Multiband antenna and smart meter

Abstract

The application provides a multi-band antenna and a smart meter. The multi-band antenna comprises a printed circuit board (PCB), a feeding unit, a multi-branch radiation unit arranged on the PCB, and an impedance matching unit. The multi-branch radiation unit is connected with a feeding end of the feeding unit. A radio frequency end of the feeding unit is connected with an external radio frequency transceiver to access radio frequency signals. The impedance matching unit is located between the multi-branch radiation unit and a power supply interface and is connected with the feeding end of the feeding unit. The multi-branch radiation unit is used to generate resonances of different frequencies under the action of the radio frequency signals transmitted by the feeding unit, so that the multi-band antenna works in multiple target frequency bands. The impedance matching unit is used to isolate the multi-branch radiation unit and the power supply interface, reduce the interference of the multi-branch radiation unit, improve the radiation efficiency and anti-interference capability of the multi-band antenna, and widen the coverage bandwidth of the multi-band antenna.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and more specifically, to a multi-band antenna and a smart meter. Background Technology

[0002] Based on the antenna system within smart meters, multiple functions can be achieved, including remote meter reading, data interaction, remote power outage, and safety alarm lights. With the development of the smart meter industry, the demand for built-in cellular antennas in meters is also increasing.

[0003] Currently, the mainboard of smart meters is usually designed as a double-layer board, and smart meters are powered by 220V, which greatly reduces the reception effect of the built-in cellular antenna. External antennas are more expensive, more easily damaged by external forces, and have greater line loss.

[0004] Therefore, the antenna design for smart meters in the existing technology has certain limitations. Utility Model Content

[0005] The purpose of this application is to address the shortcomings of the prior art by providing a multi-band antenna and a smart meter, thereby solving the practical problem of limitations in the antenna design for smart meters in the prior art.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0007] In a first aspect, embodiments of this application provide a multi-band antenna, including: a PCB, a feeding unit, a multi-branch radiating unit disposed on the PCB, and an impedance matching unit;

[0008] The multi-branch radiating element is connected to the feed terminal of the feeding element;

[0009] The radio frequency terminal of the power supply unit is connected to an external radio frequency transceiver to receive radio frequency signals;

[0010] The impedance matching unit is located between the multi-branch radiation unit and the power supply interface, and is connected to the feed terminal of the feed unit.

[0011] The multi-branch radiating element is used to generate resonances at different frequencies under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna can operate in multiple target frequency bands.

[0012] The impedance matching unit is used to isolate the multi-branch radiation unit and the power supply interface, and to reduce the interference of the multi-branch radiation unit.

[0013] As an optional implementation, the multi-branch radiating element includes: a first half-wave oscillator;

[0014] The first half-wave dipole generates a first resonance under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna operates in the first target frequency band, wherein the sum of the distances from the two ends of the first half-wave dipole to the feeding end of the feeding unit is half the wavelength of the first target frequency band.

[0015] As an optional implementation, the first half-wave oscillator includes: a first radiating branch and a second radiating branch arranged opposite each other in the vertical direction;

[0016] The ends of the first radiating branch and the ends of the second radiating branch resonate under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna operates in the first target frequency band. The distance from the end of the first radiating branch to the feeding end of the feeding unit and the distance from the end of the second radiating branch to the feeding end of the feeding unit are both one-quarter of the wavelength of the first target frequency band.

[0017] As an optional implementation, the multi-branch radiating element further includes: a second half-wave oscillator;

[0018] The second half-wave dipole generates a second resonance under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna operates in the second target frequency band, wherein the sum of the distances from the two ends of the second half-wave dipole to the feeding end of the feeding unit is half the wavelength of the second target frequency band.

[0019] As an optional implementation, the second half-wave oscillator includes: a third radiating branch and a fourth radiating branch arranged opposite each other in the vertical direction;

[0020] The ends of the third radiating branch and the fourth radiating branch resonate under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna operates in the second target frequency band. The distance from the end of the third radiating branch to the feeding end of the feeding unit and the distance from the end of the fourth radiating branch to the feeding end of the feeding unit are both one-quarter of the wavelength of the second target frequency band.

[0021] As an optional implementation, the multi-branch radiating element further includes: a fifth radiating branch disposed horizontally opposite to the third radiating branch;

[0022] The end of the fifth radiating branch parasitically generates a third resonance under the action of the radio frequency signal transmitted by the feed unit, so that the multi-band antenna operates in the third target frequency band, wherein the length of the fifth radiating branch is less than one-quarter wavelength of the third target frequency band.

[0023] As an optional implementation, the fifth radiating branch couples with the third radiating branch under the action of the radio frequency signal transmitted by the feeding unit to generate a fourth resonance, so that the multi-band antenna operates in the fourth target frequency band, wherein the third radiating branch and the fifth radiating branch are arranged in parallel.

[0024] As an optional implementation, the impedance matching unit includes: a balun coil;

[0025] The balun coil is located between the multi-branch radiating unit and the power supply interface, and is connected to the feed terminal of the feed unit to isolate the multi-branch radiating unit and the power supply interface, and reduce interference from the multi-branch radiating unit.

[0026] As an optional implementation, the first target frequency band is 700MHz-960MHz;

[0027] The second target frequency band is 1710MHz-2170MHz;

[0028] The third target frequency band is 2300MHz-2600MHz;

[0029] The fourth target frequency band is 2600MHz-2690MHz.

[0030] Secondly, embodiments of this application provide a smart meter, including: the multi-band antenna described in the first aspect above, wherein the multi-band antenna is snapped onto a buckle on the inner wall of the smart meter end cover.

[0031] The beneficial effects of this application are:

[0032] This application provides a multi-band antenna and a smart meter. The multi-band antenna includes a PCB, a feeding unit, a multi-branch radiating element mounted on the PCB, and an impedance matching unit. The feeding end of the feeding unit is connected to the multi-branch radiating element, and the RF end is connected to an external RF transceiver, transmitting RF signals to the multi-branch radiating element through the feeding unit. Under the influence of the RF signals transmitted by the feeding unit, the multi-branch radiating element generates resonances at different frequencies through different branches, enabling the multi-band antenna to operate in multiple different target frequency bands to cover low-frequency and mid-to-high-frequency bandwidths. The impedance matching unit isolates the multi-branch radiating element and the power supply interface, reducing interference from the multi-branch radiating element, thereby improving the receiving sensitivity, anti-interference capability, and radiation efficiency of the multi-band antenna, making the performance of the multi-band antenna more stable. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of a multi-band antenna provided in an embodiment of this application;

[0035] Figure 2 A schematic diagram of the voltage standing wave ratio (VSWR) of a multi-band antenna provided in an embodiment of this application;

[0036] Figure 3 This is a schematic diagram illustrating the radiation efficiency of a multi-band antenna provided in an embodiment of this application.

[0037] Icons: PCB: 10; Power supply unit: 20; Multi-branch radiating unit: 30; Impedance matching unit: 40; Power supply terminal: 21; RF terminal: 22; First half-wave oscillator: 31; Second half-wave oscillator: 32; First radiating branch: 311; Second radiating branch: 312; Third radiating branch: 321; Fourth radiating branch: 322; Fifth radiating branch: 33. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0040] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this application, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0041] In the description of this application, unless otherwise expressly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0042] Currently, the mainboard of smart meters is typically designed as a double-layer board, and the power supply voltage of smart meters is 220V. This has a significant impact on the noise of the built-in cellular antenna, resulting in a substantial reduction in the reception performance of the built-in cellular antenna. External antennas, on the other hand, are more expensive, more easily damaged by external forces, and have greater line loss. In other words, the antenna design for smart meters in existing technologies has certain limitations.

[0043] This application provides a multi-band antenna to address the aforementioned problems. The antenna includes a printed circuit board (PCB), a feeding unit, a multi-branch radiating element disposed on the PCB, and an impedance matching unit. The impedance matching unit isolates the multi-branch radiating element from the power supply interface, reduces interference from the multi-branch radiating element, and improves receiving sensitivity. The multi-branch radiating element resonates at different frequencies under the influence of the radio frequency signal transmitted by the feeding unit, enabling the multi-band antenna to operate in multiple target frequency bands. This improves the radiation efficiency and anti-interference capability of the multi-band antenna and broadens its coverage bandwidth.

[0044] Figure 1 This is a schematic diagram of the structure of a multi-band antenna provided in an embodiment of this application, as shown below. Figure 1 As shown, the multi-band antenna includes: PCB 10, feeding unit 20, multi-branch radiating unit 30 disposed on PCB 10, and impedance matching unit 40.

[0045] Optionally, refer to Figure 1 The multi-band antenna includes a PCB 10, a feeding unit 20, a multi-branch radiating unit 30, and an impedance matching unit 40. The multi-branch radiating unit 30 and the impedance matching unit 40 are disposed on the PCB 10.

[0046] For example, PCB 10 is made of flame-retardant grade 4 (FR4) material, where FR4 can be a glass fiber reinforced epoxy resin copper-clad laminate. Figure 1 The blue part represents PCB 10. PCB 10 can have a dielectric constant of 4.4, a thickness of 0.8 mm, a length of 132 mm, and a width of 52.6 mm.

[0047] The multi-branch radiation unit 30 is connected to the feed terminal 21 of the feed unit 20; the RF terminal 22 of the feed unit 20 is connected to an external RF transceiver to receive RF signals; the impedance matching unit 40 is located between the multi-branch radiation unit 30 and the power supply interface, and is connected to the feed terminal 21 of the feed unit 20.

[0048] Optionally, continue to refer to Figure 1 The multi-branch radiating unit 30 is etched on the PCB 10. The feed terminal 21 of the feed unit 20 is connected to the multi-branch radiating unit 30, and the RF terminal 22 is connected to an external RF transceiver to receive RF signals. Based on this connection method, RF signals are injected into the multi-branch radiating unit 30 through the feed unit 20.

[0049] For example, the power supply unit 20 can be a coaxial power supply line, specifically a 50-ohm coaxial power supply line, and the length of the 50-ohm coaxial power supply line can be 145mm.

[0050] Continue to refer to Figure 1 The green portion represents the impedance matching unit 40, located between the multi-branch radiating unit 30 and the power supply interface. The impedance matching unit 40 is connected to the feed terminal 21 of the feed unit 20 and the multi-branch radiating unit 30. For example, the power supply interface can be a 220V power supply interface for connecting a 220V power supply voltage.

[0051] The multi-branch radiating element 30 is used to generate resonances at different frequencies under the action of the radio frequency signal transmitted by the feeding unit 20, so that the multi-band antenna can operate in multiple target frequency bands.

[0052] Optionally, under the action of the radio frequency signal transmitted by the feed unit 20, the multi-branch radiating element 30 generates resonance at different frequencies through different branches, so that the multi-band antenna operates in multiple different target frequency bands.

[0053] Among them, the operating frequency band of the multi-band antenna can cover the low-frequency bandwidth of 700MHz-960MHz and the mid-to-high frequency bandwidth of 1700MHz-2690MHz.

[0054] Impedance matching unit 40 is used to isolate multi-branch radiation unit 30 and power supply interface, and to reduce interference of multi-branch radiation unit 30.

[0055] Optionally, the impedance matching unit 40 disposed between the multi-branch radiating unit 30 and the power supply interface plays an isolation role, which can effectively isolate the multi-branch radiating unit 30 from the power supply interface, reduce the interference of the power supply interface to the multi-branch radiating unit 30, thereby improving the receiving sensitivity of the multi-band antenna and making the performance of the multi-band antenna more stable.

[0056] Furthermore, since an impedance matching unit 40 is introduced at the feed terminal 21 of the feed unit 20, the impedance matching unit 40 can reduce the common-mode current, making the radiation of the multi-branch radiation unit 30 cleaner and improving the anti-interference capability and radiation efficiency of the multi-band antenna.

[0057] In this embodiment, the multi-band antenna includes a PCB, a feeding unit, a multi-branch radiating element mounted on the PCB, and an impedance matching unit. The feeding end of the feeding unit is connected to the multi-branch radiating element, and the RF end is connected to an external RF transceiver, transmitting RF signals to the multi-branch radiating element through the feeding unit. Under the influence of the RF signals transmitted by the feeding unit, the multi-branch radiating element generates resonances at different frequencies through different branches, enabling the multi-band antenna to operate in multiple different target frequency bands to cover low-frequency and mid-to-high-frequency bandwidths. The impedance matching unit isolates the multi-branch radiating element from the power supply interface, reducing interference from the multi-branch radiating element, thereby improving the receiving sensitivity, anti-interference capability, and radiation efficiency of the multi-band antenna, making the performance of the multi-band antenna more stable.

[0058] As an optional implementation, the multi-branch radiating element 30 includes: a first half-wave oscillator 31.

[0059] Optionally, the multi-branch radiation unit 30 includes a first half-wave dipole 31, which is in the form of a dipole and the total length of the two ends of the first half-wave dipole 31 is half the wavelength of the first target frequency band.

[0060] The first half-wave dipole 31 resonates under the action of the radio frequency signal transmitted by the feeding unit 20, causing the multi-band antenna to operate in the first target frequency band. The sum of the distances from the two ends of the first half-wave dipole 31 to the feeding end 21 of the feeding unit 20 is half the wavelength of the first target frequency band. The first target frequency band is 700MHz-960MHz.

[0061] Optionally, the feed terminal 21 of the feed unit 20 is located at the midpoint of the first half-wave dipole 31. The two ends of the first half-wave dipole 31 resonate under the action of the radio frequency signal transmitted by the feed unit 20, operating in fundamental mode, thus enabling the multi-band antenna to operate in the first target frequency band. The sum of the distances from the two ends of the first half-wave dipole 31 to the feed terminal 21 of the feed unit 20 is half the wavelength of the first target frequency band. Since the feed terminal 21 of the feed unit 20 is located at the midpoint of the first half-wave dipole 31, the total length of the two ends of the first half-wave dipole 31 is half the wavelength of the first target frequency band.

[0062] The first target frequency band is 700MHz-960MHz. That is to say, the two ends of the first half-wave dipole 31 resonate at 700MHz-960MHz under the action of the radio frequency signal transmitted by the feed unit 20, so that the multi-band antenna operates at 700MHz-960MHz.

[0063] In this embodiment, the multi-branch radiating element includes a first half-wave dipole, which is in dipole form. The two ends of the first half-wave dipole resonate under the influence of the radio frequency signal transmitted by the feeding unit, operating in fundamental mode, thus enabling the multi-band antenna to operate in the first target frequency band. The sum of the distances from the two ends of the first half-wave dipole to the feed end of the feeding unit is half the wavelength of the first target frequency band, and the total length of the two ends of the first half-wave dipole is half the wavelength of the first target frequency band. The first target frequency band is 700MHz-960MHz. The two ends of the first half-wave dipole resonate within the 700MHz-960MHz range under the influence of the radio frequency signal transmitted by the feeding unit, enabling the multi-band antenna to operate within this range. By generating the first resonance at the two ends of the first half-wave dipole, the multi-band antenna operates within the first target frequency band, covering a low-frequency bandwidth of 700MHz-960MHz.

[0064] As an optional implementation, the first half-wave oscillator 31 includes a first radiating branch 311 and a second radiating branch 312 that are arranged opposite each other in the vertical direction.

[0065] Optionally, continue to refer to Figure 1 The first half-wave oscillator 31 includes a first radiating branch 311 and a second radiating branch 312 arranged opposite each other in the vertical direction. Both the first radiating branch 311 and the second radiating branch 312 are connected to the feed terminal 21 of the feed unit 20.

[0066] The ends of the first radiating branch 311 and the ends of the second radiating branch 312 resonate under the action of the radio frequency signal transmitted by the feeding unit 20, so that the multi-band antenna operates in the first target frequency band. The distance from the end of the first radiating branch 311 to the feeding end 21 of the feeding unit 20 and the distance from the end of the second radiating branch 312 to the feeding end 21 of the feeding unit 20 are both one-quarter of the wavelength of the first target frequency band.

[0067] Optionally, the end of the first radiating branch 311 is the end away from the feed terminal 21 of the feed unit 20, i.e. Figure 1 The rightmost part of the first radiating branch 311. The distance from the end of the first radiating branch 311 to the feed terminal 21 of the feed unit 20 is one-quarter of the wavelength of the first target frequency band.

[0068] Correspondingly, the end of the second radiating branch 312 is also the end furthest from the feed terminal 21 of the feed unit 20, i.e. Figure 1 The leftmost part of the second radiation branch 312. The distance from the end of the second radiation branch 312 to the feed terminal 21 of the feed unit 20 is one-quarter of the wavelength of the first target frequency band.

[0069] The ends of the first radiating branch 311 and the second radiating branch 312 serve as the two ends of the first half-wave dipole 31. Under the action of the radio frequency signal transmitted by the feed unit 20, the first half-wave dipole 31 operates in the fundamental mode, so that the multi-band antenna operates in the first target frequency band.

[0070] In other words, the ends of the first radiating branch 311 and the ends of the second radiating branch 312 resonate at 700MHz-960MHz under the action of the radio frequency signal transmitted by the feed unit 20, so that the multi-band antenna operates at 700MHz-960MHz.

[0071] In this embodiment, the first half-wave dipole includes a first radiating branch and a second radiating branch arranged opposite each other in the vertical direction. The distance from the end of the first radiating branch to the feed end of the feed unit and the distance from the end of the second radiating branch to the feed end of the feed unit are both one-quarter of the wavelength of the first target frequency band. The ends of the first and second radiating branches serve as the two ends of the first half-wave dipole, generating a first resonance of 700MHz-960MHz under the action of the radio frequency signal transmitted by the feed unit, so that the multi-band antenna operates in the first target frequency band of 700MHz-960MHz.

[0072] As an optional implementation, the multi-branch radiating unit 30 further includes a second half-wave oscillator 32.

[0073] Optionally, continue to refer to Figure 1 The multi-branch radiation unit 30 also includes a second half-wave dipole 32, which is in the form of a dipole and the total length of the two ends of the second half-wave dipole 32 is half the wavelength of the second target frequency band.

[0074] The second half-wave dipole 32 resonates under the influence of the radio frequency signal transmitted by the feed unit 20, causing the multi-band antenna to operate in the second target frequency band. The sum of the distances from the two ends of the second half-wave dipole 32 to the feed terminal 21 of the feed unit 20 is half the wavelength of the second target frequency band. The second target frequency band is 1710MHz-2170MHz.

[0075] Optionally, the feed terminal 21 of the feed unit 20 is located at the midpoint of the second half-wave dipole 32. The two ends of the second half-wave dipole 32 generate a second resonance under the action of the radio frequency signal transmitted by the feed unit 20, operating in the fundamental mode, thus enabling the multi-band antenna to operate in the second target frequency band. The sum of the distances from the two ends of the second half-wave dipole 32 to the feed terminal 21 of the feed unit 20 is half the wavelength of the second target frequency band. Since the feed terminal 21 of the feed unit 20 is located at the midpoint of the second half-wave dipole 32, the total length of the two ends of the second half-wave dipole 32 is half the wavelength of the second target frequency band.

[0076] The second target frequency band is 1710MHz-2170MHz. That is to say, the two ends of the second half-wave dipole 32 resonate at 1710MHz-2170MHz under the action of the radio frequency signal transmitted by the feed unit 20, so that the multi-band antenna operates at 1710MHz-2170MHz.

[0077] In this embodiment, the multi-branch radiating element also includes a second half-wave dipole, which is in dipole form. The two ends of the second half-wave dipole generate a second resonance under the action of the radio frequency signal transmitted by the feeding unit, operating in fundamental mode, thus enabling the multi-band antenna to operate in the second target frequency band. Specifically, the sum of the distances from the two ends of the second half-wave dipole to the feed end of the feeding unit is half the wavelength of the second target frequency band, and the total length of the two ends of the second half-wave dipole is half the wavelength of the second target frequency band. The second target frequency band is 1710MHz-2170MHz. The two ends of the second half-wave dipole generate a resonance of 1710MHz-2170MHz under the action of the radio frequency signal transmitted by the feeding unit, enabling the multi-band antenna to operate in the 1710MHz-2170MHz range. By generating a second resonance at the two ends of the second half-wave dipole, the multi-band antenna operates in the second target frequency band, covering the intermediate frequency bandwidth of 1710MHz-2170MHz.

[0078] As an optional implementation, the second half-wave oscillator 32 includes a third radiating branch 321 and a fourth radiating branch 322 that are arranged opposite each other in the vertical direction.

[0079] Optionally, continue to refer to Figure 1 The second half-wave oscillator 32 includes a third radiating branch 321 and a fourth radiating branch 322 arranged opposite each other in the vertical direction. Both the third radiating branch 321 and the fourth radiating branch 322 are connected to the feed terminal 21 of the feed unit 20.

[0080] The ends of the third radiating branch 321 and the fourth radiating branch 322 resonate under the action of the radio frequency signal transmitted by the feeding unit 20, so that the multi-band antenna operates in the second target frequency band. The distance from the end of the third radiating branch 321 to the feeding end 21 of the feeding unit 20 and the distance from the end of the fourth radiating branch 322 to the feeding end 21 of the feeding unit 20 are both one-quarter of the wavelength of the second target frequency band.

[0081] Optionally, the end of the third radiating branch 321 is the end furthest from the feed terminal 21 of the feed unit 20, i.e. Figure 1 The rightmost part of the third radiation branch 321. The distance from the end of the third radiation branch 321 to the feed terminal 21 of the feed unit 20 is one-quarter of the wavelength of the second target frequency band.

[0082] Correspondingly, the end of the fourth radiating branch 322 is also the end furthest from the feed terminal 21 of the feed unit 20, i.e. Figure 1 The leftmost part of the fourth radiation branch 322. The distance from the end of the fourth radiation branch 322 to the feed terminal 21 of the feed unit 20 is one-quarter of the wavelength of the second target frequency band.

[0083] The ends of the third radiating branch 321 and the fourth radiating branch 322 serve as the two ends of the second half-wave dipole 32. Under the action of the radio frequency signal transmitted by the feed unit 20, the second half-wave dipole 32 generates a second resonance. The second half-wave dipole 32 operates in the fundamental mode, so that the multi-band antenna operates in the second target frequency band.

[0084] In other words, the ends of the third radiating branch 321 and the fourth radiating branch 322 resonate at 1710MHz-2170MHz under the action of the radio frequency signal transmitted by the feed unit 20, so that the multi-band antenna operates at 1710MHz-2170MHz.

[0085] In this embodiment, the second half-wave dipole includes a third radiating branch and a fourth radiating branch arranged opposite each other in the vertical direction. The distance from the end of the third radiating branch to the feed end of the feed unit and the distance from the end of the fourth radiating branch to the feed end of the feed unit are both one-quarter of the wavelength of the second target frequency band. The ends of the third and fourth radiating branches serve as the two ends of the second half-wave dipole, generating a second resonance of 1710MHz-2170MHz under the action of the radio frequency signal transmitted by the feed unit, so that the multi-band antenna operates in the second target frequency band of 1710MHz-2170MHz.

[0086] As an optional implementation, the multi-branch radiation unit 30 further includes a fifth radiation branch 33 disposed opposite to the third radiation branch in the horizontal direction.

[0087] Optionally, continue to refer to Figure 1 The multi-branch radiation unit 30 also includes a fifth radiation branch 33, which is horizontally positioned opposite the third radiation branch 321. Specifically, the fifth radiation branch 33 is located below the third radiation branch 321 and is relatively close to the third radiation branch 321 in the vertical direction. The fifth radiation branch 33 is a parasitic oscillator.

[0088] The fifth radiating branch 33 parasitically generates a third resonance at its end under the action of the radio frequency signal transmitted by the feed unit 20, causing the multi-band antenna to operate in the third target frequency band. The length of the fifth radiating branch 33 is less than one-quarter wavelength of the third target frequency band. The third target frequency band is 2300MHz-2600MHz.

[0089] Optionally, the end of the fifth radiating branch 33 is the end furthest from the feed terminal 21 of the feed unit 20, i.e. Figure 1 The rightmost part of the fifth radiating branch 33. The length of the fifth radiating branch 33 is slightly less than a quarter wavelength of the third target frequency band. Under the action of the radio frequency signal transmitted by the feed unit 20, the end of the fifth radiating branch 33 matches the wavelength of the third target frequency band, parasitically generating self-resonance, i.e., the third resonance, so that the multi-band antenna operates in the third target frequency band.

[0090] In other words, under the action of the radio frequency signal transmitted by the feed unit 20, the end of the fifth radiating branch 33 parasitically generates a self-resonance of 2300MHz-2600MHz, so that the multi-band antenna operates in the third target frequency band of 2300MHz-2600MHz.

[0091] In this embodiment, the multi-branch radiating element further includes a fifth radiating branch arranged horizontally opposite to the third radiating branch. The length of the fifth radiating branch is slightly less than a quarter wavelength of the third target frequency band. Under the action of the radio frequency signal transmitted by the feeding unit, the end of the fifth radiating branch parasitically generates a third resonance of 2300MHz-2600MHz, causing the multi-band antenna to operate in the third target frequency band of 2300MHz-2600MHz, covering a high-frequency bandwidth of 2300MHz-2600MHz.

[0092] As an optional implementation, the fifth radiating branch 33, under the influence of the radio frequency signal transmitted by the feed unit 20, couples with the third radiating branch 321 to generate a fourth resonance, causing the multi-band antenna to operate in the fourth target frequency band. The third radiating branch 321 and the fifth radiating branch 33 are arranged in parallel. The fourth target frequency band is 2600MHz-2690MHz.

[0093] Optionally, continue to refer to Figure 1The third radiating branch 321 and the fifth radiating branch 33 are arranged in parallel with a small vertical spacing, which facilitates mutual coupling. Specifically, under the action of the radio frequency signal transmitted by the feed unit 20, the fifth radiating branch 33 and the third radiating branch 321 generate a fourth resonance through electromagnetic coupling, so that the multi-band antenna operates in the fourth target frequency band.

[0094] In other words, the third radiating branch 321 and the fifth radiating branch 33, which are arranged in parallel to each other, are electromagnetically coupled under the action of the radio frequency signal transmitted by the feed unit 20, generating a resonance of 2600MHz-2690MHz, so that the multi-band antenna operates in the range of 2600MHz-2690MHz.

[0095] In this embodiment, the third and fifth radiating branches, which are arranged in parallel to each other, are electromagnetically coupled under the action of the radio frequency signal transmitted by the feed unit, generating a fourth resonance of 2600MHz-2690MHz, so that the multi-band antenna operates in the fourth operating frequency band of 2600MHz-2690MHz, covering the high-frequency bandwidth of 2600MHz-2690MHz.

[0096] It is worth noting that the first radiating branch 311, the fourth radiating branch 322, and the fifth radiating branch 33 constitute the antenna reference ground of the multi-band antenna.

[0097] As an optional implementation, the impedance matching unit 40 includes a balun coil.

[0098] The balun coil is located between the multi-branch radiation unit 30 and the power supply interface, and is connected to the power supply terminal 21 of the power supply unit 20 to isolate the multi-branch radiation unit 30 and the power supply interface, and reduce the interference of the multi-branch radiation unit 30.

[0099] Optionally, the impedance matching unit 40 is a balun (Balun) coil, i.e. Figure 1 As shown in the green section, the balun coil is the balun converter. Located between the multi-branch radiating element 30 and the power supply interface, the balun coil isolates the multi-branch radiating element 30 from the power supply interface, reducing interference from the power supply interface to the multi-branch radiating element 30. This, in turn, improves the receiving sensitivity of the multi-band antenna, making its performance more stable.

[0100] The balun coil is connected to the feed terminal 21 of the feed unit 20, which converts the unbalanced signal of the feed unit 20 into a balanced signal, ensuring the symmetry of the currents in the two arms of the dipole of the first half-wave dipole 31, that is, ensuring the symmetry of the currents in the first radiating branch 311 and the second radiating branch 312. It also ensures the symmetry of the currents in the two arms of the dipole of the second half-wave dipole 32, that is, ensuring the symmetry of the currents in the third radiating branch 321 and the fourth radiating branch 322, reducing common-mode current, making the radiation of the multi-branch radiating element 30 cleaner, and improving the anti-interference capability and radiation efficiency of the multi-band antenna.

[0101] In this embodiment, the impedance matching unit includes a balun coil, which is located between the multi-branch radiating element and the power supply interface, and connected to the feed terminal of the feeding unit to isolate the multi-branch radiating element and the power supply interface, and reduce interference from the multi-branch radiating element. The balun coil improves the receiving sensitivity and anti-interference performance of the multi-band antenna.

[0102] Figure 2 This is a schematic diagram of the voltage standing wave ratio (VSWR) of a multi-band antenna provided in an embodiment of this application. Figure 3 A schematic diagram illustrating the radiation efficiency of a multi-band antenna provided in an embodiment of this application, in conjunction with... Figure 2 and Figure 3 The multi-band antenna maintains a voltage standing wave ratio (VSWR) below 4.0 in each target frequency band, with a radiation efficiency exceeding 40%. Specifically, the multi-band antenna maintains a VSWR below 4.0 in the low-frequency bandwidth of 700MHz-960MHz and a mid-to-high-frequency bandwidth of 1700MHz-1690MHz, with a radiation efficiency exceeding 40%.

[0103] This application provides a smart meter, including: the multi-band antenna described in the foregoing embodiments, wherein the multi-band antenna is snapped onto a buckle on the inner wall of the smart meter end cover.

[0104] By attaching the multi-band antenna to the buckle on the inner wall of the smart meter's end cover, the multi-band antenna becomes the smart meter's built-in antenna, greatly improving the reception effect. It is also cheaper than an external antenna, less susceptible to damage from external forces, and can enhance the performance of the smart meter.

[0105] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A multi-band antenna, characterized in that, include: Printed circuit board (PCB), power supply unit, multi-branch radiating unit disposed on the PCB, and impedance matching unit; The multi-branch radiating element is connected to the feed terminal of the feeding element; The radio frequency terminal of the power supply unit is connected to an external radio frequency transceiver to receive radio frequency signals; The impedance matching unit is located between the multi-branch radiation unit and the power supply interface, and is connected to the feed terminal of the feed unit. The multi-branch radiating element is used to generate resonances at different frequencies under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna can operate in multiple target frequency bands. The impedance matching unit is used to isolate the multi-branch radiation unit and the power supply interface, and to reduce the interference of the multi-branch radiation unit.

2. The multi-band antenna according to claim 1, characterized in that, The multi-branch radiating element includes: a first half-wave oscillator; The first half-wave dipole generates a first resonance under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna operates in the first target frequency band, wherein the sum of the distances from the two ends of the first half-wave dipole to the feeding end of the feeding unit is half the wavelength of the first target frequency band.

3. The multi-band antenna according to claim 2, characterized in that, The first half-wave oscillator includes: a first radiating branch and a second radiating branch arranged opposite each other in the vertical direction; The ends of the first radiating branch and the ends of the second radiating branch resonate under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna operates in the first target frequency band. The distance from the end of the first radiating branch to the feeding end of the feeding unit and the distance from the end of the second radiating branch to the feeding end of the feeding unit are both one-quarter of the wavelength of the first target frequency band.

4. The multi-band antenna according to claim 1, characterized in that, The multi-branch radiating unit further includes: a second half-wave oscillator; The second half-wave dipole generates a second resonance under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna operates in the second target frequency band, wherein the sum of the distances from the two ends of the second half-wave dipole to the feeding end of the feeding unit is half the wavelength of the second target frequency band.

5. The multi-band antenna according to claim 4, characterized in that, The second half-wave oscillator includes: a third radiating branch and a fourth radiating branch arranged opposite each other in the vertical direction; The ends of the third radiating branch and the fourth radiating branch resonate under the action of the radio frequency signal transmitted by the feeding unit, so that the multi-band antenna operates in the second target frequency band. The distance from the end of the third radiating branch to the feeding end of the feeding unit and the distance from the end of the fourth radiating branch to the feeding end of the feeding unit are both one-quarter of the wavelength of the second target frequency band.

6. The multi-band antenna according to claim 5, characterized in that, The multi-branch radiation unit further includes: a fifth radiation branch disposed horizontally opposite to the third radiation branch; The end of the fifth radiating branch parasitically generates a third resonance under the action of the radio frequency signal transmitted by the feed unit, so that the multi-band antenna operates in the third target frequency band, wherein the length of the fifth radiating branch is less than one-quarter wavelength of the third target frequency band.

7. The multi-band antenna according to claim 6, characterized in that, The fifth radiating branch couples with the third radiating branch under the action of the radio frequency signal transmitted by the feed unit to generate a fourth resonance, so that the multi-band antenna operates in the fourth target frequency band, wherein the third radiating branch and the fifth radiating branch are arranged in parallel.

8. The multi-band antenna according to claim 1, characterized in that, The impedance matching unit includes: a balun coil; The balun coil is located between the multi-branch radiating unit and the power supply interface, and is connected to the feed terminal of the feed unit to isolate the multi-branch radiating unit and the power supply interface, and reduce interference from the multi-branch radiating unit.

9. The multi-band antenna according to any one of claims 1-7, characterized in that, The first target frequency band is 700MHz-960MHz; The second target frequency band is 1710MHz-2170MHz; The third target frequency band is 2300MHz-2600MHz; The fourth target frequency band is 2600MHz-2690MHz.

10. A smart meter, characterized in that, include: The multi-band antenna according to any one of claims 1-9, wherein the multi-band antenna is snapped onto a buckle on the inner wall of the end cover of the smart meter.

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