阅读说明：本技术 一种新型多模宽频带方向图分集微带天线 (Novel multimode broadband directional diagram diversity microstrip antenna ) 是由 涂治红 肖朝杰 王佑羡 于 2020-12-23 设计创作，主要内容包括：本发明公开了一种新型多模宽频带方向图分集微带天线。所述天线包括第一介质基板、第二介质基板、带有两条缝隙的金属地板、带有两个输入端口和的馈电网络和六块矩形辐射贴片；第一介质基板和第二介质基板从下至上依次堆叠,金属地板位于第一介质基板的上表面,馈电网络位于第一介质基板的下表面；六块矩形辐射贴片位于第二介质基板的上表面,分别根据两条缝隙耦合馈电。本发明具有宽阻抗带宽、宽辐射带宽、结构简单、低成本以及方向图等优势。(The invention discloses a novel multimode broadband directional diagram diversity microstrip antenna. The antenna comprises a first dielectric substrate, a second dielectric substrate, a metal floor with two gaps, a feed network with two input ports and six rectangular radiation patches; the first dielectric substrate and the second dielectric substrate are sequentially stacked from bottom to top, the metal floor is located on the upper surface of the first dielectric substrate, and the feed network is located on the lower surface of the first dielectric substrate; and the six rectangular radiation patches are positioned on the upper surface of the second dielectric substrate and are coupled and fed according to the two gaps respectively. The invention has the advantages of wide impedance bandwidth, wide radiation bandwidth, simple structure, low cost, directional diagram and the like.)

1. A novel multimode broadband directional diagram diversity microstrip antenna is characterized by comprising a first dielectric substrate (1), a second dielectric substrate (2), a metal floor (3) with two gaps (4), a feed network (7) with two input ports (8) and (9) and six rectangular radiation patches (5);

the first dielectric substrate (1) and the second dielectric substrate (2) are sequentially stacked from bottom to top, the metal floor (3) is located on the upper surface of the first dielectric substrate (1), and the feed network (7) is located on the lower surface of the first dielectric substrate (1); the six rectangular radiation patches (5) are positioned on the upper surface of the second dielectric substrate (2) and are coupled and fed according to the two gaps (4) respectively.

2. The novel multimode broadband pattern diversity microstrip antenna of claim 1 wherein: the thickness of the first dielectric substrate (1) is determined by the input impedance of the feed network (7), the thickness of the second dielectric substrate (2) is determined by the impedance conversion ratio between the slot (4) and the rectangular radiation patch (5), the thicknesses of the first dielectric substrate (1) and the second dielectric substrate (2) are adjusted to improve the coaxial cable with characteristic impedance of 50 ohms and the feed network (7), and the impedance matching between the feed network (7) and the rectangular radiation patch (5) is realized.

3. The novel multimode broadband pattern diversity microstrip antenna of claim 1 wherein: the six rectangular radiation patches (5) are distributed symmetrically with respect to the x axis in pairs, the origin of a coordinate system is located at the center of the lower surface of the first medium substrate (1), the x axis is parallel to the long side of the rectangular radiation patches (5) and points to the left lower side, the y axis is parallel to the short side of the rectangular radiation patches (5) and points to the right lower side, the z axis is perpendicular to the metal floor and points upwards, the three rectangular radiation patches (5) on the same side are sequentially arranged outwards from the x axis along the y axis, and the two rectangular radiation patches (5) symmetrical with respect to the x axis have the same size.

4. The novel multimode broadband pattern diversity microstrip antenna of claim 3 wherein: the length and the width of the six rectangular radiation patches (5) are adjusted to ensure that the length and the width of the rectangular radiation patches meet the TM within the working frequency band₁₀Mode and TM₂₀Resonant length of mode, exciting only TM₁₀Mode and TM₂₀And (5) molding.

5. The novel multimode broadband pattern diversity microstrip antenna of claim 4 wherein: among the six rectangular radiation patches (5), four slots (6) are etched on the four rectangular radiation patches (5) in the middle, each slot (6) spans the two rectangular radiation patches (5) on the same side, the lengths of the slots (6) on the two rectangular radiation patches (5) are the same, the four slots (6) are symmetrical in pairs about an x axis, and the two patches on the same side are symmetrical in pairs about a y axis;

four slots (6) are arranged on the rectangular radiation patch (5) TM₁₂Where mode current is maximum, TM not needed for cutting₁₂Current of mode, effectively suppressing TM₁₂Mode, the stable radiation pattern.

6. The novel multimode broadband pattern diversity microstrip antenna of claim 5 wherein: two etched gaps (4) on the metal floor (3) are symmetrically distributed about an x axis and are parallel to the x axis, the two gaps (4) are respectively positioned under the slots (6) on two sides in the rectangular radiation patch (5), and each gap (4) vertically bisects the two slots (6) on the same side.

7. The novel multimode broadband pattern diversity microstrip antenna of claim 1 wherein: the tail end of the feed network (7) is of a circular structure and is used for adjusting the impedance matching of the microstrip antenna.

8. The novel multimode broadband pattern diversity microstrip antenna of claim 1 wherein: the feed network (7) is provided with two input ports, namely a first feed port (8) and a second feed port (9), and directional diagram diversity characteristics are achieved by feeding the first feed port (8) and the second feed port (9) respectively.

9. The novel multimode broadband pattern diversity microstrip antenna of claim 1 wherein: the feed network (7) adopts a Wilkison power divider form, the lengths of two output arms at the input of the first feed port (8) are the same, and when the second feed port (9) feeds, the lengths of the two output arms are different by 0.5 lambda to form 180-degree phase shift, and meanwhile, the transmission coefficient between the two ports of the first feed port (8) and the second feed port (9) in the bandwidth is below minus 40 dB.

10. The novel multimode broadband directional pattern diversity microstrip antenna according to any one of claims 1 to 9, wherein: when the first feed port (8) feeds power, the two gaps (4) simultaneously excite the same-phase mode, and at the moment, the rectangular radiation patch (5) can radiate double beams; when the second feeding port (9) feeds, the reverse phase mode is excited, and the rectangular radiating patch (5) radiates a directional beam.

Technical Field

The invention belongs to the field of wireless communication, and particularly relates to a novel multimode broadband directional diagram diversity microstrip antenna.

Background

In the research and design of antennas, it has become an important research direction to improve the transceiving quality and the spectrum utilization efficiency of the antennas. The diversity technique can improve the reliability of the channel and reduce the influence of multipath fading at the same time, does not need to improve the transmission power of the signal, and is widely applied to communication systems. The diversity antenna, because it has two or more antenna performance at the same time, can be used for the transmission and reception of the wireless channel at the same time, thus is used for alleviating the fading effect, raise the channel capacity and spectral efficiency, in order to meet the demands of different business to the high data rate. There are three basic diversity antennas, namely space diversity, polarization diversity and pattern diversity antennas. The design of a space diversity antenna is the simplest of the three because it only requires a suitable distance between the antenna elements, and the performance of the antenna often increases at the expense of increasing the size of the antenna. In contrast, the design of a polarization diversity antenna is relatively difficult, but is relatively small in size since it typically requires only one antenna, polarization diversity typically utilizing several orthogonal modes. Typically, both diversity techniques have only one radiation pattern. The pattern diversity technique is more difficult than the two diversity techniques. This is because different modes of operation require different radiation patterns, but different modes typically have different operating frequencies. The use of multiple antenna combinations tends to complicate the overall structure and increase the size. The directional diagram diversity antenna can realize uncorrelated channels by utilizing directional diagram diversity, and well solves the problems that the coupling among the radiation units in the diversity system can seriously increase the correlation of signals and reduce the radiation efficiency. This also adds an additional degree of freedom to the diversity gain of the diversity system. In addition, the directional diagram diversity antenna can receive and transmit signals from different directions, wide signal coverage in space is achieved, additional frequency spectrum resources do not need to be used, and communication quality is greatly improved. The antenna with directional diagram diversity can improve the transmission quality of signals in wireless communication, further overcome interference brought by geography and environment, and realize high efficiency of information interaction between the control information center and the communication subsystem. In addition, in order to meet the demands of more users, more users are covered, a larger amount of information is effectively transmitted, the capacity of the whole communication needs to be upgraded, and the broadband and miniaturized design of the directional pattern diversity antenna becomes two important aspects for solving the problem of resource and space shortage.

According to investigation and understanding, the prior art that has been disclosed is as follows:

in 2014, l.sun, w.huang, b.sun, q.sun and j.fa in an article entitled "Two-Port Pattern Diversity Antenna for 3G and 4G MIMO Antenna Applications" published by "IEEE Antennas and Wireless transmission Antennas", broadband and Pattern Diversity characteristics were achieved by combining a monopole cone Antenna and a broadband microstrip Antenna. However, this method results in a large spatial structure of the whole antenna, which greatly limits its usage scenarios.

In an article entitled "A Single Page With broad broadcasting and cosmetic Radiation Patterns for 3G/4G Pattern Diversity" published by "IEEE Antennas and Wireless Transmission Letters" in 2016, L.Sun, G.Zhang, B.Sun, W.Tang and J.Yuan, a TM is excited via two feeding ports respectively₁₀The mode and the capacitive loading monopole radiation mode realize the broadband directional diagram diversity, and simultaneously have the characteristic of low profile, but the gain under the condition of loading the monopole radiation mode in the overlapping bandwidth is lower.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a design of a novel multimode broadband directional diagram diversity microstrip antenna. The antenna array has the characteristics of wide band, low section, simple structure, low cost, directional pattern diversity and the like.

The purpose of the invention is realized by at least one of the following technical solutions.

A novel multimode broadband directional diagram diversity microstrip antenna comprises a first dielectric substrate, a second dielectric substrate, a metal floor with two gaps, a feed network with two input ports and six rectangular radiation patches;

the first dielectric substrate and the second dielectric substrate are sequentially stacked from bottom to top, the metal floor is located on the upper surface of the first dielectric substrate, and the feed network is located on the lower surface of the first dielectric substrate; and the six rectangular radiation patches are positioned on the upper surface of the second dielectric substrate and are coupled and fed according to the two gaps respectively.

Further, the thickness of the first dielectric substrate is determined by the input impedance of the feed network, the thickness of the second dielectric substrate is determined by the impedance conversion ratio between the slot and the rectangular radiation patch, the thicknesses of the first dielectric substrate and the second dielectric substrate are adjusted to improve the impedance matching between the feed network and the rectangular radiation patch and the coaxial cable with the characteristic impedance of 50 ohms (the 50 ohm coaxial cable does not belong to the antenna structure) and the feed network.

Furthermore, the six rectangular radiation patches are distributed pairwise symmetrically about an x axis, the origin of a coordinate system is located at the center of the lower surface of the first medium substrate, the x axis is parallel to the long side of the rectangular radiation patches and points to the left lower side, the y axis is parallel to the short side of the rectangular radiation patches and points to the right lower side, the z axis is perpendicular to the metal floor and points upwards, the three rectangular radiation patches on the same side are sequentially arranged outwards along the y axis from the x axis, and the two rectangular radiation patches symmetrical about the x axis are identical in size.

Furthermore, the length and the width of the six rectangular radiation patches are adjusted to ensure that the length and the width of the rectangular radiation patches meet the TM within the working frequency band₁₀Mode and TM₂₀Resonant length of mode, exciting only TM₁₀Mode and TM₂₀And (5) molding.

Furthermore, four slots are etched on four rectangular radiation patches in the middle of the six rectangular radiation patches, each slot spans two rectangular radiation patches on the same side, the lengths of the slots on the two rectangular radiation patches are the same, the four slots are symmetrical in pairs about the x axis, and two slots on the same side are symmetrical in pairs about the y axis;

four slots on rectangular radiation patch TM₁₂Where mode current is maximum, TM not needed for cutting₁₂Current of mode, effectively suppressing TM₁₂Mode, the stable radiation pattern.

Furthermore, two etched gaps on the metal floor are symmetrically distributed about the x axis and are parallel to the x axis, the two gaps are respectively positioned right below the slots on two sides in the rectangular radiation patch, and each gap vertically bisects the two slots on the same side.

Furthermore, the tail end of the feed network is of a circular structure and is used for adjusting the impedance matching of the microstrip antenna.

Further, the feed network is provided with two input ports, namely a first feed port and a second feed port, and directional diagram diversity characteristics are achieved by feeding the first feed port and the second feed port respectively.

Furthermore, the feed network adopts a Wilkison power divider form, the lengths of the two output arms are the same when the first feed port inputs power, and when the second feed port feeds power, the length difference of the two output arms is 0.5 lambda so as to form 180-degree phase shift, meanwhile, the first feed port and the second feed port have higher isolation, and the transmission coefficient between the two ports in the bandwidth is below minus 40 dB.

Furthermore, when the first feed port feeds power, the two gaps simultaneously excite the same-phase mode, and at the moment, the rectangular radiation patch can radiate double beams; when the second feed port feeds power, the reverse phase mode is excited, and at the moment, the rectangular radiation patch radiates a directional beam.

Compared with the prior art, the invention has the following beneficial effects:

1. by exciting the TM₁₀And TM₂₀The broadband characteristic is realized by two modes, and the impedance bandwidth can reach 23% through full-wave simulation verification.

2. The design of the microstrip line isolation network between the two ports realizes higher isolation between the two ports, and full-wave simulation verification proves that the transmission coefficient between the two ports can reach below-40 dB in bandwidth.

3. Two feed ports respectively excite the same-phase mode and the opposite-phase mode at two sides of the patch to realize two radiation modes of directional wide beams and dual beams.

4. The antenna provided by the invention has the advantages of wide impedance bandwidth, wide radiation bandwidth, simple structure, low cost, directional diagram and the like.

Drawings

Fig. 1 is a perspective view of a novel dual-mode broadband directional diagram diversity microstrip antenna according to an embodiment of the present invention.

Fig. 2 is a top view of the novel dual-mode broadband directional diagram diversity microstrip antenna according to an embodiment of the present invention.

Fig. 3 is a front view of a dual-mode broadband directional diagram diversity microstrip antenna according to an embodiment of the present invention.

Fig. 4 is a simulation curve of the reflection coefficient of the dual-mode broadband directional diagram diversity microstrip antenna varying with frequency according to the embodiment of the present invention.

Fig. 5 is a simulation curve of Gain (Gain) of the dual-mode broadband directional diagram diversity microstrip antenna according to the embodiment of the present invention, which varies with frequency.

FIG. 6 shows an S-shaped dual-mode broadband directional diagram diversity microstrip antenna according to an embodiment of the present invention₁₂A simulated curve that varies with frequency, the curve reflecting the isolation of the two ports.

Fig. 7 is a gain curve of the E-plane main polarization and the cross polarization of the dual-mode broadband directional diagram diversity microstrip antenna according to the embodiment of the present invention at 3.6GHz when the port 8 feeds.

Fig. 8 is a gain curve of the E-plane main polarization and the cross polarization of the dual-mode broadband directional diagram diversity microstrip antenna according to the embodiment of the present invention at 3.6GHz when feeding at port 9.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Example (b):

a novel multimode broadband directional diagram diversity microstrip antenna is shown in figures 1, 2 and 3 and comprises a first dielectric substrate 1, a second dielectric substrate 2, a metal floor 3 with two gaps 4, a feed network 7 with two input ports 8 and 9 and six rectangular radiation patches 5;

the first dielectric substrate 1 and the second dielectric substrate 2 are sequentially stacked from bottom to top, the metal floor 3 is located on the upper surface of the first dielectric substrate 1, and the feed network 7 is located on the lower surface of the first dielectric substrate 1; the six rectangular radiation patches 5 are positioned on the upper surface of the second dielectric substrate 2 and are coupled and fed according to the two gaps 4 respectively.

The thickness of the first dielectric substrate 1 is determined by the input impedance of the feed network 7, the thickness of the second dielectric substrate 2 is determined by the impedance conversion ratio between the slot 4 and the rectangular radiation patch 5, the thicknesses of the first dielectric substrate 1 and the second dielectric substrate 2 are adjusted to improve the impedance matching between the feed network 7 and the rectangular radiation patch 5 and the coaxial cable (the 50 ohm coaxial cable does not belong to the antenna structure) with the characteristic impedance of 50 ohm and the feed network 7.

The six rectangular radiation patches 5 are distributed symmetrically with respect to the x-axis in pairs, the origin of the coordinate system is located at the center of the lower surface of the first medium substrate 1, the x-axis is parallel to the long side of the rectangular radiation patches 5 and points to the left lower side, the y-axis is parallel to the short side of the rectangular radiation patches 5 and points to the right lower side, the z-axis is perpendicular to the metal floor and points upwards, the three rectangular radiation patches 5 on the same side are sequentially arranged outwards along the y-axis from the x-axis, and the two rectangular radiation patches 5 symmetrical with respect to the x-axis have the same.

In this embodiment, the six rectangular radiation patches 5 are different in length and width. In other embodiments, the six rectangular radiation patches 5 may also be set to have the same length and height or other length and width combinations according to actual needs to adjust the impedance matching, so as to obtain a suitable impedance bandwidth.

The purpose of adjusting the length and width of the six rectangular radiation patches 5 is to ensure that the length and width of the rectangular radiation patches meet the TM within the working frequency band₁₀Mode and TM₂₀Resonant length of mode, exciting only TM₁₀Mode and TM₂₀And (5) molding.

Among the six rectangular radiation patches 5, four slots 6 are etched on the four rectangular radiation patches 5 in the middle, each slot 6 spans two rectangular radiation patches 5 on the same side, the lengths of the slots 6 on the two rectangular radiation patches 5 are the same, the four slots 6 are symmetrical in pairs about the x axis, and two slots on the same side are symmetrical in pairs about the y axis;

four slots 6 are arranged on the rectangular radiation patch 5 TM₁₂Where mode current is maximum, TM not needed for cutting₁₂Current of mode, effectively suppressing TM₁₂Mode, the stable radiation pattern.

Two gaps 4 etched on the metal floor 3 are symmetrically distributed about an x axis and are parallel to the x axis, the two gaps 4 are respectively positioned right below the two side slots 6 in the rectangular radiation patch 5, and each gap 4 vertically bisects the two slots 6 on the same side.

The tail end of the feed network 7 is of a circular structure and is used for adjusting the impedance matching of the microstrip antenna.

The feed network 7 is provided with two input ports, namely a first feed port 8 and a second feed port 9, and directional pattern diversity characteristics are realized by feeding the first feed port 8 and the second feed port 9 respectively.

The feed network 7 adopts a Wilkison power divider form, the two output arms have the same length when the first feed port 8 inputs power, and the two output arms have the difference of 0.5 lambda to form 180-degree phase shift when the second feed port 9 feeds power, meanwhile, the first feed port 8 and the second feed port 9 have higher isolation, and the transmission coefficient between the two ports in the bandwidth is below minus 40 dB.

When the first feed port 8 feeds power, the two gaps 4 simultaneously excite the same-phase mode, and at the moment, the rectangular radiation patch 5 can radiate double beams; the second feed port 9 is fed to excite the reverse mode, and the rectangular radiating patch 5 radiates a directional beam.

In this embodiment, the first dielectric substrate 1 and the second dielectric substrate 2 are made of any one of FR-4, polyimide, teflon glass cloth, and co-fired ceramic; the metal floor 3, the feed network 7 and the rectangular radiation patch 5 are made of any one of aluminum, iron, tin, copper, silver, gold and platinum or an alloy of any one of aluminum, iron, tin, copper, silver, gold and platinum.

The multimode broadband directional diagram diversity microstrip antenna of the embodiment is verified and simulated through calculation and electromagnetic field full-wave simulation, and as shown in fig. 4, reflection coefficient simulation parameters of the antenna in the frequency range of 2.5 GHz-4.5 GHz are given; it can be seen that the reflection coefficient S is within the frequency band range of 3.17 GHz-3.99 GHz₁₁And S₂₂Both are less than-10 dB, and as shown in fig. 6, the transmission coefficients of both ports are less than-40 dB in this frequency band range, indicating that in this frequency band90% of the input power at both ports is not reflected while there is very good isolation between the two ports, so the antenna has a 23% overlap bandwidth. As shown in fig. 5, a gain simulation parameter of the multimode broadband directional pattern diversity microstrip antenna in the frequency range of 2.5GHz to 4.5GHz is given; it can be seen that, in the frequency band range of 3.17GHz to 3.99GHz, the gain value when radiating dual beams is between 5.5 dBi to 6.9dBi, and the gain value when radiating directional beams is between 3.9 dBi to 8.7dBi, which indicates that 90% of the input power in the frequency band is not reflected, and compared with an isotropic antenna, the gain in the radiation dual-beam mode is increased by 5.5 dBi to 6.9dBi, and the gain in the radiation directional-beam mode is increased by 3.9 dBi to 8.7dBi, so that the antenna array has wider bandwidth, higher gain, and good performance.

The xoz plane gain diagram of the multimode broadband directional pattern diversity microstrip antenna of the embodiment in dual-beam radiation at 3.6GHz is shown in fig. 7, and the xoz plane gain diagram in directional beam radiation is shown in fig. 8. It can be seen from the figure that cross-polarization below-20 dBi is achieved in both modes.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution of the present invention and the inventive concept within the scope of the present invention disclosed by the present invention.