A three-way common-aperture hetero-frequency decoupling series-fed antenna and radio frequency communication equipment

Abstract

The application discloses a three-working-mode common-aperture different-frequency decoupling series-fed antenna and a radio frequency communication device, which has three independent input ports, each of which supports one working frequency band, and the three input ports are supported by three coaxial feed lines, the three coaxial feed lines include a first coaxial feed line, a second coaxial feed line and a third coaxial feed line, and the application comprises a multi-frequency series-fed radiator, which is provided with a multi-frequency current regulation structure and is used for realizing horizontal omnidirectional high-gain vertical polarization radiation mode of three working frequency bands; and a filtering structure, each working frequency band corresponds to one filtering structure, and the filtering structure is used for realizing independent working response of the three working frequency bands and high isolation between different-frequency ports. Through the design of the multi-frequency series-fed radiator and the filtering structure, the antenna realizes three-working-mode common-aperture working through a single antenna body and has the characteristics of high-gain horizontal omnidirectional radiation and different-frequency decoupling.

Description

Technical Field

[0001] This invention relates to the field of radio frequency communication technology, specifically to a three-channel common aperture decoupled series-fed antenna and radio frequency communication equipment. Background Technology

[0002] Wireless communication technology is booming, with new concepts such as the Internet of Things, satellite data communication, and 6G being proposed, further changing people's lives. With the large-scale application of next-generation wireless communication technologies such as 5G and WiFi 7, communication scenarios are evolving towards faster speeds, lower latency, higher throughput, and more connections. At the physical level, the bandwidth and number of frequency bands in a communication system are directly related to its communication capabilities. Therefore, for communication devices, support for more frequency bands and protocols, higher integration, and smaller size are inevitable development directions. For example, multiple communication protocols such as 4G / 5G, WiFi 7, C-V2X, DSRC, satellite communication, and navigation positioning need to be integrated into a single communication device, making multi-frequency communication a typical scenario in wireless communication system design. Stronger communication capabilities and support for more frequency bands usually mean a larger scale of radio frequency circuitry, which contradicts the current development direction of communication devices. Due to application scenario limitations, the size and weight of communication devices are often constrained, especially for consumer-facing products such as mobile phones and WiFi devices, where size, weight, and system complexity are sensitive to usage scenarios and costs. Miniaturization, integration, and weight reduction of RF front-end circuits and devices are trends in the development of modern wireless communication equipment. This also solves other problems, such as enhancing system stability in harsh environments and reducing losses introduced by cascaded components.

[0003] Currently, there are several common design approaches for antennas and some front-end circuits in multi-frequency communication systems. The first approach involves independent antennas for each frequency band, with cascaded filters achieving inter-frequency decoupling. This method results in a large antenna count proportional to the number of supported frequency bands, leading to a large aperture and deteriorating radiation patterns due to interference between antenna radiating elements. Furthermore, the cascaded filters consume significant system space. The second approach uses a filter antenna design, integrating the filter with the antenna design. This eliminates the need for additional cascaded filters, achieving inter-frequency decoupling and effectively reducing the size and complexity of the circuitry. However, the aperture issue remains unresolved. For example, a tri-band router using 2×2 MIMO technology has six antennas, the same number as the first approach. The third approach uses a multiplexer cascaded with broadband or multi-frequency antennas. This method reduces the number of antennas, but the multiplexer circuitry occupies considerable system space. As can be seen, current solutions have issues with aperture size and system space requirements. By integrating multiplexing functionality into a filter antenna, multiplexing can be achieved with a single antenna without the need for additional multiplexing and filtering circuits. This enables a filter antenna with multiplexing, common aperture, and different frequency decoupling, which is expected to solve the problems existing in current designs. This is a possible solution for multi-frequency communication scenarios in future wireless communication systems, and it is also the technical challenge that this invention aims to overcome. Summary of the Invention

[0004] To overcome the aforementioned shortcomings and deficiencies of the prior art, the first objective of this invention is to provide a three-channel common-aperture, different-frequency decoupled series-fed antenna. This antenna achieves horizontal omnidirectional high-gain vertical polarization radiation modes in three operating frequency bands through a multi-frequency series-fed radiator design, and achieves independent operating responses for the three operating frequency bands and high isolation between different-frequency ports through a filter structure design.

[0005] The second objective of this invention is to provide a radio frequency communication device comprising the aforementioned three-channel common-aperture, different-frequency decoupled series-fed antenna.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A three-channel common-aperture, different-frequency decoupled series-fed antenna has three independent input ports, each supporting one operating frequency band. The three input ports are supported by three coaxial feed lines, including a first coaxial feed line, a second coaxial feed line, and a third coaxial feed line.

[0008] A multi-frequency series-fed radiator, wherein the multi-frequency series-fed radiator is provided with a multi-frequency current control structure to realize horizontal omnidirectional high-gain vertical polarization radiation modes in three operating frequency bands;

[0009] The filter structure has one filter structure for each operating frequency band, which realizes independent operating response of the three operating frequency bands and high isolation between different frequency ports.

[0010] Furthermore, the multi-frequency series-fed radiator includes a radiator, a metal feed line, a metal stub, a choke, and a metal ground plane;

[0011] There are four radiators, which are arranged from bottom to top as a first radiator, a second radiator, a third radiator and a fourth radiator, wherein the first radiator is disposed on the back side of the dielectric substrate and the other radiators are disposed on the front side of the dielectric substrate.

[0012] The metal feed line includes a first metal feed line, a second metal feed line, and a third metal feed line. The three metal feed lines are alternately arranged with four radiators. The first metal feed line and the second metal feed line are arranged on the front side of the dielectric substrate. The third metal feed line includes two parts, one part is arranged on the front side of the dielectric substrate, and the other part is arranged on the back side of the dielectric substrate. The metal branch is arranged in the middle of the front side portion of the third metal feed line.

[0013] The choke includes a high-frequency choke and a low-frequency choke, with the high-frequency choke disposed at the top of the first radiator and the low-frequency choke disposed at the bottom of the dielectric substrate.

[0014] The metal floor includes a first metal floor and a second metal floor, both of which are composed of two metal layers and a dense array of metal vias passing through the dielectric substrate. The first metal floor is disposed at the bottom of the first radiator and serves as the electrical ground for the low-frequency band; the second metal floor is disposed at the bottom of the second radiator and serves as the common electrical ground for the first high-frequency band and the second high-frequency band.

[0015] Furthermore, the filtering structure includes a low-frequency filtering structure, a first high-frequency filtering structure, and a second high-frequency filtering structure. The low-frequency filtering structure is disposed on the first radiator, and the first and second high-frequency filtering structures are disposed on the second radiator, arranged left and right about the longitudinal centerline of the second radiator. A U-shaped resonator and a metal fence structure are disposed between the first and second high-frequency filtering structures to generate a transmission zero point and improve isolation.

[0016] Furthermore, the third metal radiator is provided with a U-shaped groove. The U-shaped groove resonates in the low-frequency range, so that the third radiator does not radiate; the U-shaped groove does not resonate in the high-frequency range, so that the current of the third radiator is in phase with that of the second and fourth radiators.

[0017] The third metal feed line is a straight feed line on the front side of the dielectric substrate and a curved feed line on the back side of the dielectric substrate. The straight feed line and the curved feed line are connected by metal vias. The straight feed line, the curved feed line, the metal stubs and the U-shaped groove constitute a multi-frequency current control structure. The metal stubs can prevent low-frequency current from passing through the straight feed line.

[0018] Furthermore, in the low-frequency band, the first radiator, the high-frequency choke, and the second radiator constitute a radiating element, and the fourth radiator, the third metal feed line, and the metal stub constitute another radiating element. The two radiating elements generate in-phase horizontal omnidirectional radiation, making the multi-frequency series-fed radiator equivalent to a second-order series-fed antenna in the low-frequency band.

[0019] In the first and second high frequency bands, the high frequency choke prevents the current from flowing downward to the first radiator, and the multi-frequency current control structure makes the second, third, and fourth radiators radiate in phase, which is equivalent to a third-order series-fed antenna.

[0020] Furthermore, the low-frequency filtering structure includes a first short-circuit resonator and a second short-circuit resonator, which are respectively disposed on different sides of the dielectric substrate. The outer conductor of the first coaxial feed line is soldered to the first metal ground plane, and its inner conductor passes through the dielectric substrate and is soldered to the first short-circuit resonator to form a first loop current closed loop to excite the antenna with a magnetic field.

[0021] The first high-frequency filter structure includes a third short-circuit resonator and a fourth short-circuit resonator, which are respectively disposed on different sides of the dielectric substrate. The outer conductor of the second coaxial feed line is welded to the second metal ground, and its inner conductor passes through the dielectric substrate and is welded to the third short-circuit resonator to form a second loop current closed loop to excite the antenna with a magnetic field.

[0022] The second high-frequency filter structure includes a fifth short-circuit resonator and a sixth short-circuit resonator, which are respectively disposed on different sides of the dielectric substrate. The outer conductor of the third coaxial feed line is soldered to the second metal ground plane, and its inner conductor passes through the dielectric substrate and is soldered to the fifth short-circuit resonator to form a third annular closed loop to excite the antenna with a magnetic field.

[0023] Furthermore, the coupling between the first loop current closed loop and the first short-circuit resonator is magnetic coupling, the coupling between the first loop current closed loop and the second short-circuit resonator is magnetic coupling, and the coupling between the second loop current closed loop and the third short-circuit resonator is magnetic coupling, the coupling between the second loop current closed loop and the fourth short-circuit resonator is magnetic coupling, and the coupling between the second loop current closed loop and the multi-frequency series-fed radiator is magnetic coupling; the coupling between the third loop current closed loop and the fifth short-circuit resonator is magnetic coupling, the coupling between the third loop current closed loop and the sixth short-circuit resonator is magnetic coupling, and the coupling between the third loop current closed loop and the multi-frequency series-fed radiator is magnetic coupling.

[0024] Furthermore, the coupling between the first short-circuit resonator and the multi-frequency series-fed radiator is electrical coupling; the coupling between the second short-circuit resonator and the multi-frequency series-fed radiator is magnetic coupling; the coupling between the third short-circuit resonator and the multi-frequency series-fed radiator is electrical coupling; the coupling between the fourth short-circuit resonator and the multi-frequency series-fed radiator is magnetic coupling; the coupling between the fifth short-circuit resonator and the multi-frequency series-fed radiator is electrical coupling; and the coupling between the sixth short-circuit resonator and the multi-frequency series-fed radiator is magnetic coupling.

[0025] Furthermore, in each operating frequency band, a closed loop current circuit, a multi-frequency series feed radiator, and two short-circuit resonators form a four-corner filter topology. The closed loop current circuit is the source node, the multi-frequency series feed radiator is the load node, and the two short-circuit resonators are the two resonant nodes. Through the coupling relationship of the above parts, a second-order bandpass filter response is generated, producing a radiation null point at the upper and lower edges of the passband. The filter structure of each frequency band uses the multi-frequency series feed radiator as a common node to form a multiplexed topology.

[0026] A radio frequency communication device includes the aforementioned three-channel common aperture decoupled series-fed antenna.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] (1) The antenna of this invention proposes a three-way common aperture design, in which multiple independently operating frequency bands share a multi-frequency series feed radiator. Through the filter structure design, three-way operation can be achieved without additional multiplexing circuits and filter circuits, effectively reducing the antenna aperture, effectively reducing the system volume and improving the integration. Each frequency band achieves a second-order bandpass filter response, generating radiation nulls outside the band, which has the effect of high roll-off suppression outside the band, generating transmission nulls between different frequency ports, and realizing different frequency decoupling.

[0029] (2) The antenna of the present invention proposes a multi-frequency series feed radiator design. Through the regulation of the multi-frequency current control structure, different parts of the radiation structure are used to perform in-phase radiation in the low frequency band, the first high frequency band and the second high frequency band, which has the effect of high-gain horizontal omnidirectional vertical polarization radiation.

[0030] (3) The low-frequency band, the first high-frequency band, and the second high-frequency band of the three-channel common aperture antenna of the present invention can cover the three working frequency bands of WiFi, namely 2.4-2.485GHz, 5.15-5.35GHz, and 5.725-5.925GHz, respectively, which have a wide range of application scenarios and commercial prospects. The number of antennas is reduced to one-third of that of discrete simplex antennas, which effectively reduces costs, reduces volume, reduces system complexity, reduces obstruction between multiple antennas, and improves coverage performance. The antenna adopts ordinary PCB board design, has mature manufacturing process, and can be mass-produced. It is especially suitable for cost-sensitive, structural and space-constrained, and system integration-required scenarios. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the present invention;

[0032] Figure 2 (a), (b), and (c) are structural diagrams of a three-channel common-aperture different-frequency decoupled series-fed antenna according to Embodiment 1 of the present invention from various perspectives.

[0033] Figure 3 (a), (b), and (c) are detailed structural diagrams of the antenna described in Embodiment 1 of the present invention, respectively.

[0034] Figure 4 This is a filter topology diagram of Embodiment 1 of the present invention;

[0035] Figure 5 Figures (a) and (b) are port S-parameter curves of the antenna described in Embodiment 1 of the present invention;

[0036] Figure 6 This is a gain curve diagram of Embodiment 1 of the present invention;

[0037] Figure 7 In Figures (a) and (b), the vertical and horizontal radiation patterns of the antenna described in Embodiment 1 of the present invention at 2.45 GHz are shown.

[0038] Figure 8 In Figures (a) and (b), the vertical and horizontal radiation patterns of the antenna described in Embodiment 1 of the present invention are shown.

[0039] Figure 9 In Figures (a) and (b), the vertical and horizontal radiation patterns of the antenna at 5.85 GHz of Embodiment 1 of the present invention are shown. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0041] Example 1

[0042] like Figure 1 and Figure 2 As shown in (a), (b), and (c), this embodiment provides a tri-channel, common-aperture, heterogeneous-frequency decoupled series-fed antenna with three independent input ports, each supporting one operating frequency band and radiating using the same antenna body. The three independent input ports are supported by three independent coaxial feed lines: a first coaxial feed line 2, a second coaxial feed line 3, and a third coaxial feed line 4, supporting tri-channel operation at a low frequency band of 2.4 GHz, a first high frequency band of 5.2 GHz, and a second high frequency band of 5.8 GHz.

[0043] The antenna comprises a dielectric substrate 1, a multi-frequency series feed radiator 26, and a filtering structure. The overall dimensions of the antenna are 180 × 25 × 0.762 mm. 3 The multi-frequency series-fed radiator 26 includes a radiator, a metal feed line, a metal stub 14, a choke, and a metal ground plane, supporting three-band horizontal omnidirectional high-gain vertical polarization radiation modes. The filtering structure has three independent parts, one for each operating frequency band, supporting independent filtering responses for the three bands and high isolation between different frequency ports. The antenna adopts a single-layer PCB design, printed on both sides of the dielectric substrate 1, namely the front and back sides of the dielectric substrate.

[0044] Furthermore, there are four radiators, which are arranged from bottom to top as first radiator 7, second radiator 8, third radiator 9 and fourth radiator 10, wherein the first radiator 7 is disposed on the back side of the dielectric substrate, and the second, third and fourth radiators are disposed on the front side of the dielectric substrate.

[0045] Furthermore, the metal feed line includes a first metal feed line 11, a second metal feed line 12, and a third metal feed line. The three metal feed lines are alternately arranged with four radiators. The first metal feed line 11 and the second metal feed line 12 are single-layered on the front side of the dielectric substrate and are straight. The third metal feed line is arranged in two layers. The third metal feed line on the front side of the dielectric substrate is a straight feed line 13, and the third metal feed line on the back side of the dielectric substrate is a curved feed line 15. The straight feed line 13 and the curved feed line 15 are connected by metal vias. The metal stub 14 is arranged in the middle of the straight feed line 13 and has the function of choking current.

[0046] Furthermore, there are two chokes, namely a high-frequency choke 24 and a low-frequency choke 25. The high-frequency choke 24 is disposed on the top of the first radiator 7, and the low-frequency choke 25 is disposed on the bottom of the dielectric substrate 1.

[0047] Furthermore, there are two metal floor plates, including a first metal floor plate 5 and a second metal floor plate 6. The first metal floor plate 5 is located at the bottom of the first radiator 7 and serves as the electrical ground for the low-frequency band. The second metal floor plate 6 is located at the bottom of the second radiator 8 and serves as the common electrical ground for the first and second high-frequency bands. Both the first and second metal floor plates are composed of two metal layers and a dense array of metal vias passing through the dielectric substrate. The two metal layers of each metal floor plate are of equal size.

[0048] Furthermore, the series-fed radiating structure consists of multiple half-wavelength structures. For the two operating frequency bands of the frequency doubling, the current on some radiators will be out of phase in one of the bands, resulting in a decrease in gain. In order to generate horizontal omnidirectional high-gain radiation in all three frequency bands, a series of designs were made on the multi-frequency series-fed radiator 26. First, a U-shaped slot is set on the third radiator 9. The U-shaped slot resonates in the low-frequency band, so that the third radiator 9 does not radiate. If the U-shaped slot is not added, the current on the third radiator 9 is out of phase relative to the other radiators in the low-frequency band. The U-shaped slot does not resonate in the high-frequency band, and the current direction on the third radiator 9 is the same as when the U-shaped slot is not added, radiating in phase with the currents of the second and fourth radiators, which is the desired mode.

[0049] Furthermore, the straight feed line 13, the curved feed line 15, the metal branch 14, and the U-shaped groove in the third metal feed line constitute as follows: Figure 3 The multi-frequency current control structure shown in Figure (c) adjusts the current phase. In the low-frequency band, the current cannot flow through the straight feed line 13 due to the cutoff of the metal stub 14, but can only flow through the curved feed line 15, resulting in appropriate phase adjustment. This allows the fourth radiator 10, the third metal feed line, and the metal stub 14 to form one radiating element, while the first radiator 7, the high-frequency choke 24, and the second radiator 8 form another radiating element. The two radiating elements generate in-phase horizontal omnidirectional radiation, making the multi-frequency series-fed radiator 26 equivalent to a second-order series-fed antenna in the low-frequency band. In the first and second high-frequency bands, the high-frequency choke 24 prevents the current from flowing downward to the first radiator 7. The multi-frequency current control structure works in the high-frequency band so that the metal stub 14 does not generate a cutoff current, and the current can pass through the straight feed line 13, making the second radiator 8, the third radiator 9, and the fourth radiator 10 radiate in phase, equivalent to a third-order series-fed antenna.

[0050] Furthermore, the filtering structure includes a low-frequency filtering structure, a first high-frequency filtering structure, and a second high-frequency filtering structure. The low-frequency filtering structure is located at the first radiator 7, and the filtering structures for the first and second high-frequency bands are located at the second radiator 8, arranged to the left and right of the longitudinal centerline of the second radiator.

[0051] Furthermore, such as Figure 3As shown in Figure (a), the low-frequency filtering structure includes a first short-circuit resonator 16 and a second short-circuit resonator 19, both of which are quarter-wavelength short-circuit resonators. The first short-circuit resonator 16 is disposed on the back side of the dielectric substrate, and the second short-circuit resonator 19 is disposed on the front side of the dielectric substrate. The outer conductor of the first coaxial feed line 2 is soldered to the front side of the first metal ground plane 5, and the inner conductor passes through the dielectric substrate 1 and is soldered to the first short-circuit resonator 16, forming a first loop current closed circuit to excite the antenna with a magnetic field.

[0052] like Figure 3 As shown in Figure (b), the filtering structure in the first high-frequency band includes a third short-circuit resonator 17 and a fourth short-circuit resonator 20, both of which are quarter-wavelength short-circuit resonators. The third short-circuit resonator 17 is disposed on the front side of the dielectric substrate, and the fourth short-circuit resonator 20 is disposed on the back side of the dielectric substrate. The outer conductor of the second coaxial feed line 3 is soldered to the back side of the second metal ground plane 6, and the inner conductor passes through the dielectric substrate 1 and is soldered to the third short-circuit resonator 17, forming a second loop current closed circuit to excite the antenna with a magnetic field.

[0053] The filtering structure in the second high-frequency band includes a fifth short-circuit resonator 18 and a sixth short-circuit resonator 21, both of which are quarter-wavelength short-circuit resonators. The fifth short-circuit resonator 18 is disposed on the front side of the dielectric substrate, and the sixth short-circuit resonator 21 is disposed on the back side of the dielectric substrate. The outer conductor of the third coaxial feed line is soldered to the back side of the second metal ground plane 6, and the inner conductor passes through the dielectric substrate 1 and is soldered to the fifth short-circuit resonator 18 to form a third annular closed loop to excite the antenna with a magnetic field.

[0054] Furthermore, in order to further enhance the isolation between the first high-frequency band port and the second high-frequency band port, a U-shaped resonator 22 and a metal fence structure 23 are provided between the filter structure of the first high-frequency band and the filter structure of the second high-frequency band, which can generate a transmission zero point and improve the isolation.

[0055] Furthermore, by modeling and analyzing the above filter structure, we can obtain the following: Figure 4 The filter topology diagram is shown below. The first loop current closed loop is node S1, and its coupling with the first short-circuit resonator 16 is M. S1,1 For magnetic coupling, the coupling M between the magnetic coupling and the second short-circuit resonator 19 S1,2 For magnetic coupling, the coupling M between the multi-frequency series feed radiator 26 and the magnetic coupling S1,L The coupling is magnetic; the second loop current closed loop is node S2, and its coupling with the third short-circuit resonator 17 is M. S2,3 For magnetic coupling, the coupling M between the magnetic coupling and the fourth short-circuit resonator 20 S2,4 For magnetic coupling, the coupling M between the multi-frequency series feed radiator 26 and the magnetic coupling S2,LThe coupling is magnetic; the third loop current closed loop is node S3, and its coupling with the fifth short-circuit resonator 18 is M. S3,5 For magnetic coupling, the coupling M between the magnetic coupling and the sixth short-circuit resonator 21 S3,6 For magnetic coupling, the coupling M between the multi-frequency series feed radiator 26 and the magnetic coupling S3,L It is magnetically coupled.

[0056] Furthermore, the coupling M between the first short-circuit resonator 16 and the multi-frequency string feed radiator 26 1,L For electrical coupling, the coupling M between the second short-circuit resonator 19 and the multi-frequency string feed radiator 26 is... 2,L For magnetic coupling; the coupling M between the third short-circuit resonator 17 and the multi-frequency string feed radiator 26 3,L For electrical coupling, the coupling M between the fourth short-circuit resonator 20 and the multi-frequency series feed radiator 26 is... 4,L For magnetic coupling; the coupling M between the fifth short-circuit resonator 18 and the multi-frequency string feed radiator 26 5,L For electrical coupling, the coupling M between the sixth short-circuit resonator 21 and the multi-frequency string feed radiator 26 is... 6,L It is magnetically coupled.

[0057] Furthermore, in the filtering structure of each frequency band, a closed loop current circuit, a multi-frequency series feed radiator, and two short-circuit resonators form a four-corner filtering topology. The closed loop current circuit is the source node, the multi-frequency series feed radiator is the load node, and the two short-circuit resonators are the two resonant nodes. Through the above coupling relationship, a second-order bandpass filtering response is generated, and a radiation null point is generated at the upper and lower edges of the passband respectively. The filtering structure of each frequency band uses the multi-frequency series feed radiator as a common node to form a multiplexed topology.

[0058] Furthermore, unlike the structure of a cascaded multiplexer antenna, in this embodiment all structures are on the antenna, and all structures can radiate, reducing cascading losses and improving system efficiency. The first, third, and fifth short-circuit resonators can radiate directly into free space, the second, fourth, and sixth short-circuit resonators can radiate directly into free space, and the multi-frequency series feed radiator 26 can radiate directly into free space.

[0059] Furthermore, the above coupling relationships and methods for adjusting the coupling strength are explained in conjunction with specific physical structures. Magnetic coupling M S1,1 M S2,3 M S3,5 The strength is related to the area of ​​the closed loop current ring. Therefore, by adjusting the welding height of the inner conductor of the coaxial feeder, the area can be adjusted, thereby adjusting the magnetic coupling strength between the first, second, and third closed loop current rings and the first, third, and fifth short-circuit resonators.

[0060] Furthermore, by adjusting the interval between the second / fourth / sixth short-circuit resonator and the first / second / third loop current closed loop, the magnetic coupling M is adjusted. S1,2 M S2,4 M S3,6 The intensity.

[0061] Furthermore, a narrow gap exists between the first / third / fifth short-circuit resonators and the multi-frequency series-fed radiator 26. By adjusting the gap width, the electrical coupling strength is made greater than the magnetic coupling strength, resulting in an overall electrical coupling type. The electrical coupling M is adjusted by modifying the gap width. 1,L M 3,L M 5,L The intensity.

[0062] Furthermore, in order to generate magnetic coupling between the second / fourth / sixth short-circuit resonator and the multi-frequency series-fed radiator 26, slots are provided at the open-circuit ends of the second / fourth / sixth short-circuit resonators of the multi-frequency series-fed radiator 26. According to the electromagnetic field distribution generated by the quarter-short-circuit resonator, the electric field is strongest at the open-circuit end. Setting slots can reduce electric coupling, thereby making the overall coupling type magnetic coupling. By adjusting the size of the slots, the magnetic coupling M can be adjusted. 2,L M 4,L M 6,L The intensity.

[0063] like Figure 5 Figures (a) and (b) show the simulated S-parameter curves of this embodiment. Figure 5 As shown in (a), S 11 The -10dB bandwidth of the (2.4G port) can cover the 2.4-2.485GHz frequency band. 22 The -10dB bandwidth of the (5.2G port) can cover the 5.15-5.35GHz frequency band. 33 The -10dB bandwidth of the (5.8G port) can cover the 5.725-5.925GHz frequency band. For example... Figure 5 As shown in Figure (b), the isolation between the 2.4G port and the other two frequency band ports is greater than 28dB, and the isolation between the 5.2G and 5.8G ports is greater than 29dB. These results demonstrate the excellent multiplexing and inter-frequency decoupling performance of this embodiment.

[0064] like Figure 6 The figure shows the gain curves for this embodiment. Each frequency band exhibits good filtering performance, generating a radiation null point at the top and bottom edges of each band, resulting in good out-of-band suppression performance. The maximum gain in the 2.4 GHz band is greater than 4.5 dB, the maximum gain in the 5.2 GHz band is greater than 7 dB, and the maximum gain in the 5.8 GHz band is greater than 7 dB, demonstrating good high-gain radiation performance.

[0065] like Figure 7 Figures (a) and (b) show the radiation pattern of this embodiment at 2.45 GHz. A good horizontal omnidirectional vertical polarization radiation pattern can be seen, with a good cross-polarization ratio and good non-circularity.

[0066] like Figure 8 Figures (a) and (b) show the radiation pattern of this embodiment at 5.25 GHz. A good horizontal omnidirectional vertical polarization radiation pattern can be seen, with a good cross-polarization ratio and good non-circularity.

[0067] like Figure 9 Figures (a) and (b) show the radiation pattern of this embodiment at 5.85 GHz. A good horizontal omnidirectional vertical polarization radiation pattern can be seen, with a good cross-polarization ratio and good non-circularity.

[0068] Example 2

[0069] A radio frequency communication device includes a three-channel common aperture different frequency decoupled series-fed antenna of embodiment 1, which is suitable for WiFi routers. Compared with the prior art, it can reduce the number of antennas to one-third, and improve coverage performance because the mutual obstruction of antennas is reduced.

[0070] In summary, the three-channel common-aperture, different-frequency decoupled series-fed antenna of this invention proposes a three-channel common-aperture design, in which multiple independently operating frequency bands share a single multi-frequency series-fed radiator. Through filter structure design, three-channel operation is achieved without additional multiplexing and filtering circuits, effectively reducing the antenna aperture, system size, and integration density. Each frequency band achieves a second-order bandpass filter response, generating radiation nulls out of band, providing high out-of-band roll-off suppression, and generating transmission nulls between different-frequency ports, thus achieving different-frequency decoupling.

[0071] The antenna of this invention proposes a multi-frequency series-fed radiator design. By adjusting the radiation structure, it can perform in-phase radiation in the low-frequency band, the first high-frequency band, and the second high-frequency band using different parts of the radiation structure, achieving the effect of high-gain horizontal omnidirectional vertical polarization radiation.

[0072] This invention provides an antenna that can cover three operating frequency bands of WiFi, suitable for RF communication devices such as WiFi routers, namely 2.4-2.485GHz, 5.15-5.35GHz, and 5.725-5.925GHz, with broad application scenarios and commercial prospects. It reduces the number of antennas to one-third of discrete simplex antennas, effectively reducing costs, size, and system complexity, minimizing obstruction between multiple antennas, and improving coverage performance. This antenna uses a common PCB board design with mature manufacturing processes, allowing for mass production, and is particularly suitable for cost-sensitive, structurally and spatially constrained, and highly integrated system scenarios.

[0073] Those skilled in the art will readily understand that the above description is merely an embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A three-channel common-aperture, different-frequency decoupled series-fed antenna, having three independent input ports, each input port supporting one operating frequency band, the three input ports being supported by three coaxial feed lines, the three coaxial feed lines including a first coaxial feed line, a second coaxial feed line, and a third coaxial feed line, characterized in that, include: A multi-frequency series-fed radiator, wherein the multi-frequency series-fed radiator is provided with a multi-frequency current control structure to realize horizontal omnidirectional high-gain vertical polarization radiation modes in three operating frequency bands; The filter structure has one filter structure for each operating frequency band, which realizes independent operating response of the three operating frequency bands and high isolation between different frequency ports.

2. The three-channel common-aperture, different-frequency decoupled series-fed antenna according to claim 1, characterized in that, The multi-frequency series-fed radiator includes a radiator, a metal feed line, a metal stub, a choke, and a metal ground plane; There are four radiators, which are arranged from bottom to top as a first radiator, a second radiator, a third radiator and a fourth radiator, wherein the first radiator is disposed on the back side of the dielectric substrate and the other radiators are disposed on the front side of the dielectric substrate. The metal feed line includes a first metal feed line, a second metal feed line, and a third metal feed line. The three metal feed lines are alternately arranged with four radiators. The first metal feed line and the second metal feed line are arranged on the front side of the dielectric substrate. The third metal feed line includes two parts, one part is arranged on the front side of the dielectric substrate, and the other part is arranged on the back side of the dielectric substrate. The metal branch is arranged in the middle of the front side portion of the dielectric substrate corresponding to the third metal feed line. The choke includes a high-frequency choke and a low-frequency choke, with the high-frequency choke disposed at the top of the first radiator and the low-frequency choke disposed at the bottom of the dielectric substrate. The metal floor includes a first metal floor and a second metal floor. The first metal floor is disposed at the bottom of the first radiator and serves as the electrical ground for the low-frequency band. The second metal floor is disposed at the bottom of the second radiator, serving as a common electrical ground for the first and second high-frequency bands.

3. The triplex co-proximity decoupled series-fed antenna according to claim 2, wherein, The filtering structure includes a low-frequency filtering structure, a first high-frequency filtering structure, and a second high-frequency filtering structure. The low-frequency filtering structure is disposed on the first radiator, and the first and second high-frequency filtering structures are disposed on the second radiator, arranged to the left and right of the longitudinal centerline of the second radiator. A U-shaped resonator and a metal fence structure are disposed between the first and second high-frequency filtering structures to generate a transmission zero point and improve isolation.

4. The triplex co-proximity decoupled series-fed antenna according to claim 2, wherein, The third metal radiator is provided with a U-shaped groove. The U-shaped groove resonates in the low-frequency range, so that the third radiator does not radiate; the U-shaped groove does not resonate in the high-frequency range, so that the current of the third radiator is in phase with that of the second and fourth radiators. The third metal feed line is a straight feed line on the front side of the dielectric substrate and a curved feed line on the back side of the dielectric substrate. The straight feed line and the curved feed line are connected by metal vias. The straight feed line, the curved feed line, the metal stubs and the U-shaped groove constitute a multi-frequency current control structure. The metal stubs can prevent low-frequency current from passing through the straight feed line.

5. The triplex co-proximity frequency-decoupled series-fed antenna according to claim 4, wherein, In the low-frequency band, the first radiator, the high-frequency choke, and the second radiator constitute a radiating element, and the fourth radiator, the third metal feed line, and the metal stub constitute another radiating element. The two radiating elements generate in-phase horizontal omnidirectional radiation, so that the multi-frequency series-fed radiator is equivalent to a second-order series-fed antenna in the low-frequency band. In the first and second high frequency bands, the high frequency choke prevents the current from flowing downward to the first radiator, and the multi-frequency current control structure makes the second, third, and fourth radiators radiate in phase, which is equivalent to a third-order series-fed antenna.

6. The triplex collinear corporate-fed dual-frequency decoupled series-fed antenna according to claim 3, wherein, The low-frequency filtering structure includes a first short-circuit resonator and a second short-circuit resonator, which are respectively disposed on different sides of the dielectric substrate. The outer conductor of the first coaxial feed line is welded to the first metal ground, and its inner conductor passes through the dielectric substrate and is welded to the first short-circuit resonator to form a first loop current closed loop to excite the antenna with a magnetic field. The first high-frequency filter structure includes a third short-circuit resonator and a fourth short-circuit resonator, which are respectively disposed on different sides of the dielectric substrate. The outer conductor of the second coaxial feed line is welded to the second metal ground, and its inner conductor passes through the dielectric substrate and is welded to the third short-circuit resonator to form a second loop current closed loop to excite the antenna with a magnetic field. The second high-frequency filter structure includes a fifth short-circuit resonator and a sixth short-circuit resonator, which are respectively disposed on different sides of the dielectric substrate. The outer conductor of the third coaxial feed line is soldered to the second metal ground plane, and its inner conductor passes through the dielectric substrate and is soldered to the fifth short-circuit resonator to form a third annular closed loop to excite the antenna with a magnetic field.

7. The triplex co-proximity dual-frequency decoupled series-fed antenna according to claim 6, wherein, The coupling between the first closed-loop current circuit and the first short-circuit resonator is magnetic coupling, the coupling between the first closed-loop current circuit and the second short-circuit resonator is magnetic coupling, and the coupling between the second closed-loop current circuit and the third short-circuit resonator is magnetic coupling, the coupling between the second closed-loop current circuit and the fourth short-circuit resonator is magnetic coupling, and the coupling between the second closed-loop current circuit and the multi-frequency series-fed radiator is magnetic coupling; the coupling between the third closed-loop current circuit and the fifth short-circuit resonator is magnetic coupling, the coupling between the third closed-loop current circuit and the sixth short-circuit resonator is magnetic coupling, and the coupling between the third closed-loop current circuit and the multi-frequency series-fed radiator is magnetic coupling.

8. The triplex co-fed decoupled series-fed antenna of claim 6, wherein, The coupling between the first short-circuit resonator and the multi-frequency series-fed radiator is electrical coupling, and the coupling between the second short-circuit resonator and the multi-frequency series-fed radiator is magnetic coupling. The coupling between the third short-circuit resonator and the multi-frequency series-fed radiator is electrical coupling, and the coupling between the fourth short-circuit resonator and the multi-frequency series-fed radiator is magnetic coupling. The coupling between the fifth short-circuit resonator and the multi-frequency series feed radiator is electrical coupling, and the coupling between the sixth short-circuit resonator and the multi-frequency series feed radiator is magnetic coupling.

9. The triplex co-proximity dual-frequency decoupled series-fed antenna according to any one of claims 6-8, characterized in that, In each operating frequency band, a closed loop current circuit, a multi-frequency series feed radiator, and two short-circuit resonators form a four-corner filter topology. The closed loop current circuit is the source node, the multi-frequency series feed radiator is the load node, and the two short-circuit resonators are the two resonant nodes. Through the coupling relationship of the above parts, a second-order bandpass filter response is generated, producing a radiation null point at the upper and lower edges of the passband. The filter structure of each frequency band uses the multi-frequency series feed radiator as a common node to form a multiplexed topology.

10. A radio frequency communication device, characterized in that, Including the three-channel common-aperture different-frequency decoupled series-fed antenna as described in any one of claims 1-9.

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