A buried antenna for narrowband Internet of Things

Abstract

The present invention provides an antenna for a narrowband Internet of Things buried underground, comprising an antenna body, the antenna body comprising a conductive sheet, the conductive sheet being provided with a U-shaped groove and a rectangular groove, one end of the rectangular groove being located in an opening of the U-shaped groove, and the rectangular groove being provided with a first feeding point and a second feeding point. The beneficial effects of the present invention are as follows: the present invention adopts a plane-symmetrical slotted PIFA antenna, which improves the anti-interference performance in a complex environment, increases the antenna bandwidth, and improves the antenna efficiency and gain, and can be used in the field of the Internet of Things such as remote intelligent meter reading.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to an underground antenna for narrowband Internet of Things. Background Art

[0002] NB-IoT Narrow Band Internet of Things (NB-IoT) has become an important branch of the Internet of Everything and is an emerging technology that can be widely used around the world. It has the characteristics of wide coverage, multiple connections, fast speed, low cost, low power consumption, and excellent architecture.

[0003] However, the bandwidth, efficiency and gain of antennas used in narrowband IoT cannot meet user needs, which needs to be urgently addressed. Summary of the invention

[0004] The present invention provides an antenna for narrowband Internet of Things buried underground, comprising an antenna body, wherein the antenna body comprises a conductive sheet, the conductive sheet is provided with a U-shaped groove and a rectangular groove, one end of the rectangular groove is located in an opening of the U-shaped groove, and the rectangular groove is provided with a first feeding point and a second feeding point.

[0005] As a further improvement of the present invention, the conductive sheet is a copper sheet made of copper material, and the first feeding point and the second feeding point are axially symmetrically arranged on both sides of the rectangular slot.

[0006] As a further improvement of the present invention, the long side length of the U-shaped groove is 39.2 mm, the short side length of the U-shaped groove is 34.4 mm, the width between the long side and the short side of the U-shaped groove is 9.6 mm, and the width between the two long sides of the U-shaped groove is 61.4 mm.

[0007] As a further improvement of the present invention, the length of the rectangular groove is 71.8 mm, and the width of the rectangular groove is 14 mm.

[0008] As a further improvement of the present invention, the length of the conductive sheet is 108 mm, the width of the conductive sheet is 82 mm, and the thickness of the conductive sheet is 0.5 mm.

[0009] As a further improvement of the present invention, two ends of the conductive sheet are respectively provided with a first protruding portion and a second protruding portion protruding outward.

[0010] As a further improvement of the present invention, the width of the first protrusion is 37.8 mm.

[0011] As a further improvement of the present invention, the outer edge of the bending portion of the U-shaped groove is respectively provided with a first recessed portion and a second recessed portion.

[0012] As a further improvement of the present invention, the antenna also includes a coaxial cable and a shell, one end of the coaxial cable is connected to the first feeding point and the second feeding point, the antenna body is installed on the top of the shell, and the other end of the coaxial cable extends from the bottom of the shell.

[0013] As a further improvement of the present invention, the thickness of the shell is 5 mm, the diameter of the shell is 122 mm, and the height of the shell is 79 mm; an SMA interface is installed at the other end of the coaxial cable, an open wire groove is provided at the bottom of the shell, the other end of the coaxial cable extends from the open wire groove, and a waterproof cap is installed at the open wire groove position.

[0014] The beneficial effects of the present invention are as follows: the present invention adopts a planar symmetrical slotted PIFA antenna, improves anti-interference performance in complex environments, increases antenna bandwidth, and improves antenna efficiency and gain, and can be used in the field of Internet of Things such as remote intelligent meter reading. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the main structure of the antenna of the present invention;

[0016] Figure 2 is a top view of the antenna of the present invention;

[0017] Figure 3 is a schematic diagram of the antenna structure of the present invention;

[0018] Figure 4 It is a schematic diagram of the usage scenario;

[0019] Figure 5 This is the antenna simulation model diagram;

[0020] Figure 6 It is the simulation S11 parameter diagram;

[0021] Figure 7 is the simulation gain graph;

[0022] Figure 8 It is the SWR graph tested by the network analyzer;

[0023] Fig. 9 This is the S11 diagram of the network analyzer test;

[0024] Fig.10 It is the XY plane orientation diagram;

[0025] Fig.11 It is the YZ plane orientation diagram;

[0026] Fig.12 It is the XZ plane orientation diagram. DETAILED DESCRIPTION

[0027] like Figure 1-4As shown, the present invention discloses a buried antenna for narrowband Internet of Things, including an antenna body 10, wherein the antenna body 10 includes a conductive sheet 5, wherein the conductive sheet 5 is provided with a U-shaped groove 3 and a rectangular groove 4, wherein one end of the rectangular groove 4 is located in an opening of the U-shaped groove 3, and the rectangular groove 4 is provided with a first feeding point 1 and a second feeding point 2.

[0028] The conductive sheet 5 is a copper sheet made of copper material, and the first feeding point 1 and the second feeding point 2 are axially symmetrically arranged on both sides of the rectangular slot 4 .

[0029] The first feeding point 1 and the second feeding point 2 are connected with a 50 ohm coaxial cable 11. The bandwidth and resonance frequency of the antenna can be changed by adjusting the spacing, length and width of the U-shaped slot 3 and the rectangular slot 4 and the positions of the first feeding point 1 and the second feeding point 2. By adopting a coaxial feeding method between the rectangular slots 4, an antenna form with vertical symmetry is realized, and the antenna is a PIFA antenna type, thereby improving the anti-interference performance of the antenna, thereby reducing the impact on the antenna in the harsh environment of the groundwater well and the ground surface, and greatly improving the overall radiation efficiency and gain of the antenna.

[0030] The length L1 of the long side of the U-shaped groove 3 is 39.2 mm, the length L2 of the short side of the U-shaped groove 3 is 34.4 mm, the width W1 between the long side and the short side of the U-shaped groove 3 is 9.6 mm, and the width W4 between the two long sides of the U-shaped groove 3 is 61.4 mm.

[0031] The length L3 of the rectangular groove 4 is 71.8 mm, and the width W2 of the rectangular groove 4 is 14 mm.

[0032] The length L of the conductive sheet 5 is 108 mm, the width W of the conductive sheet 5 is 82 mm, and the thickness of the conductive sheet 5 is 0.5 mm.

[0033] The conductive sheet 5 has two ends respectively provided with a first protruding portion 51 and a second protruding portion 52 protruding outward.

[0034] The width W3 of the first protruding portion 51 is 37.8 mm.

[0035] The outer edges of the bent portions of the U-shaped groove 3 are respectively provided with a first recessed portion 31 and a second recessed portion 32 .

[0036] The antenna also includes a coaxial cable 11 and a shell 12 . One end of the coaxial cable 11 is connected to the first feeding point 1 and the second feeding point 2 . The antenna body 10 is installed on the top of the shell 12 . The other end of the coaxial cable 11 extends from the bottom of the shell 12 .

[0037] The thickness H1 of the shell 12 is 5 mm, the diameter R2 of the shell 12 is 122 mm, the height H3 of the shell 12 is 79 mm, and the shell 12 is made of PVC material.

[0038] The other end of the coaxial cable 11 is installed with an SMA interface 14 .

[0039] A wire slot is provided at the bottom of the housing 12 , and the other end of the coaxial cable 11 extends out of the wire slot. A waterproof cap 13 is installed at the position of the wire slot.

[0040] The antenna body 10 is connected to the RG58*3 meter coaxial cable 11, which is convenient for installing the groundwater well and connecting it to the equipment.

[0041] The HFSS simulation software is used to simulate the buried surface of the antenna of the present invention. First, the HFSS model simulation verification (sweep frequency: 800-960Hz) of the antenna of the present invention is performed. Figure 5-7 shown.

[0042] Simulation results analysis: S11<-10db at antenna frequency 850-950MHz, maximum gain 7.9dbi.

[0043] The network analyzer tests the antenna standing wave ratio and return loss, such as Figure 8 and Fig. 9 shown.

[0044] ,

[0045] Antenna actual gain and efficiency table

[0046] Conclusion: By adopting the planar symmetrical slotted PIFA antenna, the actual standing wave ratio SWR in the NB-lot band (800-950MHz frequency) is less than 1.5, S11 is less than -10db, the maximum gain is 6.4dbi, and the efficiency reaches 50-80%. It can meet the complex usage requirements of antennas buried underground, and can be used in IoT fields such as remote smart meter reading and groundwater wells.

[0047] The present invention is an NB-lot antenna designed by simulating groundwater wells and the ground surface. The antenna adopts a planar symmetrical slotted PIFA antenna, which improves the anti-interference performance in complex environments, increases the antenna bandwidth, and improves the antenna efficiency and gain. It can be used in the field of Internet of Things such as remote smart meter reading.

[0048] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A buried antenna for narrowband Internet of Things, characterized by: The antenna comprises an antenna body (10), wherein the antenna body (10) comprises a conductive sheet (5), wherein the conductive sheet (5) is provided with a U-shaped groove (3) and a rectangular groove (4), wherein one end of the rectangular groove (4) is located in the opening of the U-shaped groove (3), wherein the rectangular groove (4) is provided with a first feeding point (1) and a second feeding point (2), wherein the first feeding point (1) and the second feeding point (2) are axially symmetrically arranged on both sides of the rectangular groove (4); a first recessed portion (31) and a second recessed portion (32) are respectively provided at the outer edge of the bent portion of the U-shaped groove (3); and a first protruding portion (51) and a second protruding portion (52) protruding outwards are respectively provided at both ends of the conductive sheet (5).

2. The antenna according to claim 1, characterized in that: The conductive sheet (5) is a copper sheet made of copper material.

3. The antenna according to claim 1, characterized in that: The length (L1) of the long side of the U-shaped groove (3) is 39.2 mm, the length (L2) of the short side of the U-shaped groove (3) is 34.4 mm, the width (W1) between the long side and the short side of the U-shaped groove (3) is 9.6 mm, and the width (W4) between the two long sides of the U-shaped groove (3) is 61.4 mm.

4. The antenna according to claim 1, characterized in that: The length (L3) of the rectangular groove (4) is 71.8 mm, and the width (W2) of the rectangular groove (4) is 14 mm.

5. The antenna according to claim 1, characterized in that: The length (L) of the conductive sheet (5) is 108 mm, the width (W) of the conductive sheet (5) is 82 mm, and the thickness of the conductive sheet (5) is 0.5 mm.

6. The antenna according to claim 1, characterized in that: The width (W3) of the first protruding portion (51) is 37.8 mm.

7. The antenna according to any one of claims 1 to 6, characterized in that: The antenna further comprises a coaxial cable (11) and a housing (12); one end of the coaxial cable (11) is connected to the first feeding point (1) and the second feeding point (2); the antenna body (10) is mounted on the top of the housing (12); and the other end of the coaxial cable (11) extends out from the bottom of the housing (12).

8. The antenna according to claim 7, characterized in that: The shell (12) has a thickness of 5 mm, a diameter of 122 mm, and a height of 79 mm; an SMA interface (14) is installed at the other end of the coaxial cable (11); a wire slot is provided at the bottom of the shell (12); the other end of the coaxial cable (11) extends out of the wire slot; and a waterproof cap (13) is installed at the position of the wire slot.

Images