Liquid-crystal phased array capable of implementing dual-beam generation and two-dimensional scanning

Abstract

A liquid-crystal phased array capable of implementing dual-beam generation and two-dimensional scanning. The liquid-crystal phased array comprises: an upper substrate; a lower substrate; a liquid-crystal medium, which is arranged between the upper substrate and the lower substrate; alignment layers, which are arranged above and below the liquid crystal medium; a coplanar waveguide transmission line and a slow-wave liquid-crystal phase-shifting feed network, which are arranged on the upper surface of the lower substrate; a plurality of slot-coupled patch antenna units, which are arranged on the upper surface of the upper substrate; and a metal ground, which is arranged on the lower surface of the upper substrate, wherein the coplanar waveguide transmission line is connected to the slow-wave liquid-crystal phase-shifting feed network, a plurality of coupling slots are provided in the metal ground, slow-wave liquid-crystal phase shifters of the slow-wave liquid-crystal phase-shifting feed network are correspondingly coupled to the slot-coupled patch antenna units by means of the coupling slots, and the slot-coupled patch antenna units are independently regulated and controlled by means of the corresponding slow-wave liquid-crystal phase shifters, so as to realize dual-beam generation and two-dimensional scanning. By means of innovative design, the liquid-crystal phased array in the present invention achieves dual-beam generation, two-dimensional scanning, a high gain and the characteristic of easy integration.

Description

A dual-beam, two-dimensional scanning liquid crystal phased array TECHNICAL FIELD

[0001] The present application relates to the field of wireless communication, in particular to a dual-beam, two-dimensional scanning liquid crystal phased array. BACKGROUND

[0002] To meet the mobile terminal in L, C, Ku, Ka or W band operation of a variety of services, such as wireless Internet, multimedia, communication and broadcast services, electronic reconfigurable millimeter wave system with its small volume, multi-functional, high spectral efficiency, flexibility and other advantages become the current research hotspot, for industrial ground station applications, including airborne, shipborne or automotive mobile terminal. The common method for phased array beam scanning technology includes radio frequency micro electro mechanical system (RF MEMS), semiconductor solutions and ferroelectric, such as barium strontium titanate (BST). Another method is to use liquid crystal material with low loss at high frequency band. Among these methods, liquid crystal is superior to MEMS in terms of life, continuity and packaging; it is superior to BST in terms of frequency range and bias voltage, and is an ideal material for developing beam scanning phased array. Benefiting from the mature manufacturing process of liquid crystal display panel, liquid crystal phased array also has unique advantages in manufacturing cost. In the third generation partnership and new radio band, liquid crystal based phased array module with cost competitiveness and high performance can support the ability of beamforming and beam steering, which is the key technology of emerging small cell base station and client device. Therefore, the research on liquid crystal phased array suitable for various mobile terminals is of great significance to the wireless communication system.

[0003] Liquid crystal phased array is small in size, light in weight and low in power consumption, meeting the light and thin and low power consumption requirements of modern communication equipment. Moreover, due to the electric tuning characteristics of liquid crystal, continuous pattern scanning can be realized. However, the gain of ordinary liquid crystal phased array is generally low. Because during pattern scanning, a long liquid crystal microstrip line is usually needed to provide a large phase difference between the antenna radiation units, which will bring huge loss to the phased array. In addition, the introduction of multiple liquid crystal DC bias lines will also cause high loss. Ordinary liquid crystal phased array also has the disadvantages of high cost, difficulty in integration and slow response.

[0004] It should be noted that the information disclosed in the above background section is only for understanding the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0005] The main purpose of the present application is to overcome the defects of the above background technology, and provide a dual-beam, two-dimensional scanning liquid crystal phased array.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A dual-beam, two-dimensional scanning liquid crystal phased array includes an upper substrate, a lower substrate, a liquid crystal medium disposed between the upper substrate and the lower substrate, and orientation layers disposed above and below the liquid crystal medium, a coplanar waveguide transmission line and a slow wave liquid crystal phase shift feed network arranged on the upper surface of the lower substrate, a plurality of slot-coupled patch antenna units arranged on the upper surface of the upper substrate, and a metal ground arranged on the lower surface of the upper substrate; wherein the coplanar waveguide transmission line is connected to the slow wave liquid crystal phase shift feed network, a plurality of coupling slots are formed in the metal ground, each slow wave liquid crystal phase shifter of the slow wave liquid crystal phase shift feed network is coupled to a corresponding slot-coupled patch antenna unit through a coupling slot, and each slot-coupled patch antenna unit is independently regulated by a corresponding slow wave liquid crystal phase shifter to achieve dual-beam and two-dimensional scanning.

[0008] Further, the slow wave liquid crystal phase shift feed network includes 16 slow wave liquid crystal phase shifters configured as a symmetric feed network in an H-shaped configuration, wherein each group of 4 slow wave liquid crystal phase shifters is arranged according to the geometric layout of the H-shaped configuration, and is arranged on the four arms of the H-shaped configuration, respectively, and the adjacent two slow wave liquid crystal phase shifters in each group form feed signals in opposite directions to generate the required phase difference; accordingly, 16 slot-coupled patch antenna units and 16 coupling slots are configured.

[0009] Further, the slot-coupled patch antenna unit is a long rectangular shape, and the length direction is perpendicular to the extension direction of the slow wave transmission line of the corresponding slow wave liquid crystal phase shifter, and the 16 slot-coupled patch antenna units form a 4x4 antenna array.

[0010] Further, the slot-coupled patch antenna units are arranged in a uniform surface array with a spacing of 0.25λ to 1λ.

[0011] Further, the coupling slot is an H-shaped slot or a linear slot, and the length direction is perpendicular to the extension direction of the slow wave transmission line of the corresponding slow wave liquid crystal phase shifter.

[0012] Further, the slow wave liquid crystal phase shift feed network further includes a bias network, a DC block, and a one-sixteenth power divider, and the 16 slow wave liquid crystal phase shifters are respectively located at the output ports of the one-sixteenth power divider, the bias network is symmetrically distributed on both sides of the one-sixteenth power divider, the DC block is arranged before each slow wave liquid crystal phase shifter, and the bias network includes 16 DC bias lines and is symmetrically distributed.

[0013] Further, the coplanar waveguide transmission line has a coplanar ground, which is not in the same plane as the metal ground of the slow wave liquid crystal phase shift feed network and is arranged in an interleaved and overlapping manner.

[0014] Further, the coplanar waveguide transmission line is rounded at the corners of the coplanar metal ground.

[0015] Further, the upper substrate and the lower substrate are quartz glass substrates.

[0016] Further, the orientation layer is a polyimide film.

[0017] In some embodiments, a liquid crystal based dual-beam, two-dimensional scanning, high gain and easily integrated phased array includes a coplanar waveguide transmission line, a slow wave liquid crystal phase shifter feed network, a slot coupled patch antenna element, and upper and lower quartz glass substrates. The phased array also includes polyimide films disposed above and below the liquid crystal medium as orientation layers for liquid crystal medium molecules.

[0018] In some embodiments, the slow wave liquid crystal phase shifter feed network includes a liquid crystal medium, a polyimide film, a bias network, a DC pad, a DC block, a one-sixteenth power divider, and a slow wave transmission line. The liquid crystal medium is oriented by the polyimide film and is fixed between the upper and lower quartz glass substrates.

[0019] In some embodiments, the coplanar waveguide transmission line is connected to the front end of a one-sixteenth power divider, and sixteen slow wave liquid crystal phase shifters are respectively located below the lower glass substrate of the sixteen slot coupled patch antenna elements and are located in the same layer as the DC block and the bias network. The sixteen slot coupled patch antenna elements are uniformly distributed on the upper surface of the upper glass substrate.

[0020] Optionally, the sixteen slot coupled patch antenna elements are fed in the same direction. Preferably, the sixteen slot coupled patch antenna elements are fed in reverse by an H-type feed network.

[0021] Optionally, the DC block is loaded at the output port of a one-fourth power divider. Preferably, the DC block is loaded at the output port of a one-sixteenth power divider.

[0022] Optionally, the bias network is loaded on the same side of a one-sixteenth power divider. Preferably, the bias network is symmetrically arranged and located on both sides of a one-sixteenth power divider.

[0023] Optionally, the slot coupled patch antenna elements are arranged in a uniform surface array with a spacing of 0.25λ to 1λ. Preferably, the slot coupled patch antenna elements are uniformly arranged in a planar array with a spacing of 0.8λ.

[0024] Optionally, the coplanar waveguide transmission line and the metal ground of the upper quartz glass substrate are symmetrically arranged. Preferably, the coplanar waveguide transmission line and the metal ground overlap.

[0025] Optionally, the coplanar metal ground of the coplanar waveguide transmission line is not chamfered; preferably, the coplanar metal ground of the coplanar waveguide transmission line is chamfered.

[0026] Compared with the prior art, the application has the following beneficial effects:

[0027] The liquid crystal phased array of the application realizes the characteristics of double-beam, two-dimensional scanning, high gain and easy integration by innovative design, significantly improving the performance of the wireless communication system. Through the design of the patch antenna unit fed by slot coupling, the phased array of the application can realize double-beam and two-dimensional scanning based on liquid crystal electric regulation and control, realize 7.65dBi high radiation gain and 2GHz-10dB impedance bandwidth at 30GHz frequency, and well meet the regulation and control requirements of two-dimensional scanning. The application can realize a larger phase modulation range in a limited physical size, not only optimizing the scanning ability of the directional diagram of the phased array, but also being conducive to the miniaturization and integrated processing of the liquid crystal phased array.

[0028] The H-type feed network of the embodiment of the application utilizes the reverse feedback characteristics of current to realize optimized double-beam forming of the 4x4 surface array, and enhances the flexibility and application range of the phased array. At the same time, the application solves the problems of low gain and large loss of the traditional liquid crystal phased array, realizes 2GHz wide bandwidth and high gain at 30GHz frequency, and reduces the insertion loss of the slow-wave liquid crystal phase shifter.

[0029] The cooperation of the H-type feed network and the slow-wave liquid crystal phase shifter realizes a low-profile double-beam and two-dimensional scanning phased array, which is conducive to improving the flexibility of the liquid crystal phased array, and can realize continuous beam scanning in the 30GHz frequency range, with a scanning angle of ±30° and a gain of 12.1dBi to 15.3dBi in the scanning range.

[0030] In summary, the liquid crystal phased array of the application has the characteristics of high gain, flexible double-beam scanning ability and easy integration, which provides strong technical support for reconfigurable millimeter wave systems and has wide application prospects in the field of wireless communication.

[0031] Other beneficial effects in the embodiment of the application will be further described below. BRIEF DESCRIPTION OF DRAWINGS

[0032] Fig. 1 is a three-dimensional view of a double-beam, two-dimensional scanning and high-gain liquid crystal phased array according to an embodiment of the application;

[0033] Fig. 2 is a top view of a lower quartz glass substrate of a double-beam, two-dimensional scanning and high-gain liquid crystal phased array according to an embodiment of the application;

[0034] Fig. 3 is a bottom view (left) and a top view (right) of a top quartz glass substrate of a dual-beam, two-dimensional scanning, high-gain liquid crystal phased array according to an embodiment of the present application;

[0035] Fig. 4 is a schematic diagram of current flow of a feed network of a dual-beam, two-dimensional scanning, high-gain liquid crystal phased array according to an embodiment of the present application;

[0036] Fig. 5 is S-parameters of a slot-coupled patch antenna element of a dual-beam, two-dimensional scanning, high-gain liquid crystal phased array according to an embodiment of the present application;

[0037] Fig. 6 is a gain plot of a slot-coupled patch antenna element of a dual-beam, two-dimensional scanning, high-gain liquid crystal phased array according to an embodiment of the present application;

[0038] Fig. 7 is S-parameters of a one-sixteenth power divider of a dual-beam, two-dimensional scanning, high-gain liquid crystal phased array according to an embodiment of the present application;

[0039] Fig. 8 is S-parameters of a dual-beam, two-dimensional scanning, high-gain liquid crystal phased array according to an embodiment of the present application;

[0040] Fig. 9 is a gain plot of a dual-beam, two-dimensional scanning, high-gain liquid crystal phased array according to an embodiment of the present application;

[0041] Fig. 10 is a dual-beam scanning gain plot of a Theta = 50 plane of a dual-beam, two-dimensional scanning, high-gain liquid crystal phased array according to an embodiment of the present application;

[0042] Fig. 11 is a dual-beam scanning gain plot of a Phi = 90 plane of a dual-beam, two-dimensional scanning, high-gain liquid crystal phased array according to an embodiment of the present application.

[0043] Fig. 12 is a schematic diagram of dual-beam scanning of a liquid crystal phased array according to an embodiment of the present application. DETAILED DESCRIPTION

[0044] The embodiments of the present application will be described in detail below. It should be noted that the following description is only exemplary and is not intended to limit the scope of the present application and its applications.

[0045] It is noted that when an element is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or indirectly on or connected to the other element by way of one or more other elements. In addition, the connection can be fixed or it can be a removable connection.

[0046] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like, indicate directions or positions based on the directions or positions shown in the drawings, and are used for convenience of description and simplification of description only, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0047] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0048] Referring to FIGS. 1-4, the embodiments of the present application provide a liquid crystal phased array with dual-beam and two-dimensional scanning, comprising an upper substrate (such as an upper quartz glass substrate 102), a lower substrate (such as a lower quartz glass substrate 109), a liquid crystal medium 105 disposed between the upper substrate and the lower substrate, and orientation layers 104, 106 disposed above and below the liquid crystal medium 105, a coplanar waveguide transmission line 108 and a slow-wave liquid crystal phase shifter feed network 110 arranged on the upper surface of the lower substrate, a plurality of slot-coupled patch antenna units 101 arranged on the upper surface of the upper substrate, and a metal ground 103 arranged on the lower surface of the upper substrate; wherein the coplanar waveguide transmission line 108 is connected to the slow-wave liquid crystal phase shifter feed network 110, the metal ground 103 has a plurality of coupling slots 115, each slow-wave liquid crystal phase shifter 113 of the slow-wave liquid crystal phase shifter feed network 110 is coupled to each slot-coupled patch antenna unit 101 through the coupling slot 115, and each slot-coupled patch antenna unit 101 is independently regulated by the corresponding slow-wave liquid crystal phase shifter 113 to achieve dual-beam and two-dimensional scanning.

[0049] As shown in FIGS. 2 and 4, in a preferred embodiment, the slow-wave liquid crystal phase shifter feed network 110 includes 16 slow-wave liquid crystal phase shifters 113, configured as a symmetric feed network in an H-shaped configuration, wherein each group of 4 slow-wave liquid crystal phase shifters 113 is arranged according to the geometric layout of the H shape, arranged on the four arms of the H shape respectively, and the adjacent two slow-wave liquid crystal phase shifters 113 in each group form feed current signals in opposite directions (see FIG. 4), thereby generating the required phase difference; accordingly, as shown in FIGS. 1 and 3, 16 slot-coupled patch antenna units 101 and 16 coupling slots 115 are configured corresponding to the 16 slow-wave liquid crystal phase shifters 113.

[0050] As shown in FIG. 1 and FIG. 3, the slot-coupled patch antenna unit 101 is preferably long-strip rectangular, and the length direction is perpendicular to the extension direction of the slow-wave transmission line of the corresponding slow-wave liquid crystal phase shifter 113. The 16 slot-coupled patch antenna units 101 form a 4x4 antenna array. Preferably, the slot-coupled patch antenna units 101 are arranged in a uniform surface array with a spacing of 0.25λ-1λ. Preferably, the coupling slot 115 is an H-shaped slot or a straight-line slot, and the length direction is perpendicular to the extension direction of the slow-wave transmission line of the corresponding slow-wave liquid crystal phase shifter 113. The slow-wave transmission line can adopt (but is not limited to) the slow-wave transmission line structure disclosed in the patent with the publication number CN116960585B of the applicant.

[0051] The liquid crystal phased array of the embodiment of the present application realizes the characteristics of dual-beam, two-dimensional scanning, high gain and easy integration through innovative design. Through the design of the slot-coupled patch antenna unit, the phased array of the present application can perform dual-beam and two-dimensional scanning based on liquid crystal electric control, realize a high radiation gain of 7.65dBi and an impedance bandwidth of 2GHz at a frequency of 30GHz, and well meet the control requirements of two-dimensional scanning. Compared with the prior art, the present application can realize a larger phase modulation range in a limited physical size, not only optimizing the directional diagram scanning capability of the phased array, but also being conducive to the miniaturization and integrated processing of the liquid crystal phased array. The H-shaped feed network of the preferred embodiment of the present application utilizes the reverse feed characteristics of current, realizes optimized dual-beam forming of the 4x4 surface array, and enhances the flexibility and application range of the phased array. The cooperation of the H-shaped feed network and the slow-wave liquid crystal phase shifter realizes a low-profile dual-beam and two-dimensional scanning phased array, which is conducive to improving the flexibility of the liquid crystal phased array, and can realize continuous beam scanning in a frequency range of 30GHz, with a scanning angle of ±30° and a gain of 12.1dBi to 15.3dBi in the scanning range. The present application realizes a wide bandwidth of 2GHz and high gain at a frequency of 30GHz, while reducing the insertion loss of the slow-wave liquid crystal phase shifter.

[0052] The specific embodiments of the present application are further described below.

[0053] As shown in FIG. 1 to FIG. 3, the liquid crystal phased array of the embodiment of the present application for dual-beam, two-dimensional scanning and high gain includes a coplanar waveguide transmission line 108, a slow-wave liquid crystal phase shifter feed network 110, a slot-coupled patch antenna unit 101, a metal ground 103, a coupling slot 115, and upper and lower quartz glass substrates 102, 109, and further includes polyimide films arranged above and below the liquid crystal medium 105, which serve as orientation layers 104, 106 of the molecules of the liquid crystal medium 105. In one embodiment, there are sixteen slot-coupled patch antenna units 101, which are uniformly distributed on the quartz glass substrate 102.

[0054] The slow-wave liquid crystal phase shifter feed network 110 includes a liquid crystal medium 105, alignment layers 104, 106, a bias network 107, DC pads 111, DC blocks 114, a one-sixteenth power divider 112, and slow-wave liquid crystal phase shifters 113. The liquid crystal is aligned by the alignment layers 104, 106, encapsulated between the quartz glass substrates 102, 109, and distributed over the slow-wave liquid crystal phase shifters 113.

[0055] The coplanar waveguide transmission line 108 is connected to the front end of the one-sixteenth power divider 112, and sixteen slow-wave liquid crystal phase shifters 113 are located at the sixteen power distribution ports of the one-sixteenth power divider 112, respectively. Sixteen slot-coupled patch antenna units 101 are located above the sixteen power distribution ports of the one-sixteenth power divider 112, respectively. The bias network 107 and the DC pads 111 are symmetrically arranged on both sides of the one-sixteenth power divider 112. The DC blocks 114 are arranged in front of each slow-wave liquid crystal phase shifter. The sixteen DC blocks isolate each liquid crystal phase shifter from each other, so as to individually control each slot-coupled patch antenna unit. By optimizing the layout of the bias network and the arrangement of the DC pads and the DC blocks, the insertion loss of the slow-wave liquid crystal phase shifter can be reduced.

[0056] The coplanar waveguide transmission line 108, the one-sixteenth power divider 112, the slow-wave liquid crystal phase shifters 113, the bias network 107, and the DC pads 111 are located on the upper surface of the lower quartz glass substrate 109. The metal ground 103 and the coupling slot 115 are located on the lower surface of the upper quartz glass substrate 102. The slot-coupled patch antenna units 101 are located on the upper surface of the upper quartz glass substrate 102.

[0057] The gain of the slot-coupled patch antenna unit described above can be further improved by increasing the size of the patch. Depending on the required radiation pattern, the coupling slot can be loaded directly below or laterally below the slot-coupled patch antenna unit. In one embodiment, the coupling slot is designed as an H-shaped slot. In another embodiment, a straight slot can also be used. By optimizing the geometry of the slot, better coupling efficiency can be achieved.

[0058] The bias network can be loaded on the same side of the one-sixteenth power divider or on both sides of the one-sixteenth power divider. Although the bias network on the same side is convenient for processing, when the bias network is loaded on the same side of the slow-wave liquid crystal phase shifter, the spacing between the bias network lines is reduced, resulting in an increase in unnecessary coupling loss. Therefore, it is preferred to use a symmetrically arranged bias network to optimize the loss of the system.

[0059] The embodiment of the present application utilizes the reverse characteristic of the H-shaped slow-wave liquid crystal phase-shifting feed network current, as shown in FIG. 4, to realize double-beam forming. At the same time, the slow-wave structure is introduced into the liquid crystal phase shifter, so that a larger range of phase modulation is realized in a limited physical size. Each slot-coupled patch antenna unit can be individually regulated by the slow-wave liquid crystal phase shifter, so as to realize two-dimensional scanning of the double beam.

[0060] Further details are shown in FIGS. 1-3. A double-beam, two-dimensional scanning, high-gain liquid crystal phased array includes a coplanar waveguide transmission line 108, a slow-wave liquid crystal phase-shifting feed network 110, a slot-coupled patch antenna unit 101, a metal ground 103, a coupling slot 115, and upper and lower quartz glass substrates 102, 109. It also includes polyimide films 104, 106 arranged above and below the liquid crystal medium 105 as the orientation layer of the molecules of the liquid crystal medium 105. The slot-coupled patch antenna unit 101 is composed of sixteen units, which are evenly distributed on the quartz glass substrate 102.

[0061] As shown in FIG. 1, the liquid crystal phased array is composed of a lower quartz glass substrate, an upper quartz glass substrate, and a liquid crystal medium and copper metal lines to form a sandwich structure. The overall size of the liquid crystal phased array is 50x50x1.056mm 3 . Among them, the upper quartz glass substrate is 40x35x0.5mm 3 ; the lower quartz glass substrate is 50x50x0.5mm 3 ; the size of the metal ground is 40x35x0.5mm 3 ; the thickness of the liquid crystal medium is 0.05mm, and the thickness of all copper metal lines is 0.003mm. The overall size of the coplanar ground of the coplanar waveguide transmission line is 14x10mm 2 , the width of the coplanar waveguide transmission line is 0.4mm; the gap between the coplanar waveguide transmission line and the coplanar ground is 0.1mm. Moreover, the position where the coplanar ground of the coplanar waveguide transmission line and the metal ground of the slow-wave liquid crystal phase-shifting feed network are staggered is rounded with a radius of 5mm, which facilitates the smoother transition of alternating current and prevents the metal ground from being on the same plane.

[0062] As shown in FIG. 2, the slow-wave liquid crystal phase-shifting feed network, the bias network, the DC block, the coplanar waveguide transmission line, and the one-sixteenth power divider are all located on the upper surface of the lower quartz glass substrate. The bias network is symmetrically distributed on both sides of the one-sixteenth power divider; the DC block is arranged before each slow-wave liquid crystal phase shifter.

[0063] As shown in FIG. 3, the metal ground and the coupling slot are located on the lower surface of the upper quartz glass substrate, and the slot-coupled patch antenna units are evenly distributed on the upper surface of the upper quartz glass substrate.

[0064] As shown in Figure 4, the H-type feed current of the one-sixteenth power divider flows in opposite directions respectively two by two, that is, the phase of one antenna unit is 0 degree and the other is 180 degrees. Specifically, in one direction, the radiation fields of the two antenna units can add up, while in the other direction, the radiation fields of the two antenna units can cancel each other out. In one direction, due to the phase difference of 180 degrees, the radiation fields of the two antenna units add up to produce enhancement (constructive interference), and in these directions, the radiation intensity becomes larger. In the other direction, due to the phase difference of 0 degree or 360 degrees, the radiation fields of the two antenna units cancel each other out (destructive interference), and in these directions, the radiation intensity decreases or even disappears completely. Therefore, this feed structure can form double beams.

[0065] As shown in Figures 5 to 6, the -10dB bandwidth of the slot-coupled patch antenna unit is 2GHz at the center frequency of 30GHz, covering the frequency band range of 28.5GHz-30.5GHz, and having a gain of 7.65dBi.

[0066] As shown in Figure 7, the -10dB bandwidth of the one-sixteenth power divider is 14GHz, covering the frequency band range of 23.5GHz-37.5GHz, and the port loss is about 14dB.

[0067] As shown in Figures 8 to 9, the liquid crystal phased array with double beams, two-dimensional scanning and high gain has double beams and a gain of 15.3dBi in the radiation pattern at the frequency of 30GHz.

[0068] As shown in Figure 10, the liquid crystal phased array with double beams, two-dimensional scanning and high gain can perform double beam scanning in the Theta plane by regulating the feed phase of each slot-coupled patch antenna unit, and the scanning angle range is: ±35°.

[0069] As shown in Figure 11, the liquid crystal phased array with double beams, two-dimensional scanning and high gain can perform double beam scanning in the Phi plane by regulating the feed phase of each slot-coupled patch antenna unit, and the scanning angle range is: ±30°.

[0070] The liquid crystal phased array with double beams, two-dimensional scanning and high gain provided by the application improves the phase modulation range under the limited physical size, thereby improving the flexibility of the liquid crystal phased array. By utilizing the reverse characteristics of the feed current of the slow-wave liquid crystal phase-shifting feed network in the H-type configuration, the liquid crystal phased array with double beams and two-dimensional scanning is realized. The liquid crystal phased array can realize two-dimensional continuous beam scanning in the frequency range of 30GHz, and the scanning angle can reach ±30°, and the gain in the scanning range reaches 12.1dBi-15.3dBi. Therefore, the application realizes a liquid crystal phased array with double beams, two-dimensional scanning and high gain, which is expected to be widely applied in the field of future wireless communication.

[0071] The above further describes the present application in connection with specific / preferred embodiments, and cannot be deemed to limit the specific implementation of the present application to these descriptions. For those skilled in the art to which the present application belongs, without departing from the concept of the present application, they can make several substitutions or variations to the described embodiments, and these substitutions or variations shall be deemed to fall within the protection scope of the present application. In the description of the present application, the description of the terms "an embodiment", "some embodiments", "a preferred embodiment", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. Those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction. Although the embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of the patent application.

Claims

1. A dual-beam, two-dimensional scanning liquid crystal phased array, characterized in that, The system includes an upper substrate, a lower substrate, a liquid crystal medium disposed between the upper substrate and the lower substrate, alignment layers disposed above and below the liquid crystal medium, a coplanar waveguide transmission line and a slow-wave liquid crystal phase-shifting feed network disposed on the upper surface of the lower substrate, multiple slot-coupled patch antenna elements disposed on the upper surface of the upper substrate, and a metal ground plane disposed on the lower surface of the upper substrate. The coplanar waveguide transmission line is connected to the slow-wave liquid crystal phase-shifting feed network. Multiple coupling slots are formed on the metal ground plane. Each slow-wave liquid crystal phase shifter of the slow-wave liquid crystal phase-shifting feed network is coupled to a corresponding slot-coupled patch antenna element through the coupling slots. Each slot-coupled patch antenna element is independently controlled by a corresponding slow-wave liquid crystal phase shifter to achieve dual-beam and two-dimensional scanning.

2. The dual-beam, two-dimensional scanning liquid crystal phased array as described in claim 1, characterized in that, The slow-wave liquid crystal phase-shifting feed network includes 16 slow-wave liquid crystal phase shifters configured in an H-shaped symmetrical feed network. Each group of four slow-wave liquid crystal phase shifters is arranged in an H-shaped geometric layout, and is respectively arranged on the four arms of the H-shape. In each group, two adjacent slow-wave liquid crystal phase shifters form feed signals with opposite directions, thereby generating the required phase difference. Correspondingly, 16 slot-coupled patch antenna elements and 16 coupling slots are configured.

3. The dual-beam, two-dimensional scanning liquid crystal phased array as described in claim 2, characterized in that, The slot-coupled patch antenna element is a long rectangle, and its length direction is perpendicular to the extension direction of the slow wave transmission line of the corresponding slow wave liquid crystal phase shifter. The 16 slot-coupled patch antenna elements form a 4×4 antenna array.

4. The dual-beam, two-dimensional scanning liquid crystal phased array as described in claim 2, characterized in that, The slot-coupled patch antenna elements are arranged in a uniform array with intervals of 0.25λ to 1λ.

5. The dual-beam, two-dimensional scanning liquid crystal phased array as described in claim 3, characterized in that, The coupling gap is an H-shaped gap or a straight gap, and its length direction is perpendicular to the extension direction of the slow wave transmission line of the corresponding slow wave liquid crystal phase shifter.

6. The dual-beam, two-dimensional scanning liquid crystal phased array as described in any one of claims 2 to 5, characterized in that, The slow-wave liquid crystal phase-shifting feed network also includes a bias network, a DC block, and a 1-to-16 power divider. The 16 slow-wave liquid crystal phase shifters are located at the output ports of the 1-to-16 power divider. The bias network is symmetrically distributed on both sides of the 1-to-16 power divider. The DC block is set in front of each slow-wave liquid crystal phase shifter. The bias network includes 16 DC bias lines, which are symmetrically distributed.

7. The dual-beam, two-dimensional scanning liquid crystal phased array as described in any one of claims 1 to 5, characterized in that, The coplanar waveguide transmission line has a coplanar ground, which is not on the same plane as the metal ground of the slow-wave liquid crystal phase-shifting feed network, and is arranged in an alternating and overlapping manner.

8. The dual-beam, two-dimensional scanning liquid crystal phased array as described in claim 7, characterized in that, The coplanar metal ground of the coplanar waveguide transmission line is rounded.

9. The dual-beam, two-dimensional scanning liquid crystal phased array as described in any one of claims 1 to 5, characterized in that, The upper substrate and the lower substrate are quartz glass substrates.

10. The dual-beam, two-dimensional scanning liquid crystal phased array as described in any one of claims 1 to 5, characterized in that, The orientation layer is a polyimide film.

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