously supplying the phase difference of multiple radiating sources and has a metamaterial structure lens suitable for that wavefront and inputs it thereto.

[0006] In addition, another problem to be solved by the present invention is to provide a metamaterial flat lens used in a metasurface flat lens radar and a communication beamforming antenna capable of controlling an electromagnetic wave beam direction angle by selecting an electromagnetic wave source without requiring the above-described chipset active phase shifter.

[0007] In addition, another problem to be solved by the present invention is to provide a unit cell structure for a metamaterial flat lens used in a metasurface flat lens radar and a communication beamforming antenna capable of controlling an electromagnetic wave beam direction angle by electromagnetic wave source selection without requiring the above-described chipset active phase shifter.

[0008] In order to solve the above problem, a metasurface flat lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam direction angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to an embodiment of the present invention is provided.

[0009] A radiating portion comprising a plurality of radiating patches arranged one-dimensionally and spaced apart from each other by a predetermined distance; and

[0010] The method may include a metamaterial planar lens in which single-layer or multi-layer unit cell structures are arranged at a predetermined distance from the above-mentioned radiating portion and are arranged in accordance with a phase compensation distribution to compensate for the phase in order to increase gain and steer the incident wave radiated from one of the plurality of radiating patches.

[0011] In a metasurface planar lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam direction angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to one embodiment of the present invention, the unit cell structure is,

[0012] metal ring; and

[0013] The metal ring may include a deformed circular patch positioned within the metal ring at a predetermined distance from the metal ring.

[0014] In addition, in a metasurface flat lens radar and a communication beamforming antenna capable of controlling the electromagnetic wave beam direction angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to an embodiment of the present invention, the modified circular patch is,

[0015] A first capacitance control unit in which the metal in the central portion of the above circular patch is removed in a circular shape; and

[0016] It includes a second capacitance control unit in which the metal on the upper, lower, left and right sides of the outer peripheral portion of the above circular patch is partially removed,

[0017] The above circular patch can be formed point-symmetrically.

[0018] In addition, in a metasurface flat lens radar and a communication beamforming antenna capable of controlling the electromagnetic wave beam direction angle by selecting an electromagnetic wave source without an unnecessary chip set active phase shifter according to one embodiment of the present invention,

[0019] The phase of the incident electromagnetic wave is compensated by the combination of the inductance of the metal ring and the capacitance of the circular patch,

[0020] As the incident electromagnetic wave passes through each layer of the multilayer unit cell structure, the phase value required for each unit cell structure can be compensated.

[0021] In addition, in a metasurface planar lens radar and a communication beamforming antenna capable of controlling an electromagnetic wave beam directivity angle by selecting an electromagnetic wave source without an unnecessary chipset active phase shifter according to an embodiment of the present invention, a phase value to be compensated can be determined according to at least one of a diameter of the circular patch and a gap, which is a distance between the metal ring and the circular patch.

[0022] In addition, the metasurface flat lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam directivity angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to one embodiment of the present invention may further include a switch for providing an input electromagnetic wave to one of the plurality of radiation patches.

[0023] In addition, the metasurface planar lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam directivity angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to one embodiment of the present invention may further include a switch controller for controlling the operation of the switch.

[0024] In addition, in a metasurface planar lens radar and a communication beamforming antenna capable of controlling an electromagnetic wave beam directivity angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to an embodiment of the present invention, the unit cell structure formed in multiple layers can be formed by stacking a plurality of single-layer unit cells of the same structure in multiple layers.

[0025] A metamaterial plane lens according to one embodiment of the present invention for solving the above problem includes single-layer or multi-layer unit cell structures that compensate for phase for high gain and steering of incident waves.

[0026] The above single-layer or multi-layer unit cell structures can be arranged to suit the phase compensation distribution.

[0027] In a metamaterial plane lens according to one embodiment of the present invention, the unit cell structure is:

[0028] metal ring; and

[0029] The metal ring may include a deformed circular patch positioned within the metal ring at a predetermined distance from the metal ring.

[0030] In addition, in the metamaterial flat lens according to one embodiment of the present invention, the deformed circular patch,

[0031] A first capacitance control unit in which the metal in the central portion of the above circular patch is removed in a circular shape; and

[0032] It includes a second capacitance control unit in which the metal on the upper, lower, left and right sides of the outer peripheral portion of the above circular patch is partially removed,

[0033] The above circular patch can be formed point-symmetrically.

[0034] In addition, in the metamaterial flat lens according to one embodiment of the present invention, the phase of the incident electromagnetic wave is compensated by the combination of the inductance of the metal ring and the capacitance of the circular patch,

[0035] As the incident electromagnetic wave passes through each layer of the multilayer unit cell structure, the phase value required for each unit cell structure can be compensated.

[0036] In addition, in a metamaterial plane lens according to one embodiment of the present invention, a phase value to be compensated can be determined according to at least one of a diameter of the circular patch and a gap, which is a distance between the metal ring and the circular patch.

[0037] In addition, in the metamaterial flat lens according to one embodiment of the present invention, the unit cell structure formed in multiple layers can be formed by stacking multiple single-layer unit cells of the same structure in multiple layers.

[0038] A unit cell structure for a metamaterial plane lens according to one embodiment of the present invention for solving the above problem is a unit cell structure for a metamaterial plane lens for high gain and steering of an incident wave,

[0039] The above unit cell structure is formed as a single layer or multiple layers, and can compensate for the phase to increase the gain and steer the incident wave.

[0040] In a unit cell structure for a metamaterial plane lens according to one embodiment of the present invention, the unit cell structure comprises:

[0041] metal ring; and

[0042] The metal ring may include a deformed circular patch positioned within the metal ring at a predetermined distance from the metal ring.

[0043] In addition, in the unit cell structure for the metamaterial plane lens according to one embodiment of the present invention, the deformed circular patch,

[0044] A first capacitance control unit in which the metal in the central portion of the above circular patch is removed in a circular shape; and

[0045] It includes a second capacitance control unit in which the metal on the upper, lower, left and right sides of the outer peripheral portion of the above circular patch is partially removed,

[0046] The above circular patch can be formed point-symmetrically.

[0047] In addition, in the unit cell structure for the metamaterial plane lens according to one embodiment of the present invention, the phase of the incident electromagnetic wave is compensated by the combination of the inductance of the metal ring and the capacitance of the circular patch,

[0048] As the incident electromagnetic wave passes through each layer of the multilayer unit cell structure, the phase value required for each unit cell structure can be compensated.

[0049] In addition, in a unit cell structure for a metamaterial plane lens according to one embodiment of the present invention, a phase value to be compensated can be determined according to at least one of a diameter of the circular patch and a gap, which is a distance between the metal ring and the circular patch.

[0050] In addition, in the unit cell structure for the metamaterial plane lens according to one embodiment of the present invention, the unit cell structure formed in the multilayer is,

[0051] Multiple single-layer unit cells of the same structure can be formed by stacking them in multiple layers.

[0052] Conventional beamforming antennas or beam steering antennas have high development and operation costs, high power consumption, and weight because they connect active phase shifters to each radiating element, and when active phase shifters are attached to each radiating element, phase shifters are required in the square of the number of radiating elements. In contrast, according to a metasurface flat lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam directivity angle by selecting an electromagnetic wave source that does not require a chipset active phase shifter according to an embodiment of the present invention, it is possible to steer highly directive electromagnetic wave energy required for radar and 5G and 6G mobile communications to follow a moving object while significantly reducing the manufacturing cost and the operating power consumption, and in addition to such practical value, it is possible to provide a new technology that combines a metamaterial structure lens suitable for the wavefront of only one of the radiating source arrays and incidents it onto it, rather than the conventional method of simultaneously supplying the phase difference of multiple radiating sources, so it has a clear advantage in both technological innovation and economic feasibility.

[0053] Figures 1a to 1d are conceptual diagrams of the structure and operation of a conventional beamforming array antenna that has problems of power consumption, heat generation, and cost.

[0054] FIG. 2 is a conceptual diagram of a metasurface planar lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam directivity by electromagnetic wave source selection that does not require a chipset active phase shifter according to an embodiment of the present invention, in which, unlike the conventional method of simultaneously supplying power to all array antenna elements, patches to operate as radiating sources for each steering angle are arranged in a one-dimensional array, and then a patch with a number corresponding to a target steering angle is selected by an RF switch, and the patch is incident on a metamaterial planar lens existing thereon, the gain is increased, and then the beam is propagated in the direction of a receiver.

[0055] FIG. 3 is a conceptual diagram for determining the focal length of an optical lens so that electromagnetic waves passing through a metamaterial surface have high gain in a specific direction in order to determine the overall size of the metamaterial plane and the spacing between patch elements in a structure in which only one element is selected in the invention structure of FIG. 2 and an RF signal is applied.

[0056] Figures 4a and 4b are the most basic drawings explaining a metamaterial lens. When a horn antenna, which is generally selected as a radiation source, generates an electromagnetic wave and sends it upward, the metamaterial structure adjusts the phase of each point where the light rays enter, creating an effect similar to inputting a phase difference into elements of an array antenna to form a beam and control the direction of the beam.

[0057] Fig. 4c, together with the three-dimensional structural schematic diagrams of Figs. 4a and 4b, illustrates a phase difference distribution or phase compensation distribution that changes the surface phase distribution of the electromagnetic wave generated by the radiating source and sent to the lower surface of the metamaterial into the phase required for beam steering and gain increase. This phase compensation distribution may vary depending on the type of radiating source, the distance and direction of the wavefront of the electromagnetic wave propagating from the aperture of the radiating source to the observation plane, and the shape of the final radiation pattern after passing through the metamaterial surface, i.e., the expected steering angle and gain increase. For physical implementation, a metal pattern is deposited on a PCB substrate, and although the phase compensation distribution is continuous, due to the precision limitations of the PCB etching process, it is composed of pixels, which are a discrete grid shape, to implement the required phase value for each unit section.

[0058] Figure 5 is a flowchart illustrating the design procedure of the proposed device.

[0059] Fig. 6a shows a representative view of a radiating source element of a device for determining a beam steering angle of a transmit array antenna by selecting one from an array of radiating sources of a novel concept proposed by the present invention. Fig. 6b shows reflection loss, and Fig. 6c shows gain according to phase.

[0060] Figures 7a and 7b illustrate a single radiating source of Figure 6a arranged in a one-dimensional (1D) array. Note that this array is not a conventional array antenna, i.e., not a typical array antenna with a power divider on the bottom or in the same plane as the patches. Rather, it is comprised of independently operating radiating sources, rather than elements of an array antenna having a phase difference relationship that is selected based on the steering angle input. Figure 7c illustrates the reflection loss.

[0061] Fig. 8a is a discretization of the phase compensation distribution that compensates for the phase observed on the bottom of the metamaterial structure for high gain and beam steering of the wide beam width radiation of the radiating source. Fig. 8b illustrates the structure of one layer of the unit cell structure, and Fig. 8c illustrates a multilayer unit cell structure formed of three layers. The required phase value can be determined for each unit cell, i.e. pixel, of the metamaterial structure. As a novel structure that combines a deformed circular patch inside a metal ring and replicates it in three layers, it increases the degree of design freedom by increasing the number of design variables, and by combining the inductance of the ring and the capacitance of the circular patch, it is advantageous in preventing attenuation of the millimeter-wave signal and narrowing the bandwidth by simultaneous operation of L and C. In addition, the unit cell structure is a symmetrical structure that is less sensitive to polarization in both the transmitting and receiving waves and can transmit and receive well. By adjusting geometric variables such as the diameter of the deformable circular patch, the size of the ring, the gap which is the distance between the circular patch and the ring, and the filling ratio which is the ratio of the circular patch area to the ring area, the transmission coefficient (the transmission coefficient, or S21, when the bottom of the pixel is the input port and the top of the pixel is the output port) is maximized while first increasing the phase, and the phase value that increases as it passes through each layer of the multilayer reaches the required phase value of one pixel. Fig. 8d shows the transmission loss, and Fig. 8e shows the transmission phase. Fig. 8f shows the phase profile of the transmission coefficient, or the diameter of the circular patch (R1), which is a geometric variable, versus the pixel transmission coefficient. The dimensions are determined through this graph. Fig. 8g shows a metamaterial flat lens in which these pixel structures are assembled into a special pattern such as a checkerboard or a dragonfly compound eye.

[0062] Figures 9a and 9b show a metamaterial structure lens, such as the holographic surface of Figure 8g, combined with a radiation source array layer.

[0063] FIGS. 10a to 10i are diagrams showing the electromagnetic characteristics of a structure in which the metamaterial structure lens and the radiation source array layer illustrated in FIGS. 9a and 9b are combined, and the advantages of the present invention. Port 1 means selecting patch 1, port 2 means selecting patch 2, …, and port 9 means selecting patch 9. As illustrated in FIG. 10a, when port 1 is selected, it can be seen from the three-dimensional radiation pattern and the two-dimensional rectangular frame radiation pattern plot that the radiation beam points to the right. Furthermore, as illustrated in FIGS. 10b to 10i, by moving the selected radiation source from port 2 to port 9, the direction of the beam can be moved while maintaining the high gain characteristic. FIG. 10j is a diagram illustrating a one-dimensional radiation pattern.

[0064] The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings.

[0065] Prior to this, the terms and words used in this specification and claims should not be interpreted in their usual or dictionary meanings, but should be interpreted in the sense and concept that conforms to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0066] When adding reference numbers to components of each drawing in this specification, it should be noted that identical components are given the same numbers as much as possible even if they are shown in different drawings.

[0067] Additionally, terms such as “first,” “second,” “one side,” and “the other side” are used to distinguish one component from another, and the components are not limited by these terms.

[0068] In addition, when describing the embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included within the spirit and technical scope of the present invention.

[0069] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0070] The present invention can provide a technology for supplying electromagnetic waves by selecting only one element at a time as an array of radiating elements other than an array antenna, a metamaterial structure, a metamaterial lens, a beamforming antenna, a beam steering antenna, a surface phase distribution and a phase compensation structure.

[0071] The present invention achieves phase shift using a novel passive method, which has been impossible with previous passive methods. The device selects a radiation source paired to a specific beam angle among a one-dimensional array of electromagnetic wave sources via a low-power RF switch at an input terminal for each beam angle, and transmits the electromagnetic wave through a metamaterial flat lens suitable for beam direction located on the upper layer, thereby transmitting it in the selected direction as high-gain wireless energy toward a long distance.

[0072] The present invention has the meaning of a new low-power consumption beamforming array antenna device that uses only switches and passive elements, without using an expensive active phase shifter that has an amplifier that is not necessarily required for each radiating element, and by minimizing power consumption in the internal phase shifter and the transmission line for connection.

[0073] Figure 1a illustrates a typical radar system. Electromagnetic waves radiate from an antenna, and when they strike a metal object, such as an aircraft, they are scattered and reflected. This system utilizes a high-power, bulky antenna with very high input power, a free-space environment with minimal electromagnetic loss (unlike walls).

[0074] And, the problem in the development and operation of the existing beamforming array antenna, as shown in FIGS. 1b to 1d, begins when an expensive active phase shifter in the form of a semiconductor chip (chip set) is combined with each radiating element. The active phase shifter contains a variable amplifier and a variable phase shifter together, and as a product of the semiconductor process, it amplifies the control DC power and RF signal for variable functions, so the RF power usage is high, and even with just one element, it is expensive and the minimum power consumption is high.

[0075] However, as the requirements for electromagnetic radiation gain and beam width increase, the number of active phase shifters increases along with the size of the array and the number of radiating elements, which acts as a disadvantage in power consumption, weight, and cost for the entire array antenna. Despite being aware of this problem, when beamforming and beam steering are necessary, alternatives such as high-speed mechanical rotation, multi-channel receivers, and multiplexing of frequency-scanning leaky wave antennas have been proposed. However, these have resulted in reduced speed and accuracy, and ultimately in costs similar to those of using active phase shifter chipsets. To solve this problem, a passive method that can reduce weight, heat, and cost is required, but this is not possible with the existing passive method, so a new solution is needed.

[0076] In addition, in the beamforming array antenna, which is the core of 5G millimeter-wave band communication devices and mobile detection radar, the change in the main beam direction is achieved by the difference in the phases supplied to the radiating elements (array elements), and the output of the RF phase shifter for each radiating element is determined. The biggest problem here is that, as shown in FIGS. 1b to 1d, which show the inside of the AESA radar and 5G beamforming transceiver, the beamforming antennas combine expensive active phase shifters in the form of semiconductor chips (chip sets) for each radiating element, and when the requirements for electromagnetic wave radiation gain and beam width are strict, the number of active phase shifters increases as the size of the array and the number of radiating elements rapidly increase, resulting in enormous costs.

[0077] Moreover, since all radiating elements are combined with unnecessary amplifiers and active phase shifters that induce large phase shifts when such changes are not required, weight increases are inevitable. In addition to high cost, the active components consume significant RF power for operation and DC power (for amplifier bias and control). The present invention aims to reduce high cost, power consumption, weight increase, and unnecessary investment of high-end resources, while achieving the goal of beam steering.

[0078] The present invention, which aims to solve the above problem, is a new concept in which an arrangement of electromagnetic wave radiating source patches is determined by a target angle, and only the source for the desired target angle is selected by an RF switch to send electromagnetic waves upward, and a metamaterial flat lens designed in consideration of the incident angles compensates for the phase of the incident wave and multiplies the gain to send electromagnetic waves at the selected target angle.

[0079] Although it may seem similar to an array antenna, the fundamental difference is that unlike array antennas, which apply power to all elements such as patches simultaneously, only one of the arrayed elements is selected. The problems mentioned above and their corresponding solutions are described in order as follows.

[0080] FIG. 2 is a diagram illustrating a metasurface flat lens radar and a communication beamforming antenna capable of controlling an electromagnetic wave beam directivity angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to one embodiment of the present invention.

[0081] Referring to FIG. 2, a metasurface planar lens radar and communication beamforming antenna (200) capable of controlling an electromagnetic wave beam directivity angle by electromagnetic wave source selection without requiring a chipset active phase shifter according to an embodiment of the present invention may include a radiating section (204) including a plurality of radiation patches (SA0 to SA6) arranged one-dimensionally and spaced apart from each other by a predetermined distance, and a metamaterial planar lens (202) in which single-layer or multi-layer unit cell structures are arranged spaced apart from the radiating section (204) by a predetermined distance and compensate for the phase to increase the gain and steering of the angle and the incident wave front phase distribution of the incident wave radiated from one of the plurality of radiation patches (SA0 to SA6) according to the phase compensation distribution.

[0082] As illustrated in FIG. 8b, the unit cell structure (800) may include a metal ring (802) and a deformed circular patch (804) positioned within the metal ring (802) and spaced apart from the metal ring (802) by a predetermined distance.

[0083] Referring to FIG. 8b, the modified circular patch (804) may include a first capacitance adjusting portion (807) in which the metal of the central portion of the circular patch (804) is removed in a circular shape, and a second capacitance adjusting portion (808) in which the metal of the upper, lower, left, and right sides of the outer peripheral portion of the circular patch (804) is removed in an equal amount symmetrically.

[0084] The phase of the incident electromagnetic wave is compensated by the combination of the inductance of the metal ring (802) and the capacitance of the circular patch (804), and as illustrated in FIG. 8c, the phase value required for one unit cell structure (803) can be compensated as the incident electromagnetic wave passes through the multilayer unit cell structure (803) formed of three layers (810, 812, 814) one by one. The multilayer unit cell structure (803) formed of multiple layers can be formed by stacking multiple single-layer unit cells (810, 812, 814) of the same structure in multiple layers.

[0085] A phase value to be compensated can be determined depending on at least one of the diameter (R1) of the circular patch (804) and the gap, which is the distance between the metal ring (802) and the circular patch (804).

[0086] Referring to FIG. 2, a metasurface planar lens radar and communication beamforming antenna (200) capable of controlling an electromagnetic wave beam directivity angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to an embodiment of the present invention may further include an RF switch (206) for providing an input electromagnetic wave, that is, an RF signal, to one of the plurality of radiation patches (SA0 to SA6), and a switch controller (208) for controlling the operation of the RF switch (206).

[0087] The operation of a metasurface planar lens radar and communication beamforming antenna (200) capable of controlling the electromagnetic wave beam direction angle by selecting an electromagnetic wave source without an unnecessary chip set active phase shifter according to an embodiment of the present invention configured as described above will be described in detail below with reference to FIGS. 2 to 10.

[0088] FIG. 2 illustrates a metasurface planar lens radar and communication beamforming antenna (200) capable of controlling the electromagnetic wave beam directivity angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to an embodiment of the present invention. The concept is that, without attaching expensive chipset active phase shifters to the radiating elements of the array antenna, radiating patches (SA0 to SA6) that will operate as radiating sources for each steering angle are arranged in a one-dimensional array, and then a radiating patch having a number corresponding to a target steering angle is selected by an RF switch (206) under the control of a switch controller (208), so that an input RF signal is radiated from the selected radiating patch, and the electromagnetic wave radiated from the selected radiating patch is incident on a metamaterial planar lens (202) present thereon, and the metamaterial planar lens (202) increases the gain of the incident wave and then propagates it in the direction of the receiver. The positions of the first radiation source, the radiation patch (SA0 to SA6), and the second source, the metamaterial flat lens (202) that focuses the electromagnetic waves at the desired steering angle must be prepared simultaneously.

[0089] For example, the incoming RF signal is directed at the target steering angle (θ f ), the switch controller (208) controls the RF switch (206) to select the radiating patch (SA4) so ​​that the RF signal is provided to one of the radiating patches (SA0 to SA6). When the RF switch (206) selects the radiating patch (SA4), the RF signal is applied to the radiating patch (SA4) selected by the RF switch (206), and the electromagnetic wave radiated from the selected radiating patch (SA4) is incident on the metamaterial flat lens (202). The metamaterial flat lens (202) can output the beam (B4) by compensating for the angle of the incident wave radiated and incident from the radiating patch (SA4) and the phase for high gain and steering of the incident wave front phase distribution.

[0090] In this way, the metasurface flat lens radar and communication beamforming antenna (200) capable of controlling the electromagnetic wave beam directivity angle by selecting an electromagnetic wave source without requiring a chipset active phase shifter according to an embodiment of the present invention is configured such that the switch controller (208) controls the RF switch (206) to select a radiation patch (SA4) so ​​that an RF signal is provided only to one of the radiation patches (SA0 to SA6), the RF signal is applied to the radiation patch (SA4) selected by the RF switch (206), the electromagnetic wave radiated from the selected radiation patch (SA4) is incident on the metamaterial flat lens (202), and the metamaterial flat lens (202) increases the gain of the incident electromagnetic wave and changes it to a required phase to output the electromagnetic wave, so that a power divider does not need to be connected, and further, since the RF signal is applied only to one of the radiation patches, which are radiation sources, and thus unwanted interference does not occur even if the radiation patches are close together, the radiation patches are not connected. Can be deployed.

[0091] FIG. 3 shows that, unlike the array antenna of FIG. 2, in a structure in which only one element (302) is selected from an array of radiating elements and an RF signal is applied, a method of obtaining a focal length in an optical lens is utilized to determine the overall size of a metamaterial flat lens (300) and the spacing with the patch element (302) so that the electromagnetic wave after passing through the metamaterial surface has high gain in a specific direction.

[0092] FIG. 4a and FIG. 4b are the most basic drawings explaining a metamaterial plane lens (400). When a horn antenna (402), which is generally selected as a radiation source, generates electromagnetic waves as a primary source and sends them upward, the metamaterial structure (400) adjusts the phase of each point where the rays enter, thereby creating an effect similar to inputting a phase difference to elements of an array antenna to form a beam and adjust the direction of the beam.

[0093] Controlling the phase of the point where light enters means that if the incident angle and phase value of the incident electromagnetic wave are referred to as input, and the electromagnetic wave coming out of the metamaterial structure (400) is referred to as output, it means that the phase compensation surface must be formed so that the gain of the output increases and the output can be tilted at a desired angle. Currently, a horn antenna (402) is drawn for conceptual purposes, but in the present invention, a patch antenna is used as the primary element, and these can be easily manufactured through a PCB process, so that they can be manufactured at a lower cost and more effectively than a horn antenna.

[0094] Fig. 4c, together with the three-dimensional structural schematic diagrams of Figs. 4a and 4b, illustrates a phase difference distribution or phase compensation distribution that changes the surface phase distribution of the electromagnetic wave generated by the radiating source and sent to the lower surface of the metamaterial into a phase required for beam steering and gain increase. This phase compensation distribution may vary depending on the type of radiating source, the distance and direction of the wavefront of the electromagnetic wave propagating from the aperture of the radiating source to the observation plane, and the shape of the final radiation pattern after passing through the metamaterial surface, that is, the expected steering angle and gain increase. For physical implementation, a metal pattern is deposited on a PCB substrate, and although the phase compensation distribution is continuous, due to the precision limitations of the PCB etching process, it is composed of pixels, which are a discrete grid shape, to implement the required phase value for each unit section.

[0095] Figure 5 shows the design procedure of the proposed device as follows. First, in step S500, the type of radiation source is selected. Second, in step S502, the initial design variables such as the aperture size of the metamaterial surface and the shape of the unit structure (pixel) are determined. Third, in step S504, the geometric variables vs. transmission coefficient and phase profile are created while designing the unit structure. Fourth, in step S506, the phase distribution of the wavefront on the observation surface from the radiation source is known, and the phase compensation distribution of the metasurface lens for creating the radiation beam pattern, which is the output of the target metamaterial structure surface, is calculated.

[0096] Fifth, in step S508, the focal length per aperture (f / D) is optimized to maximize antenna gain, and in step S510, the continuous phase compensation distribution is discretized (into a grid with pixels) by mathematical calculation, and the geometric variables for each unit cell are optimized to obtain the required phase value for each section, and in step S512, it is determined whether optimization has been achieved.

[0097] Sixth, in step S514, the angle of the beam is changed based on the phase for beam steering of the transmitarray antenna. Seventh, in step S516, a patch for each steering angle corresponding to the position of each element of the radiating source array is selected, and the degree of electromagnetic phase compensation between the patch and the surface is confirmed. Eighth, in step S518, a radiation beam pattern, which is the output of the metalens, is obtained through a full-structure EM simulation test that includes a detailed electromagnetic analysis of the surface of the metamaterial structure as well as the selected radiating source, and the beam steering characteristics and gain are confirmed.

[0098] Fig. 6a shows a representative view of a radiating source element of a device for determining a beam steering angle of a transmit array antenna by selecting one patch (600) from an array of radiating sources of a novel concept proposed by the present invention. Fig. 6b illustrates reflection loss, and Fig. 6c illustrates gain according to phase. Although a horn antenna can be used, it is bulky and heavy, and the long distance to the metamaterial structure lens is a prerequisite, making the entire antenna structure heavy. Therefore, considering low cost and practicality, a patch antenna is used as a radiating element.

[0099] Referring to FIGS. 6b and 6c, the input port reflection coefficient (S11) of the patch antenna indicates that the point corresponding to the dip points to the target frequency, which is a resonance phenomenon, and at this time, a beam with a wide width and a gain of 5 dBi is generated, as shown in the 2D rectangular plot. This wide beam has low gain, but after passing through the metamaterial flat lens (202), it points to the steering angle with high gain.

[0100] FIG. 7a and FIG. 7b illustrate a single radiating source of FIG. 6a arrayed in a one-dimensional (1D) manner. Note that this array (700) is not a conventional array antenna, that is, not a typical array antenna with a power divider on the same plane or bottom surface as the patches, but rather radiating patches (700_1 to 700_9) that are independently operable radiating sources, rather than elements of an array antenna having a phase difference relationship to be selected according to the steering angle input. FIG. 7c illustrates the reflection loss. The radiating patches (700_1 to 700_9) are simply RF switch-connected feeders, not millimeter-wave power dividers that increase dielectric substrate loss and metal transmission line loss. Depending on the position of the radiating source patch, the final steering angle of the radiating beam varies. As illustrated in FIG. 7c, it can be seen from the input port reflection coefficient that resonance occurs at the desired frequency at each port of the array elements.

[0101] Figure 8a is a discretization of the phase compensation distribution that compensates for the phase of a wide beam width radiating wave from a radiating source observed on the bottom surface of a metamaterial structure for high gain and beam steering.

[0102] FIG. 8b illustrates the structure of one layer of the multilayer unit cell structure (803), and FIG. 8c illustrates the multilayer unit cell structure (803) formed of three layers (810, 812, 814), and the required phase value can be determined for each unit cell of the metamaterial structure, i.e., pixel, and a new structure in which a deformed circular patch (804) is combined inside a metal ring (802) and a structure (811, 813, 815) in which a deformed circular patch (804) is combined inside a metal ring (802) is replicated in three layers (810, 812, 814), thereby increasing the degree of design freedom through an increase in the number of design variables, and by combining the inductance of the ring (802) and the capacitance of the circular patch (804), the desired phase value per pixel is written as layers that can operate L and C simultaneously, thereby achieving millimeter wave. It is advantageous in preventing signal attenuation and bandwidth narrowing. In one embodiment of the present invention, the multilayer unit cell structure (803) is formed of three layers, but the present invention is not limited thereto, and may be formed of a smaller or larger number of layers.

[0103] Also, referring to FIGS. 8b and 8c, the single-layer unit cell structure (800) and the multi-layer unit cell structure (803) are point-symmetric structures that are less sensitive to polarization in both transmitting and receiving waves and can transmit and receive well. By adjusting geometric variables such as the diameter (R1) of the deformable circular patch (804), the size of the ring (802), the gap which is the distance between the circular patch (804) and the ring (802), and the filling ratio which is the ratio of the area of ​​the circular patch (804) to the area of ​​the ring (802), the size of the transmission coefficient (i.e., S21) in the case where the bottom of the pixel is the input port and the top of the pixel is the output port) is maximized, and the phase is first raised, and the phase value that goes up while passing through each layer of the multi-layer reaches the required phase value of one pixel. Fig. 8d shows the transmission loss, and Fig. 8e shows the transmission phase. Fig. 8f shows the phase profile of the transmission coefficient, that is, the diameter (R1) of the circular patch, which is a geometric variable, versus the pixel transmission coefficient. The dimensions are determined through this graph. That is, the phase value to be compensated can be determined according to at least one of the diameter (R1) of the circular patch (804) and the gap, which is the distance between the metal ring (802) and the circular patch (804). Fig. 8g shows a metamaterial flat lens (820) in which the structures (803) of these pixels are assembled into a special pattern such as a checkerboard or a dragonfly compound eye.

[0104] FIGS. 9A and 9B illustrate a structure (900) in which a metamaterial flat lens (902), such as the holographic surface of FIG. 8G, is combined with a radiation source array layer (901). In one embodiment of the present invention, the metamaterial flat lens (902) may be formed of three layers (904_1, 904_2, 904_3), but the present invention is not limited thereto and may be formed of a smaller or larger number of layers.

[0105] Referring to the structure (900) in which the metamaterial flat lens (902) and the radiating source array layer (901) are combined as shown in FIGS. 9a and 9b, the feeding section is much simpler than that of an array antenna of the same diameter, and it is a structure that overcomes the problem of loss during the propagation of electromagnetic waves in a power distributor and the problem of a chipset active phase shifter array antenna.

[0106] FIGS. 10A to 10I are drawings showing the electromagnetic wave characteristics of a structure (900) in which a metamaterial flat lens (902) and a radiation source array layer (901) are combined as shown in FIGS. 9A and 9B, and the advantages of the present invention. Port 1 means selecting patch 1, port 2 means selecting patch 2, …, and port 9 means selecting patch 9. As shown in FIG. 10A, when port 1 is selected, it can be seen through the three-dimensional radiation pattern and the two-dimensional rectangular frame radiation pattern plot that the radiation beam points to the right. Furthermore, as shown in FIGS. 10B to 10I, by moving the selected radiation source from port 2 to port 9, the direction of the beam can be moved while maintaining the high gain characteristic. FIG. 10J is a drawing showing a one-dimensional radiation pattern. The characteristics of the present invention can overcome the shortcomings of existing mechanical steering antennas or phased array antennas.

[0107] The present invention is not limited to the above-described embodiments and the attached drawings. It will be apparent to those skilled in the art that components of the present invention can be substituted, modified, and altered without departing from the technical spirit of the present invention.

Claims

1. A radiating section including a plurality of radiating patches arranged one-dimensionally and spaced apart from each other by a predetermined distance; and A metasurface flat lens radar and communication beamforming antenna capable of controlling an electromagnetic wave beam directivity angle by electromagnetic wave source selection without requiring a chip set active phase shifter, comprising a metamaterial flat lens in which single-layer or multi-layer unit cell structures are arranged in accordance with a phase compensation distribution to compensate for phase for high gain and steering of an incident wave radiated and incident from one of the plurality of radiation patches, and are arranged at a predetermined distance from the above-mentioned radiating portion.

2. In claim 1, The above unit cell structure is, metal ring; and A metasurface planar lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam direction angle by electromagnetic wave source selection without requiring a chip set active phase shifter, comprising a deformed circular patch arranged inside the metal ring at a predetermined distance from the metal ring.

3. In claim 2, The above modified circular patch is, A first capacitance control unit in which the metal in the central portion of the above circular patch is removed in a circular shape; and It includes a second capacitance control unit in which the metal on the upper, lower, left and right sides of the outer peripheral portion of the above circular patch is partially removed, The above circular patch is a metasurface flat lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam direction angle by selecting an electromagnetic wave source without requiring a chip set active phase shifter, wherein the circular patch is formed point-symmetrically.

4. In claim 2, The phase of the incident electromagnetic wave is compensated by the combination of the inductance of the metal ring and the capacitance of the circular patch, A metasurface flat lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam direction angle by electromagnetic wave source selection without requiring a chipset active phase shifter, in which the phase value required for one unit cell structure is compensated as the incident electromagnetic wave passes through each layer of the multilayer unit cell structure.

5. In claim 2, A metasurface planar lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam directivity angle by electromagnetic wave source selection without requiring a chipset active phase shifter, wherein a phase value compensated for is determined according to at least one of the diameter of the circular patch and the gap, which is a distance between the metal ring and the circular patch.

6. In claim 1, A metasurface planar lens radar and communication beamforming antenna capable of controlling the electromagnetic wave beam direction angle by electromagnetic wave source selection without requiring a chipset active phase shifter, further comprising a switch for providing an input electromagnetic wave to one of the plurality of radiation patches.

7. In claim 6, A metasurface planar lens radar and communication beamforming antenna capable of controlling the electromagnetic beam direction angle by electromagnetic wave source selection without requiring a chipset active phase shifter, further comprising a switch controller for controlling the operation of the above switch.

8. In claim 1, The unit cell structure formed by the above multilayer is, A metasurface flat lens radar and communication beamforming antenna capable of controlling the electromagnetic beam direction angle by selecting an electromagnetic wave source without requiring a chip set active phase shifter, formed by stacking multiple single-layer unit cells of the same structure in multiple layers.

9. Includes single-layer or multi-layer unit cell structures that compensate for phase to increase gain and steer the incident wave. The above single-layer or multi-layer unit cell structures are arranged in a phase compensation distribution, and are metamaterial flat lenses.

10. In claim 9, The above unit cell structure is, metal ring; and A metamaterial planar lens comprising a deformed circular patch positioned within the metal ring at a predetermined distance from the metal ring.

11. In claim 10, The above modified circular patch is, A first capacitance control unit in which the metal in the central portion of the above circular patch is removed in a circular shape; and It includes a second capacitance control unit in which the metal on the upper, lower, left and right sides of the outer peripheral portion of the above circular patch is partially removed, The above circular patch is a metamaterial flat lens formed point-symmetrically.

12. In claim 10, The phase of the incident electromagnetic wave is compensated by the combination of the inductance of the metal ring and the capacitance of the circular patch, A metamaterial flat lens in which the phase value required for each unit cell structure is compensated as the incident electromagnetic wave passes through each layer of the multilayer unit cell structure.

13. In claim 10, A metamaterial planar lens, wherein a phase value to be compensated is determined according to at least one of the diameter of the circular patch and the gap, which is a distance between the metal ring and the circular patch.

14. In claim 9, The unit cell structure formed by the above multilayer is, A metamaterial flat lens formed by stacking multiple single-layer unit cells of the same structure in multiple layers.

15. A unit cell structure for a metamaterial plane lens for high gain and steering of incident waves. The above unit cell structure is formed as a single layer or multiple layers, and is a unit cell structure for a metamaterial plane lens that compensates for the phase to increase gain and steer the incident wave.

16. In claim 15, The above unit cell structure is, metal ring; and A unit cell structure for a metamaterial planar lens, comprising a deformed circular patch positioned within the metal ring at a predetermined distance from the metal ring.

17. In claim 16, The above modified circular patch is, A first capacitance control unit in which the metal in the central portion of the above circular patch is removed in a circular shape; and It includes a second capacitance control unit in which the metal on the upper, lower, left and right sides of the outer peripheral portion of the above circular patch is partially removed, The above circular patch is a unit cell structure for a metamaterial planar lens formed point-symmetrically.

18. In claim 16, The phase of the incident electromagnetic wave is compensated by the combination of the inductance of the metal ring and the capacitance of the circular patch, A unit cell structure for a metamaterial flat lens in which the phase value required for each unit cell structure is compensated as the incident electromagnetic wave passes through each layer of the multilayer unit cell structure.

19. In claim 16, A unit cell structure for a metamaterial planar lens, wherein a phase value compensated for is determined according to at least one of a diameter of the circular patch and a gap, which is a distance between the metal ring and the circular patch.

20. In claim 15, The unit cell structure formed by the above multilayer is, A unit cell structure for a metamaterial planar lens, formed by stacking multiple single-layer unit cells of the same structure in multiple layers.

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