Multi-beam liquid crystal phased array antenna device based on glass substrate

Abstract

The invention discloses a multi-beam liquid crystal phased-array antenna device based on a glass substrate, and belongs to the field of phased-array antennas. Comprising a composite substrate formed by laminating a plurality of layers of PCBs and a glass panel, a chip-on-film driving board is bound on one side of the composite substrate, a special driving chip for a liquid crystal display circuit is arranged on the chip-on-film driving board, and a flexible circuit board is bound on the other side of the composite substrate; the composite substrate at least comprises an antenna plate layer, an upper glass layer, a lower glass layer and a feed plate layer; microwave liquid crystal is packaged between the upper glass layer and the lower glass layer to form a liquid crystal box; the multi-beam liquid crystal phased-array antenna device is provided with two mutually independent receiving beam forming networks, an independent transmitting beam forming network, two receiving beams and a transmitting beam. In an application scene of satellite communication, the two receiving beams of the multi-beam liquid crystal phased-array antenna device can be respectively aligned with and track different target satellites.

Description

Technical Field

[0001] The present invention relates to the technical field of phased array antennas, and in particular to a multi-beam liquid crystal phased array antenna device based on a glass substrate. Background Art

[0002] Phased array antenna refers to an antenna that changes the shape of the radiation pattern by controlling the feeding phase of the radiating elements in the array antenna. By controlling the phase, the direction of the maximum value of the antenna radiation pattern is changed to achieve the purpose of beam scanning. Due to the beam scanning characteristics of phased array antennas, it is widely used in fields such as communication and detection.

[0003] Phased array antenna architectures are divided into two categories: active phased array and passive phased array antennas. The current phased array antenna based on glass-based liquid crystal technology is essentially a typical passive phased array, which is a highly mature, low-cost, and low-power phased array architecture. Liquid crystal phased array antennas use the dielectric anisotropy of liquid crystals to provide deflection voltages to the upper and lower sides of the liquid crystal layer through transmission lines, and control the deflection direction of the liquid crystal to change the phase shift of the phase shifter, thereby adjusting the beam direction of the phased array antenna. In related technologies, a series of phase shifter structures based on liquid crystal technology and their phased array solutions have been proposed. Liquid crystal materials are filled between dielectric substrates such as glass or PCB boards, and different DC voltages are applied to control the material properties of the liquid crystal materials to form different transmission phase values, thereby realizing passive phased array technology based on liquid crystal technology, which can be widely used in communication, detection and other fields.

[0004] The common points of the above solutions are mainly that they all include a radiation unit group, an RF power division network, and an electrically adjustable delay phase shifter group. Since it is a passive phased array system, the main problems now are: first, the passive phased array architecture is adopted. Due to the cascade architecture formed by the multi-stage power division network and the lack of a power compensation mechanism (that is, there is no active chip for compensation), it will cause a transmission link insertion loss of more than 5-6dB; second, the traditional analog beamforming method is adopted, so a single synthesis channel only generates one beam, which cannot meet the needs of multiple beams. Summary of the invention

[0005] The present invention provides a multi-beam liquid crystal phased array antenna device based on a glass substrate. A low noise amplifier (LNA) chip is added in front of a liquid crystal phase shifter through a common aperture arrangement, and a single antenna channel adopts a dual phase shifter architecture to form two sets of beamforming power division networks. At the same time, an independent transmitting beamforming network is provided, thereby realizing dual receiving beams for receiving signals and one transmitting beam for transmitting signals.

[0006] The embodiment of the present invention provides a multi-beam liquid crystal phased array antenna device based on a glass substrate, comprising the following steps: a composite substrate formed by laminating a multi-layer PCB and a glass panel, a chip-on-film driving board is bound to one side of the composite substrate, and a dedicated driving chip for a liquid crystal display circuit is provided on the chip-on-film driving board, and a flexible circuit board is bound to the other side of the composite substrate;

[0007] The composite substrate is provided with N×M (M≥1 and N≥1) liquid crystal phased array receiving units arranged periodically, and is provided with an active LNA chip corresponding to the liquid crystal phased array receiving units, and J×K (J≥1 and K≥1) periodically arranged liquid crystal phased array transmitting units;

[0008] The composite substrate at least comprises an antenna board layer, an upper glass layer, a lower glass layer and a feed board layer; and microwave liquid crystal is encapsulated between the upper glass layer and the lower glass layer to form a liquid crystal box;

[0009] The flexible circuit board is used to provide power signals and control signals to the active LNA chip;

[0010] The chip-on-film driving board is used to provide driving and control signals to the liquid crystal phase shifter in the liquid crystal box;

[0011] The multi-beam liquid crystal phased array antenna device is provided with two independent receiving channels and one independent transmitting channel, and has two mutually independent receiving beamforming networks and one independent transmitting beamforming network, and has two receiving beams and one transmitting beam.

[0012] Optionally, in one embodiment of the present invention, the liquid crystal phase shifter transmission line in the liquid crystal box is a coplanar waveguide line structure consisting of strip lines with branches.

[0013] Optionally, in one embodiment of the present invention, the material of the liquid crystal phase shifter transmission line in the liquid crystal box is one or more of indium tin oxide, silver, graphene, copper, nickel, and molybdenum.

[0014] Optionally, in one embodiment of the present invention, a metallized glass through hole is provided in the glass layer of the composite substrate.

[0015] Optionally, in one embodiment of the present invention, a beamforming network consisting of multi-stage power division is provided on the feed board layer of the composite substrate, and the beamforming network is in the form of one or more of stripline, microstrip line or coplanar waveguide line.

[0016] Optionally, in one embodiment of the present invention, in an application scenario of satellite communication, two receiving beams are respectively aimed at and track different target satellites.

[0017] Optionally, in one embodiment of the present invention, in an application scenario of satellite communication, two receiving beams are respectively aimed at and track the main target satellite and the backup satellite, and the transmitting beam is aimed at and track the main target satellite to form a main communication link and an alternative communication link.

[0018] Optionally, in one embodiment of the present invention, two receiving beams are respectively aimed at and track two target satellites, and the transmitting beam is switched between the two target satellites to form two communication links in a time-division situation.

[0019] The glass-based multi-beam liquid crystal phased array antenna device according to the embodiment of the present invention has the following beneficial effects:

[0020] 1. The present invention has a single transmitting beam and dual receiving beams. When applied in a satellite communication scenario, it can search for and track another satellite while maintaining the current satellite communication link to achieve agile switching of the satellite network.

[0021] 2. An active LNA chip is added to the receiving link to compensate for the insertion loss of the multi-stage reactive power distribution network, and has a better G / T value than the traditional purely passive liquid crystal phased array antenna.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0024] Figure 1 Schematic diagram of a glass-based multi-beam liquid crystal phased array antenna device according to an embodiment of the present invention;

[0025] Figure 2 This is a principle block diagram of a glass-based multi-beam liquid crystal phased array antenna device according to an embodiment of the present invention;

[0026] Figure 3 An example of a layered structure of a composite substrate according to an embodiment of the present invention;

[0027] FIG. 4 is a specific implementation example of each layer of the layered structure of the composite substrate according to an embodiment of the present invention, wherein Figures 4a to 4f Corresponding to Figure 3 Layers 81 to 84;

[0028] Figure 5 The figure illustrates an application scenario of a glass-based multi-beam liquid crystal phased array antenna device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0030] The glass-based multi-beam liquid crystal phased array antenna device includes: a composite substrate formed by laminating a multi-layer PCB and a glass panel, a chip-on-film (COF) driver board is bound on one side of the composite substrate, and a dedicated driver chip for a liquid crystal display circuit is arranged on the chip-on-film driver board, and a flexible circuit (FPC) board is bound on the other side of the composite substrate;

[0031] The composite substrate is provided with N×M (M≥1 and N≥1) liquid crystal phased array receiving units arranged periodically, an active LNA chip corresponding to the liquid crystal phased array receiving units, and J×K (J≥1 and K≥1) periodically arranged liquid crystal phased array transmitting units;

[0032] The composite substrate at least comprises an antenna board layer, an upper glass layer, a lower glass layer and a feed board layer; and microwave liquid crystal is encapsulated between the upper glass layer and the lower glass layer to form a liquid crystal box;

[0033] The flexible circuit board is used to provide power signals and control signals to the active LNA chip;

[0034] The chip-on-film driver board is used to provide driving and control signals to the liquid crystal phase shifter in the liquid crystal box;

[0035] The multi-beam liquid crystal phased array antenna device is provided with two independent receiving channels and one independent transmitting channel, and has two mutually independent receiving beam forming networks and one independent transmitting beam forming network, and has two receiving beams and one transmitting beam.

[0036] like Figure 1 and Figure 2As shown, the multi-beam liquid crystal phased array antenna device based on glass substrate includes: N×M liquid crystal phased array receiving units 1 are arranged periodically (M≥1 and N≥1), and are provided with active LNA chips 2 corresponding to the liquid crystal phased array receiving units 1, and J×K liquid crystal phased array transmitting units 11 are arranged periodically (J≥1 and K≥1); the above-mentioned liquid crystal phased array receiving units 1, liquid crystal phased array transmitting units 11, and active LNA chips 2 are all arranged on a composite substrate 8 formed by laminating a multi-layer PCB and a glass panel; a chip-on-film (COF) driving board 6 is bound to one side of the composite substrate 8, and a dedicated driving chip 61 for a liquid crystal display circuit is provided on the COF driving board 6, and a flexible circuit (FPC) board 7 is bound to the other side of the composite substrate 8, the COF driving board 6 is a control cable for driving the liquid crystal phase shifters 3, 3', and 13 in the liquid crystal phased array, and the FPC board 7 is a cable for driving and controlling the active LNA chip 2.

[0037] In the above-mentioned multi-beam liquid crystal phased array antenna device, its receiving antenna channel, that is, the subsequent stage of the active LNA chip 2 corresponding to each liquid crystal phased array receiving unit 1, is respectively provided with two liquid crystal phase shifters 3 and 3', and the arrays of the liquid crystal phase shifters 3 and 3' respectively correspond to two multi-stage power division networks 4 and 4', thus forming two independent receiving channels Rx1 and Rx2, that is, having dual receiving beams.

[0038] Similarly, in the above-mentioned multi-beam liquid crystal phased array antenna device, its transmitting antenna channel, that is, the rear stage of each liquid crystal phased array transmitting unit 11 is provided with a liquid crystal phase shifter 13, and the array of the liquid crystal phase shifter 13 corresponds to the multi-stage power division network 14, thus forming a transmitting channel Tx, that is, having a transmitting beam.

[0039] Optionally, in one embodiment of the present invention, the liquid crystal phase shifter transmission line in the liquid crystal box is a coplanar waveguide line structure consisting of strip lines with branches.

[0040] Combine the following Figure 3 FIG. 4 further illustrates the detailed structure of the composite substrate 8 .

[0041] The composite substrate 8 is formed by laminating a multi-layer PCB and a glass panel, and the various board layers are laminated with optical glue or semi-cured sheets and other materials, and includes from top to bottom: an antenna board layer 81, an upper glass layer 82, a lower glass layer 83, and a feed board layer 84, wherein the upper glass layer 82, the lower glass layer 83, and the frame glue 85 form a liquid crystal box, and microwave liquid crystal 86 is encapsulated inside, and the antenna board layer 81 and the feed board layer 84 are typically made of multi-layer PCB boards. Figure 1 The COF driving board 6 shown is bound to the inner side of the glass plate layer 82 of the composite substrate 8. Figure 1The FPC board 7 shown is pressed in the middle of the multi-layer PCB of the antenna board layer 81 of the composite substrate 8 .

[0042] Optionally, in one embodiment of the present invention, the material of the liquid crystal phase shifter transmission line in the liquid crystal box is one or more of indium tin oxide, silver, graphene, copper, nickel, and molybdenum.

[0043] Optionally, in one embodiment of the present invention, a metallized glass through hole is provided in the glass layer of the composite substrate.

[0044] Optionally, in one embodiment of the present invention, a beamforming network consisting of multi-stage power division is provided on the feed board layer of the composite substrate, and the beamforming network is in the form of one or more of stripline, microstrip line or coplanar waveguide line.

[0045] On the upper surface of the antenna board layer 81 of the composite substrate 8, there are N×M radiation patches 811 of liquid crystal phased array receiving units 1 arranged periodically (M≥1 and N≥1), and there are active LNA chips 2 corresponding to the liquid crystal phased array receiving units 1, and there are J×K radiation patches 812 of liquid crystal phased array transmitting units 11 arranged periodically (J≥1 and K≥1). Because the antenna board layer 81 is made of a multi-layer PCB board, the radiation patch 811 is connected to the input end of the active LNA chip 2 (not marked in the figure) through metallized vias and RF transmission lines in the form of strip lines, microstrip lines, or coplanar waveguide lines inside the board layer, and the power line and control line of the active LNA chip 2 are set on the FPC board 7 (not marked in the figure) through internal connections; and then the output end of the active LNA chip 2 is connected to the RF terminal 813 on the lower surface of the antenna board layer 81 through metallized vias and RF transmission lines in the form of strip lines, microstrip lines, or coplanar waveguide lines inside the board layer.

[0046] Similarly, the radiation patch 812 on the upper surface of the antenna board layer 81 is connected to the RF terminal 814 on the lower surface of the antenna board layer 81 through metallized vias inside the board layer and RF transmission lines in the form of strip lines, microstrip lines, or coplanar waveguide lines.

[0047] Generally, the radiation patches 811 and 812 are in a rectangular, square, or circular shape.

[0048] Metallized glass through holes (TGV) 821 and 822 are provided in the upper glass layer 82, which correspond to the RF endpoints 813 and 814 on the lower surface of the antenna board layer 81 respectively, and ensure RF conduction after bonding, so as to connect the RF signal of the antenna board layer 81 with the upper glass layer 82 (i.e., the phase shifter of the liquid crystal box).

[0049] On the lower surface of the upper glass layer 82, there are periodically arranged strip lines 823 and 823' with branches, the number of which corresponds to the number of radiation patches 811, and the strip lines 823 and 823' are connected to the metallized glass through hole 821 through a one-to-two power division structure; similarly, on the lower surface of the upper glass layer 82, there are periodically arranged strip lines 824 with branches, the number of which corresponds to the number of radiation patches 812, and one end of the strip line 824 is connected to the metallized glass through hole 822.

[0050] On the upper surface of the lower glass layer 83, strip metal grounds 831 and 832 are arranged periodically. The strip metal grounds 831 correspond to the branches of the strip lines 823 and 823' with branches of the upper glass layer 82, and the strip metal grounds 832 correspond to the branches of the strip line 824 with branches of the upper glass layer 82, that is, the strip metal grounds 831 and the strip lines 823 and 823' with branches of the upper glass layer 82 respectively form a group of parallel coplanar waveguide (CPW) lines, and the strip metal grounds 832 and the strip line 824 with branches of the upper glass layer 82 form another group of coplanar waveguide (CPW) lines. The beneficial effect of using coplanar waveguide (CPW) lines is that the liquid crystal phase shift structure can be miniaturized, and it has a higher quality factor (FoM value).

[0051] The strip lines 823 and 823' with branches, the strip metal ground 831, and the microwave liquid crystal 86 encapsulated between the upper and lower glass layers 82 and 83 form Figure 2 The liquid crystal phase shifter structures 3 and 3'; similarly, the strip line 824 with branches and the strip metal ground 832, as well as the microwave liquid crystal 86 encapsulated between the upper and lower glass layers 82 and 83 form Figure 2 The liquid crystal phase shifter structure 13; at the same time, an ITO control line (not shown in the figure) connected to the strip lines 823 and 823', and the strip line 824 is provided on the upper glass layer 82, which is used to provide a driving / control voltage value to the liquid crystal phase shifter structures 3 and 3', and the liquid crystal phase shifter structure 13. The ITO control line will eventually be connected to the dedicated driving chip 61 for the liquid crystal display circuit on the COF driving board 6.

[0052] A metal ground 843 that almost covers the entire surface is provided on the upper surface of the feed plate layer 84. A pair of slits 841 and 841' are provided on the metal ground 843 in N×M groups arranged periodically, and correspond one to one with the ends of the strip lines 823 and 823'. Similarly, a pair of slits 842 are provided on the metal ground 843 in J×K groups arranged periodically, and correspond one to one with the ends of the strip line 824. The slits 841, 841', and 842 connect the RF signal of the lower glass layer 83 (i.e., the phase shifter in the liquid crystal cell) with the feed plate layer 84.

[0053] The feed board layer 84 is a multi-layer PCB board, and a multi-level power division network (not shown in the figure) is formed inside the board layer through metallized vias and RF transmission lines in the form of strip lines, microstrip lines, or coplanar waveguide lines, etc., and finally two receiving ports Rx1 and Rx2 and a transmitting port Tx are formed on the lower surface of the feed board layer 84, that is, corresponding to the formation of two receiving beams and one transmitting beam. It should be noted that the multi-level power division network in the feed board layer 84 is independently provided with a multi-level power division network of two receiving channels and a multi-level power division network of one transmitting channel (i.e. Figure 2 The multi-stage power division networks 4, 4' and 14) are respectively connected to Figure 2 The liquid crystal phase shifter structures 3 and 3 ′ and the liquid crystal phase shifter structure 13 are connected to realize two receiving channels and one transmitting channel.

[0054] Optionally, in one embodiment of the present invention, in an application scenario of satellite communication, two receiving beams are respectively aimed at and track different target satellites.

[0055] Optionally, in one embodiment of the present invention, in an application scenario of satellite communication, two receiving beams are respectively aimed at and track the main target satellite and the backup satellite, and the transmitting beam is aimed at and track the main target satellite to form a main communication link and an alternative communication link.

[0056] Optionally, in one embodiment of the present invention, two receiving beams are respectively aimed at and track two target satellites, and the transmitting beam is switched between the two target satellites to form two communication links in a time-division situation.

[0057] Combine the following Figure 5 To illustrate the application scenario of the above-mentioned multi-beam liquid crystal phased array antenna device, when the multi-beam liquid crystal phased array antenna device 53 works in the scenario of satellite communication, during the communication process, the receiving beam 531 and the transmitting beam 532 of the multi-beam liquid crystal phased array antenna device 53 are respectively aimed at the target satellite 51, and a link of two-way communication of sending and receiving is established and maintained, and the receiving beam 531 and the transmitting beam 532 are respectively always tracking the target satellite 51; at the same time, the receiving beam 531' of the multi-beam liquid crystal phased array antenna device 53 is used to aim at another target satellite 52, and always keep tracking the target satellite 52, forming an alternative communication link. When satellite switching is required, the link can be quickly switched to communication with the target satellite 52, that is, only the control software needs to aim the transmitting beam 532 at the target satellite 52, that is, to establish a communication link, and then the original receiving beam 531 can set the next alternative target satellite for tracking.

[0058] Without loss of generality, during the communication process, the receiving beam 531 and the receiving beam 531' of the multi-beam liquid crystal phased array antenna device 53 are respectively aligned with and keep tracking the target satellites 51 and 52, while the transmitting beam 532 is switched between the target satellites 51 and 52 according to the time slot requirements of different transmitting carriers, forming a two-way communication link with the target satellites 51 and 52 simultaneously under time division.

[0059] The glass-based multi-beam liquid crystal phased array antenna device proposed in an embodiment of the present invention includes a composite substrate formed by laminating a multi-layer PCB and a glass panel, a chip-on-film (COF) driver board is bound on one side of the composite substrate, and a dedicated driver chip for a liquid crystal display circuit is provided on the COF driver board, and a flexible circuit (FPC) board is bound on the other side of the composite substrate; the composite substrate at least includes an antenna board layer, an upper glass layer, a lower glass layer, and a feed board layer; and microwave liquid crystal is encapsulated between the upper glass layer and the lower glass layer to form a liquid crystal box. The device has two independent receiving beam forming networks and an independent transmitting beam forming network, and has two receiving beams and one transmitting beam. In the application scenario of satellite communication, the two receiving beams of the multi-beam liquid crystal phased array antenna device can be respectively aimed at and track different target satellites.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0061] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. A multi-beam liquid crystal phased array antenna device based on a glass substrate, characterized in that: include: A composite substrate formed by laminating a multi-layer PCB and a glass panel, a chip-on-film driver board is bound to one side of the composite substrate, and a dedicated driver chip for a liquid crystal display circuit is provided on the chip-on-film driver board, and a flexible circuit board is bound to the other side of the composite substrate; The composite substrate is provided with N×M (M≥1 and N≥1) liquid crystal phased array receiving units arranged periodically, and is provided with an active LNA chip corresponding to the liquid crystal phased array receiving units, and J×K (J≥1 and K≥1) periodically arranged liquid crystal phased array transmitting units; The composite substrate at least comprises an antenna board layer, an upper glass layer, a lower glass layer and a feed board layer; and microwave liquid crystal is encapsulated between the upper glass layer and the lower glass layer to form a liquid crystal box; The flexible circuit board is used to provide power signals and control signals to the active LNA chip; The chip-on-film driving board is used to provide driving and control signals to the liquid crystal phase shifter in the liquid crystal box; The multi-beam liquid crystal phased array antenna device is provided with two independent receiving channels and one independent transmitting channel, and has two mutually independent receiving beamforming networks and one independent transmitting beamforming network, and has two receiving beams and one transmitting beam.

2. The device according to claim 1, characterized in that The liquid crystal phase shifter transmission line in the liquid crystal box is a coplanar waveguide line structure composed of strip lines with branches.

3. The device according to claim 1 or 2, characterized in that: The liquid crystal phase shifter transmission line material in the liquid crystal box is one or more of indium tin oxide, silver, graphene, copper, nickel, and molybdenum.

4. The device according to claim 1, characterized in that A metallized glass through hole is arranged in the glass layer of the composite substrate.

5. The device according to claim 1, characterized in that A beamforming network consisting of multi-stage power dividers is provided on the feed board layer of the composite substrate. The beamforming network is in the form of one or more of strip lines, microstrip lines or coplanar waveguide lines.

6. The device according to claim 1, characterized in that In the application scenario of satellite communication, two receiving beams are respectively aimed at and tracked different target satellites.

7. The device according to claim 1, characterized in that In the application scenario of satellite communication, two receiving beams are respectively aimed at and track the main target satellite and the backup satellite, and the transmitting beam is aimed at and track the main target satellite, forming a main communication link and an alternative communication link.

8. The device according to claim 1, characterized in that The two receiving beams are respectively aimed at and track the two target satellites, and the transmitting beam is switched between the two target satellites to form two communication links in a time-division situation.

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