LoRa antenna

Abstract

The utility model discloses a LoRa antenna, which comprises a dielectric substrate, a mounting base body, a grounding part, a first radiation unit, a second radiation unit and a feed part, and is characterized in that the grounding part is arranged at the bottom end of the dielectric substrate, the first radiation unit covers one surface of the dielectric substrate, and the second radiation unit covers the other surface of the dielectric substrate; comprising a first radiation sheet, a tuning radiation sheet used for prolonging the effective length of the first radiation unit, and a snake-shaped oscillator located at the top end of the dielectric substrate and used for shifting resonance of a standing-wave ratio to low frequency. And the second radiation unit covers one surface, opposite to the first radiation unit, of the dielectric substrate, and is electrically connected with the first radiation sheet of the first radiation unit through at least one via hole. The feed part is located at one end, close to the grounding part, of the first radiation unit, and current input is carried out in a feed line welding mode. The antenna is simple in process, convenient to process, convenient for mass production of a production line, wide in coverage frequency band, high in radiation efficiency, and suitable for more environments.

Description

Technical Field

[0001] The utility model belongs to the technical field of antenna equipment, and in particular relates to a LoRa antenna. Background Art

[0002] LoRa is a long-distance wireless transmission technology based on spread spectrum technology. The LoRa external antenna is an external antenna specifically used for the LoRa communication system. It has the advantages of simple structure, low cost, easy installation and debugging, and is widely used in the Internet of Things, smart home, industrial control and other fields.

[0003] The internal part of the Lora external antenna can choose a steel tube welded spring array solution. The steel tube welded spring array has good directionality and high efficiency, but there will be a riveting process during production, which increases the labor cost and production time during the assembly process. There is a certain risk that the sample defective rate will increase. The Lora antenna in the form of a steel sheet is easy to produce and assemble, but it occupies more space outside the machine's RF module, is easy to deform, and has certain requirements for the machine installation environment.

[0004] PCB antennas are easy to produce and assemble, and are low in cost. However, the bandwidth of a single-layer PCB is relatively narrow, and most PCB antennas are relatively single in frequency band range. For example, a universal PCB antenna with a built-in 450MHz frequency band, published as CN207069056U, and a dual-band dipole PCB antenna, published as CN114678690A, only meet the needs of analog circuits in the frequency band of about 450MHz, or a single frequency band such as 470MHz-510MHz, and are difficult to meet the needs of different application scenarios. Utility Model Content

[0005] The purpose of the utility model is to provide a LoRa antenna to solve the deficiencies of the prior art.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A LoRa antenna, comprising: a dielectric substrate (1), a grounding portion (2) arranged at the bottom of one side of the dielectric substrate (1), a first radiating unit covering the same side of the dielectric substrate (1) as the grounding portion (2), a second radiating unit covering the side of the dielectric substrate (1) opposite to the first radiating unit, and a feeding portion (5) located on the first radiating unit and close to the grounding portion (2);

[0008] The first radiation unit comprises a first radiation plate, a tuning radiation plate (7) for extending the effective length of the first radiation unit, and a serpentine array (8) located at the top of the dielectric substrate (1) for shifting the resonance of the standing wave ratio to a low frequency; the second radiation unit is electrically connected to the first radiation plate of the first radiation unit through at least one via (6).

[0009] Furthermore, the first radiation piece includes a lower blade-shaped radiation piece and an upper blade-shaped radiation piece arranged oppositely above the lower blade-shaped radiation piece.

[0010] Furthermore, the lower blade-shaped radiation sheet comprises a lower blade-shaped radiation sheet body (301) and a first extension portion (302) located on the upper portion of the lower blade-shaped radiation sheet body (301), and the first extension portion (302) extends to a side edge of the dielectric substrate (1) with a certain width.

[0011] Furthermore, the upper blade-shaped radiation sheet comprises an upper blade-shaped radiation sheet body (303) and a second extension portion (304) located on the upper portion of the upper blade-shaped radiation sheet body (303), wherein the second extension portion (304) extends to a certain width toward the other side of the dielectric substrate (1) opposite to the first extension portion (302).

[0012] Furthermore, the lower blade-shaped radiation sheet body (301) and the upper blade-shaped radiation sheet body (303) are located on the same axis and have the same width, both being between one quarter and one third of the width of the dielectric substrate (1).

[0013] Furthermore, the dielectric substrate (1) is a PCB board with a length between 140 mm and 145 mm, a width between 7 mm and 7.4 mm, and a thickness between 0.8 mm and 1.2 mm.

[0014] Furthermore, the bearing surface at the top of the dielectric substrate (1) is trapezoidal, and correspondingly, the serpentine array (8) is a thin copper sheet that is reciprocatingly bent and covered on the trapezoidal bearing surface at the top of the dielectric substrate (1), one end of the thin copper sheet is connected to the tuning radiation sheet (7), and the other end extends vertically upward.

[0015] Furthermore, the second radiation unit comprises a second radiation plate (401) located on the back side of the first radiation plate and two slender branches (402) symmetrically arranged on the back side of the tuning radiation plate (7).

[0016] Furthermore, the width of the second radiation plate (401) is greater than the width of the first radiation plate, and the inner distance between the two branches (402) is greater than the width of the tuning radiation plate (7).

[0017] Furthermore, it is characterized in that: the via hole (6) is located at one end of the first radiation plate close to the tuning radiation plate (7). Compared with the prior art, the LoRa antenna provided by the utility model has the following beneficial technical effects:

[0018] 1. The utility model has simple process and convenient processing, only one step of welding is required, and the rest is the process of assembling the antenna rubber rod, which is convenient for mass production of the production line, simple and reliable structure, long life of the antenna, and not easy to be damaged.

[0019] 2. The utility model designs the PCB antenna to be double-sided conductive, the PCB board is about 142mm long, and the copper-clad length on the double-sided board can meet the theoretical size of one-quarter of the wavelength in the low frequency band. It can be applied to the 410MHz-510MHz frequency band, covers a wide frequency band, can meet the low-frequency performance of LORA, and has high radiation efficiency, and can adapt to more environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described below are only some embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0021] Figure 1 A schematic diagram of the front structure of a LoRa antenna provided in an embodiment of the utility model;

[0022] Figure 2 A schematic diagram of the back structure of a LoRa antenna provided in an embodiment of the utility model;

[0023] Figure 3 A schematic diagram of return loss of a LoRa antenna provided in an embodiment of the utility model;

[0024] Figure 4 A LoRa antenna voltage standing wave ratio simulation diagram provided for an embodiment of the utility model;

[0025] Figure 5 A schematic diagram of antenna efficiency of a LoRa antenna provided in an embodiment of the utility model;

[0026] Figure 6 A gain diagram of a LoRa antenna provided in an embodiment of the utility model;

[0027] Figure 7 A 2D radiation pattern of a LoRa antenna on the xoy plane provided by an embodiment of the utility model;

[0028] Figure 8 A 2D radiation pattern of a LoRa antenna on the yoz plane provided by an embodiment of the utility model;

[0029] Fig. 9 A 2D radiation pattern of a LoRa antenna on the xoz plane provided in an embodiment of the utility model.

[0030] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0031] 1- dielectric substrate, 101- mounting slot, 2- grounding portion, 301- lower knife-shaped radiation plate body, 302- first extension portion, 303- upper knife-shaped radiation plate body, 304- second extension portion, 401- second radiation plate, 402- branch, 5- feeding portion, 6- via, 7- tuning radiation plate, 8- snaking array. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] The embodiment of the utility model provides a LoRa antenna, comprising a dielectric substrate 1, a grounding portion 2, a first radiating unit, a second radiating unit, a feeding portion 5, a coaxial cable and an SMA adapter. Specifically:

[0034] like Figures 1 to 7 As shown, in this embodiment, the dielectric substrate 1 is used as a mounting base and is cut from a PCB board. In order to meet the theoretical size of 1 / 4 wavelength of the LORA antenna, the dielectric substrate 1 is specifically made of an FR4 substrate with a length between 140mm-145mm, a width between 7mm-7.4mm, and a thickness between 0.8mm-1.2mm. FR4 is a dielectric material with a dielectric constant between 4-5, which can provide reliable mechanical support, low dielectric loss, and good high-frequency performance. In addition, a mounting slot 101 is provided at the bottom of the dielectric substrate 1, which can facilitate the better installation and fixing of the dielectric substrate 1 to the rubber rod base of the antenna, and also improve the stability of the antenna structure.

[0035] The grounding portion 2 is arranged on the front of the dielectric substrate 1 and is close to the mounting slot 101; the grounding portion 2 adopts single-point grounding, which can make the charge of the microstrip line at the feed source flow back to the ground, forming a complete loop to radiate electromagnetic waves, and can also eliminate some clutter interference caused by the environment. Compared with multi-point grounding, single-point grounding will not have extra branches 402 to interfere with the feeding point, and single-point grounding can also deepen the resonance depth of the standing wave ratio. Since the antenna body is a monopole antenna, the pad of the grounding portion 2 can also assist the dielectric substrate 1 to maintain an upright state, protecting the coaxial line core from detaching from the PCB board.

[0036] As a preferred embodiment, the first radiation unit is integrally formed and covers the front of the dielectric substrate 1, and includes a first radiation plate, a tuning radiation plate 7 and a serpentine array 8. Among them, the first radiation plate is composed of two upper and lower knife-shaped radiation plates, namely a lower knife-shaped radiation plate and an upper knife-shaped radiation plate, and the lower knife-shaped radiation plate and the upper knife-shaped radiation plate are arranged in opposite directions and covered on the dielectric substrate 1. The first radiation plate adopts this design from narrow to wide and then from wide to narrow, which can increase the current flow path, make the bandwidth of the antenna wider, and increase the effective size of the antenna, and at the same time make the antenna radiate more comprehensively and the directional pattern less out of roundness.

[0037] Specifically in this embodiment, the lower knife-shaped radiation piece includes a lower knife-shaped radiation piece body 301 and a first extension portion 302, the first extension portion 302 is located at the upper part of the lower knife-shaped radiation piece body 301, and extends to the left side of the dielectric substrate 1 with a width twice that of the lower knife-shaped radiation piece body 301, the upper knife-shaped radiation piece includes an upper knife-shaped radiation piece body 303 and a second extension portion 304, the second extension portion 304 is located at the upper part of the upper knife-shaped radiation piece body 303, and extends to the right side of the dielectric substrate 1 opposite to the first extension portion 302 with a width twice that of the upper knife-shaped radiation piece body 303, the lower knife-shaped radiation piece body 301 and the upper knife-shaped radiation piece body 303 are on the same axis and have the same width, both of which are one quarter to one third of the width of the dielectric substrate 1, so as to ensure that the antenna input impedance matches the signal source output impedance, so that the effective power of the signal source is transmitted to the antenna to the maximum extent.

[0038] The tuning radiation sheet 7 is arranged at the end of the second extension part 304, and is used to extend the effective length of the first radiation unit and push the resonance to the low frequency. The bearing surface at the top of the dielectric substrate 1 is trapezoidal, and correspondingly, the serpentine array 8 is a thin copper sheet that is reciprocally bent and covered on the trapezoidal bearing surface at the top of the dielectric substrate 1. One end of the thin copper sheet is connected to the tuning radiation sheet 7, and the other end extends vertically upward, and is used to shift the resonance of the standing wave ratio to the low frequency; in addition, since the outer envelope shape of the serpentine array 8 matches the shape of the trapezoidal bearing surface, the folding angle includes an acute angle, so that the current flow before and after the folding angle can present an acute angle intersection, thereby generating electromagnetic waves in a new direction, expanding the antenna bandwidth, and meeting the requirements of the two free frequency bands of 433MHz and 470-510MHz.

[0039] In this embodiment, the second radiation unit is covered on the back side of the dielectric substrate 1 (i.e., the side opposite to the first radiation unit), and is electrically connected to the first radiation sheet of the first radiation unit through the via 6. The via 6 has at least one hole, which is located at one end of the first radiation sheet close to the tuning radiation sheet 7, and serves as a channel connecting the positive and negative radiation units, and can conduct the current from the front side to the back side of the PCB board, so that there are charges distributed on both sides of the PCB board, the charges attract and repel each other, and the charges move in the positive direction to generate electromagnetic waves to radiate energy outward.

[0040] As a preferred embodiment, the second radiation unit includes a second radiation sheet 401 and two slender branches 402. The second radiation sheet 401 is located on the back of the first radiation sheet. The length of the second radiation sheet 401 is the same as that of the first radiation sheet, and the width is greater than the width of the first radiation sheet, which can reduce the electromagnetic interference and signal reflection between the front and back radiation sheets. At the same time, through the coupling effect generated by the two radiation sheets, the antenna can be more efficient and have more stable performance. The branches 402 are symmetrically arranged on the back of the tuning radiation sheet 7, so that the two branches 402 are distributed on both sides of the metal guide hole, and the inner spacing of the two branches 402 is greater than the width of the tuning radiation sheet 7 to receive the current flowing out of the first radiation unit, and produce an anti-interference effect through the board edge of the tuning radiation sheet 7, so that the antenna can adapt to more complex environments and improve the stability of the antenna.

[0041] The feeder 5 is the starting point for the antenna to receive signals and begin to radiate energy. It is located on one end of the first radiation unit close to the grounding part 2. The feeder 5 uses a coaxial cable to input current, and an SMA adapter (not shown) is also provided at the end of the coaxial cable. During assembly, it is only necessary to weld the coaxial line to the processed double-sided PCB board, and then assemble it into the rubber rod base to complete the installation. Compared with antennas composed of multiple materials (such as spring crimping copper tubes, PCB assembly springs), the utility model only has one step of welding, and the rest is the process of assembling the antenna rubber rod, which reduces the riveting process, makes the process simpler, reduces the product's working hours, improves production efficiency, and can also prevent the inside of the rubber rod shell from being touched during assembly. The proofed samples have good consistency and can be installed within 1 meter of the RF end when used. The antenna can be flexibly disassembled and assembled. In addition, the coaxial cable has low loss, can transmit the RF carrier signal transmitted by the RF device to a greater extent, transmit the RF carrier signal to the antenna end, and let the antenna convert it into an electromagnetic wave signal to better radiate energy. (Of course, in addition to coaxial cables, it can also be microstrip lines, strip lines, or other forms of transmission lines.)

[0042] The above-mentioned embodiments only express the implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A LoRa antenna, characterized in that: include: A dielectric substrate (1), a grounding portion (2) disposed at the bottom of one side of the dielectric substrate (1), a first radiating unit covering the same side of the dielectric substrate (1) as the grounding portion (2), a second radiating unit covering the side of the dielectric substrate (1) opposite to the first radiating unit, and a feeding portion (5) located on the first radiating unit and close to the grounding portion (2); The first radiation unit comprises a first radiation plate, a tuning radiation plate (7) for extending the effective length of the first radiation unit, and a serpentine array (8) located at the top of the dielectric substrate (1) for shifting the resonance of the standing wave ratio to a low frequency; the second radiation unit is electrically connected to the first radiation plate of the first radiation unit through at least one via (6).

2. A LoRa antenna according to claim 1, characterized in that: The first radiation piece includes a lower blade-shaped radiation piece and an upper blade-shaped radiation piece which is arranged oppositely above the lower blade-shaped radiation piece.

3. A LoRa antenna according to claim 2, characterized in that: The lower blade-shaped radiation sheet comprises a lower blade-shaped radiation sheet body (301) and a first extension portion (302) located on the upper portion of the lower blade-shaped radiation sheet body (301), wherein the first extension portion (302) extends to one side of the dielectric substrate (1) with a certain width.

4. A LoRa antenna according to claim 3, characterized in that: The upper blade-shaped radiation sheet comprises an upper blade-shaped radiation sheet body (303) and a second extension portion (304) located on the upper portion of the upper blade-shaped radiation sheet body (303), wherein the second extension portion (304) extends to another side of the dielectric substrate (1) opposite to the first extension portion (302) with a certain width.

5. A LoRa antenna according to claim 4, characterized in that: The lower blade-shaped radiation sheet body (301) and the upper blade-shaped radiation sheet body (303) are located on the same axis and have the same width, both being between one quarter and one third of the width of the dielectric substrate (1).

6. A LoRa antenna according to claim 1, characterized in that: The dielectric substrate (1) is a PCB board with a length between 140 mm and 145 mm, a width between 7 mm and 7.4 mm, and a thickness between 0.8 mm and 1.2 mm.

7. A LoRa antenna according to claim 1, characterized in that: The bearing surface at the top of the dielectric substrate (1) is trapezoidal, and correspondingly, the serpentine array (8) is a thin copper sheet that is reciprocatingly bent and covers the trapezoidal bearing surface at the top of the dielectric substrate (1), one end of the thin copper sheet is connected to the tuning radiation sheet (7), and the other end extends vertically upward.

8. A LoRa antenna according to claim 1, characterized in that: The second radiation unit comprises a second radiation plate (401) located on the back side of the first radiation plate and two slender branches (402) symmetrically arranged on the back side of the tuning radiation plate (7).

9. A LoRa antenna according to claim 8, characterized in that: The width of the second radiation plate (401) is greater than the width of the first radiation plate, and the inner distance between the two branches (402) is greater than the width of the tuning radiation plate (7).

10. A LoRa antenna according to claim 1, characterized in that: The via hole (6) is located at one end of the first radiation plate close to the tuning radiation plate (7).

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