Omnidirectional radiation medium loading slot antenna with large grounding plate

Abstract

The invention discloses an omnidirectional radiation medium loading slot antenna with a large grounding plate. The antenna comprises four ground slot antennas and a dielectric resonator, wherein the four ground slot antennas are uniformly arranged on a substrate in the circumferential direction; the dielectric resonator comprises a semicircular dielectric block, a fan-shaped dielectric plate and a fan-shaped ring dielectric block which are located on a substrate. Wherein the center line of the semicircular dielectric block is collinear with the axis of the circumference, two sides of the center line of the semicircular dielectric block are respectively and vertically connected with a fan-shaped dielectric plate, a fan-shaped ring dielectric block is arranged between each fan-shaped dielectric plate and the adjacent semicircular dielectric block, and the middle part of the bottom side of each fan-shaped ring dielectric block is respectively connected with a ground groove antenna. Dielectrics of different shapes are loaded on the four large grounding slot antennas arranged along the circumference, so that the purpose of improving a directional diagram is achieved, the antenna can well work at 2.5 GHz, and upper and lower side lobes of the antenna are basically inhibited.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle-mounted communication networks, and particularly relates to a large ground plane omnidirectional radiation dielectric loaded slot antenna. Background Art

[0002] Vehicle-to-Everything (V2X) technology is gradually becoming a research hotspot and development direction in the transportation field because it can significantly improve traffic safety, optimize traffic flow, support autonomous driving, and promote the development of intelligent transportation systems. As a device for transmitting and receiving signals in a communication system, the performance of an antenna directly affects the quality and reliability of V2X communication. Traditional automotive antenna designs often face challenges such as space limitations, external environmental interference, and multipath propagation. Therefore, optimizing antenna design to improve parameters such as its gain, directivity, and bandwidth is particularly crucial for achieving efficient and stable V2X communication.

[0003] Researchers have conducted extensive research on antenna designs for Vehicle-to-Vehicle (V2V) communication, focusing on key areas such as increasing bandwidth and gain, developing low-profile designs, pattern reconfiguration, multi-band, and multiple-input multiple-output (MIMO) systems. However, for V2V communication, some components of the vehicle body can be approximated as a huge reflecting surface, which often leads to changes in the antenna pattern. For example, if the vehicle body floor area is large, the omnidirectional antenna pattern will become a conical pattern, which will limit the communication range and adaptability to mobile scenarios, causing fluctuations in communication signals between vehicles. In addition, the large-area vehicle body acting as a ground plane will change the impedance characteristics of the antenna, resulting in an increase in the voltage standing wave ratio (VSWR), and some signal energy will be reflected rather than radiated, reducing the antenna efficiency. Summary of the Invention

[0004] To overcome the drawbacks and deficiencies of the prior art, the purpose of the present invention is to provide a large ground plane omnidirectional radiation dielectric loaded slot antenna.

[0005] The present invention is implemented as follows. A large ground plane omnidirectional radiation dielectric loaded slot antenna includes four slot antennas and a dielectric resonator circumferentially and uniformly arranged on a substrate. The dielectric resonator includes a semi-circular dielectric block, a sector-shaped dielectric plate, and a sector-ring dielectric block located on the substrate. Among them, the center line of the semi-circular dielectric block is collinear with the axis of the circle, and a sector-shaped dielectric plate is vertically connected to each side of the center line of the semi-circular dielectric block. A sector-ring dielectric block is provided between each sector-shaped dielectric plate and the adjacent semi-circular dielectric block, and the middle part of the bottom side of each sector-ring dielectric block is connected to a slot antenna.

[0006] Preferably, the semi-circular dielectric block, the sector-shaped dielectric plate, and the sector-ring dielectric block are all made of ceramic materials with a relative dielectric constant of 8.9.

[0007] Preferably, the substrate is a PCB board with a relative dielectric constant of 3.38 and a loss tangent of 0.0027.

[0008] Preferably, the semi-circular dielectric block is semi-circular, and the sector-shaped dielectric plate is sector-shaped; wherein, the radius of the arc edge of the sector-shaped dielectric plate from the center of the circle of the circumference is equal to the radius of the semi-circular dielectric block.

[0009] Preferably, the fan-shaped ring dielectric block is arc-shaped, wherein the radius of the outer arc edge of the fan-shaped ring dielectric block is equal to the radius of the circumference.

[0010] Preferably, the combined parts between the substrate, the semi-circular dielectric block, the sector-shaped dielectric plate, and the fan-shaped ring dielectric block are bonded with glue.

[0011] Compared with the disadvantages and deficiencies of the prior art, the present invention has the following beneficial effects: By loading dielectrics with different shapes on four large ground slot antennas arranged along the circumference, the present invention aims to improve the radiation pattern. The antenna is studied using the electromagnetic simulation tool HFSS, and the antenna is fabricated and measured in a microwave anechoic chamber. The antenna can operate well at 2.5 GHz, and the upper and lower side lobes of the antenna are basically suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 shows the evolution process of the antenna structure from ANTI to ANTIV;

[0013] Figure 2 shows the S11 parameter curves of the corresponding antennas during the evolution process of the antenna structure from ANTI to ANTIV;

[0014] Figure 3 is a schematic assembly structure diagram of a large ground plane omnidirectional radiation dielectric-loaded slot antenna; wherein, Figure 3 a is a schematic diagram of the overall assembled structure, Figure 3 b is the substrate and the feeder structure arranged on the substrate, Figure 3 c are two sector-shaped dielectric plates, Figure 3 d is the semi-circular dielectric block, Figure 3 e is the fan-shaped ring dielectric block;

[0015] Figure 4 is a physical diagram of the large ground plane omnidirectional radiation dielectric-loaded slot antenna of the present invention;

[0016] Figure 5 is a simulation size marking diagram of the large ground plane omnidirectional radiation dielectric-loaded slot antenna of the present invention from different perspectives; wherein, Figure 5 a is a three-dimensional view, Figure 5 b is a front view, Figure 5 c is a top view, Figure 5 d is a top view state diagram after removing the dielectric resonator;

[0017] Figure 6 It is a diagram of the simulation and measurement results of the main polarization and cross polarization of the antenna when PHI = 0°. The blue line represents the simulation result, and the red line represents the test result;

[0018] Figure 7 It is a diagram of the simulation and measurement results of the main polarization and cross polarization of the antenna when PHI = 90°. The blue line represents the simulation result, and the red line represents the test result;

[0019] Figure 8 It is a diagram of the simulation and measurement results of the main polarization and cross polarization of the antenna when THETA = 90°. The blue line represents the simulation result, and the red line represents the test result; Specific implementation manners

[0020] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] The present invention designs and simulates the antenna using HFSS2023, and the evolution of the antenna structure is as Figure 1 shown. Figure 2 Shows the S11 parameter curves of the corresponding antennas during the evolution of the antenna structure from ANTI to ANTIV. The simulated S11 curves show that when the slotted antenna is not loaded with the dielectric (see ANTI), a single resonance occurs at around 2.5 GHz. The center frequencies of the slotted antennas loaded with the dielectric (ANTII - ANTIV) are also 2.5 GHz, but the bandwidths are slightly different.

[0022] On this basis, the present invention discloses a large ground plane omnidirectional radiation dielectric loaded slot antenna, as Figure 3 shown. The antenna includes four ground slot antennas 2 and dielectric resonators arranged circumferentially and evenly on the substrate 1; the dielectric resonators include a semi-circular dielectric block 3, a fan-shaped dielectric plate 4 and a fan-shaped ring dielectric block 5 located on the substrate 1; wherein, the center line of the semi-circular dielectric block 3 is collinear with the axis of the circle, and a fan-shaped dielectric plate is vertically connected to each side of the center line of the semi-circular dielectric block 3, and a fan-shaped ring dielectric block is provided between each fan-shaped dielectric plate and the adjacent semi-circular dielectric block 3, and the middle of the bottom side of each fan-shaped ring dielectric block is connected to a ground slot antenna 2 respectively.

[0023] In an embodiment of the present invention, as a preferred structure, the semi-circular dielectric block is semi-circular, and the sector-shaped dielectric plate is sector-shaped; wherein, the radius of the arc edge of the sector-shaped dielectric plate from the center of the circle of the circumference is equal to the radius of the semi-circular dielectric block. As a preferred structure, the fan-shaped ring dielectric block is arc-shaped, wherein the radius of the outer arc edge of the fan-shaped ring dielectric block is equal to the radius of the circumference.

[0024] In an embodiment of the present invention, preferably, the substrate 1 (PCB board) is integrally processed using Rogers 4003C, with a relative dielectric constant of 3.38 and a loss tangent of approximately 0.0027. This kind of circuit board has a lower cost, and the board thickness of 1.524 mm can also better maintain the flatness and mechanical properties of the PCB board, minimizing test and simulation errors. The feeder structure adopts a microstrip end-feeder configuration. There are four identical power feeder interfaces at the bottom of the substrate 1, and a ground plane at the top. The feeder interfaces can provide in-phase power supply, and each feeder is responsible for exciting 1 slotted line. During the simulation process, the four feeder ports need to be configured as Lumport to simulate the feeder, thereby shortening the simulation time. The dielectric block is composed of a ceramic material (JJD08-3) with a relative dielectric constant of 8.9.

[0025] To avoid the increase in production cost caused by one-piece processing, the dielectric block needs to be divided and processed, as shown in Figure 3 (c) to 3(d). Subsequently, the substrate 1 and the dielectric resonator need to be bonded, and this process may bring additional errors. As shown in Figure 4 In the embodiment of the present invention, a prototype antenna is fabricated, and the simulation results and actual measurement results (measuring relevant data with a vector network analyzer for comparison with the simulation) of several key parameters are compared. Among them, the size markings of each dielectric plate in the dielectric resonator are as shown in Figure 5 shown, and the specific sizes are as shown in Table 1 below:

[0026] Table 1

[0027]

[0028]

[0029] Figures 6 - 8 This is the gain pattern of the antenna at 2.5 GHz. The blue line represents the simulation result, the red line represents the test result, the dotted line represents the main polarization, and the short line represents the cross polarization.

[0030] From Figures 6 - 8It can be seen that the main polarization and cross-polarization radiation characteristics are the same at phi = 0° (XOZ plane) and phi = 90° (YOZ plane), and the maximum radiation occurs at both 90° and 270°. From the measurement results, when phi = 0°, similar side lobes appear on the upper half of the main polarization and cross-polarization patterns. However, the cross-polarization level increases significantly on the upper half and the pattern splits on the right side. This is because the dielectric constant of the dielectric block material is large, there are processing errors, and it is more sensitive to the electromagnetic field distribution. When phi = 90°, the side lobes on the upper half of the main polarization pattern shift and the side lobes on the lower left half become prominent, but the overall level is the same as that at phi = 0°. The side lobes on the upper half of the cross-polarization pattern further expand, and the splitting on the right side is more obvious. This may be related to the processing size of the dielectric and the glue bonding the dielectric block.

[0031] In the direction of theta = 90° (XOY plane), the simulation results of the main polarization level are in good agreement with the measured results, and the main polarization level is significantly higher than the cross-polarization. There are differences in the cross-polarization in some angular directions, which may be caused by the asymmetry of the dielectric block structure and the feeding circuit, but the overall difference is not significant. In summary, the antenna has stable performance in the main radiation direction, shows good cross-polarization in both the XOZ plane and the YOZ plane, the cross-polarization is below -10 dB, and the simulation results are in good agreement with the measured results.

[0032] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An omnidirectional radiation dielectric-loaded slot antenna with a large ground plane, characterized in that, The antenna includes four slot antennas and a dielectric resonator arranged circumferentially and evenly on a substrate; the dielectric resonator includes a semi-circular dielectric block, a sector-shaped dielectric plate, and a sector-ring dielectric block located on the substrate; wherein, the center line of the semi-circular dielectric block is collinear with the axis of the circumference, and a sector-shaped dielectric plate is vertically connected to each side of the center line of the semi-circular dielectric block, and a sector-ring dielectric block is provided between each sector-shaped dielectric plate and the adjacent semi-circular dielectric block, and the middle of the bottom side of each sector-ring dielectric block is connected to a slot antenna respectively.

2. The dielectric loaded slot antenna according to claim 1, wherein The semi-circular dielectric block, the sector-shaped dielectric plate, and the sector-ring dielectric block are all made of ceramic material with a relative dielectric constant of 8.

9.

3. The dielectric loaded slot antenna according to claim 1, characterized in that, The substrate is a PCB board with a relative dielectric constant of 3.38 and a loss tangent of 0.0027.

4. The dielectric loaded slot antenna according to claim 1, wherein The semi-circular dielectric block is semi-circular, and the sector-shaped dielectric plate is sector-shaped; wherein, the radius of the arc edge of the sector-shaped dielectric plate from the center of the circumference is equal to the radius of the semi-circular dielectric block.

5. The dielectric loaded slot antenna according to claim 1, characterized in that, The sector-ring dielectric block is arc-shaped, wherein, the radius of the outer arc edge of the sector-ring dielectric block is equal to the radius of the circumference.

6. The dielectric loaded slot antenna according to claim 1, wherein The combined parts between the substrate, the semi-circular dielectric block, the sector-shaped dielectric plate, and the sector-ring dielectric block are bonded with glue.

Images