CN209266563U - A Flexible Dual Stopband Ultra-Wideband MIMO Antenna - Google Patents

Abstract

The utility model relates to a flexible dual-restriction-band ultra-wideband MIMO antenna, comprising a substrate, a grounding plate and a MIMO antenna patch, the grounding plate and the MIMO antenna patch are located on the substrate, and the substrate is made of liquid crystal polymer The MIMO antenna patch includes two unit antennas with the same structure, the unit antennas are U-shaped ultra-wideband monopole antennas, and the opening directions of the two unit antennas are the same. Compared with the prior art, the utility model adopts liquid crystal polymer as the substrate, which has the advantages of low thermal expansion coefficient, low cost, and small loss; the MIMO structure has high isolation; after engraving on the U-shaped ultra-wideband monopole antenna Two U-shaped slots are made, so that the stop band for WiMAX and WLAN is added to the working frequency of the antenna, preventing interference to the existing wireless communication frequency band.

Description

A Flexible Dual Stopband Ultra-Wideband MIMO Antenna

technical field

The utility model relates to a MIMO antenna, in particular to a flexible double-stop band ultra-wideband MIMO antenna.

Background technique

In recent years, with the rapid development of modern wireless technology, the fifth-generation mobile communication technology (5G), which can greatly improve system capacity, spectrum and energy efficiency, has emerged as the times require, and has quickly attracted widespread attention. One of the most important means is the multiple-input multiple-output (Multiple-Input Multiple-Output, MIMO) technology, which is also recognized as one of the most promising technologies. In order to effectively expand the channel capacity of the system and improve the quality of communication, it is necessary to eliminate the multipath effect, and MIMO technology can solve this problem by introducing multiple antennas at the transceiver end.

In addition, the wireless communication system centered on the human body has become an important part of the fifth generation mobile communication system. At present, medical treatment, military affairs, search and positioning, etc. all need such wireless communication systems. For example: In terms of medical treatment, some instruments are implanted into the human body. These instruments can measure the temperature, pulse, heartbeat and other information of the human body. After the information is measured, the information can be sent to the monitoring terminal through a wearable antenna. Now, in the research of human body-centered wireless communication system, a very important research direction is the research on wearable antenna. Wearable antennas, as the name implies, are antenna systems that can be worn on the body. Wearable antennas can easily complete the sending and receiving of information between people or between people and machines. It is a vital component for a wireless communication system centered on the human body. Its importance cannot be overstated. Self-explanatory.

Utility model content

The purpose of the present utility model is to provide a flexible dual stopband ultra-wideband MIMO antenna in order to overcome the above-mentioned defects in the prior art.

The purpose of this utility model can be achieved through the following technical solutions:

A kind of flexible dual stop band ultra-wideband MIMO antenna, comprises substrate, ground plate and MIMO antenna patch, and described ground plate and MIMO antenna patch are positioned on the substrate, and described substrate is the sheet material that liquid crystal polymer is made, The MIMO antenna patch includes two unit antennas with the same structure, the unit antennas are U-shaped ultra-wideband monopole antennas, and the opening directions of the two unit antennas are the same.

Two U-shaped grooves are engraved on each unit antenna, which serve as WiMAX stop band and WLAN stop band.

The U-shaped grooves have different widths and the same radian, and the width of the inner U-shaped groove is smaller than that of the outer U-shaped groove.

The ground plate and the MIMO antenna patch are respectively located on the upper and lower surfaces of the substrate.

The ground plane is close to the arc portion of the unit antenna.

The ground plate is provided with two rectangular protrusions, which are respectively close to the arc-shaped tops of the two unit antennas. A rectangular groove is opened in the middle of the rectangular protrusions, and the depth of the rectangular grooves is higher than the height of the rectangular protrusions.

The unit antenna is connected with a feeder, and the feeder extends from the arc-shaped top of the unit antenna through the rectangular slot and reaches the lower edge of the antenna.

A T-shaped branch is provided on the ground plate, and the T-shaped branch is located between the two unit antennas as an isolation structure for the two unit antennas.

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

(1) The substrate is a plate made of liquid crystal polymer. As a new type of flexible material, liquid crystal polymer (LCP) has low thermal expansion coefficient, low cost, and low loss, and the dielectric constant of LCP is in a sufficiently wide range. It is very stable in the frequency range, which is conducive to the design of low-cost, high-performance, and small-sized devices, especially in the wearable field. Liquid crystal polymers have excellent flexibility, can be bent at will, and cover the surface of the carrier. Excellent development prospects.

(2) The MIMO antenna patch contains two unit antennas with the same structure. The basic radiating unit is a U-shaped ultra-wideband monopole antenna, which is obtained by deformation on the basis of a semicircular monopole antenna. By removing its center Partially, the semi-circular periphery replaces the complete semi-circular patch, and two rectangular patches are added on the top of both sides of the semi-circular patch. The perimeter of the radiation patch has been extended and increased through the deformation of this step. radiated current path at the periphery of the patch.

(3) Two U-shaped slots are engraved on each unit antenna, which are used as WiMAX stop band and WLAN stop band, and will not interfere with other existing wireless communication frequency bands.

(4) There are two rectangular protrusions on the ground plate, which are respectively close to the arc-shaped tops of the two unit antennas. There is a rectangular slot in the middle of the rectangular protrusions, which can improve the matching characteristics of the antenna and expand the working bandwidth.

(5) In the middle of the two unit antennas, a T-shaped floor branch is introduced as an isolation structure, which reduces the coupling caused by the near field and improves the isolation of the antenna.

Description of drawings

FIG. 1 is a schematic diagram of the antenna structure of this embodiment;

Fig. 2 is the S11 simulation result of the antenna of the present embodiment;

FIG. 3 is a simulation result of the isolation degree of the antenna of this embodiment.

Reference signs:

1 is a grounding plate; 2 is a unit antenna; 3 is a U-shaped slot; 4 is a rectangular protrusion; 5 is a T-shaped branch; 6 is a feeder.

Detailed ways

The utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is carried out on the premise of the technical solution of the utility model, and the detailed implementation and specific operation process are given, but the protection scope of the utility model is not limited to the following examples.

Example

As shown in Figure 1, a flexible dual stopband ultra-wideband MIMO antenna includes a substrate, a ground plane and a MIMO antenna patch. The ground plane and the MIMO antenna patch are located on the substrate, and the substrate is a plate made of liquid crystal polymer. The MIMO antenna patch includes two unit antennas with the same structure, the unit antennas are U-shaped ultra-wideband monopole antennas, and the opening directions of the two unit antennas are the same.

Each unit antenna is engraved with two U-shaped slots, serving as the WiMAX stop band and the WLAN stop band. The U-shaped slots have different widths and the same radian. The width of the inner U-shaped slot is smaller than that of the outer U-shaped slot.

The ground plane and the MIMO antenna patch are respectively located on the upper and lower surfaces of the substrate.

The grounding plate is close to the arc part of the unit antenna. There are two rectangular protrusions on the grounding plate, which are respectively close to the arc-shaped tops of the two unit antennas. There is a rectangular groove in the middle of the rectangular protrusion, and the depth of the rectangular groove is higher than that of the rectangular protrusion. the height of. A T-shaped branch is arranged on the ground plate, and the T-shaped branch is located between the two unit antennas and serves as an isolation structure for the two unit antennas.

The unit antenna is connected with a feeder, and the feeder extends from the arc-shaped top of the unit antenna through the rectangular slot and reaches the lower edge of the antenna.

The following is an introduction to the improved part of this embodiment:

(1) Flexible material

Liquid crystal polymer (LCP) is used as the dielectric substrate material of the antenna. At present, in the field of microwave and millimeter wave circuits, liquid crystal polymer (LCP), as a new type of flexible substrate material, has excellent application prospects. LCP has many excellent characteristics, including low thermal expansion coefficient, low cost, small loss, etc., and the dielectric constant of LCP is very stable in a wide enough frequency range, which makes LCP low cost, high performance, It is the best choice in the design of small size devices.

Especially in the wearable field, liquid crystal polymer (LCP) material, as a flexible material, has excellent flexibility, can be bent at will, and covers the surface of the carrier, so it has excellent and development prospects.

(2) MIMO structure

For MIMO antennas, if the antenna correlation between the receiving end and the transmitting end is too high, the performance of the MIMO system will be deteriorated. Therefore, a sufficiently high isolation is a necessary condition that should exist between antenna elements. With the wide application of MIMO technology, many methods that can improve the isolation have been extensively studied, such as neutral line technology, floor stubs, parasitic units, defect ground structures, and metamaterial technology.

In this embodiment, a T-shaped floor stub is added between the unit antennas as an isolation structure. On the one hand, the floor stub can change the distribution of the floor surface current to improve the impedance matching of the port; on the other hand, it can be regarded as a reflection plate to reduce near-field coupling between antennas. Therefore, the isolation of almost all working frequency bands of the antenna can be reduced to below -15dB.

(3) Dual stopband performance

First, for the ultra-wideband MIMO antenna without a stop band, the simulation results in Figure 2 show that the antenna covers 2-10.62 GHz. After engraving two U-shaped slots on the U-shaped ultra-wideband monopole antenna, the stop band for WiMAX and WLAN is added to the working frequency of the antenna, preventing the occurrence of the existing wireless communication frequency band. interference.

Figure 2 is the S11 simulation result of the antenna, it can be seen that it is used for WiMAX (3.4-3.6GHz) and WLAN (5.15-5.825GHz) stop band. Figure 3 shows the simulation results of the isolation of the antenna. If the correlation between the antennas at the receiving end and the transmitting end is too high, the performance of the MIMO system will be deteriorated. Therefore, a sufficiently high isolation degree is a necessary condition between the antenna elements.

Claims (8)

1. a kind of flexible dual stop band ultra-wideband MIMO antenna, comprises substrate, ground plate and MIMO antenna patch, and described ground plate and MIMO antenna patch are positioned on substrate, it is characterized in that, described substrate is liquid crystal polymerization The MIMO antenna patch includes two unit antennas with the same structure, the unit antennas are U-shaped ultra-wideband monopole antennas, and the opening directions of the two unit antennas are the same. 2. A kind of flexible dual stopband ultra-wideband MIMO antenna according to claim 1, characterized in that two U-shaped slots are engraved on each element antenna as WiMAX stopband and WLAN stopband. 3. A flexible dual stopband ultra-wideband MIMO antenna according to claim 2, wherein the U-shaped slots have different widths and the same radian, and the inner U-shaped slot has a smaller width than the outer U-shaped slot. 4 . A flexible dual stopband ultra-wideband MIMO antenna according to claim 1 , wherein the ground plate and the MIMO antenna patch are respectively located on the upper and lower surfaces of the substrate. 5 . A flexible dual stopband ultra-wideband MIMO antenna according to claim 1 , wherein the ground plane is close to the arc portion of the unit antenna. 6 . 6. A kind of flexible dual stop band ultra wideband MIMO antenna according to claim 1, is characterized in that, described ground plate is provided with two rectangular projections, is close to the curved top of two unit antennas respectively, A rectangular groove is formed in the middle of the rectangular protrusion, and the depth of the rectangular groove is higher than the height of the rectangular protrusion. 7. A kind of flexible dual stop band ultra wideband MIMO antenna according to claim 6, is characterized in that, described unit antenna is connected with feeder, and described feeder passes through the rectangle from the arc top of unit antenna The slot extends out to the lower edge of the antenna. 8. A kind of flexible dual stopband ultra wideband MIMO antenna according to claim 1, characterized in that, the ground plate is provided with a T-shaped stub, and the T-shaped stud is located between two element antennas , as an isolation structure for two element antennas.