A multi-mode resonant based omni-directional broadband antenna

Abstract

The application belongs to the technical field of antenna in the communication system comprehensive design, and particularly relates to a kind of omnidirectional broadband antenna based on multimode resonance, L-shaped folded dipole, rectangular loop, U-shaped branch and SMA joint are located at the lower surface of dielectric substrate, feed line is located at the upper surface of dielectric substrate, first metallized via hole and second metallized via hole in the up-down direction are opened on dielectric substrate, the outer conductor of SMA joint is connected with the right arm of L-shaped folded dipole, the inner conductor of SMA joint is connected with one end of feed line by passing through the right arm of L-shaped folded dipole and first metallized via hole, the other end of feed line is connected with the left arm of L-shaped folded dipole by passing through second metallized via hole, the application generates new resonance frequency by bending traditional dipole to form L-shaped folded dipole;rectangular loop is added around L-shaped folded dipole, two new resonance modes are introduced, and the bandwidth of antenna is further widened.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology in the integrated design of communication systems, and specifically relates to an omnidirectional broadband antenna based on multimode resonance. Background Technology

[0002] With the development of wireless communication technology, there is a demand for antenna devices that can meet the continuous development needs of current wireless communication systems. Broadband antennas, as a key component in wireless communication systems for transmitting or receiving electromagnetic waves, have received widespread attention and research.

[0003] Among the various designs of broadband antennas, multimode broadband antennas have attracted much attention. By introducing one or more operating modes and adjusting the resonant frequency spacing of each mode, the bandwidth can be extended. Most existing multimode resonant antenna technologies, both domestically and internationally, employ multiple resonant elements or stacked patches. Their common drawbacks are large antenna size, complex structure, and high cost.

[0004] To achieve both antenna miniaturization and wide bandwidth, this invention proposes a multimode resonant composite antenna that bends a traditional dipole to form an L-shaped folded dipole and couples it with a rectangular ring patch. Compared with existing technologies, this multimode omnidirectional broadband antenna based on an L-shaped folded dipole and a rectangular ring patch features a wide operating bandwidth, simple structure, easy integration, low cost, high reliability, and easy manufacturing. Its frequency coverage includes Wi-Fi, WLAN, WiMAX, 5G Sub-6GHz, and RFID bands, making it suitable for a wide range of applications. Summary of the Invention

[0005] This invention addresses the problems of narrow operating bandwidth, complex structure, and poor radiation performance of current antennas by providing an omnidirectional broadband antenna based on multimode resonance. By effectively exciting the four resonant frequencies of the antenna, the performance within the frequency band is improved, achieving broadband requirements while maintaining good omnidirectional radiation performance.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] An omnidirectional broadband antenna based on multimode resonance includes an L-shaped folded dipole, a rectangular ring, a U-shaped stub, a dielectric substrate, an SMA connector, and a feed line. The L-shaped folded dipole, rectangular ring, U-shaped stub, and SMA connector are all located on the lower surface of the dielectric substrate, and the feed line is located on the upper surface of the dielectric substrate. A first metallized via and a second metallized via are formed on the dielectric substrate in a vertical direction. The first and second metallized vias are symmetrically distributed about the longitudinal centerline of the dielectric substrate. The outer conductor of the SMA connector is connected to the right arm of the L-shaped folded dipole, and the inner conductor of the SMA connector passes through the right arm of the L-shaped folded dipole and the first metallized via to connect to one end of the feed line. The other end of the feed line passes through the second metallized via to connect to the left arm of the L-shaped folded dipole.

[0008] Furthermore, the L-shaped folded dipole consists of a left arm and a right arm. The left arm and the right arm have the same structure, both consisting of a horizontal patch and a vertical patch. The left arm and the right arm are arranged symmetrically about the longitudinal center line of the dielectric substrate.

[0009] Furthermore, the horizontal distance between the left and right arms of the L-shaped folded dipole is 1.3 mm, the length of the left arm in the horizontal direction is 16.1 mm, the width in the vertical direction is 16 mm, the cross-sectional width of the horizontal patch is 4.5 mm, the cross-sectional width of the vertical patch is 3.95 mm, and the vertical distance between the lower end of the vertical patch and the rectangular ring is 0.5 mm.

[0010] Furthermore, the rectangular ring is composed of four connected patches, and the center point of the rectangular ring coincides with the center point of the dielectric substrate.

[0011] Furthermore, the rectangular ring has a length of 42mm, a width of 34.5mm, and a cross-sectional width of 3mm.

[0012] Furthermore, there are four U-shaped branches, arranged in pairs on the left and right sides of the inner cavity of the rectangular ring, and the four U-shaped branches are symmetrical about the center point of the dielectric substrate.

[0013] Furthermore, the U-shaped branch consists of two horizontal branches and one vertical branch, wherein the cross-sectional width of the horizontal branch is 0.5 mm, the cross-sectional width of the vertical branch is 0.7 mm, the length of the U-shaped branch in the horizontal direction and the width in the vertical direction are both 6 mm, and the vertical distance between the U-shaped branch and the rectangular ring is 0.75 mm.

[0014] Furthermore, the dielectric substrate has a size of 50mm × 45mm and is made of FR4 epoxy resin with a dielectric constant of 4.4, a loss tangent of 0.02, and a thickness of 1mm.

[0015] Furthermore, the radius of the first metallized via and the second metallized via is 0.3 mm, the height is 1 mm, the horizontal distance between the first metallized via and the second metallized via is 6.3 mm, and the vertical distance between the first metallized via and the second metallized via and the lower edge of the vertical patch is 4.15 mm.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] This invention generates a new resonant frequency by bending a traditional dipole to form an L-shaped folded dipole; a rectangular ring is added around the L-shaped folded dipole to introduce two new resonant modes, further widening the antenna bandwidth; finally, four U-shaped stubs are symmetrically introduced inside the rectangular ring to improve impedance matching and cross-polarization at high frequencies; by effectively exciting the four resonant modes of the antenna, good wide-side radiation performance is achieved while obtaining broadband.

[0018] This invention forms an L-shaped folded dipole by bending a traditional dipole and coupling it with a rectangular ring for radiation. The structure is simple, easy to integrate, low in cost, and highly reliable. It meets the requirements of broadband wireless communication and can be applied in Wi-Fi, WLAN, WIMAX, 5G Sub-6GHz and RFID bands. It has a wide range of applications and high engineering practical value. Attached Figure Description

[0019] Figure 1 This is a top perspective view of the present invention;

[0020] Figure 2 This is a side view of the present invention;

[0021] Figure 3 This is a schematic diagram of the rectangular ring structure of the present invention;

[0022] Figure 4 This is a schematic diagram of the left arm of the L-shaped folded dipole of the present invention;

[0023] Figure 5 This is a schematic diagram of the U-shaped branch structure of the present invention;

[0024] Figure 6 The diagram shows the reflection coefficient of the antenna of this invention.

[0025] Figure 7 This is a gain diagram of the antenna of the present invention;

[0026] Figure 8 This is the radiation pattern of the antenna in the XOZ plane when the antenna frequency of the present invention is 1.89 GHz;

[0027] Figure 9 This is the radiation pattern of the antenna in the YOZ plane when the antenna frequency of this invention is 1.89 GHz;

[0028] Figure 10 This is the radiation pattern of the antenna in the XOZ plane when the antenna frequency of this invention is 2.64 GHz;

[0029] Figure 11 This is the radiation pattern of the antenna in the YOZ plane when the antenna frequency of this invention is 2.64 GHz;

[0030] Figure 12 This is the radiation pattern of the antenna in the XOZ plane when the antenna frequency of this invention is 4.18 GHz;

[0031] Figure 13 This is the radiation pattern of the antenna in the YOZ plane when the antenna frequency of this invention is 4.18 GHz;

[0032] Figure 14 This is the radiation pattern of the antenna in the YOZ plane when the antenna frequency of this invention is 5.49 GHz;

[0033] Figure 15 This is the radiation pattern of the antenna in the YOZ plane when the antenna frequency of this invention is 5.49 GHz;

[0034] In the figure, 1 is an L-shaped folded dipole, 2 is a rectangular ring, 3 is a U-shaped stub, 4 is a dielectric substrate, 5 is an SMA connector, 6 is a feed line, 7 is a first metallized via, and 8 is a second metallized via. Detailed Implementation

[0035] To further illustrate the technical solution of the present invention, the present invention will be further described below through embodiments.

[0036] like Figures 1 to 5 As shown, an omnidirectional broadband antenna based on multimode resonance includes an L-shaped folded dipole 1, a rectangular ring 2, a U-shaped stub 3, a dielectric substrate 4, an SMA connector 5, and a feed line 6. The L-shaped folded dipole 1, rectangular ring 2, U-shaped stub 3, and SMA connector 5 are all located on the lower surface of the dielectric substrate 4, and the feed line 6 is located on the upper surface of the dielectric substrate 4. A first metallized via 7 and a second metallized via 8 are formed on the dielectric substrate 4 in a vertical direction. The first metallized via 7 and the second metallized via 8 are symmetrically distributed about the longitudinal centerline of the dielectric substrate 4. The outer conductor of the SMA connector is connected to the right arm of the L-shaped folded dipole. The inner conductor of the SMA connector 5 passes through the right arm of the L-shaped folded dipole 1 and the first metallized via 7 and is connected to one end of the feed line 6. The other end of the feed line 6 passes through the second metallized via 8 and is connected to the left arm of the L-shaped folded dipole 1.

[0037] The L-shaped folded dipole 1 consists of a left arm and a right arm. The left and right arms have the same structure, each consisting of a horizontal patch and a vertical patch. The left and right arms are symmetrically arranged about the longitudinal center line of the dielectric substrate 4. The horizontal distance between the left and right arms of the L-shaped folded dipole 1 is 1.3 mm. The left arm has a horizontal length of 16.1 mm and a vertical width of 16 mm. The horizontal patch has a cross-sectional width of 4.5 mm, the vertical patch has a cross-sectional width of 3.95 mm, and the vertical distance between the lower end of the vertical patch and the rectangular ring 2 is 0.5 mm.

[0038] The rectangular ring 2 is composed of four patches connected together. The center point of the rectangular ring 2 coincides with the center point of the dielectric substrate 4. The rectangular ring 2 has a length of 42mm, a width of 34.5mm, and a cross-sectional width of 3mm.

[0039] There are four U-shaped branches 3, arranged in pairs on the left and right sides of the inner cavity of the rectangular ring 2. The four U-shaped branches 3 are symmetrical about the center point of the dielectric substrate 4. Each U-shaped branch 3 consists of two horizontal branches and one vertical branch. The cross-sectional width of the horizontal branch is 0.5 mm, and the cross-sectional width of the vertical branch is 0.7 mm. The length of the U-shaped branch 3 in the horizontal direction and the width in the vertical direction are both 6 mm. The vertical distance between the U-shaped branch 3 and the rectangular ring 2 is 0.75 mm.

[0040] The dielectric substrate 4 has a size of 50mm × 45mm and is made of FR4 epoxy resin with a dielectric constant of 4.4, a loss tangent of 0.02, and a thickness of 1mm.

[0041] The radius of the first metallized through hole 7 and the second metallized through hole 8 are both 0.3 mm and the height is both 1 mm. The horizontal distance between the first metallized through hole 7 and the second metallized through hole 8 is 6.3 mm, and the vertical distance between the first metallized through hole 7 and the second metallized through hole 8 and the lower edge of the vertical patch is both 4.15 mm.

[0042] Figure 6 The reflection coefficient diagram of an omnidirectional broadband antenna based on multimode resonance according to the present invention is shown, where the horizontal axis represents the frequency variable in GHz and the vertical axis represents the amplitude variable in dB. The antenna operates in the frequency band of 1.81-5.67 GHz, with four resonant frequencies at 1.89 GHz, 2.64 GHz, 4.18 GHz, and 5.49 GHz, respectively. Within the 1.81-5.67 GHz frequency band, the impedance bandwidth reaches 103.2%, indicating that the antenna has a wide bandwidth effect.

[0043] Figure 7The gain diagram of an omnidirectional broadband antenna based on multimode resonance according to the present invention is shown. As can be seen from the figure, the antenna gain range is 1.5dBi-3dBi in the operating frequency band of 1.81-5.67GHz, indicating that the antenna can achieve omnidirectional radiation performance to a certain extent.

[0044] Figures 8 to 15 Normalized radiation patterns of the XOZ and YOZ planes of an omnidirectional broadband antenna based on multimode resonance are presented at four frequency points: 1.89 GHz, 2.64 GHz, 4.18 GHz, and 5.49 GHz. At these four frequencies, the antenna exhibits a good wide-side dipole-shaped radiation pattern with a symmetrical profile, maintaining good omnidirectional radiation performance while achieving a wide bandwidth.

[0045] The foregoing has shown and described the main features and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0046] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A multi-mode resonance based omni-directional broadband antenna, characterized by, The device includes an L-shaped folded dipole (1), a rectangular ring (2), a U-shaped stub (3), a dielectric substrate (4), an SMA connector (5), and a feed line (6). The L-shaped folded dipole (1), rectangular ring (2), U-shaped stub (3), and SMA connector (5) are all located on the lower surface of the dielectric substrate (4), and the feed line (6) is located on the upper surface of the dielectric substrate (4). A first metallized via (7) and a second metallized via (8) in the thickness direction are formed on the dielectric substrate (4). A metallized via (7) and a second metallized via (8) are symmetrically distributed about the longitudinal centerline of the dielectric substrate (4). The outer conductor of the SMA connector (5) is connected to the right arm of the L-shaped folded dipole (1). The inner conductor of the SMA connector (5) passes through the right arm of the L-shaped folded dipole (1) and the first metallized via (7) and is connected to one end of the feed line (6). The other end of the feed line (6) passes through the second metallized via (8) and is connected to the left arm of the L-shaped folded dipole (1). The L-shaped folded dipole (1) is located inside the rectangular ring (2). The L-shaped folded dipole (1) is composed of a left arm and a right arm. The left arm and the right arm have the same structure, both composed of a horizontal patch and a vertical patch. The left arm and the right arm are symmetrically arranged about the longitudinal center line of the dielectric substrate (4). The horizontal patch is located at the upper end of the vertical patch. The vertical patch is located at the end of the horizontal patch close to the longitudinal center line of the dielectric substrate (4). The vertical distance between the lower end of the vertical patch and the lower edge of the rectangular ring (2) is 0.5 mm. There are four U-shaped branches (3), arranged in pairs on the left and right sides of the inner cavity of the rectangular ring (2). The four U-shaped branches (3) are symmetrical about the center point of the dielectric substrate (4).

2. The multi-mode resonant based omni-directional broadband antenna according to claim 1, wherein, The horizontal distance between the left and right arms of the L-shaped folded dipole (1) is 1.3 mm. The left arm has a horizontal length of 16.1 mm and a vertical width of 16 mm. The horizontal patch has a cross-sectional width of 4.5 mm and the vertical patch has a cross-sectional width of 3.95 mm.

3. The multi-mode resonant based omni-directional broadband antenna according to claim 1, wherein, The rectangular ring (2) is composed of four patches connected together, and the center point of the rectangular ring (2) coincides with the center point of the dielectric substrate (4).

4. The omni-directional broadband antenna based on multi-mode resonances according to claim 3, characterized in that, The rectangular ring (2) has a length of 42mm, a width of 34.5mm, and a cross-sectional width of 3mm.

5. The multi-mode resonant based omni-directional broadband antenna according to claim 1, wherein, The U-shaped branch (3) consists of two horizontal branches and one vertical branch, wherein the cross-sectional width of the horizontal branch is 0.5 mm and the cross-sectional width of the vertical branch is 0.7 mm. The length of the U-shaped branch (3) in the horizontal direction and the width in the vertical direction are both 6 mm. The vertical distance between the U-shaped branch (3) and the rectangular ring (2) is 0.75 mm.

6. The multi-mode resonant based omni-directional broadband antenna according to claim 1, wherein, The dielectric substrate (4) has a size of 50mm×45mm and is made of FR4 epoxy resin with a dielectric constant of 4.4, a loss tangent of 0.02 and a thickness of 1mm.

7. The multi-mode resonant based omni-directional broadband antenna according to claim 1, wherein, The radius of the first metallized through hole (7) and the second metallized through hole (8) are both 0.3 mm and the height is both 1 mm. The horizontal distance between the first metallized through hole (7) and the second metallized through hole (8) is 6.3 mm. The vertical distance between the first metallized through hole (7) and the second metallized through hole (8) and the lower edge of the vertical patch is both 4.15 mm.

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