Distributed liquid crystal phased array antenna

Abstract

The invention discloses a distributed liquid crystal phased array antenna, which comprises a plurality of antenna units, the plurality of antenna units are arranged into an array antenna according to a certain rule, two adjacent antenna units in the array antenna form a sub-array, and each antenna unit in the sub-array is cascaded with a first phase shifter; the two antenna units in the sub-array are connected in parallel and then are connected in parallel with the sub-arrays of the same type in the array antenna, all the sub-arrays of the same type in the array antenna are connected in parallel and then are combined to the same feed port, and the feed port is cascaded with the second phase shifter. According to the distributed liquid crystal phased-array antenna provided by the invention, the two-stage phase shift network array is adopted, the antenna loss and cost are reduced, and the antenna efficiency is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of phased array antennas, and in particular to a distributed liquid crystal phased array antenna. Background Art

[0002] With the increasing demand for high-speed communications, communication systems must not only achieve higher transmission rates but also improve system efficiency and reduce costs. Against this backdrop, phased array antenna technology, an advanced technology capable of rapidly and precisely adjusting beams, has become a key solution to meet these demands. The efficient performance of phased array antennas makes them a vital component of modern communication systems.

[0003] Traditional passive phased array antennas achieve beam steering by placing phase shifters between the antenna and the feed network, incorporating the principles of phased array antennas. These phase shifters adjust the phase of each antenna element as needed, precisely controlling the direction and shape of the transmitted signal. However, the high losses in these phase shifters lead to low antenna system efficiency. As active phased array technology matures, the use of purely passive phased arrays will likely decrease in the future.

[0004] Traditional active phased array antennas incorporate amplifier chips or components between the antenna and phase shifter. This reduces the impact of phase shifter losses on the antenna array by amplifying small signals. This design not only improves the overall system efficiency but also enhances signal stability and reliability, making it particularly suitable for long-distance communications or applications requiring high precision. However, traditional active phased array antennas also face several challenges. First, due to size and process limitations, the final power amplifier has low power amplification efficiency, typically less than 20%, requiring high power consumption. Second, the high-integration active TR chip has high wafer production costs, and its high heat dissipation significantly increases its operating cost and the structural cost of the cooling system.

[0005] Emerging antenna forms, such as reconfigurable smart surfaces (RIS), achieve flexible beam control by manipulating the phase shift of transmitted or reflected waves. These antennas utilize electromagnetic wave phase modulation technology to make signal propagation paths more flexible and efficient, offering low cost and high performance, making them suitable for complex communication environments. However, new antenna forms such as RIS typically require a suitable focal diameter ratio, resulting in a larger overall antenna size and limiting their application scenarios. Furthermore, these antennas typically have only a maximum of 2-bit phase shifters, resulting in low phase shift accuracy, making precise beam control impossible, and thus affecting directivity and gain performance.

[0006] With the advancement of technology, low-loss liquid crystal phased array antennas based on glass substrates have emerged in recent years. Liquid crystal phase shifters are used as core components, achieving phase control by adjusting the electro-optical effect of liquid crystals. This structure effectively reduces signal loss and improves the overall antenna performance, making it particularly suitable for applications requiring high precision and low power consumption. While low-loss liquid crystal phased array antennas based on glass substrates have, to some extent, addressed the high loss issues of purely passive phased arrays, they still exhibit losses exceeding 50%. Summary of the Invention

[0007] To this end, the present application provides a distributed liquid crystal phased array antenna to solve the problems of high cost and loss and low efficiency of phased array antennas in the prior art.

[0008] In order to achieve the above objectives, this application provides the following technical solutions:

[0009] A distributed liquid crystal phased array antenna includes multiple antenna units, which are arranged according to a certain rule to form an array antenna. Two adjacent antenna units in the array antenna form a subarray, and each antenna unit in the subarray is cascaded with a first phase shifter. The two antenna units in a subarray are connected in parallel and then connected in parallel with a subarray of the same type in the array antenna. All subarrays of the same type in the array antenna are connected in parallel and then combined to the same feed port, which is cascaded with a second phase shifter.

[0010] Preferably, the phase shift amount of the first phase shifter is in the range of 120° to 240°.

[0011] Preferably, the phase shift amount of the first phase shifter is 180°.

[0012] Preferably, the second phase shifter is a phase shifter with full phase shift.

[0013] Preferably, different types of sub-arrays in the array antenna are arranged in a staggered manner.

[0014] Preferably, the device further comprises an amplifier, wherein the amplifier is cascaded with the feeding port and is located before the second phase shifter.

[0015] Preferably, the types of the sub-arrays can be increased or decreased according to antenna pointing accuracy requirements.

[0016] Preferably, if the distributed liquid crystal phased array antenna needs to be circularly polarized, a rotation method is first used to reduce the antenna axial ratio of the antenna unit, and then a two-stage phase shift network is used to form the array.

[0017] Compared with the prior art, this application has at least the following beneficial effects:

[0018] 1. The present application provides a distributed liquid crystal phased array antenna, comprising a plurality of antenna units arranged according to a certain rule to form an array antenna. Two adjacent antenna units in the array antenna form a subarray, and each antenna unit in the subarray is cascaded with a first phase shifter. After the two antenna units in the subarray are connected in parallel, they are connected in parallel with the subarrays of the same type in the array antenna. All the subarrays of the same type in the array antenna are connected in parallel and then combined to the same feed port, which is cascaded with a second phase shifter. The distributed liquid crystal phased array antenna provided in the present application uses a two-stage phase shifting network to form an array, reducing antenna loss and cost, and effectively improving antenna efficiency.

[0019] 2. The distributed liquid crystal phased array antenna provided herein also includes an amplifier, cascaded with the feed port and positioned before the second phase shifter. The addition of the amplifier transforms the entire distributed liquid crystal phased array antenna into a combined active and passive phased array antenna, further reducing antenna loss and cost, ensuring high power output from the antenna system, and thus further improving antenna efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To more intuitively illustrate the prior art and the present application, exemplary drawings are provided below. It should be understood that the specific shapes and structures shown in the drawings should not generally be considered as limiting conditions for implementing the present application; for example, based on the technical concepts disclosed in this application and the exemplary drawings, those skilled in the art are capable of easily making routine adjustments or further optimizations to the addition / reduction / attribution division, specific shapes, positional relationships, connection methods, dimensional ratios, etc. of certain units (components).

[0021] Figure 1 A schematic diagram of the structure of a distributed liquid crystal phased array antenna provided in this application;

[0022] Figure 2 A schematic diagram of a sub-array structure of a distributed liquid crystal phased array antenna provided in this application;

[0023] Figure 3 A schematic diagram of the first-stage phase shifter network structure of a distributed liquid crystal phased array antenna provided in this application;

[0024] Figure 4 A schematic diagram of the triangular array structure of a distributed liquid crystal phased array antenna provided in this application;

[0025] Figure 5 A schematic diagram of the first active and passive combined array structure of a distributed liquid crystal phased array antenna provided in this application;

[0026] Figure 6 A schematic diagram of the second active-passive combination array structure of a distributed liquid crystal phased array antenna provided in this application;

[0027] Figure 7 A schematic diagram of the structure of a distributed liquid crystal phased array antenna provided in this application having more sub-arrays;

[0028] Figure 8 This is a structural diagram of a distributed liquid crystal phased array antenna provided in this application when circular polarization is required.

[0029] Description of reference numerals:

[0030] 1. Antenna unit; 2. First phase shifter; 3. Second phase shifter; 4. Amplifier. DETAILED DESCRIPTION

[0031] The present application will be further described below in detail through specific embodiments in conjunction with the accompanying drawings.

[0032] In the description of this application: unless otherwise specified, the meaning of "plurality" is two or more. The terms "first", "second", "third", etc. in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (for example, they should not be understood as emphasizing the importance or order, etc.). Expressions such as "including", "comprising", "having", etc. also mean "not limited to" (certain units, components, materials, steps, etc.).

[0033] The terms such as "upper", "lower", "left", "right", "middle", etc. cited in this application are usually used to indicate the general relative position relationship for the convenience of intuitive understanding by referring to the drawings, and are not absolute limitations on the position relationship in the actual product.

[0034] See also Figure 1 The present application provides a distributed liquid crystal phased array antenna, comprising a plurality of antenna units 1, wherein the plurality of antenna units 1 are arranged into an array antenna according to certain rules, and two adjacent antenna units 1 in the array antenna form a sub-array (e.g. Figure 1 (as shown in the dotted box), each antenna unit 1 in the subarray is cascaded with the first phase shifter 2; the two antenna units 1 in the subarray are connected in parallel and then connected in parallel with the subarrays of the same type in the array antenna. All subarrays of the same type in the array antenna are connected in parallel and then combined to the same feed port, which is cascaded with the second phase shifter 3.

[0035] See also Figure 2 This application divides the array antenna into 1×2 subarrays. Each antenna unit in the subarray is cascaded with an independent phase shifter (i.e., first phase shifter 2). Identical subarrays are combined into the same port via a low-loss network. This application provides a distributed liquid crystal phased array antenna that reduces antenna loss by cascading antennas within the subarray with low-phase-shift and low-loss components.

[0036] See also Figure 3 In a distributed liquid crystal phased array antenna provided in the present application, the phase shift amount of the first phase shifter 2 is in the range of 120° to 240°, and the phase shift amount is preferably 180° to meet the beam pointing requirement.

[0037] See also Figure 4 In a distributed liquid crystal phased array antenna provided by the present application, different types of sub-arrays in the array antenna are arranged in a staggered manner, that is, the sub-arrays are arranged in a triangular array. After the triangular array, the array antenna is staggered and networked, and synthesized to a unified feeding port. The total port is cascaded with a full phase shift (360°) phase shifter (i.e., the second phase shifter 3), forming a phased array antenna system composed of two-stage phase shifters. Among them, the first stage is directly cascaded with the antenna, with a small phase shift and low loss; the second stage phase shifter is cascaded after the synthesis port, with a full phase shift and large loss.

[0038] See also Figure 5 and Figure 6 To further reduce losses, the distributed liquid crystal phased array antenna provided in this application further includes an amplifier 4, which is cascaded with the feed port and located before the second phase shifter 3. It should be noted that after the addition of amplifier 4, the entire distributed liquid crystal phased array antenna is a phased array antenna that combines active and passive arrays.

[0039] Since the first-stage phase shifter (i.e., the first phase shifter 2) has low loss, it is directly connected to the antenna unit 1 and placed between the amplifier 4 and the antenna, which not only plays the role of phase shift control but also reduces the loss of the antenna system. Since the phase shift amount of the first-stage phase shifter is insufficient, the full phase shifter (i.e., the second phase shifter 3) is placed after the amplifier 4, away from the antenna, and the amplification function of the amplifier 4 is utilized to ensure that the antenna system has a higher power output, which can effectively improve the antenna efficiency.

[0040] This application uses a two-stage phase-shifting network with inconsistent phase shift amounts. On the one hand, it reduces the number of power amplifiers used and reduces system costs. On the other hand, the reduction in the number of power amplifiers and the increase in the distance between amplifiers can transform the less efficient gallium arsenide low-power amplifier into a more efficient gallium nitride power amplifier, thereby effectively improving the efficiency of the antenna system.

[0041] In the distributed liquid crystal phased array antenna provided in this application, the types of sub-arrays can be increased or decreased according to the antenna pointing accuracy requirements. If the antenna pointing accuracy requirements are too high, more sub-arrays can be added (with the increase in the number of sub-arrays, the antenna pointing accuracy will be effectively improved), such as Figure 7 As shown (for example, four sub-arrays are used); if the antenna pointing accuracy requirement is not too high, the sub-arrays can be reduced.

[0042] See also Figure 8 In a distributed liquid crystal phased array antenna provided in the present application, if the distributed liquid crystal phased array antenna needs to be circularly polarized, the rotation method is first used to reduce the antenna axial ratio of the antenna unit 1, and then a two-level phase shift network is used to form an array (that is, the structure provided in the present application).

[0043] It should be noted that, for the convenience of observation, Figure 8 Only the first stage phase shifter is shown.

[0044] In summary, the distributed liquid crystal phased array antenna provided in this application adopts a two-stage phase-shifting network array, which reduces antenna loss and cost and effectively improves antenna efficiency.

[0045] The technical features of the above embodiments can be combined arbitrarily (as long as there is no contradiction in the combination of these technical features). In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described; these embodiments that are not explicitly written should also be considered to be within the scope of this specification.

Claims

1. A distributed liquid crystal phased array antenna, characterized in that: The invention comprises a plurality of antenna units, wherein the plurality of antenna units are arranged into an array antenna according to a certain rule, wherein two adjacent antenna units in the array antenna form a subarray, and each antenna unit in the subarray is cascaded with a first phase shifter; the two antenna units in the subarray are connected in parallel and then connected in parallel with a subarray of the same type in the array antenna, and all subarrays of the same type in the array antenna are connected in parallel and then combined to the same feed port, and the feed port is cascaded with a second phase shifter.

2. The distributed liquid crystal phased array antenna according to claim 1, characterized in that: The phase shift amount of the first phase shifter is in the range of 120° to 240°.

3. The distributed liquid crystal phased array antenna according to claim 2, characterized in that: The phase shift amount of the first phase shifter is 180°.

4. The distributed liquid crystal phased array antenna according to claim 1, wherein: The second phase shifter is a phase shifter with a full phase shift amount.

5. The distributed liquid crystal phased array antenna according to claim 1, characterized in that: Different types of sub-arrays in the array antenna are arranged in a staggered manner.

6. The distributed liquid crystal phased array antenna according to claim 1, characterized in that: The device further includes an amplifier, which is cascade-connected to the feeding port and is located before the second phase shifter.

7. The distributed liquid crystal phased array antenna according to claim 1, characterized in that: The types of sub-arrays can be increased or decreased according to the antenna pointing accuracy requirements.

8. The distributed liquid crystal phased array antenna according to claim 1, characterized in that: If the distributed liquid crystal phased array antenna needs to be circularly polarized, a rotation method is first used to reduce the antenna axial ratio of the antenna unit, and then a two-stage phase shift network is used to form the array.

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