High integration level LTCC broadband circularly polarized antenna array

Abstract

According to the high-integration-level LTCC broadband circularly polarized antenna array, LTCC is adopted as an antenna medium, through LTCC lamination design, a filter, a signal processing system and other parts which occupy a large space originally are integrated on a lamination structure which occupies a small space, and connection is carried out through a BGA structure, so that the space occupied by the antenna array is effectively reduced; by introducing the coaxial slotted balun, the metal isolation frame and other structures, the wide working bandwidth and the good scanning performance are achieved; the axial ratio is further optimized through the dual-circular-polarization array arrangement mode, and meanwhile + / -60-degree wide beam scanning in the azimuth dimension and the pitching dimension can be achieved; and the requirement of a mobile communication system on a new-generation phased-array antenna can be well met.

Description

Technical Field

[0001] This utility model relates to the field of antenna technology in the field of electronic communication technology, and particularly to a highly integrated LTCC broadband circularly polarized antenna and its array in the fields of satellite communication and microwave communication. Background Technology

[0002] As modern communication systems evolve towards miniaturization and mobility, antennas are required to possess not only high performance but also high integration and low cost.

[0003] LTCC (Low Temperature Co-fired Ceramic) technology, proposed in the 1980s, has been widely used in the design and fabrication of microwave passive devices. Compared to traditional thin-film technology, LTCC's multilayer structure allows for higher module integration and smaller size; the use of high-conductivity materials such as gold, silver, and copper as printed circuit pastes reduces module power loss. LTCC technology features high Q value and high reliability, and has been widely used in the fabrication of miniaturized electronic devices.

[0004] When electromagnetic waves propagate in free space, the trajectory of the instantaneous electric field changes according to certain specific laws; these laws can be called antenna polarization. Based on the different laws governing the propagation of the electric field trajectory in space, antenna polarization is divided into three types: circular polarization, elliptical polarization, and linear polarization. A circularly polarized wave is an electromagnetic wave whose instantaneous electric field vector trajectory changes in a circle within a plane. Compared to linearly polarized antennas, circularly polarized antennas have unique advantages: First, circularly polarized antennas can receive any linearly polarized wave, and simultaneously, circularly polarized waves generated by a circularly polarized antenna can be received by any linearly polarized antenna. Second, circularly polarized antennas are very effective at combating multipath effects and signal fading.

[0005] A complete antenna array system typically comprises many parts: array elements, filters, signal processing circuits, power distribution, etc. Traditional antenna systems often employ a cascaded approach, designing each part separately. While this method is convenient and flexible, with the increasing frequency and miniaturization of modern communications, on the one hand, higher operating frequencies often lead to greater losses and standing wave ratios, degrading antenna performance. On the other hand, the lack of integrated design often results in larger space requirements, increasing the overall system size. Therefore, selecting a suitable structure that meets performance specifications while integrating the array system into a single module to reduce size is a key challenge in current antenna array research. Summary of the Invention

[0006] To address the issues of high loss and large space occupation associated with the direct cascading method used in existing antenna array systems, this disclosure provides a highly integrated LTCC broadband circularly polarized antenna array. It adopts an LTCC stacked design, which can integrate all parts of the entire antenna array onto a 40mm*40mm*6mm stacked circuit board, greatly reducing the size of the system.

[0007] The highly integrated LTCC broadband circularly polarized antenna array disclosed herein comprises two parts: an upper part is the antenna section, and a lower part is the active network section. Both parts are LTCC stacked structures, connected and transitioned by a BGA structure.

[0008] The antenna section includes: several arrayed antenna elements, and a filter corresponding to each antenna element;

[0009] The active network portion includes: an active network that functions as a low-noise amplifier, and a synthesis network;

[0010] Each antenna element and its filter share a single LTCC laminate; the active network and the synthesized network share a single laminate.

[0011] The spacing between antenna elements is constant, and the parts between elements other than the medium are filled with metal.

[0012] Furthermore, the antenna element consists of 16 layers of LTCC and a 17th layer of copper located on the 16th dielectric layer;

[0013] The 17th layer of copper is the radiating patch of the dipole antenna. The copper layers from the 16th layer to the 1st layer are all coaxial feed lines. The outer conductors of the coaxial lines from the 17th layer to the 4th layer have slots on both sides with a slot length of λ / 4, forming a slotted coaxial balun to maintain the antenna feed balance.

[0014] Furthermore, the bottom port of the antenna unit is a coaxial line, which is directly connected to the coaxial line input port of the filter;

[0015] The filter is also a stacked structure, consisting of 13 layers of LTCC and a 14th layer of copper on the 13th layer of dielectric. The 14th layer of copper is the same layer as the 1st layer of copper of the antenna element above.

[0016] The filter's passband is consistent with the antenna bandwidth. After being input from the coaxial line, it is converted to a stripline filter and finally converted back to the coaxial line input to the BGA layer.

[0017] Furthermore, in the active network section, the upper layer is a low-noise amplifier circuit, which amplifies the signal input from the BGA and splits it into two paths, which are then input to the two 9-in-1 synthesized networks in the lower layer.

[0018] Furthermore, the 9-in-1 composite network consists of 13 layers of LTCC and a 14th layer of copper located on the 13th dielectric layer. Both 9-in-1 networks are located on the same layer, and their specific structure is as follows:

[0019] A 16-in-1 network is formed by four Wilkinson power dividers that split into two stages. On this basis, one branch of the second stage is connected to a 50-ohm matching resistor, and then one branch of each of the three fourth-stage power dividers is connected to a 50-ohm matching load, for a total of four matching loads. The remaining ports form the 9-in-1 combined network.

[0020] The first and second stages of the two synthetic networks are located on the fourth copper layer, and are connected by a coaxial line to the third and fourth stages located on the tenth copper layer.

[0021] Furthermore, the two-way 9-in-1 combined network finally outputs high-frequency signals through two connectors located at the bottom layer of the antenna array;

[0022] Some low-frequency signals are directly output from the low-noise amplifier circuit via a coaxial cable to the bottommost pad.

[0023] Furthermore, the antenna section adopts a dual-circular polarization array arrangement.

[0024] Compared with the prior art, the beneficial effects of this disclosure are: (1) By adopting the LTCC stacked design, the filter, signal processing system and other parts that originally occupied a large space are integrated into the stacked structure that occupies a small space, and are connected by the BGA structure, which effectively reduces the space occupied by the antenna array; (2) By introducing structures such as coaxial slotted balun and metal isolation frame, a wider working bandwidth and good scanning performance are achieved; (3) The dual circular polarization array arrangement further optimizes the axial ratio, and can achieve ±60° wide beam scanning in azimuth and elevation dimensions; (4) It can well meet the requirements of mobile communication systems for the next generation of phased array antennas. Attached Figure Description

[0025] The above and other objects, features and advantages of this disclosure will become more apparent from the more detailed description of exemplary embodiments of this disclosure taken in conjunction with the accompanying drawings, in which the same reference numerals generally represent the same components.

[0026] Figure 1 This is a schematic diagram of an exemplary highly integrated LTCC broadband circularly polarized antenna array antenna element structure according to this disclosure;

[0027] Figure 2 This is a schematic diagram of the overall disassembly structure for an exemplary embodiment;

[0028] Figure 3 This is a schematic diagram of the filter structure in an exemplary embodiment;

[0029] Figure 4 This is a schematic diagram of the power distribution network structure in an exemplary embodiment. Detailed Implementation

[0030] Preferred embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0031] This disclosure provides a highly integrated LTCC broadband circularly polarized antenna array. In one exemplary embodiment, the complete antenna array structure diagram is shown below. Figure 2 As shown, it mainly includes: antenna elements, filters, BGA connection structure, active network, synthesis network, output connector, etc.

[0032] The overall system is divided into two parts: the upper part is the antenna section, and the lower part is the active network section. Both parts are LTCC stacked structures, connected and transitioned by BGA; among them:

[0033] The antenna section includes: several arrayed antenna elements and a filter corresponding to each antenna element; the active network section includes: an active network that serves as a low-noise amplifier and a synthesis network.

[0034] Each antenna element and its filter share a single LTCC laminate; the active network and the synthesized network share a single laminate.

[0035] The spacing between antenna elements is constant, and the parts between elements other than the medium are filled with metal.

[0036] (1) Antenna section

[0037] Array structure: First, a 2*2 subarray is obtained by rotating a single array element around a height. Then, the 2*2 subarrays are combined to form a complete 3*3 array. Overall, it is a 6*6 array.

[0038] like Figure 1 As shown, the array antenna element consists of 16 layers of LTCC (each LTCC layer includes a 0.008mm thick copper plate and a 0.088mm thick LTCC dielectric layer on top of it) and a 17th copper layer located on the 16th dielectric layer. The 17th copper layer is the radiating patch of the dipole antenna. From the 16th layer to the 1st layer, all copper layers are coaxial feed lines. The outer conductors of the coaxial lines from the 17th layer to the 4th layer have slots on both sides, with a slot length of λ / 4, forming a slotted coaxial balun to maintain antenna feed balance.

[0039] The bottom port of the antenna element is a coaxial cable, which is directly connected to the coaxial cable input port of the filter. For example... Figure 3 As shown, this filter also has a stacked structure, consisting of 13 layers of LTCC and a 14th layer of copper on top of the 13th layer (the 14th layer of copper is the same layer as the 1st layer of copper in the antenna above, and is referred to as the 14th layer for convenience). The passband of this filter is consistent with the antenna bandwidth. After being input from the coaxial line, it is converted to stripline filtering and finally converted back to the coaxial line input to the BGA layer.

[0040] (2) Active network section

[0041] The upper layer of the active network section consists of a low-noise amplifier circuit. After amplifying the signal input from the BGA, it is divided into two paths and input to the two 9-in-1 synthesized networks in the lower layer.

[0042] like Figure 4 As shown, the 9-in-1 combined network part of the lower layer of the active network consists of a 13-layer LTCC and a 14-layer copper layer located on the 13th layer dielectric. Both 9-in-1 networks are located on the same layer. The specific structure uses a 4-stage Wilkinson power divider to form a 16-in-1 network. On this basis, one branch of the second stage is connected to a 50-ohm matching resistor, and then one branch of each of the three fourth-stage power dividers is connected to a 50-ohm matching resistor. Thus, from the perspective of the entire power divider network, there is a total of 4 matching loads: one branch of the second stage is connected to a 50-ohm matching load, and one branch of each of the three fourth-stage power dividers is connected to a 50-ohm matching load. The remaining ports constitute the 9-in-1 power divider network.

[0043] The first and second stages of the two power divider networks are located on the fourth copper layer and are connected by a coaxial line to the third and fourth stages located on the tenth copper layer.

[0044] The two-way 9-in-1 combined network finally outputs high-frequency signals through two connectors located at the bottom layer of the antenna array, while some low-frequency signals are directly connected from the low-noise amplifier circuit to the bottom layer pads via coaxial cable.

[0045] The antenna array described in this embodiment uses LTCC as the antenna medium, and the feed line and dipole antenna are configured with a slotted coaxial balun structure, which can meet the 18% relative bandwidth operating frequency band. The dual circular polarization array arrangement further optimizes the axial ratio and can achieve ±60° wide beam scanning in the azimuth and elevation dimensions.

[0046] The above technical solutions are merely exemplary embodiments of this utility model. For those skilled in the art, based on the application methods and principles disclosed in this utility model, it is easy to make various types of improvements or modifications, and not limited to the methods described in the specific embodiments of this utility model. Therefore, the methods described above are only preferred and not restrictive.

Claims

1. A highly integrated LTCC broadband circularly polarized antenna array, characterized in that, include: The system consists of two parts: the upper part is the antenna section, and the lower part is the active network section. Both parts are LTCC stacked structures, connected and transitioned by a BGA structure. The antenna section includes: several arrayed antenna elements, and a filter corresponding to each antenna element; The active network portion includes: an active network that functions as a low-noise amplifier, and a synthesis network; Each antenna element and its filter share a single LTCC laminate; the active network and the synthesized network share a single laminate. The spacing between antenna elements is constant, and the parts between elements other than the medium are filled with metal.

2. The antenna array according to claim 1, characterized in that, The antenna element consists of 16 layers of LTCC and a 17th layer of copper located on the 16th dielectric layer; The 17th layer of copper is the radiating patch of the dipole antenna. The copper layers from the 16th layer to the 1st layer are all coaxial feed lines. The outer conductors of the coaxial lines from the 17th layer to the 4th layer have slots on both sides with a slot length of λ / 4, forming a slotted coaxial balun to maintain the antenna feed balance.

3. The antenna array according to claim 2, characterized in that: The bottom port of the antenna unit is a coaxial line, which is directly connected to the coaxial line input port of the filter; The filter is also a stacked structure, consisting of 13 layers of LTCC and a 14th layer of copper on the 13th layer of dielectric. The 14th layer of copper is the same layer as the 1st layer of copper of the antenna element above. The filter's passband is consistent with the antenna bandwidth. After being input from the coaxial line, it is converted to a stripline filter and finally converted back to the coaxial line input to the BGA layer.

4. The antenna array according to claim 1, characterized in that: The active network section has a low-noise amplifier circuit at the upper layer. After amplifying the signal input from the BGA, it is divided into two paths and input to the two 9-in-1 synthesized networks at the lower layer.

5. The antenna array according to claim 4, characterized in that: The 9-in-1 composite network consists of 13 layers of LTCC and a 14th layer of copper located on the 13th dielectric layer. Both 9-in-1 networks are located on the same layer, and their specific structure is as follows: A 16-in-1 network is formed by four Wilkinson power dividers that split into two stages. On this basis, one branch of the second stage is connected to a 50-ohm matching resistor, and then one branch of each of the three fourth-stage power dividers is connected to a 50-ohm matching load, for a total of four matching loads. The remaining ports form the 9-in-1 combined network. The first and second stages of the two synthetic networks are located on the fourth copper layer, and are connected by a coaxial line to the third and fourth stages located on the tenth copper layer.

6. The antenna array according to claim 4, characterized in that: The two-way 9-in-1 combined network finally outputs high-frequency signals through two connectors located at the bottom layer of the antenna array; Some low-frequency signals are directly output from the low-noise amplifier circuit via a coaxial cable to the bottommost pad.

7. The antenna array according to any one of claims 1-6, characterized in that, The antenna section adopts a dual-circular polarization array arrangement.

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