Ultra-wideband (UWB) dual-band antenna with low cross-polarization suppression

Abstract

This invention provides an ultra-wideband UWB dual-band antenna with low cross-polarization suppression, comprising an LCP stacked layer and an antenna layer; the antenna layer is disposed above the LCP stacked layer; the antenna layer includes multiple antenna elements; the feed point position and transmission line length of each antenna element are consistent, so that the transmission line impedance of each antenna element is the same. The UWB antenna of this invention, based on LCP stacking technology and employing an equal-length transmission line design with identical excitation positions, can improve low cross-polarization suppression performance while meeting the high requirements of amplitude, phase, and radiation pattern for UWB positioning antennas. Simultaneously, it significantly improves antenna bandwidth to enhance signal transmission power and positioning accuracy; furthermore, it can be integrated into portable devices, increasing its application value.

Description

Technical Field

[0001] This invention relates to the field of antennas, and more specifically to an ultra-wideband UWB dual-band antenna with low cross-polarization suppression. Background Technology

[0002] With the development of smart wearable products, people have higher and higher requirements for indoor positioning. However, existing UWB antenna designs are difficult to meet the requirements of ultra-wideband and low cross-polarization suppression while satisfying dual-band requirements.

[0003] Most existing UWB antenna designs employ PCB onboard and LDS processes, connecting to devices via BTBs soldered onto transmission lines. These PCB-onboard and LDS-based UWB antennas require significant space; furthermore, as antennas used for positioning, they not only need traditional S-parameters and efficiency but also demand higher requirements for amplitude, phase, and radiation patterns. However, the high thickness of existing antenna processes and the suppression of antenna bandwidth performance by transmission line impedance matching designs not only fail to meet the low cross-polarization performance requirements but also necessitate larger antenna spaces, making them unsuitable for conformal design with wearable products.

[0004] Therefore, there is an urgent need for an ultra-wideband UWB dual-band antenna with low cross-polarization suppression to meet the requirements of technological development. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an ultra-wideband UWB dual-band antenna with low cross-polarization suppression, which has optimized low cross-polarization suppression, ultra-wideband performance, dual-band compatibility and integrability, and can significantly improve signal transmission efficiency and positioning accuracy.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A low cross-polarization suppression ultra-wideband UWB dual-band antenna includes an LCP stack layer and an antenna layer; the antenna layer is disposed above the LCP stack layer; the antenna layer includes multiple antenna elements; the feed point position and transmission line length of each antenna element are consistent, so that the transmission line impedance of each antenna element is the same.

[0008] In some embodiments, the transmission line includes a feed line and a trace; the feed line corresponds to the transmission line from the feed point to the edge of the antenna element; the trace corresponds to the transmission line from the edge of the antenna element to the BTB connector.

[0009] On a horizontal plane, if the feed line and trace of an antenna element have a bend of 90 degrees or more at the edge of the antenna element, then the line width of the feed line of the antenna element is greater than the width of the feed lines of other antenna elements.

[0010] In some implementations, the feed line width of the antenna unit is 0.2mm-0.28mm.

[0011] In some implementations, the feed point is located at the upper left, upper right, lower left, or lower right corner of the antenna element.

[0012] In some embodiments, an RF line layer is provided in the LCP stack layer; the feed line is located in the antenna layer, the trace is located in the RF line layer, and the feed line and the trace are connected via vias.

[0013] In some embodiments, metal vias are provided on the outer edge of the radio frequency line layer corresponding to each antenna element and / or the trace.

[0014] In some embodiments, the distance between the metal via and the edge of the antenna element is determined based on the bandgap width BW.

[0015] In some embodiments, the metal vias are arranged at equal intervals along the outer edge of the antenna element.

[0016] In some embodiments, the metal vias are arranged at equal intervals along the outer edge of the antenna element and / or the trace.

[0017] In some embodiments, the diameter of the metal via is 0.1-0.2 mm.

[0018] In some embodiments, the antenna layer includes a first antenna element, a second antenna element, and a third antenna element; the first antenna element is located at the upper left corner of the antenna layer; the second antenna element is located at the lower left corner of the antenna layer; and the third antenna element is located at the upper right corner of the antenna layer.

[0019] The feed points of the first antenna unit, the second antenna unit, and the third antenna unit are all located at their upper right corners; the feed line width of the first antenna unit is 0.2 mm; and the feed line width of the second antenna is 0.28 mm.

[0020] The beneficial effects of this invention are as follows: The UWB antenna of this invention is designed based on LCP stacking technology, with consistent feed point positions and transmission line lengths for each antenna element, ensuring that the impedance equivalent matching circuit between each antenna and its respective transmission line is identical. This results in low cross-polarization suppression performance for the UWB antenna at 6.5G and 8G dual resonances, while significantly improving the main lobe level compared to existing designs, thereby significantly improving antenna bandwidth, signal transmission power, and positioning accuracy. Furthermore, the design based on LCP stacking technology allows for a more compact overall structure, smaller footprint, and lower losses, enabling integration into portable devices and enhancing application value. Attached Figure Description

[0021] Figure 1 This is a front perspective view illustrating a specific embodiment of an ultra-wideband UWB dual-band antenna with low cross-polarization suppression;

[0022] Figure 2 This is a schematic diagram illustrating the stacking hierarchy of an ultra-wideband UWB dual-band antenna with low cross-polarization suppression according to a specific embodiment;

[0023] Figure 3 This is an equivalent circuit diagram showing the antenna and transmission line in a specific embodiment;

[0024] Figure 4 This is an equivalent circuit diagram showing the antenna, metal via plate, and transmission line in a specific embodiment.

[0025] Figure 5 This is a perspective view illustrating a specific example of an ultra-wideband UWB dual-band antenna with low cross-polarization suppression;

[0026] Figure 6 This shows the S-parameters of the first antenna element before optimization;

[0027] Figure 7 This shows the S-parameters of the second antenna element before optimization;

[0028] Figure 8 This shows the S-parameters of the third antenna element before optimization;

[0029] Figure 9 This shows the S-parameters of the first antenna element after optimization of the transmission line impedance and metal via design according to the present invention.

[0030] Figure 10 This shows the S-parameters of the second antenna element after optimization of the transmission line impedance and metal via design according to the present invention;

[0031] Figure 11 This shows the S-parameters of the third antenna element after optimization of the transmission line impedance and metal via design according to the present invention.

[0032] Figure 12 This is a graph showing the efficiency of the antenna system after optimization of the transmission line impedance and metal via design according to the present invention;

[0033] Figure 13 This illustrates the inter-antenna isolation after optimizing the transmission line impedance and metal via design described in this invention.

[0034] Figure 14 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the first antenna element at 6.5 GHz before optimization;

[0035] Figure 15 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the second antenna unit at a frequency of 6.5 GHz before optimization;

[0036] Figure 16 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the third antenna element at 6.5 GHz before optimization;

[0037] Figure 17 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the first antenna element after optimization at a frequency of 6.5 GHz;

[0038] Figure 18 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the second antenna unit after optimization at a frequency of 6.5 GHz;

[0039] Figure 19 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the third antenna element after optimization at a frequency of 6.5 GHz;

[0040] Figure 20 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the first antenna element at 8G frequency before optimization;

[0041] Figure 21 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the second antenna unit at 8 GHz before optimization;

[0042] Figure 22 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the third antenna element at 8G frequency before optimization;

[0043] Figure 23 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the first antenna element at 8G frequency after optimization;

[0044] Figure 24 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the second antenna unit at 8 GHz after optimization;

[0045] Figure 25 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the third antenna element after optimization at 8 GHz.

[0046] Label Explanation:

[0047] 1. Dielectric substrate; 2. Ground layer 2; 3. First LCP layer; 4. Copper layer;

[0048] 5. RF line layer; 6. Second LCP layer; 7. Adhesive layer; 8. Third LCP layer;

[0049] 9. Antenna layer; 10. Coverlay layer; 11. Antenna element; 12. Feed point location;

[0050] 13. Transmission line; 13-1. Feeder line; 13-2. Trace; 14. Metal via; 15. Spacing. Detailed Implementation

[0051] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0052] The most crucial concept of this invention lies in designing each antenna element with the same feed point location and transmission line length based on LCP stacking technology, so that the impedance equivalent matching circuit between each antenna and its respective transmission line is the same, while having the advantages of optimized low cross-polarization suppression, increased bandwidth, and integrability.

[0053] Please refer to Figure 1 as well as Figure 2 This invention provides an ultra-wideband UWB dual-band antenna with low cross-polarization suppression, comprising an LCP stack layer and an antenna layer; the antenna layer is disposed above the LCP stack layer; the antenna layer comprises a plurality of antenna elements; the feed point position and transmission line length of each antenna element are consistent, so that the transmission line impedance of each antenna element is the same.

[0054] As can be seen from the above description, the beneficial effects of the present invention are as follows: The UWB antenna of the present invention is designed based on LCP stacking technology, and the feed point position and transmission line length of each antenna element are consistent, so that the impedance equivalent matching circuit between each antenna and its respective transmission line is the same; thereby forming a low cross-polarization suppression performance of 6.5G and 8G dual resonance for the UWB antenna, while the main lobe level will be significantly improved compared with the existing design, thereby significantly improving the antenna bandwidth, signal transmission power and positioning accuracy; furthermore, the design based on LCP stacking technology makes the overall structure more compact, with less space and less loss, and can be integrated into portable devices, thus improving the application value.

[0055] Furthermore, the transmission line includes a feed line and a trace; the feed line corresponds to the transmission line from the feed point to the edge of the antenna element; the trace corresponds to the transmission line from the edge of the antenna element to the BTB connector;

[0056] On a horizontal plane, if the feed line and trace of an antenna element have a bend of 90 degrees or more at the edge of the antenna element, then the line width of the feed line of the antenna element is greater than the width of the feed lines of other antenna elements.

[0057] As can be seen from the above description, under the constraint that the transmission line length must be equal, for transmission lines that must be bent horizontally at the edge of the antenna element due to wiring requirements, the transmission impedance bandwidth reduction caused by the bend can be compensated by increasing the line width of the feed line, thereby ensuring that the transmission line impedance of each antenna element is equivalent.

[0058] Furthermore, the wire width of the feeder wire of the antenna unit is 0.2mm-0.28mm.

[0059] As described above, compared to the maximum line width of 0.09mm for conventional feeder lines, increasing the line width of feeder lines to 0.2mm-0.28mm for transmission lines that require horizontal bending can ensure equivalent transmission line impedance for each antenna element by improving feed performance.

[0060] Furthermore, the feed point is located at the upper left, upper right, lower left, or lower right corner of the antenna element.

[0061] As can be seen from the above description, there are multiple options for the feed point location of the antenna element, and by providing diverse feed designs, we can better meet the different needs of users.

[0062] Furthermore, an RF line layer is provided in the LCP stack layer; the feed line is located in the antenna layer, the trace is located in the RF line layer, and the feed line and the trace are connected via vias.

[0063] As can be seen from the above description, placing the portion of the transmission line routing to the BTB layer separately on the RF line layer makes routing design more convenient.

[0064] Furthermore, metal vias are provided on the outer edge of each antenna element and / or the trace on the radio frequency line layer.

[0065] As described above, the design of metal vias can disrupt the distribution of the TM02 mode without changing the antenna form, and thus further reduce the antenna cross-polarization based on the coupling effect.

[0066] Furthermore, the distance between the metal via and the edge of the antenna element is determined based on the bandgap width BW.

[0067] Furthermore, the metal vias are arranged at equal intervals along the outer edge of the antenna element.

[0068] Furthermore, the metal vias are arranged at equal intervals along the outer edge of the antenna element and / or the trace;

[0069] Furthermore, the diameter of the metal via is 0.1-0.2 mm.

[0070] As described above, multiple optional metal via designs are provided, allowing users to flexibly configure them according to their actual usage scenarios and maximize the reduction of cross-polarization.

[0071] Furthermore, the antenna layer includes a first antenna unit, a second antenna unit, and a third antenna unit; the first antenna unit is located at the upper left corner of the antenna layer; the second antenna unit is located at the lower left corner of the antenna layer; and the third antenna unit is located at the upper right corner of the antenna layer.

[0072] The feed points of the first antenna unit, the second antenna unit, and the third antenna unit are all located at their upper right corners; the feed line width of the first antenna unit is 0.2 mm; and the feed line width of the second antenna is 0.28 mm.

[0073] As can be seen from the above description, an optimal antenna element arrangement is provided to obtain the best antenna performance.

[0074] Example 1

[0075] Please see Figures 1 to 3 , Figure 1 This is a front perspective view illustrating a specific embodiment of an ultra-wideband UWB dual-band antenna with low cross-polarization suppression; Figure 2 This is a schematic diagram illustrating the stacking hierarchy of an ultra-wideband UWB dual-band antenna with low cross-polarization suppression according to a specific embodiment. Figure 3 This is an equivalent transmission line impedance diagram illustrating a specific embodiment of an ultra-wideband UWB dual-band antenna with low cross-polarization suppression.

[0076] This embodiment provides an ultra-wideband UWB dual-band antenna with low cross-polarization suppression, including an LCP stack layer and an antenna layer; the antenna layer is disposed above the LCP stack layer;

[0077] In some specific implementations, such as Figure 2 As shown, the LCP stack layer includes, in sequence, a dielectric substrate 1, a ground layer 2, a first LCP layer 3, an RF line layer 5, a second LCP layer 6, a copper layer 4, an adhesive layer 7, and a third LCP layer 8. The antenna layer 9 is stacked on the topmost layer of the LCP stack layer (the third LCP layer 8); then, a Coverlay layer 10 (copper-clad film layer) is superimposed on top of the antenna layer 9, thereby forming a complete UWB dual-band antenna structure.

[0078] Please see Figure 1In this embodiment, the antenna layer 9 includes two or more antenna elements 11; the feed point position 12 and the transmission line 13 length of each antenna element 11 are the same, so that the transmission line impedance of each antenna element 11 is the same. The equivalent circuit of the transmission line impedance of each antenna element 11 is as follows. Figure 3 As shown.

[0079] The transmission line 13 includes two parts: a feed line 13-1 and a trace 13-2; wherein, the feed line 13-1 is from the feed point to the edge of the antenna element; and the trace 13-2 is from the edge of the antenna element to the BTB connector.

[0080] In some specific embodiments, the feed line 13-1 is located on the antenna layer 9, the trace 13-2 is located on the radio frequency line layer (i.e., RF line layer 5), and the feed line 13-1 and the trace 13-2 are connected via vias.

[0081] In some specific implementations, assuming that the feed points of all antenna elements are at the same location and the transmission lines are of equal length, in order to ensure that the transmission line impedances of all antenna elements are the same, the feed lines and traces of some antenna elements may need to be bent at an angle of 90 degrees or greater at the edge of the antenna element when viewed from the horizontal plane during actual transmission line routing. For ease of description, these antenna elements will be referred to as bent antenna elements below. For further understanding, please refer to [reference needed]. Figure 1 The two antenna elements on the left are the bent antenna elements. It can be understood that if the feed line 13-1 and trace 13-2 need to be bent at an angle of 90 degrees or more at the edge of antenna element 11, the feed performance will decrease (i.e., transmission performance will decrease), which will correspondingly lead to a decrease in the transmission line impedance of the antenna element. Therefore, to ensure that the transmission line impedance of each antenna element is the same, the linewidth of the corresponding feed line can be increased; that is, the linewidth of the feed line corresponding to the bent antenna element is set to be greater than the linewidth of the feed lines corresponding to other antenna elements. This improves the transmission performance of the bent antenna element, obtains the required transmission impedance, and thus ensures that the ideal bandwidth gain and low cross-polarization suppression effect are achieved.

[0082] Preferably, the feed line width of the bent antenna element is 0.2mm-0.28mm.

[0083] The specific line width value of the feeder varies depending on the different feeder line routes.

[0084] As a specific example, if the feed line in the bent antenna element is straight, its line width is preferably 0.2 mm.

[0085] As another specific example, if the feed line in the bent antenna element is a zigzag shape, its line width is preferably 0.28 mm.

[0086] As can be seen, the varying degrees of impedance reduction caused by different feed line routes result in different degrees of linewidth expansion, thus ensuring that the transmission line impedances of each antenna element are matched to obtain ideal bandwidth gain and low cross-polarization suppression.

[0087] In some specific implementations, the feed position of each antenna element can be uniformly located at the upper left, upper right, lower left, or lower right corner of the corresponding antenna element. This can be flexibly configured according to different needs or application scenarios.

[0088] It should be noted that most existing antenna optimization schemes for low cross-polarization are achieved by changing the feed point location, i.e., changing the radiation pattern. However, for UWB positioning antennas, there are strict requirements for the antenna radiation pattern, amplitude, and phase. Therefore, existing optimization schemes for low cross-polarization are not very suitable for UWB positioning antennas.

[0089] The UWB antenna provided in this embodiment is based on LCP stacking technology. By using the same feed position, it achieves high requirements for radiation pattern, amplitude, and phase. At the same time, the equivalent impedance circuits of each antenna are designed to be the same, which can not only effectively suppress low cross-polarization suppression performance, but also significantly improve antenna bandwidth. Thus, while meeting the ultra-wideband performance of UWB antennas, it can improve signal transmission power and positioning accuracy. In addition, based on LCP stacking technology, it can also achieve smaller space and lower loss, and can be integrated into portable devices, thereby improving application value.

[0090] Example 2

[0091] Please see Figure 1 This embodiment, based on Embodiment 1, can further reduce cross-polarization without changing the antenna configuration.

[0092] Specifically, in this embodiment of the UWB dual-band antenna structure, metal vias 14 are respectively provided on the outer edge of each antenna element 11 on the radio frequency line layer. The metal vias 14 are perpendicular to the antenna layer, that is, perpendicular to the UWB antenna plane and the reference ground plane. Preferably, this is achieved by providing a metal via plate on the radio frequency line layer, that is, metal vias are provided on the outer edge of each antenna element on the metal via plate.

[0093] The design of metal vias can reduce cross-polarization based on coupling effects. This achieves the effect of reducing cross-polarization by disrupting the distribution of the TM02 mode through the equivalent coupling of the metal via design without changing the antenna form.

[0094] In some specific embodiments, the spacing 15 between the metal via 14 and the edge position of the antenna element 11 is determined according to the bandgap width BW.

[0095] Specifically, please refer to Figure 4 , Figure 4 This is an equivalent circuit diagram showing the antenna, metal via plate, and transmission line in a specific embodiment. Based on Figure 4 The equivalent circuit expression is as follows:

[0096] (1)

[0097] (2)

[0098] (3)

[0099] (4)

[0100] (5)

[0101] in, The operating center frequency of the LC circuit. The resonant angular frequency, Let j be the relative permittivity of the substrate. , These represent the imaginary part, the permittivity in vacuum, the permeability, and the wave impedance, respectively.

[0102] In this context, expressions (1) and (2) represent the resonant frequency and surface impedance of the LC resonant circuit, respectively. Expressions (1) and (2) can be transformed using conformal geometry to obtain the capacitance and inductance in the equivalent circuit, i.e., expressions (3) and (4) above, and thus the bandgap width BW of the in-phase reflection can be obtained (5). The conformal geometry transformation formula represents the mathematical reasoning process used in calculating capacitance and inductance. Therefore, the bandgap width BW, i.e., the distance between the metal via and the edge of the antenna element, can be calculated.

[0103] In some specific implementations, such as Figure 1 As shown, multiple metal vias 14 are arranged at equal intervals along the outer edge of each antenna element 11.

[0104] In other specific implementations, such as Figure 1 As shown, metal vias 14 are also arranged at equal intervals on the outer edge of the RF line layer corresponding to the trace 13-2. That is, metal vias 14 are arranged at equal intervals on both sides of the trace 13-2. This achieves the reduction of cross polarization of the transmission line on the trace based on coupling effect.

[0105] As a preferred example, the diameter of the metal via 14 on the RF line layer is between 0.1 and 0.2 mm, preferably 0.15 mm. This achieves the best effect in reducing cross-polarization.

[0106] Example 3

[0107] This embodiment is based on the above embodiment two and provides an example of an ultra-wideband UWB dual-band antenna with low cross-polarization suppression.

[0108] Please see Figure 5 , Figure 5 This is a front view illustrating a specific example of an ultra-wideband UWB dual-band antenna with low cross-polarization suppression. (See image.) Figure 5 As shown, the preferred dimensions of the low cross-polarization suppression ultra-wideband UWB dual-band antenna are 31mm*32.58*0.403mm, with a thickness of 0.403mm. It employs a conventional patch antenna design, with the antenna layer comprising a first antenna element, a second antenna element, and a third antenna element. The first antenna element is located at the upper left corner of the antenna layer; the second antenna element is located at the lower left corner; and the third antenna element is located at the upper right corner. Preferably, the first, second, and third antenna elements are all positioned close to the corners of the antenna layer. Preferably, the dimensions of the first, second, and third antenna elements are all 13.4mm*10.59mm*0.03mm. The feed points of the first, second, and third antenna elements are all located at the upper right corner of their respective antenna elements. A BTB connector is provided at the lower right corner of the RF layer corresponding to the antenna layer; the metal via plate on the RF layer has metal holes at equal intervals along the outer edges of the first antenna unit, the second antenna unit, and the third antenna unit, while maintaining a horizontal distance of BW from the edges of the first antenna unit, the second antenna unit, and the third antenna unit. Preferably, the diameter of the metal holes is 0.15mm.

[0109] Based on the aforementioned antenna element layout and the constraints of identical transmission line length and feed point location, the transmission line routing of the first, second, and third antenna elements is as follows: Figure 1 and Figure 5 As shown, the transmission lines of the first and second antenna elements (excluding the third antenna element) require significant bends at the edges of the antenna elements during wiring. The unavoidable reduction in transmission performance due to these bends can be mitigated by widening the bend's feed line, thus ensuring equivalent impedance across the three antenna elements. For more details, please refer to... Figure 1 Its corresponding Figure 5 The antenna structure also shows a schematic diagram of the internal transmission flow of the antenna element. For example... Figure 1The bending angle of the feed line and trace of the third antenna element in the horizontal plane is not greater than or equal to 90°, therefore its feed line can use a linewidth of 0.09mm, which is the minimum linewidth. However, the bending angles of the feed lines and traces of the first and second antenna elements in the horizontal plane are both greater than or equal to 90°, and the feed line of the second antenna element itself is also bent. Therefore, the feed line of the second antenna element will have a greater impact on transmission performance than the feed line of the first antenna element; thus, the linewidth of the feed line of the second antenna element needs to be larger than that of the first antenna element. Based on the equivalent transmission line impedance of the three antenna elements, the feed linewidth of the first antenna element is preferably the minimum value in the range, i.e., 0.2mm; while the feed linewidth of the second antenna element is preferably the maximum value in the range, i.e., 0.28mm.

[0110] Please see Figures 6-8 .in, Figure 6 This shows the S-parameters of the first antenna element before optimization; Figure 7 This shows the S-parameters of the second antenna element before optimization; Figure 8 This shows the S-parameters of the third antenna element before optimization. It can be seen that at the 8GHz resonant frequency and a reference level of -7dB, the signal bandwidth is less than 200MHz.

[0111] Please see Figures 9 to 11 , Figure 9 This shows the S-parameters of the first antenna element after optimization of the transmission line impedance and metal via design according to the present invention. Figure 10 This shows the S-parameters of the second antenna element after optimization of the transmission line impedance and metal via design according to the present invention; Figure 11 This shows the S-parameters of the third antenna element after optimization of the transmission line impedance and metal via design as described in this invention. It can be seen that, at a reference level of -7dB, after optimization, the impedance bandwidth of the 6.5G resonator can reach over 100MHz; the impedance bandwidth of the 8G resonator increases by 20MHz to 80MHz; and the bandwidth can reach over 200MHz.

[0112] Please see Figure 12 , Figure 12 This is a graph showing the efficiency of the antenna system after optimization of the transmission line impedance and metal via design as described in this invention. It can be seen that the antenna efficiency is -4.16dB to -2.32dB in the CH-5 frequency band (6250MHz~6750MHz); and -2.62dB to -2.32dB in the CH-9 frequency band (7750MHz~82050MHz).

[0113] Please see Figure 13 , Figure 13This illustrates the antenna isolation after optimization of the transmission line impedance and metal via design described in this invention. It can be seen that the isolation between the three antenna elements reaches below -20 dB.

[0114] Please see Figures 14 to 19 , Figure 14 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the first antenna element at 6.5 GHz before optimization; Figure 15 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the second antenna unit at a frequency of 6.5 GHz before optimization; Figure 16 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the third antenna element at 6.5 GHz before optimization; Figure 17 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the first antenna element after optimization at a frequency of 6.5 GHz; Figure 18 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the second antenna unit after optimization at a frequency of 6.5 GHz; Figure 19 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the third antenna element after optimization at a frequency of 6.5 GHz;

[0115] Please see Figures 20 to 25 , Figure 20 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the first antenna element at 8G frequency before optimization; Figure 21 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the second antenna unit at 8 GHz before optimization; Figure 22 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the third antenna element at 8G frequency before optimization; Figure 23 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the first antenna element at 8G frequency after optimization; Figure 24 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the second antenna unit at 8 GHz after optimization; Figure 25 This is a schematic diagram showing the cross-polarization suppression and main lobe mode level of the third antenna element after optimization at 8 GHz.

[0116] As can be seen, the main lobe level of the optimized antenna increases significantly, especially at some angles where it can reach 40dB, representing an increase of 5.1~13.4dB.

[0117] In summary, the ultra-wideband UWB dual-band antenna with low cross-polarization suppression provided by this invention has at least the following advantages:

[0118] 1. No additional matching devices are required to improve bandwidth;

[0119] 2. The high-frequency bandwidth can fully cover 200MHz;

[0120] 3. Low cross-polarization suppression makes localization more accurate;

[0121] 4. The generation of dual resonances is relatively easy to tune and optimize;

[0122] 5. Applicable to the design of various UWB antennas;

[0123] 6. Suitable for smaller spaces.

[0124] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A low-cross-polarization suppression ultra-wideband UWB dual-band antenna, characterized in that, It includes an LCP stack layer and an antenna layer; the antenna layer is disposed above the LCP stack layer; the antenna layer includes multiple antenna elements; the feed point position and transmission line length of each antenna element are consistent, so that the transmission line impedance of each antenna element is the same; The transmission line includes a feed line and a trace; the feed line corresponds to the transmission line from the feed point to the edge of the antenna element; the trace corresponds to the transmission line from the edge of the antenna element to the BTB connector. On a horizontal plane, if the feed line and trace of an antenna element have a bend of 90 degrees or more at the edge of the antenna element, then the line width of the feed line of the antenna element is greater than the width of the feed lines of other antenna elements.

2. The ultra-wideband UWB dual-band antenna with low cross-polarization suppression as described in claim 1, characterized in that, The feeder wire width of the antenna unit is 0.2mm-0.28mm.

3. The ultra-wideband UWB dual-band antenna with low cross-polarization suppression as described in claim 1, characterized in that, The feed point is located at the upper left, upper right, lower left, or lower right corner of the antenna element.

4. The ultra-wideband UWB dual-band antenna with low cross-polarization suppression as described in claim 1, characterized in that, An RF line layer is provided in the LCP stack layer; the feed line is located in the antenna layer, the trace is located in the RF layer, and the feed line and the trace are connected via vias.

5. The ultra-wideband UWB dual-band antenna with low cross-polarization suppression as described in claim 4, characterized in that, Metal vias are provided on the outer edge of each antenna element and / or the trace on the radio frequency line layer.

6. The ultra-wideband UWB dual-band antenna with low cross-polarization suppression as described in claim 5, characterized in that, The spacing between the metal via and the edge of the antenna element is determined based on the bandgap width BW.

7. The ultra-wideband UWB dual-band antenna with low cross-polarization suppression as described in claim 5, characterized in that, The metal vias are arranged at equal intervals along the outer edge of the antenna element and / or the trace.

8. The ultra-wideband UWB dual-band antenna with low cross-polarization suppression as described in claim 5, characterized in that, The diameter of the metal via is 0.1-0.2 mm.

9. A low cross-polarization suppression ultra-wideband UWB dual-band antenna as described in any one of claims 1-8, characterized in that, The antenna layer includes a first antenna unit, a second antenna unit, and a third antenna unit; the first antenna unit is located at the upper left corner of the antenna layer; the second antenna unit is located at the lower left corner of the antenna layer; and the third antenna unit is located at the upper right corner of the antenna layer. The feed points of the first antenna unit, the second antenna unit, and the third antenna unit are all located at their upper right corners; the feed line width of the first antenna unit is 0.2 mm; and the feed line width of the second antenna is 0.28 mm.

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