A directional kick antenna

Abstract

This invention provides a directional kick-to-the-foot antenna, applicable to the field of intelligent vehicle technology. The directional kick-to-the-foot antenna comprises: a substrate, a planar dipole antenna, a differential dual-line transmission line, and a grounded coplanar waveguide. The planar dipole antenna, the differential dual-line transmission line, and the grounded coplanar waveguide are arranged on a first surface of the substrate. The antenna body of the planar dipole antenna forms an angle with the horizontal direction. The first and second halves of the planar dipole antenna are respectively connected to the signal end and the reference ground end of the grounded coplanar waveguide via the differential dual-line transmission line. This invention can control the antenna pattern of the planar dipole antenna to shift towards the vehicle interior direction based on the angle, avoiding signal interference in the rear side or rear area of ​​the vehicle, improving the signal quality of the beam coverage area, and enhancing the stability of the rear kick-to-the-foot function.

Description

Technical Field

[0001] This invention relates to the field of intelligent vehicle technology, and in particular to a directional kick antenna. Background Technology

[0002] With the development of automotive intelligence, contactless interaction functions have become an important direction for improving user experience. Among them, the rear-end kick-sensor function, which triggers the automatic opening of the tailgate by the user's leg quickly swinging under the rear of the vehicle, has been widely used in the passenger car field due to its convenience. The rear-end kick-sensor function requires the use of Ultra Wideband (UWB) radar. UWB radar has high time resolution, strong anti-interference ability, and penetration of nanosecond-level narrow pulse signals, which can be the core technology for realizing the rear-end kick-sensor function. It can detect leg movements in a specific area under the rear of the vehicle, and combine the time-distance characteristics of the signal and the Doppler effect to distinguish between valid kicking actions and environmental interference. Currently, antennas compatible with UWB radar include monopole or dipole antennas, microstrip directional antennas, small array antennas, horn antennas, and waveguide antennas. However, these antennas all have some drawbacks when used in actual vehicles. For example, while dipole antennas have a simple structure and are easy to integrate into the rear of the vehicle, their omnidirectional or wide-beam characteristics make them prone to receiving signals from non-target areas on the sides or rear of the vehicle, leading to accidental activation of the rear-end kick-to-kick function and affecting its accuracy. Small array antennas require beamforming optimization of 2 to 4 antenna elements to optimize coverage and require a multi-channel RF front-end. Space constraints at the rear of the vehicle limit the installation of small array antennas, and their cost is too high. Therefore, to address these issues, a directional kick-to-kick antenna is urgently needed to achieve signal coverage within the target area of ​​the rear-end kick-to-kick function, reduce the impact of interference signals from the sides or rear of the vehicle, and match the installation space at the rear of the vehicle. Summary of the Invention

[0003] This invention provides a directional kick antenna to reduce signal interference in non-target areas and enhance signal coverage in the target area, thereby improving the stability of the rear kick function.

[0004] According to one aspect of the present invention, a directional kick antenna is provided, wherein the directional kick antenna includes: a substrate, a planar dipole antenna, a differential dual-line transmission line, and a ground coplanar waveguide, wherein the planar dipole antenna, the differential dual-line transmission line, and the ground coplanar waveguide are arranged on a first surface of the substrate; The planar dipole antenna has an angle between its main body and the horizontal direction. The first and second halves of the planar dipole antenna are connected to the signal end and reference ground end of the grounded coplanar waveguide respectively through the differential two-wire transmission line.

[0005] In some embodiments of the invention, the directional kick antenna further includes a coupling element, which is disposed on a second surface of the substrate opposite to the first surface, and the coupling element is parallel to and spaced apart from the planar dipole antenna.

[0006] In some embodiments of the invention, the length of the coupling element is equal to half the arm length of the planar dipole antenna.

[0007] In some embodiments of the invention, the length of the first and second half-arms of the planar dipole antenna is 6.9 mm.

[0008] In some embodiments of the invention, the reference ground of the grounded coplanar waveguide is disposed around the planar dipole antenna on the outside of the substrate.

[0009] In some embodiments of the invention, the location of the reference ground of the grounded coplanar waveguide is matched with the included angle of the planar dipole antenna.

[0010] In some embodiments of the invention, the length of the differential two-wire transmission line is 8.2 mm.

[0011] In some embodiments of the invention, the planar dipole antenna, the differential dual-line transmission line, and the ground-coplanar waveguide are printed on the substrate.

[0012] In some embodiments of the invention, the ground coplanar waveguide includes at least a radio frequency transmission line.

[0013] In some embodiments of the invention, a reference ground is disposed in an L-shape at the edge of the substrate, and the opening direction of the reference ground is toward the tilt direction of the planar dipole antenna.

[0014] The technical solution of this invention provides a directional kick antenna, which consists of a substrate, a planar dipole antenna, a differential dual-line transmission line, and a grounded coplanar waveguide. The planar dipole antenna, differential dual-line transmission line, and grounded coplanar waveguide are disposed on the first surface of the substrate. The planar dipole antenna is positioned at an angle to the horizontal direction, causing the antenna pattern of the planar dipole antenna to be offset towards the inward direction of the vehicle, avoiding signal interference in the rear side or rear area of ​​the vehicle, improving the quality of the coverage signal in the beam detection area, and thus improving the stability of the rear kick function.

[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a directional kick antenna according to an embodiment of the present invention; Figure 2 This is a schematic diagram of another directional kick antenna provided according to an embodiment of the present invention; Figure 3 This is a schematic diagram of another directional kick antenna provided according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the key dimensions of a directional kick antenna according to an embodiment of the present invention; Figure 5 This is a simulation diagram of return loss parameters provided by an embodiment of the present invention; Figure 6 This is a schematic diagram of antenna direction simulation provided according to an embodiment of the present invention; Figure 7 This is another antenna direction simulation diagram provided according to an embodiment of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] Figure 1 This is a schematic diagram of a directional kick antenna according to an embodiment of the present invention. See also... Figure 1 This invention provides a directional kick antenna, which includes a substrate 101, a planar dipole antenna 102, a differential two-wire transmission line 103, and a grounded coplanar waveguide 104. The planar dipole antenna 102, the differential two-wire transmission line 103, and the grounded coplanar waveguide 104 are arranged on the first surface of the substrate 101. The antenna body direction of the planar dipole antenna 102 is at an angle to the horizontal direction. The first half-arm and the second half-arm of the planar dipole antenna 102 are respectively connected to the signal end and the reference ground end of the grounded coplanar waveguide 104 through the differential two-wire transmission line 103.

[0021] In this embodiment of the invention, the planar dipole antenna 102 can be an antenna with a planar radiating dipole. The planar dipole antenna can include two half-arms, which can be a pair of symmetrically arranged metal patches. The two half-arms can be referred to as the first half-arm and the second half-arm, and their lengths can be the same. The length of the half-arms of the planar dipole antenna can conform to half a wavelength. The planar dipole antenna 102, the differential two-wire transmission line 103, and the grounded coplanar waveguide 104 can be printed on the first surface of the substrate 101, enabling the integration of the radio frequency circuit and reducing processing costs. The planar dipole antenna 102 can be connected to the signal break and the reference ground of the grounded coplanar waveguide 104 through the differential two-wire transmission line 103, respectively.

[0022] Specifically, to ensure that the antenna direction of the planar dipole antenna 102 is offset from the direction inside the vehicle, thereby reducing signal interference in the rear side or rear area of ​​the vehicle, the antenna body direction of the planar dipole antenna 102 disposed on the first surface of the substrate 101 can not be set along the horizontal direction, but rather the antenna body direction can be at a certain angle with the horizontal direction. The size of this angle can be related to the installation position of the directional kick antenna and the vehicle to which the directional kick antenna is adapted. For example, the angle between the antenna body direction and the horizontal direction can be 30 degrees, 37.5 degrees, 40 degrees, 45 degrees, etc.

[0023] Figure 2 This is a schematic diagram of another directional kick antenna provided in an embodiment of the present invention. The directional kick antenna provided in this embodiment of the present invention further includes: a coupling element 105, the coupling element 102 is arranged on the second surface of the substrate 101 opposite to the first surface, and the coupling element 105 is parallel to the planar dipole antenna 102 and is spaced apart.

[0024] In this embodiment of the invention, the directional kick antenna may further include a coupling element 105. The coupling element 105 may be disposed on a second surface of the substrate relative to the first surface. The second surface may be the back surface of the first surface. If the planar dipole antenna 102 is disposed on the first surface of the substrate, then the coupling element 105 is disposed on the second surface of the substrate. The coupling element 105 may be a passive coupling element. The coupling element 105 may be parallel to the planar dipole antenna 102, and there may be a gap between the coupling element and the planar dipole antenna 102. The coupling element 105 may be close to the planar dipole antenna 102. After the planar dipole antenna 102 is energized and resonates, the near-field coupling excites the coupling element 105 to generate an induced current, causing the coupling element to form a second independent resonant frequency point, thereby expanding the antenna's operating frequency band. It may form a combined radiation unit with the planar dipole antenna, thereby changing the superposition distribution of the spatial field, thereby optimizing beam coverage, improving antenna gain, suppressing sidelobes, and avoiding signal interference from the side or rear area of ​​the vehicle's rear. The gap between the coupled dipole 105 and the planar dipole antenna 102, or the length of the coupled dipole 105, changes the coupling strength between the coupled dipole 105 and the planar dipole antenna 102, thereby correcting the antenna impedance and reducing return loss.

[0025] Based on the above embodiments of the invention, the length of the coupled element is equal to the half-arm length of the planar dipole antenna.

[0026] Specifically, the length of the coupling element 105 can be the same as the half-arm length of the planar dipole antenna 102, so that the resonant frequencies of the coupling element 105 and the planar dipole antenna 102 coincide, thereby achieving strong electromagnetic coupling and forming a double resonant peak at the center frequency, thus expanding the antenna bandwidth. Furthermore, by making the coupling element 105 and the planar dipole antenna 102 of equal length, the current amplitudes of the coupling element 105 and the planar dipole antenna 102 are made similar, thereby controlling the distortion in the radiation superposition direction to be small, and making the beam offset stable and controllable.

[0027] Based on the above-described embodiments of the invention, the lengths of the first and second halves of the planar dipole antenna are 6.9 mm.

[0028] Specifically, the lengths of the first and second half arms of the planar dipole antenna 102 are set to 6.9 mm, which makes the total length of the two arms of the planar dipole antenna close to λ / 2, resulting in a smaller size for the directional kick antenna, making it easier to install the directional kick antenna in the space-constrained rear part of the vehicle.

[0029] In some embodiments of the invention, the reference ground of the grounded coplanar waveguide 104 is disposed on the outer half of the substrate 101 surrounding the planar dipole antenna 102.

[0030] In this embodiment of the invention, a planar dipole antenna 102 is disposed on a substrate 101, and the reference ground of the grounded coplanar waveguide 104 can also be disposed on the same surface of the substrate 101 as the planar dipole antenna 102. The reference ground can be located on the outside of the planar dipole antenna 102 on the substrate 101, and can be disposed semi-surrounding the planar dipole antenna 102. The reference ground can have an opening on the antenna radiation side of the planar dipole antenna 102, so that the planar dipole antenna can radiate along the opening direction.

[0031] Based on the above embodiments of the invention, the location of the reference ground of the grounded coplanar waveguide is matched with the included angle of the planar dipole antenna.

[0032] Specifically, the location of the reference ground of the ground coplanar waveguide 101 can be matched with the angle between the planar dipole antenna and the horizontal direction. The opening direction corresponding to the location of the reference ground on the substrate 101 can be the same as the angle mentioned above, so that the tilt direction of the planar dipole antenna 102 is the same, so that the signal of the planar dipole antenna 102 can be radiated along the opening direction of the reference ground, thereby reducing signal interference from other directions.

[0033] Based on the above-described embodiments of the invention, the length of the differential two-wire transmission line is 8.2 mm.

[0034] In some embodiments of the invention, the planar dipole antenna, the differential two-wire transmission line, and the ground-coplanar waveguide are printed on the substrate.

[0035] Specifically, the planar dipole antenna 102, the differential dual-line transmission line 103, and the grounded coplanar waveguide 104 can all be printed on the same surface of the same substrate 101. The planar dipole antenna 102, differential dual-line transmission line 103, and grounded coplanar waveguide 104 can be seamlessly integrated into a single unit. The grounded coplanar waveguide 104 can be arranged in a semi-enclosed configuration on the substrate 101, with an opening on the radiating side of the planar dipole antenna 102. Two parallel metal lines form a differential port in the middle of the grounded coplanar waveguide 104. The substrate surrounding the radiating element of the planar dipole antenna 102 is left blank, thus achieving outward beam radiation. The ends of the differential dual-line transmission line 103 are connected to the two halves of the planar dipole antenna 102, and the other end is connected to the differential port of the grounded coplanar waveguide 104. For example, the ground copper, feed line, and antenna element can be etched onto a single layer of the PCB in a single process and integrated onto a single side of the same substrate.

[0036] Specifically, a ground-coplanar waveguide includes at least a radio frequency transmission line.

[0037] Based on the above embodiments of the invention, a reference ground is arranged in an L-shape at the edge of the substrate, and the opening direction of the reference ground is toward the tilt direction of the planar dipole antenna.

[0038] In one exemplary implementation, see Figure 3 This invention provides a directional kick antenna, which includes component 1 - FR4 substrate, component 2 - heterocoupled dipole, component 3 - planar dipole antenna, component 4 - differential dual-line transmission line and component 5 - grounded coplanar waveguide. Component 2 - heterocoupled dipole is printed on the reverse side of the substrate, and component 4 - differential dual-line transmission line is used for radio frequency signal switching.

[0039] Component 3—the planar dipole antenna—has a horizontal tilt angle relative to the horizontal direction. This tilt angle, combined with component 5—the ground-coplanar waveguide—controls the left-right shift of the antenna pattern, thereby ensuring the coverage of the kick antenna at a specific installation location. Simultaneously, the guiding characteristics of component 2—the non-planar coupled vibrator—shift the kick antenna's pattern towards the interior of the vehicle, thus reducing signal spillover outside the vehicle. See also Figure 4 The key dimensions of the components of the directional kick antenna are shown in the table below: For details, see Figure 5 The simulation results of the return loss parameters of the directional kick antenna provided in this embodiment of the invention show that the return loss is better than -10dB in the 7.4GHz to 8.5GHz frequency band, which meets the requirements of UWB radar. The operating bandwidth is approximately 1.171GHz, and the return loss at the center resonant frequency of 8GHz can reach approximately -16dB. It exhibits excellent port impedance matching, low RF signal reflection loss, and high radiation efficiency. See also... Figure 6 In the antenna radiation diagram of a directional kick antenna, the radial coordinate represents the gain dBi, the circumference represents the elevation angle Theta, and the arrow indicating the 0-degree direction is the radiation direction outside the vehicle. In the antenna radiation envelope of the directional kick antenna, the maximum radiation beam is concentrated in the range of 0 degrees (outside the vehicle) ±30 degrees, and the gain inside the vehicle is significantly reduced. The directional kick antenna can radiate energy in a directional manner towards the outside of the vehicle and suppress the radiation characteristics inside the vehicle, which can prevent signal interference in the area outside or behind the rear of the vehicle.

[0040] In an embodiment of the present invention, see Figure 7 The radiation pattern of the directional kick antenna in the horizontal direction shows that the main radiating beam is concentrated in the 0-degree (right side of the vehicle) ±30-degree angle range, where the antenna gain is optimal. Gain is significantly attenuated and radiation is suppressed towards the inside of the vehicle (180-degree direction), achieving directional radiation of radio frequency energy towards the right side of the vehicle body. Unwanted radiation from the inside of the vehicle is effectively suppressed, and the directional radiation performance meets the requirements for lateral transmission and reception in vehicles. It is understandable that the directional radiation of radio frequency energy towards the left side of the vehicle body can be achieved by adjusting the antenna tilt angle of the planar dipole antenna of the directional kick antenna.

[0041] In this embodiment of the invention, the horizontal tilt angle of the planar dipole antenna is adjusted, and the left and right offset of the antenna pattern is controlled by combining it with a ground coplanar waveguide structure, thereby ensuring that the signal of the directional kick antenna covers a specific range at the rear of the vehicle. The antenna pattern is shifted towards the inside of the vehicle by the guiding characteristics of the coupled vibrator, so as to reduce the signal overflow outside the vehicle.

[0042] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A directional kick antenna characterized by, The directional kick antenna includes: a substrate, a planar dipole antenna, a differential dual-wire transmission line, and a ground-band coplanar waveguide; The planar dipole antenna, the differential dual-line transmission line, and the ground-coplanar waveguide are arranged on the first surface of the substrate. The planar dipole antenna has an angle between its main body and the horizontal direction. The first and second halves of the planar dipole antenna are connected to the signal end and reference ground end of the grounded coplanar waveguide respectively through the differential two-wire transmission line.

2. The directional kicker antenna according to claim 1, characterized in that, It also includes a coupling element, which is disposed on the second surface of the substrate opposite to the first surface, and the coupling element is parallel to the planar dipole antenna and spaced apart.

3. The directional kick antenna according to claim 1 or 2, characterized in that, The length of the coupled element is equal to half the arm length of the planar dipole antenna.

4. The directional kick antenna according to claim 1, characterized in that, The lengths of the first and second halves of the planar dipole antenna are 6.9 mm.

5. The directional kick antenna according to claim 1, characterized in that, The reference ground of the grounded coplanar waveguide is disposed on the outer half of the planar dipole antenna on the substrate.

6. The directional kick antenna according to claim 1 or 5, characterized in that, The reference ground of the grounded coplanar waveguide is positioned to match the included angle of the planar dipole antenna.

7. The directional kick antenna according to claim 1, characterized in that, The length of the differential two-wire transmission line is 8.2 mm.

8. The directional kick antenna according to claim 1, characterized in that, The planar dipole antenna, the differential dual-line transmission line, and the ground-coplanar waveguide are printed on the substrate.

9. The directional kick antenna according to claim 1, characterized in that, The ground-coplanar waveguide includes at least a radio frequency transmission line.

10. The directional kick antenna according to claim 5, characterized in that, The reference ground is L-shaped and disposed at the edge of the substrate, with the opening of the reference ground facing the tilt direction of the planar dipole antenna.

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