CN211743396U

CN211743396U - High-isolation gap ultra-wideband MIMO antenna

Info

Publication number: CN211743396U
Application number: CN202020354435.7U
Authority: CN
Inventors: 杜成珠; 郑炜晴; 徐家铭; 靳高雅; 赵卓琳; 李凯佳
Original assignee: Shanghai Electric Power University
Current assignee: Shanghai University of Electric Power; Shanghai Electric Power University; University of Shanghai for Science and Technology
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2020-10-23
Anticipated expiration: 2030-03-19

Abstract

The utility model relates to a gap ultra wide band MIMO antenna of high isolation, including base plate and antenna, the antenna be the groove antenna, including two radiating element, two radiating element form symmetrical structure, are equipped with three isolating construction that are parallel to each other between two radiating element. Compared with the prior art, the utility model has the advantages of high isolation, small-size, and have the stop band of WiMAX frequency channel and C wave band.

Description

High-isolation gap ultra-wideband MIMO antenna

Technical Field

The utility model relates to a MIMO antenna especially relates to a gap ultra wide band MIMO antenna of high isolation.

Background

In 1901, gulimoconi realized telegraph communication by using radio waves on both sides of the english girli strait, and opened the history of mobile communication, which has been for over 100 years so far. Mobile communication has been rapidly developed in the more than 100 years, and radio stations have come to be widely used in world war ii. In the seventies to eighties of the last century, the concept of the honeycomb is put forward by the bell laboratory for the first time, so that the frequency reuse problem is effectively solved, and the communication capacity is greatly improved. This stage is known as the 1G era. From the 80 s of the 20 th century to the present, people enter 2G, 3G, 4G and 5G in turn, and will enter the 6G era in the future. With the continuous development of various mobile communications, data information flow is larger and larger, and massive images, audio, video, characters and navigation need to be transmitted by means of various mobile terminal devices, so people put forward higher and higher requirements on the transmission data rate, channel capacity and communication quality of a system, but the frequency spectrum resources of a wireless communication system are limited, the increasing demands of people undoubtedly cause the increasing tension of the frequency spectrum resources of the wireless communication system, and one of the solutions to the problem is to expand the bandwidth of the system, namely to improve the available amount of the frequency spectrum. This has led to a enthusiasm for the research of Ultra-wideband (UWB) technology.

In 2002, 2 months, the Federal Communications Commission (FCC) of the united states formulated civilization specifications for ultra-wideband (UWB) technology, formally determined the band range of 3.1GHz-10.6GHz as ultra-wideband, and gradually opened the civilized communication field. The UWB technology has the characteristics of large system capacity, strong multipath fading resistance, high communication rate, low interception rate, strong signal penetration capacity, high communication quality, low power consumption, low system complexity, low cost and the like. UWB technology has been widely used in the fields of imaging, radar, communications, and the like.

The antenna is used as an important component of a radio frequency front end, conversion of guided waves and free space waves is achieved, and performance of the antenna directly influences communication quality. Therefore, it is necessary to develop a research for the ultra-wideband antenna in the whole ultra-wideband communication system. As miniaturization of mobile communication devices inevitably leads to miniaturization of antennas, miniaturization technology is an important research direction in the field of ultra-wideband antenna research. Meanwhile, because the frequency band of the UWB antenna covers the communication frequency bands of the bands such as WLAN, C, and X, in order to avoid electromagnetic interference, the bands such as WLAN, C, and X need to be filtered, so that an antenna with a band-stop characteristic, also called an antenna with a notch function, needs to be designed. Therefore, how to make the ultra-wideband antenna have the notch characteristic under the condition of maintaining the ultra-wideband characteristic is also an important research hotspot.

Another measure to cope with the shortage of spectrum resources is to increase the spectrum utilization. By using a Multiple Input Multiple Output (MIMO) technology, the spectrum utilization rate can be greatly improved and the communication quality can be improved without increasing spectrum resources. The MIMO technology is to use multiple sets of antennas at a transmitting end and a receiving end of a communication system, respectively, so that communication signals are transmitted and received by using the multiple sets of antennas at the transmitting end and the receiving end of the communication system, thereby improving communication quality. With the development of mobile communication devices, mobile communication devices are increasingly developing in miniaturization, multi-functionalization and intellectualization. How to maintain various performances of the antenna in a limited space range is an important research subject, and in the MIMO antenna system, it is necessary to overcome the problem that mutual coupling between antenna units is strengthened and the overall performance of the antenna is affected due to too small pitch of the antenna units, so that it is an important subject to improve the isolation of the ultra-wideband MIMO antenna and reduce the mutual coupling of the antenna.

The revolutionary development of mobile wireless communication technology in this century changes the life style of human beings, the requirements of people on communication quality and speed are improved, and the requirements on light weight and portability of mobile equipment are higher and higher. Whether the communication system can work normally depends on the quality of the antenna performance to a certain extent, and the research significance of the antenna technology is self-evident. Two key technologies for improving communication quality and speed include Multiple Input Multiple Output (MIMO) technology and Ultra Wide Band (UWB) technology, and the MIMO technology and the UWB technology are combined to realize the complementary advantages and disadvantages of the two technologies. Ultra-wideband (UWB) wireless communication technology has been developed rapidly in the fields of high-speed wireless communication, radar tracking, ranging, precise positioning guidance and the like due to its excellent characteristics such as high rate and low error rate, and has become a research hotspot of next-generation short-distance and high-rate commercial wireless communication systems. The performance of the antenna, which is used as the rf front end of the wireless communication system, directly affects the quality of communication. Therefore, for the UWB wireless communication system, the research of the UWB antenna has extremely important practical significance and application value.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a gap ultra wide band MIMO antenna of high isolation just in order to overcome the defect that above-mentioned prior art exists.

The purpose of the utility model can be realized through the following technical scheme:

the utility model provides a gap ultra wide band MIMO antenna of high isolation, includes base plate and antenna, the antenna be the groove antenna, including two radiating element, two radiating element form symmetrical structure, are equipped with three isolating construction that are parallel to each other between two radiating element.

The three isolation structures are also connected with five branch knots, and the five branch knots are vertically intersected with the isolation structures.

The substrate is square, the isolation structure is located at the diagonal position of the substrate, and the radiation units are respectively arranged at the diagonal positions of two sides of the isolation structure.

The shape of the gap in the radiation unit is a combination of an arch and a rectangle, and the rectangle is vertically connected with the straight edge of the arch.

The slot is internally provided with an arched patch and a rectangular patch, the outer contours of the arched patch and the rectangular patch are the same as the shape of the slot, and the outer edge of the rectangular patch is tightly attached to the inner edge of the slot.

The rectangular patch is provided with a semi-open annular groove.

The back of the substrate is also provided with a semi-open annular groove, and the position of the semi-open annular groove corresponds to that of the semi-open annular groove on the rectangular patch.

The substrate material is FR 4.

Compared with the prior art, the utility model has the advantages of it is following:

(1) high isolation for MIMO architecture

For MIMO antennas, if the antenna correlation at the receiving end and the transmitting end is too high, the performance of the MIMO system is deteriorated, and therefore, a sufficiently high isolation is a necessary condition that should be provided between antenna elements. With the widespread use of MIMO technology, many methods capable of improving isolation, such as neutral line technology, floor stubs, parasitic elements, defected ground structures, and metamaterial technology, have been studied in large quantities.

Firstly, the utility model adds three linear transverse branches between the unit antennas as isolation structures, on one hand, the floor branches can change the distribution of the surface current of the floor so as to improve the impedance matching of the ports; on the other hand, it can be regarded as a reflector plate to reduce the near-field coupling between the antennas; then, five vertical branches perpendicular to the three transverse branches are added among the three transverse branches to form gaps among the three transverse branches, so that a part of floor surface current can be distributed around the three transverse branches, and the floor surface current flowing from the excitation port to the non-excitation port is reduced. Simulation results show that the isolation of all required operating frequency bands is reduced to below-20 dB.

(2) Antenna size miniaturization

The UWB-MIMO slot antenna enables the size of the antenna to be minimum through a slotting mode, has obvious advantages in size compared with a common antenna, is simple in structure and small in size, and can be applied to UWB terminal equipment. The patch consists of a circular patch and a rectangular patch, and a gap structure is used around the patches. The antenna bandwidth is broadened by using a circular patch. The rectangular patch and the surrounding gap structure enable the antenna to be compact in structure and reduce the size of the antenna.

(3) Double stop band performance

The antenna obtains stopbands of a WiMAX frequency band and a C wave band through simulation test, the two frequency bands are very wide in the practical application process, and the antenna has enough bandwidth for the two frequency bands and completely meets the working requirement.

Drawings

Fig. 1 is a schematic front view of the antenna of the present embodiment;

fig. 2 is a schematic diagram of a back structure of the antenna of the present embodiment;

fig. 3 shows the simulation result of S11 of the antenna of the present embodiment;

fig. 4 is a simulation result of the isolation of the antenna according to the present embodiment;

reference numerals:

1 is a substrate; 2 is a radiation unit; 3 is an isolation structure; 4 is an arch patch; 5 is a rectangular patch; and 6 is a semi-open annular groove.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

Examples

The present embodiment designs a dual-stopband MIMO antenna using FR4 material as a substrate. The slot antenna is more beneficial to miniaturization through analysis, so that the slot antenna is designed as a prototype antenna, and a coplanar waveguide feeding mode is utilized. The antenna is composed of two radiating units, and the two radiating units have the same structure and are symmetrical in the direction of 45 degrees. The slot structure is a combination of a sector circle and a rectangle, the rectangular patch is positioned in the slot, the outer edge of the patch is tightly attached to the inner edge of the slot, and the structure can excite more current to be distributed around the slot to obtain broadband matching. Two half-open annular grooves are respectively loaded on the back surface of the antenna and the patch by using an open groove method, and the forbidden bands of the UWB antenna in WiMAX (5.11-5.96GHZ) and C-band (6.82-7.86GHz) are formed.

The isolation structure is better than a linear isolation structure in the isolation effect achieved by a high-frequency part, but the low-frequency part cannot meet the requirement, so that five transverse branches perpendicular to the three vertical branches are introduced into the upper half parts of the three vertical branches, inductors are introduced through the mutually staggered decoupling isolation structure, the Q value of the three transverse branches is improved through a gap structure in the middle of the staggered structure, energy is prevented from radiating to the antennas on two sides, the decoupling effect is realized, and the coupling between the two units is reduced.

As shown in fig. 1 and 2, the high-isolation slot ultra-wideband MIMO antenna of the present embodiment includes a substrate 1 and an antenna, the antenna is a slot antenna, and includes two radiation units 2, the two radiation units 2 form a symmetrical structure, and three isolation structures 3 parallel to each other are disposed between the two radiation units 2.

The three isolation structures 3 are also connected with five branch knots, and the five branch knots are vertically intersected with the isolation structures 3.

The substrate 1 is square, the isolation structure 3 is located at the diagonal position of the substrate 1, and the radiation units 2 are respectively arranged at the diagonal positions of two sides of the isolation structure 3.

The shape of the slit in the radiation unit 2 is a combination of an arch and a rectangle, the rectangle being vertically connected to the straight side of the arch.

An arched patch 4 and a rectangular patch 5 are arranged in the gap, the outer contours of the arched patch 4 and the rectangular patch 5 are the same as the shape of the gap, and the outer edge of the rectangular patch 4 is tightly attached to the inner edge of the gap.

The rectangular patch 4 is provided with a semi-open annular groove 6.

The back of the substrate is also provided with a semi-open annular groove 6, and the radius of the semi-open annular groove 6 is slightly larger than that of the semi-open annular groove 6 on the rectangular patch.

As shown in fig. 3 and 4, the S11 curve indicates that the antenna bandwidth covers 3.1-10.6GHz, completely covers the ultra-wideband frequency range, and forms stop bands in the 5.11-5.96GHz band and the 6.8-7.86GHz band, respectively corresponding to the WiMAX band and the C band. And it can be seen from the S12 graph that the isolation of the antenna in the frequency range is below 20dB, the isolation is high, and the antenna elements are not easily affected, so that the antenna is easier to process and manufacture and is widely applied in real life.

Claims

1. The utility model provides a gap ultra wide band MIMO antenna of high isolation, includes base plate and antenna, its characterized in that, the antenna be the groove antenna, including two radiating element, two radiating element form symmetrical structure, are equipped with three isolating construction that are parallel to each other between two radiating element.

2. The high-isolation slot ultra-wideband MIMO antenna as claimed in claim 1, wherein the three isolation structures are further connected with five branches, and the five branches are perpendicularly intersected with the isolation structures.

3. The high-isolation slot ultra-wideband MIMO antenna as claimed in claim 1, wherein the substrate is square, the isolation structure is located at a diagonal position of the substrate, and the radiating elements are respectively located at diagonal positions at two sides of the isolation structure.

4. The high-isolation slot ultra-wideband MIMO antenna as claimed in claim 3, wherein the slot shape in the radiating element is a combination of an arch and a rectangle, and the rectangle is vertically connected with the straight side of the arch.

5. The high-isolation slot ultra-wideband MIMO antenna as claimed in claim 4, wherein the slot is provided with an arch patch and a rectangular patch, the outer contours of the arch patch and the rectangular patch are the same as the shape of the slot, and the outer edge of the rectangular patch is tightly attached to the inner edge of the slot.

6. The high-isolation slot ultra-wideband MIMO antenna as claimed in claim 5, wherein the rectangular patch is provided with a semi-open annular slot.

7. The high-isolation slot ultra-wideband MIMO antenna as claimed in claim 6, wherein the substrate is also provided with a semi-open annular groove on the back surface, and the position of the semi-open annular groove corresponds to that of the rectangular patch.

8. The high-isolation slot ultra-wideband MIMO antenna as claimed in claim 1, wherein the substrate material is FR 4.