A dual-resonant ultra-wideband antenna

Abstract

The application provides a double-resonance ultra-wideband antenna, in which an isolation sheet is added in a transmission link between an antenna unit and a coplanar waveguide transmission line, and a metal ground layer and the isolation sheet are not connected with each other. Compared with the prior art in which a center conductor of the coplanar waveguide transmission line and a conductor plane are connected with the metal ground layer, the center conductor of the coplanar waveguide transmission line and the conductor plane are connected with the isolation sheet and the metal ground layer respectively in the application, and the ground layers of the two are completely isolated, so that the isolation sheet, the conductor plane of the coplanar waveguide transmission line and the metal ground layer are coupled to form a capacitance effect, the capacitance effect and an inductance effect generated when the center conductor is connected with the isolation sheet form an impedance matching effect, thereby improving the output power of the antenna and improving the bandwidth when the antenna resonates.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a dual-resonant ultra-wideband antenna. Background Technology

[0002] With the application and development of UWB (Ultra-Wideband) antennas in mobile electronic devices, UWB antenna technology has received increasing attention, and the performance requirements for UWB antennas are also rising. However, the 500MHz bandwidth required by the current UWB protocol is difficult to meet with existing antenna designs. This is because existing UWB antenna designs use multi-layered LCP / MPI (Liquid Crystal Polymer / Modified PI) materials stacked together, and then connected to the corresponding BTB (Board to Board) connector on the motherboard via LCP transmission lines. The thickness of the LCP / MPI stack determines the height of the UWB antenna, affecting antenna efficiency and resulting in a narrow bandwidth. Although UWB antennas use pulse excitation, such antennas have a large radiation dead zone during user experience. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a dual-resonant ultra-wideband antenna that achieves dual-resonant performance and meets the 500MHz bandwidth requirement of UWB antennas.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A dual-resonant ultrawideband antenna includes a dielectric motherboard and an antenna module;

[0006] The antenna module includes an antenna element and a coplanar waveguide transmission line;

[0007] The coplanar waveguide transmission line is disposed on one side of the dielectric motherboard, and a metal ground layer and an isolation sheet are disposed on the other side of the dielectric motherboard; the metal ground layer and the isolation sheet are not connected to each other;

[0008] The antenna unit connects the center conductor of the coplanar waveguide transmission line and the isolating plate, and the conductor plane of the coplanar waveguide transmission line is connected to the metal ground layer.

[0009] The beneficial effects of this invention are as follows: An isolator is added to the transmission link between the antenna element and the coplanar waveguide transmission line, and the metal ground layer and the isolator are not connected to each other. Compared to the prior art, where the center conductor and conductor plane of the coplanar waveguide transmission line are both connected to the metal ground layer, in this invention, the center conductor and conductor plane of the coplanar waveguide transmission line are respectively connected to the isolator and the metal ground layer, completely isolating their ground layers. This creates a capacitive effect through vertical coupling between the isolator, the conductor plane of the coplanar waveguide transmission line, and the metal ground layer. This capacitive effect, combined with the inductive effect generated when the center conductor is connected to the isolator, creates an impedance matching effect, thereby increasing the antenna's output power and improving the bandwidth during antenna resonance. Attached Figure Description

[0010] Figure 1 A front view of a dual-resonant ultra-wideband antenna provided in an embodiment of the present invention;

[0011] Figure 2 A rear view of a dual-resonant ultra-wideband antenna provided in an embodiment of the present invention;

[0012] Figure 3 This is a schematic diagram of the antenna support structure provided in an embodiment of the present invention;

[0013] Figure 4 This is a schematic diagram of the structure of the media motherboard provided in an embodiment of the present invention;

[0014] Figure 5 for Figure 4 Detail A structural diagram;

[0015] Figure 6 for Figure 4 Detailed structural diagram of section B;

[0016] Figure 7 for Figure 4 Detailed C-structure diagram;

[0017] Figure 8 This is a return loss curve diagram in the existing technology;

[0018] Figure 9 A return loss curve of a dual-resonant ultra-wideband antenna provided for an embodiment of the present invention;

[0019] Figure 10 An efficiency curve of a dual-resonant ultra-wideband antenna provided for an embodiment of the present invention;

[0020] Label Explanation:

[0021] 1. Dielectric motherboard; 2. Antenna module; 3. Antenna bracket; 11. Metal ground layer; 12. Isolator; 21. Antenna element; 22. Coplanar waveguide transmission line; 23. Probe structure; 31. First through-hole; 32. Fixing structure; 101. Second through-hole; 102. Third through-hole; 210. Feed point; 221. Center conductor of coplanar waveguide transmission line; 222. Conductor plane of coplanar waveguide transmission line. Detailed Implementation

[0022] 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.

[0023] Please refer to Figure 1 The present invention provides a dual-resonant ultra-wideband antenna, comprising a dielectric motherboard and an antenna module;

[0024] The antenna module includes an antenna element and a coplanar waveguide transmission line;

[0025] The coplanar waveguide transmission line is disposed on one side of the dielectric motherboard, and a metal ground layer and an isolation sheet are disposed on the other side of the dielectric motherboard; the metal ground layer and the isolation sheet are not connected to each other;

[0026] The antenna unit connects the center conductor of the coplanar waveguide transmission line and the isolating plate, and the conductor plane of the coplanar waveguide transmission line is connected to the metal ground layer.

[0027] As described above, the beneficial effects of this invention are as follows: An isolator is added to the transmission link between the antenna element and the coplanar waveguide transmission line, and the metal ground layer and the isolator are not connected to each other. Compared to the prior art, where the center conductor and conductor plane of the coplanar waveguide transmission line are both connected to the metal ground layer, in this invention, the center conductor and conductor plane of the coplanar waveguide transmission line are respectively connected to the isolator and the metal ground layer, completely isolating their ground layers. This creates a capacitive effect through vertical coupling between the isolator, the conductor plane of the coplanar waveguide transmission line, and the metal ground layer. This capacitive effect, combined with the inductive effect generated when the center conductor is connected to the isolator, forms an impedance matching effect, thereby increasing the antenna's output power and improving the bandwidth during antenna resonance.

[0028] Furthermore, it also includes antenna supports;

[0029] The antenna support is disposed on the side of the dielectric motherboard on which the coplanar waveguide transmission line is provided;

[0030] The antenna unit is disposed on the side of the antenna bracket away from the dielectric motherboard;

[0031] The antenna support is provided with a first through hole;

[0032] The first through-hole connects the antenna element and the center conductor of the coplanar waveguide transmission line.

[0033] As described above, the antenna unit is fed through the first through-hole to the coplanar waveguide transmission line disposed on the dielectric motherboard, and the antenna bracket fixes the antenna module to facilitate the connection between the transmission line and the antenna unit.

[0034] Furthermore, the number of antenna elements includes three, and the three antenna elements are arranged in an L-shape.

[0035] As described above, the three antenna elements are arranged in an L-shape, which can form a simple positioning system with the fewest number of antenna elements, achieving target detection and positioning while improving the miniaturization of the antenna module.

[0036] Furthermore, the antenna module also includes a probe structure, which is disposed on the side of the dielectric motherboard where the coplanar waveguide transmission line is disposed;

[0037] The antenna unit is connected to one end of the probe structure, and the other end of the probe structure is connected to the center conductor of the coplanar waveguide transmission line and the isolating plate, respectively.

[0038] As described above, the antenna module is connected to the coplanar waveguide transmission line through a probe structure to achieve a precise connection between the two. The structure is simple, and the input impedance can be controlled by changing the feed position, making it easy to match.

[0039] Furthermore, the dielectric main board is provided with at least one second through hole and a third through hole; conductive material is disposed in both the second through hole and the third through hole;

[0040] The other end of the probe structure is connected to the center conductor of the coplanar waveguide transmission line and one end of the conductive material in the second through hole; the other end of the conductive material in the second through hole is connected to the insulating sheet.

[0041] The conductor plane of the coplanar waveguide transmission line is connected to one end of the conductor material in the third through hole, and the other end of the conductor material in the third through hole is connected to the metal ground layer.

[0042] As described above, a coplanar waveguide transmission line and a ground layer are respectively arranged on both sides of the dielectric motherboard. Different layers of the dielectric motherboard are fed or grounded through a second and a third via. The conductive material inside the second via, connected to the isolator, acts as the parasitic inductance of the antenna. Simultaneously, the conductor plane of the coplanar waveguide transmission line and the isolator are on different layers and not connected; their vertical coupling creates a capacitive effect. This capacitive effect matches the impedance with the parasitic inductance within the via, thereby improving the antenna's resonant bandwidth. Furthermore, the conductor plane of the coplanar waveguide transmission line is grounded through the conductive material of the third via, forming a complete circuit structure.

[0043] Furthermore, the isolation plate is circular in shape; the diameter of the isolation plate is 0.4mm-0.68mm.

[0044] As described above, the diameter of the isolation plate corresponding to the antenna element varies due to the difference in position, resulting in different capacitance effects. This capacitance effect is used to match the different inductance effects due to the different positions, thereby achieving impedance matching, improving the antenna output efficiency, and enhancing the antenna resonant bandwidth.

[0045] Furthermore, the distance between the antenna unit and the dielectric motherboard is greater than 0.5 mm.

[0046] As described above, the distance between the antenna element and the dielectric motherboard determines the distance between the antenna element and its ground plane. A greater distance between the antenna element and the ground plane results in a lower frequency response for the high-frequency antenna; however, a greater distance also provides more headroom and higher efficiency. Therefore, the distance between the antenna element and the dielectric motherboard must ensure both high-frequency resonance and high efficiency.

[0047] Furthermore, the antenna element is rectangular in shape, with a length of 12-14 mm, a width of 9-12 mm, and a thickness of 0.01-0.04 mm.

[0048] As described above, the long side of the antenna element corresponds to the low-frequency resonance, and the short side corresponds to the high-frequency resonance. The longer the long side, the lower the low-frequency resonance frequency; the longer the short side, the lower the high-frequency resonance frequency. The thickness of the antenna element determines the efficiency of the antenna resonance. The dimensions of the antenna elements are designed in a coordinated manner to ensure the dual resonant frequencies and efficiency of the antenna.

[0049] Furthermore, the antenna element is a dielectric antenna.

[0050] As described above, dielectric antennas are small in size, easy to integrate, allowing multiple antennas to be placed in a small space. They also have high radiation efficiency, can be excited by various simple feeding methods, and their operating bandwidth can be changed by selecting appropriate resonant parameters. Furthermore, they exhibit good isolation between similar antennas and have good resistance to detuning caused by nearby objects.

[0051] Furthermore, the probe structure is a pogo-pin connector.

[0052] As described above, a Pogo pin is a spring-loaded probe formed by riveting and pre-pressing three basic components: a pin shaft, a spring, and a pin tube, using precision instruments. It contains a precise spring structure. Because a Pogo pin is a very fine probe, its application in precision connectors can reduce the weight and size of the connector, making it more refined and aesthetically pleasing, and suitable for use in electronic products such as mobile phones.

[0053] This invention provides a dual-resonant ultra-wideband antenna that can be applied to mobile electronic devices, improving antenna performance, enhancing the positioning accuracy of UWB antennas, and improving user experience. Specific embodiments are described below:

[0054] Please refer to Figures 1 to 10 Embodiment 1 of the present invention is as follows:

[0055] A dual-resonant ultra-wideband antenna includes a dielectric motherboard 1 and an antenna module 2; the antenna module 2 includes an antenna element 21 and a coplanar waveguide transmission line 22; the coplanar waveguide transmission line 22 is disposed on one side of the dielectric motherboard 1, and a metal ground layer 11 and an isolation sheet 12 are disposed on the other side of the dielectric motherboard 1;

[0056] The metal ground layer 11 and the isolation plate 12 are not connected to each other;

[0057] The antenna unit 21 is connected to the center conductor 221 of the coplanar waveguide transmission line 22 and the isolator 12, and the conductor plane 222 of the coplanar waveguide transmission line 22 is connected to the metal ground layer 11.

[0058] It should be noted that one end of the coplanar waveguide transmission line 22 is connected to the antenna element 21, and the other end of the coplanar waveguide transmission line 22 is connected to the PA (power amplifier of the transmitting circuit). In this embodiment, the impedance value of the coplanar waveguide transmission line 22 is 50 ohms. The materials of the isolator 12 and the metal ground layer 11 are copper. The dielectric main board 1 is a multilayer board structure. The antenna element 21 has no size or shape restrictions; the shape of the antenna element 21 can be rectangular, circular, or other shapes; its size and shape only need to meet the requirements of the UWB frequency band.

[0059] Specifically, the dual-resonant ultra-wideband antenna also includes an antenna support 3;

[0060] The antenna support 3 is disposed on the side of the dielectric motherboard 1 where the coplanar waveguide transmission line 22 is disposed; the antenna unit 21 is disposed on the side of the antenna support 3 away from the dielectric motherboard 1; the antenna support 3 is provided with a first through hole 31; the first through hole 31 connects the antenna unit 21 and the center conductor 221 of the coplanar waveguide transmission line 22.

[0061] It should be noted that the antenna support 3 is a planar plate with a rounded rectangular shape. Fixing structures 32 are respectively provided at the four corners of the antenna support 3, and the antenna support 3 is mounted on the dielectric main board 1 through the fixing structures 32. In this embodiment, a feed point 210 is provided at one corner of the antenna unit 21, and the feed point 210 is embedded in the first through hole 31 to connect the antenna unit 21 and the center conductor 221 of the coplanar waveguide transmission line 22.

[0062] Specifically, the number of antenna elements 21 includes three; the three antenna elements 21 are arranged in an L-shape.

[0063] Reference Figure 1 In this embodiment, the three antenna units 21 can be either transmitting antenna units or receiving antenna units.

[0064] It should be noted that the number of coplanar waveguide transmission lines 22 is the same as the number of antenna elements 21. Each antenna element 21 corresponds to one coplanar waveguide transmission line 22, and the three coplanar waveguide transmission lines 22 are isolated from each other. The length of the coplanar waveguide transmission lines 22 is designed according to the requirements of the UWB chip in the actual application. The lengths of the three coplanar waveguide transmission lines 22 can be the same or different.

[0065] Specifically, the antenna module 2 further includes a probe structure 23, which is disposed on the side of the dielectric motherboard 1 where the coplanar waveguide transmission line 22 is disposed;

[0066] The antenna unit 21 is connected to one end of the probe structure 23, and the other end of the probe structure 23 is connected to the center conductor 221 of the coplanar waveguide transmission line 22 and the isolator 12, respectively.

[0067] It should be noted that the number of probe structures 23 is the same as the number of antenna elements 21, with each antenna element 21 corresponding to one probe structure 23. The projection of the antenna element 21 on the dielectric motherboard 1 corresponds one-to-one with the probe structure 23. After the feed point 210 of the antenna element 21 is embedded in the first through hole 31, it connects one end of the antenna element 21 and one end of the probe structure 23. The other end of the probe structure 23 is connected to the center conductor 221 of the coplanar waveguide transmission line 22 and the isolator 12, respectively.

[0068] Specifically, the dielectric main board 1 is provided with at least one second through hole 101 and a third through hole 102; conductive material is provided in both the second through hole 101 and the third through hole 102.

[0069] The other end of the probe structure 23 is connected to the center conductor 221 of the coplanar waveguide transmission line 22 and one end of the conductive material in the second through hole 101; the other end of the conductive material in the second through hole 101 is connected to the isolation sheet 12.

[0070] The conductor plane 222 of the coplanar waveguide transmission line 22 is connected to one end of the conductor material in the third through hole 102, and the other end of the conductor material in the third through hole 102 is connected to the metal ground layer 11.

[0071] It should be noted that the number of the second through holes 101 is the same as the number of the antenna units 21. Each antenna unit 21 corresponds to one second through hole 101, and the projection of the antenna unit 21 on the dielectric motherboard 1 corresponds one-to-one with the second through hole 101.

[0072] The third through-holes 102 are arranged on the entire dielectric motherboard 1, and the arrangement density of the third through-holes 102 is related to the setting position of the antenna element 21. In this embodiment, the areas with a higher arrangement density of the third through-holes 102 are the projection area of ​​the antenna support 3 on the dielectric motherboard 1 and the area around the coplanar waveguide transmission line 22; no third through-holes 102 are provided around the probe structure 23.

[0073] In this embodiment, the metal ground layer 11 covers one side of the surface of the dielectric motherboard 1, and the isolation sheet 12 covers the opening of the second through hole 101 on the dielectric motherboard 1, but the metal ground layer 11 and the isolation sheet 12 are completely isolated from each other.

[0074] In one optional embodiment, the isolating plate 12 is circular in shape; the diameter of the isolating plate 12 is 0.4mm-0.68mm. The diameter of the isolating plate 12 is designed according to the actual requirements of the antenna.

[0075] It should be noted that the number of isolation plates 12 is the same as the number of antenna elements 21, with each antenna element 21 corresponding to one isolation plate 12. However, due to differences in their positions, the diameters of the isolation plates 12 corresponding to the antenna elements 21 differ. Based on the original performance of the antenna, when the antenna element 21 requires capacitive impedance matching, a larger diameter isolation plate 12 results in a larger equivalent capacitance when the isolation plate 12 is connected to the antenna element 21. In other words, the diameter of the isolation plate 12 is determined by the impedance matching performance of the antenna.

[0076] In this embodiment, refer to Figure 7 The diameter of the isolation plate 12 near the edge of the dielectric motherboard 1 is 0.4 mm; (Refer to...) Figure 5 and Figure 6 The diameter of the other two isolation plates 12 is 0.68 mm.

[0077] In one optional embodiment, the distance between the antenna element 21 and the dielectric main board 1 is greater than 0.5 mm. When the distance between the antenna element 21 and the dielectric main board 1 changes, the linewidth and spacing of the coplanar waveguide transmission line 22 also need to be adjusted accordingly, and the diameter of the isolator 12 will also change.

[0078] In one optional embodiment, the antenna element is rectangular in shape, with the antenna element 21 having a length of 12-14 mm, a width of 9-12 mm, and a thickness of 0.01-0.04 mm.

[0079] In this embodiment, the antenna element 21 has a length of 13.4 mm, a width of 10.2 mm, and a thickness of 0.03 mm.

[0080] It should be noted that the spacing between antenna elements 21 is set according to user requirements and varies accordingly based on the application scenario of the antenna. The distance between antenna element 21 and the edge of the dielectric motherboard 1 is not limited, but the distance between them will affect the antenna performance, especially the antenna pattern.

[0081] In one alternative embodiment, the antenna element 21 is a dielectric antenna.

[0082] In one alternative implementation, the probe structure 23 is a pogo-pin connector.

[0083] This embodiment provides a dual-resonant ultra-wideband antenna with dual-resonant characteristics, center frequencies of 6.5 GHz and 8.0 GHz, a bandwidth of 500 MHz, and antenna dimensions of 150 mm × 70 mm × 1.3 mm.

[0084] Reference Figure 8In an ultra-wideband antenna without an isolator to isolate it from the metal ground layer, according to its corresponding return loss curve, when the reference level is -6dB, the bandwidths corresponding to the center frequencies of 6.5GHz and 8.0GHz are 186MHz and 292MHz, respectively.

[0085] Reference Figure 9 The dual-resonant ultra-wideband antenna provided in this embodiment, also at a reference level of -6dB, has a bandwidth of 749MHz corresponding to a center frequency of 6.5GHz and a bandwidth of 895MHz corresponding to a center frequency of 8.0GHz, thus improving the antenna resonance bandwidth and enabling it to fully cover 500MHz. (Refer to...) Figure 10 The dual-resonant ultra-wideband antenna provided in this embodiment has an efficiency of -5dB to -7dB at center frequencies of 6.5GHz and 8.0GHz.

[0086] In one optional embodiment, the dual-resonant ultra-wideband antenna is fabricated using LDS (Laser Direct Structuring) technology. This LDS process directly laser-embeds the antenna onto the phone, effectively reducing the thickness of the stacked structure under LCP technology, decreasing the antenna height, and avoiding interference from internal phone components, thus ensuring signal strength. It also enhances the phone's space utilization, allowing for a relatively thinner phone body.

[0087] In summary, the dual-resonant ultra-wideband antenna provided by this invention incorporates an isolator design in the transmission link between the antenna element and the coplanar waveguide transmission line, with the metal ground layer and the isolator being unconnected. Compared to existing technologies where the center conductor and conductor plane of the coplanar waveguide transmission line are both connected to the metal ground layer, the center conductor and conductor plane of the coplanar waveguide transmission line in this invention are respectively connected to the isolator and the metal ground layer, completely isolating their ground layers. This creates a capacitive effect through vertical coupling between the isolator, the conductor plane of the coplanar waveguide transmission line, and the metal ground layer. This capacitive effect, combined with the inductive effect generated when the center conductor is connected to the isolator, forms an impedance matching effect, thereby improving the antenna's output power and bandwidth at resonance. Furthermore, this method eliminates the need for additional matching devices, effectively reducing antenna production costs. Moreover, the impact of the capacitive effect on the antenna can be adjusted by changing the diameter of the isolator, thus adjusting the bandwidth at resonance, facilitating production design and optimization. The isolator design is not limited by UWB antenna type, has a wide range of applications, and does not occupy any additional volume for antenna modules with limited installation space.

[0088] 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 dual-resonant ultra-wideband antenna, characterized in that, Including the dielectric motherboard and antenna module; The antenna module includes an antenna element and a coplanar waveguide transmission line; The coplanar waveguide transmission line is disposed on one side of the dielectric motherboard, and a metal ground layer and an isolation sheet are disposed on the other side of the dielectric motherboard; the metal ground layer and the isolation sheet are not connected to each other; The antenna unit connects the center conductor of the coplanar waveguide transmission line and the isolation plate, and the conductor plane of the coplanar waveguide transmission line is connected to the metal ground layer; It also includes the antenna support; The antenna support is disposed on the side of the dielectric motherboard on which the coplanar waveguide transmission line is provided; The antenna unit is disposed on the side of the antenna bracket away from the dielectric motherboard; The antenna support is provided with a first through hole; The first through-hole connects the antenna element and the center conductor of the coplanar waveguide transmission line; The antenna module further includes a probe structure, which is disposed on the side of the dielectric motherboard where the coplanar waveguide transmission line is disposed; The antenna unit is connected to one end of the probe structure, and the other end of the probe structure is connected to the center conductor of the coplanar waveguide transmission line and the isolating plate, respectively. The dielectric main board is provided with at least one second through hole and a third through hole; conductive material is disposed in both the second through hole and the third through hole; The other end of the probe structure is connected to the center conductor of the coplanar waveguide transmission line and one end of the conductive material in the second through hole; the other end of the conductive material in the second through hole is connected to the insulating sheet. The conductor plane of the coplanar waveguide transmission line is connected to one end of the conductor material in the third through hole, and the other end of the conductor material in the third through hole is connected to the metal ground layer. The antenna element is a dielectric antenna.

2. The dual-resonant ultra-wideband antenna according to claim 1, characterized in that, The number of antenna elements includes three; the three antenna elements are arranged in an L-shape.

3. The dual-resonant ultra-wideband antenna according to claim 2, characterized in that, The isolation plate is circular in shape; the diameter of the isolation plate is 0.4mm-0.68mm.

4. The dual-resonant ultra-wideband antenna according to claim 1, characterized in that, The distance between the antenna unit and the dielectric motherboard is greater than 0.5 mm.

5. A dual-resonant ultra-wideband antenna according to claim 1, characterized in that, The antenna element is rectangular in shape, with a length of 12-14mm, a width of 9-12mm, and a thickness of 0.01-0.04mm.

6. The dual-resonant ultra-wideband antenna according to claim 1, characterized in that, The probe structure is a pogo-pin connector.

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