Novel miniaturized accurate positioning antenna

Abstract

The utility model discloses a novel miniaturized accurate positioning antenna comprising a dielectric substrate, the upper surface of the dielectric substrate is provided with a metal radiation patch, and the central position of the metal radiation patch is connected with the lower metal ground of the dielectric substrate through a metal short circuit column; wherein the metal radiation patch is in a cross shape and comprises a first metal patch and a second metal patch, the first metal patch and the second metal patch are rectangular metal patches, and the length of the first metal patch is larger than that of the second metal patch; the first metal patch and the second metal patch cooperate with each other through the corresponding metal probe and the metal capacitor for feeding, and through the above technical scheme, the problem that impedance matching cannot be effectively carried out by a high dielectric constant material can be solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of radio frequency antennas, and in particular relates to a novel miniaturized precise positioning antenna. Background Art

[0002] With the rapid development of modern wireless communication technology and systems, there are more and more types of antennas used for various ground terminal systems to receive positioning and navigation signals, and the use scenarios of antennas are becoming more and more extensive. The Beidou satellite navigation system consists of a series of satellites, ground monitoring stations and user terminals, providing accurate positioning, navigation and time services. The goal of the Beidou system is to provide navigation services with global coverage, including global positioning, navigation and time services. The Beidou system supports multi-band and multi-system navigation signals, which can be used to provide higher-precision positioning and navigation services and increase anti-interference capabilities. With the rapid development of communication technology, people expect terminal systems to become smaller and more convenient to carry, and can be used in mobile devices such as mobile phones and positioning cards. Therefore, the miniaturization of navigation antennas has become one of the research hotspots. Miniaturization refers to the effect of reducing the overall size of the antenna at its fixed operating frequency. At the same time, multi-band integrated positioning antennas can not only work in different operating frequency bands, but also improve the accuracy and precision of positioning. Methods to achieve antenna miniaturization include changing the current path of the antenna so that the current flows through a longer path, lowering the resonance point, such as making slits on the radiation patch, adding metal branches, etc.; using materials with high dielectric constants as the dielectric substrate of the antenna is the most intuitive and effective way to reduce the size of the antenna.

[0003] Although using high dielectric constant materials as dielectric substrates can have a very direct effect on reducing the size of the antenna, the feeding method has become a difficult problem to overcome. Recently, an article entitled "A Compact Symmetrical BeiDou Antenna with Circular Polarization for Satellite Navigation and Positioning System" was published. The article used a material with a dielectric constant of ε=16 as a dielectric substrate. Although miniaturization was achieved to a certain extent, the side length of its square dielectric substrate still reached 43mm, and only single-band operation was achieved.

[0004] At present, there is still a lot of room for improvement in the miniaturization of navigation and positioning antennas. The utility model uses high dielectric constant ceramic materials as the dielectric substrate of the navigation patch antenna, which greatly reduces the size of the antenna. At the same time, a "cross" shaped single-layer radiation patch is used to achieve dual-band signal reception, further avoiding the problem of increased size caused by the stacked patch antenna. However, the use of high dielectric constant materials will cause the impedance characteristics of the patch antenna to change. Due to the influence of the medium, the impedance of the patch antenna may increase or decrease. Through simulation, it is found that the input port impedance becomes larger, making the impedance matching of the antenna more difficult. High dielectric constant materials may also cause changes in the radiation loss of the antenna, increase the occurrence of radiation loss and energy loss, affect the antenna radiation efficiency, and reduce the antenna gain. For such a miniaturized high dielectric constant patch antenna, the utility model proposes a new type of two-point coupling feeding, which solves the impedance matching problem of high dielectric constant materials. Utility Model Content

[0005] In order to solve the above technical problems, the utility model proposes a novel miniaturized precise positioning antenna to solve the above problems existing in the prior art.

[0006] To achieve the above objectives, the utility model provides a novel miniaturized precise positioning antenna, comprising:

[0007] A dielectric substrate, wherein a metal radiation patch is disposed on the upper surface of the dielectric substrate, wherein a metal grounding layer is disposed on the lower surface of the dielectric substrate, and the center position of the metal radiation patch is connected to the metal grounding layer through a metal short-circuit column;

[0008] The metal radiation patch is in a "cross" shape, including a first metal patch and a second metal patch, wherein the first metal patch and the second metal patch are both rectangular metal patches and the length of the first metal patch is greater than the length of the second metal patch;

[0009] A metal circular hole is provided inside the first metal patch, wherein a first metal capacitor is provided in the metal circular hole, the first metal capacitor is connected to a first metal probe, and the first metal probe is provided in a corresponding lower surface circular hole in the metal grounding layer;

[0010] The two short sides of the first metal patch are respectively connected with metal branches;

[0011] A second metal capacitor is arranged outside one side of a short side of the second metal patch, and the second metal capacitor is not in contact with the second metal patch, wherein the second metal capacitor is connected to a second metal probe, and the second metal probe is arranged in a corresponding lower surface circular hole in the metal grounding layer.

[0012] Optionally, the dielectric substrate is made of KM02 ceramic material.

[0013] Optionally, the metal branches at both ends are symmetrically structured, with gaps provided between the metal branches and the metal patch, and the length of the metal branches is smaller than the width of the first metal patch.

[0014] Optionally, the dielectric substrate is in a cylindrical shape.

[0015] Optionally, the second metal capacitor and the first metal capacitor are metal capacitor sheets.

[0016] Optionally, the second metal capacitor is a square metal capacitor sheet.

[0017] Compared with the prior art, the utility model has the following advantages and technical effects:

[0018] The utility model provides a single-layer dual-frequency miniaturized patch antenna with high dielectric constant ceramic material and new coupling feeding, which can be used for satellite precise positioning. Aiming at the characteristic requirements of antenna miniaturization, the utility model uses ceramic material with a dielectric constant of ε=45 to more directly reduce the size of the antenna, and adopts a single-layer "cross" patch, which can be regarded as a first metal sheet and a second metal sheet placed crosswise. The two feeding points work on the two radiating patches respectively, generate different resonant frequencies, and realize dual-band operation on the same layer of dielectric substrate. In order to overcome the difficulties of the high dielectric constant dielectric substrate feeding method, the utility model proposes a new coupling feeding method, which is simple and has a good matching effect. The utility model designs a novel miniaturized precise positioning antenna. The overall size of the antenna is miniaturized by using KM02 ceramic material with a high dielectric constant, so that the diameter of the antenna is less than 25mm, only 22mm; in combination with the requirement of single-layer dual-frequency to achieve precise navigation information reception, only one layer of dielectric substrate is used, and the thickness of the antenna is only 2.5mm; two-point capacitive coupling feeding is adopted to achieve good impedance matching for different frequency bands, the return loss is less than -10dB, and the high-frequency gain reaches up to 2.59dB. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0020] Figure 1 It is a schematic diagram of the antenna plane of the embodiment of the utility model;

[0021] Figure 2 It is an overall schematic diagram of the antenna of an embodiment of the utility model;

[0022] Figure 3 A schematic diagram of the low-frequency reflection coefficient of an embodiment of the utility model;

[0023] Figure 4 A schematic diagram of the high-frequency reflection coefficient of an embodiment of the utility model;

[0024] Figure 5 A schematic diagram of gain in the low frequency band of an embodiment of the utility model;

[0025] Figure 6 A schematic diagram of the gain of the high frequency band of an embodiment of the utility model;

[0026] Among them, 1. metal radiation patch, 2. dielectric substrate, 3. metal grounding layer, 4. metal short-circuit column, 5. first metal probe, 6. first metal capacitor, 7. second metal probe, 8. second metal capacitor, 9. circular hole on the lower surface. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0029] The utility model proposes a novel miniaturized precise positioning antenna, comprising the following contents:

[0030] Based on the operating frequency bands of B1I (1561MHz) and B3I (1268MHz) of the Beidou satellite navigation system, a dual-frequency positioning patch antenna is designed, which includes a dielectric substrate 2, a metal radiation patch 1, a metal capacitor and a metal probe for feeding, a metal short-circuit column 4, and a conductive metal grounding layer 3; the metal radiation patch 1 and the metal capacitor 6 are arranged on the upper surface of the dielectric substrate 2, the metal probe is arranged inside the dielectric substrate 2, and the metal grounding layer 3 is arranged below the dielectric substrate 2. The metal probe and the corresponding metal capacitor form coupled feeding for the metal radiation patch 1, and the feeding methods of the two frequency bands are different. The low-frequency band feeding point is located inside the metal radiation patch 1, and the high-frequency band feeding point is located outside the metal radiation patch 1. The metal radiation patch 1 is provided with metal branches and gaps;

[0031] Based on the performance requirements of miniaturization, the navigation antenna uses a high dielectric constant material as the dielectric substrate 2 (circular in shape), and the dielectric substrate 2 uses KM02 ceramic material with a dielectric constant ε=45, which greatly reduces the overall size of the antenna;

[0032] Based on the performance requirements of miniaturization, a single-layer dual-band method is selected instead of a multi-layer stacking method, which reduces the thickness of the antenna;

[0033] Based on the requirement of realizing single-layer dual-frequency antenna, a cross-shaped structure is selected for design. Two rectangular metal patches (first metal patch and second metal patch) of different lengths are placed crosswise and overlapped as radiation patches. The long one (first metal patch) realizes low-frequency resonance (such as Figure 1 The vertical patch), the short one (the second metal patch) achieves high frequency resonance (such as Figure 1 Patches in the horizontal direction), the resonant frequency is changed by adjusting the length of different radiating patches. The width of the rectangular metal sheet has little effect on the resonant frequency. The two metal sheets are combined into a cross shape to generate a dual-polarization signal, which can work in dual frequency bands at the same time. It has the advantages of higher signal capacity, anti-interference ability and spatial multiplexing, and can be used for satellite precise positioning;

[0034] Based on the requirements of dual-band operation, two-point feeding is adopted to feed the B1I and B3I frequency bands respectively, which can realize simultaneous feeding and dual-band operation, or only one feeding point can be fed and single-band operation can be realized;

[0035] Due to the influence of high dielectric constant materials, if a probe or coaxial line is used for direct feeding, the field distribution disturbance in the dielectric substrate 2 will be greatly affected, and impedance matching becomes difficult. Through simulation, it is found that the two feeding points need to be close to the center position at the same time to achieve better impedance matching, but at this time the two feeding points are prone to overlap, causing the circuit to not work normally. The utility model proposes two-point coupling feeding. For a long metal sheet (first metal patch) in the low frequency band, the first metal probe 5 is first directly fed, the feeding point position is moved along the length direction of the radiation sheet to find the best matching position, and then a metal ring is dug above the probe, and a first metal capacitor 6 is introduced into the metal ring to eliminate the inductance effect brought by the probe. The size and position of the ring are adjusted in combination with the size of the first metal capacitor 6 to achieve the best matching of the low-frequency resonance point; in order to avoid overlapping with the low-frequency probe, a rectangular metal sheet with an area much smaller than the metal radiation patch is added to one side of the edge of the short metal sheet (second metal patch) in the high frequency band, that is, the external medium surface close to the radiation sheet, i.e., the second metal capacitor 8, and then a second metal probe 7 is vertically placed directly below the second metal capacitor 8 to feed the second metal capacitor 8, and the high-frequency radiation sheet is coupled and fed through the second metal capacitor 8, and the position of the second metal probe 7 and the size of the second metal capacitor 8 are adjusted to obtain the best matching effect;

[0036] Based on miniaturization processing, symmetrical metal branches are added to both ends of a longer metal sheet (the first metal patch), leaving a gap in the middle, introducing capacitance, and reducing the Q value (quality factor), thereby achieving the effect of widening the bandwidth; metal branches are arranged on both ends of the wide side of the first metal patch, wherein the metal branch is a rectangular metal sheet with grooves, and its symmetry axis parallel to the short side is in a straight line with the symmetry axis parallel to the long side of the first metal patch, and the groove is rectangular and located on the side close to the first metal patch, and the groove and the long axis of the first metal patch form a rectangular gap, and are symmetrical about the above-mentioned symmetry axis.

[0037] Based on phase stability, a metal short-circuit column 4 is added at the center of the metal radiation patch 2 to make the field distribution more orderly, which is conducive to the stability of the phase center.

[0038] In summary, the utility model proposes a novel miniaturized precise positioning antenna.

[0039] Combined with the accompanying drawings, the above content is described in detail:

[0040] like Figure 1 , 2As shown, a novel miniaturized precise positioning antenna comprises a metal radiation patch 1, a dielectric substrate 2, a metal grounding layer 3, a metal short-circuit column 4, a metal probe and a metal capacitor sheet; the metal radiation patch 1 is arranged on the upper surface of the dielectric substrate 2, the metal grounding layer is arranged on the lower surface of the dielectric substrate 2, the metal short-circuit column 4 is arranged inside the dielectric substrate 2, the center position of the metal radiation patch 1 is connected to the metal grounding layer 3 through the metal short-circuit column 4, the metal short-circuit column 4 is arranged perpendicular to the metal radiation patch 1, the metal probe comprises a first metal probe 5 and a second metal probe 7, the metal capacitor sheet comprises a first metal capacitor 6 and a second metal capacitor 8, the metal radiation patch 1 comprises a first metal patch and a second metal patch, wherein the first metal patch and the second metal patch are placed vertically so that the metal radiation patch 1 is in a "cross" shape, wherein the first metal patch and the second metal patch are both rectangular metal patches and the length of the first metal patch is greater than the length of the second metal patch, and when arranged, the symmetry axis of the first metal patch parallel to the long side and the symmetry axis of the second metal patch parallel to the short side coincide, so that the metal radiation patch 1 forms a vertically or left-right symmetrical structure. The intersection of the symmetry axis of the metal radiation patch 1 about the vertical symmetry and the symmetry axis about the left and right symmetry is used as the center of the metal radiation patch 1. The center of the metal radiation patch 1 coincides with the center of the upper surface of the dielectric substrate 2. In the direction of the symmetry axis of the first metal patch parallel to the long side, a metal circular hole, i.e., a circular ring aperture, is provided on the metal radiation patch 1 at a fixed distance from the metal radiation patch 1, wherein the fixed distance is the distance between the center of the metal circular hole and the center of the metal radiation patch 1. A first metal capacitor 6 is provided in the metal circular hole, and the first metal capacitor 6 is provided on the upper surface of the dielectric substrate 2. The metal circular hole and the first metal capacitor 6 are located at the same center and there is a gap between them. The first metal capacitor 6 is connected to the first metal probe 5, and the first metal probe 5 is provided inside the dielectric substrate 2 and perpendicular to the first metal capacitor 6. The first metal capacitor 6 is perpendicular to the first metal probe 5 directly above. A second metal capacitor 8 is disposed outside one side of the short side of the second metal patch, wherein the center of the second metal capacitor 8 is located on a straight line of the symmetry axis of the second metal patch parallel to the long side, the second metal capacitor 8 is spaced apart from the metal radiation patch 1, and the second metal capacitor 8 is connected to the second metal probe 7. The second metal capacitor 8 is perpendicular to the first metal probe 7 and is directly above it.

[0041] A lower surface circular hole 9 is provided on the metal grounding layer 3, wherein the lower surface circular hole 9 is a circular hole structure dug in the metal grounding layer 3, wherein the lower surface circular hole 9 is directly below the first metal probe 5 and the second metal probe 7 respectively, and the center of the circle thereof is repeated, and the first metal probe 5 and the second metal probe 7 serve as inner conductors and cannot directly contact the metal grounding layer 3, and the metal grounding layer 3 and the metal probe are separated by the lower surface circular hole 9, and the center of the circular hole of the lower surface circular hole 9 provided on the metal grounding layer 3 serves as a coaxial feeding point, and the metal probe passes through the coaxial feeding point to perform coaxial feeding for the metal capacitor.

[0042] The dielectric substrate 2 is made of KM02 ceramic material with a dielectric constant ε=45. Its high dielectric constant characteristic intuitively reduces the size of the overall antenna. The dielectric substrate 2 is cylindrical in shape with a diameter of only 22mm and a thickness of only 2.5mm. The metal radiation patch 1 is in a "cross" structure, and its operating frequency band includes the B3I (1268MHz) and B1I (1561MHz) bands of Beidou satellite navigation. The "cross" patch can be regarded as two sections of metal patches (including the first metal patch and the second metal patch). The resonant frequency is changed by adjusting the length of the two sections of metal patches. The width has little effect on the resonant frequency. The two metal radiation patches work in different frequency bands. The longer patch (first metal patch) works in the B3I frequency band, with a length of 18.14 mm and a width of 11.5 mm. It is connected to metal branches at both ends in the length direction, and its width is less than the width of the first metal patch. It is connected to the first metal patch to form a capacitor, which can also be regarded as a slot on the first metal patch, so that the current flows through a longer path, thereby reducing the resonant frequency. This not only reduces the overall size of the antenna, but also reduces the Q value by adding capacitance, achieving the effect of widening the bandwidth. The first metal patch is coupled and fed by the first metal capacitor 6. First, the first metal probe 5 is used for direct feeding to find a suitable position, which is close to the center point of the first metal patch. Then, a ring is cut off above the first metal probe 5, so that the first metal probe 5 is in direct contact with the first metal capacitor 6 (circular capacitor), and is indirectly fed with the metal radiation patch 2. The size of the annular gap and the first metal capacitor 6 can be adjusted by setting the simulation scanning parameter, and the best position for impedance matching can be found to achieve a good matching effect.

[0043] Finally, it is determined that the radius of the first metal capacitor 6 segment is 0.33mm, the distance between the first metal capacitor 6 and the metal radiation patch 2 is 0.17mm, that is, the width of the annular aperture is 0.17mm, the first probe and the first metal capacitor sheet feed the first metal radiation patch, and the feeding point is located in the long direction of the first metal patch, and the fixed distance from the center point of the metal radiation patch 1 is 1.48mm. The shorter patch (the second metal patch) works in the B1I frequency band, with a length of 14.518mm and a width of 10mm. If the same feeding method as the low-frequency band is used, it is also close to the center position, and the two feeding points are easy to overlap. Therefore, the second metal capacitor 8 located outside the metal radiation patch 1 is coupled and fed, and a second metal probe 7 is placed on one side of the second metal patch. The second metal capacitor 8 (rectangular capacitor sheet) is placed directly above the second metal probe 7. The size of the second metal capacitor 8 and the distance of the second metal probe 7 from the metal radiation patch 1 can be adjusted by setting the simulation scanning parameter so that the impedance matching achieves the best effect. In this example, the second metal probe 7 is placed 2 mm away from the edge of the metal radiation patch 1, and the second metal capacitor 8 is a square with a side length of 2 mm. The above two capacitor coupling feeds work without affecting the antenna size, and the antenna is suitable for precise measurement positioning terminals.

[0044] Specific parameters include: the upper surface radius r=11mm, height h=2.5mm of the dielectric substrate 2, the metal grounding layer 4 is a square with a side length of 55mm, the first metal patch in the metal radiation patch 1 is a1=18.14mm long, b1=11.5mm wide, the second metal patch is a2=14.518mm long, b2=10mm wide, the metal branch is a rectangular metal sheet with a groove, la1=6.518mm long, lb1=1mm wide, the rectangular groove is la2=4.918mm long, lb2=0.4mm wide, the radius rr1=0.3mm of the first metal probe 5, the radius rr2=0.3mm of the second metal probe 7, the radius rr0=0.3mm of the metal short-circuit column, the radius r=0.3mm of the first metal capacitor 6, the side length of the second metal capacitor 8 is lw=2mm, and the interval d1=1mm with the metal radiation patch 1. The radius rr2=1mm of the circular hole 9 on the lower surface.

[0045] like Figure 3-6 As shown, in the antenna provided by the utility model, Figure 3 The results shown indicate that the input reflection coefficient (also known as S11 parameter) in the low frequency band can meet -10dB, and the lowest point reaches -17dB, indicating a good matching effect. Figure 4 The results shown indicate that the input reflection coefficient (also known as S11 parameter) in the high frequency band can meet -10dB, and the lowest point reaches -35dB, indicating a good matching effect. Figure 5The results shown indicate that the maximum gain in the low frequency band exceeds 1dB and the radiation effect is good. Figure 6 The results shown indicate that the maximum gain exceeds 2.5dB in the high frequency band and the radiation effect is good.

[0046] The utility model realizes the miniaturization of antenna size based on high dielectric constant materials. This small patch antenna can work in dual frequency bands at the same time. The metal radiation patch is in a "cross" shape. On this basis, the branch and slot technology is added to further miniaturize the antenna, realize the single-layer dual-frequency dual-polarization effect, and reduce the antenna diameter to 22mm (B3I frequency band is less than λ / 10), and the thickness is reduced to 2.5mm (B3I frequency band is less than λ / 94);

[0047] For high dielectric constant materials as the dielectric substrate of the antenna, the utility model adopts a new feeding method, using two-point coupling feeding method for feeding, which is applied to different frequency bands. The capacitor slices for low-frequency coupling feeding are placed inside the metal radiation piece, and the capacitor slices for high-frequency coupling feeding are placed outside the metal radiation piece. It not only does not affect the area of ​​the radiation patch and the thickness of the overall antenna, but also can achieve good matching and achieve good results.

[0048] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A novel miniaturized precision positioning antenna, characterized in that: include: A dielectric substrate, wherein a metal radiation patch is disposed on the upper surface of the dielectric substrate, wherein a metal grounding layer is disposed on the lower surface of the dielectric substrate, and the center position of the metal radiation patch is connected to the metal grounding layer through a metal short-circuit column; The metal radiation patch is in a "cross" shape, including a first metal patch and a second metal patch, wherein the first metal patch and the second metal patch are both rectangular metal patches and the length of the first metal patch is greater than the length of the second metal patch; A metal circular hole is provided inside the first metal patch, wherein a first metal capacitor is provided in the metal circular hole, the first metal capacitor is connected to a first metal probe, and the first metal probe is provided in a corresponding lower surface circular hole in the metal grounding layer; The two short sides of the first metal patch are respectively connected with metal branches; A second metal capacitor is arranged outside one side of a short side of the second metal patch, and the second metal capacitor is not in contact with the second metal patch, wherein the second metal capacitor is connected to a second metal probe, and the second metal probe is arranged in a corresponding lower surface circular hole in the metal grounding layer.

2. The antenna according to claim 1, characterized in that The dielectric substrate is made of KM02 ceramic material.

3. The antenna according to claim 1, characterized in that The metal branches at both ends are symmetrically structured, with gaps between them and the metal patch, and the length of the metal branches is smaller than the width of the first metal patch.

4. The antenna according to claim 1, characterized in that: The dielectric substrate is in a cylindrical shape.

5. The antenna according to claim 1, characterized in that The second metal capacitor and the first metal capacitor are made of metal capacitor sheets.

6. The antenna according to claim 1, characterized in that The second metal capacitor is a square metal capacitor sheet.

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