CN107732443A - A kind of high-isolation double work state dual polarization ultra wide band mimo antenna - Google Patents

Abstract

The invention provides a kind of high-isolation double work state dual polarization ultra wide band mimo antenna, there is very high isolation, dual polarization, and realize that bifurcation works, and volume is smaller；The present invention is made up of rectangular dielectric medium substrate, radiating surface, rectangular ring metal ground plate and rectangular patch, radiating surface is made up of four symmetrical trapezoidal radiating elements and feeder line, the back side is rectangular ring floor, and the skew of antenna operating band is realized by adjusting the rectangular patch among back；Pass through the isolation for introducing the X-shaped slit of positive X-shaped narrow metallic tapes and back to improve under antenna list feedback state；The size of final antenna is 32 × 32mm², can be worked in the case of difference-mode input high isolation, also dual-mode of operation state can be presented in single normal work under presenting input state.

Description

A dual-polarized ultra-wideband MIMO antenna with high isolation and dual working states

technical field

The invention belongs to the technical field of microwave antennas, and in particular relates to a high-isolation dual-working-state dual-polarization ultra-wideband MIMO antenna.

Background technique

Multiple-input and multiple-output technology (MIMO) optimizes the multipath wireless channel, transmission and reception as a whole, so as to achieve high communication capacity and spectrum utilization, and is a near-optimal combination of space and time domain diversity. And interference cancellation processing, these advantages make MIMO technology receive more and more attention in recent years. Ultra Wide Band (UWB, UltraWide Band) technology is a new type of wireless communication technology. The U.S. Federal Communications Commission released the 3.1-10.6GHz bandwidth range in 2002 as ultra-wideband (UWB). UWB technology has many advantages such as wide bandwidth, high data rate wireless transmission, high capacity and low power consumption. Combining UWB technology with MIMO technology, taking advantage of spatial multipath, and transmitting multiple signals in parallel, can obtain obvious multiplexing gain and diversity gain, and it is hopeful to realize long-distance stable transmission of signals. Isolation is very important to the performance of a MIMO antenna, and achieving both high isolation and small size is a challenge.

Two differential-mode feeds reported in the literature "Compact, high isolation and dual-polarized differential dual-notched UWB-MIMO slot antenna" and "Compact Differential Band-Notched Stepped-Slot UWB-MIMO Antenna with Common-Mode Suppression" Antennas also have a high degree of isolation, but they have a common problem, that is, both antennas can only work under the condition of differential mode excitation, and cannot work normally in other modes, such as working in a single-port feeding state .

Contents of the invention

The purpose of the present invention is to overcome the defects and deficiencies of the above-mentioned prior art, and provide a dual-polarized ultra-wideband MIMO antenna with high isolation and dual working states. The antenna can perfectly cover the 3.1-10.6GHz ultra-wideband frequency band and has a dual-state working property. It works in a differential mode state with a very high degree of isolation, and can work normally in a single-feed state. Furthermore, the feeding method of the antenna is simple, and the size of the antenna is obviously smaller than that of the same type of antenna.

The technical scheme that the present invention adopts to solve described technical problem is:

A high-isolation double-working state dual-polarization ultra-wideband MIMO antenna, including a rectangular insulating dielectric substrate 1, a radiation surface, a rectangular ring-shaped metal ground plate 2, and a rectangular patch 3; the radiation surface includes four trapezoidal radiation elements 4 , four rectangular metal patches 5 and X-shaped metal strips 6; the four sides of the rectangular ring-shaped metal grounding plate 2 are respectively provided with rectangular holes 7 of the same size; the opposite corners of the rectangular ring-shaped metal grounding plate 2 A floor slit 8 is opened at the line position; a patch slit 9 is opened at the diagonal position of the rectangular patch 3;

The radiating surface is located on the upper surface of the rectangular insulating dielectric substrate 1, and the rectangular annular metal ground plate 2 and the rectangular patch 3 are located on the lower surface of the rectangular insulating dielectric substrate 1; the size and shape of the four trapezoidal radiating units 4 are exactly the same and placed symmetrically with each other; the size and shape of the four rectangular metal patches 5 are exactly the same and placed symmetrically with each other; one end of each rectangular metal patch 5 is located at the edge of the rectangular insulating dielectric substrate 1, and the other end is connected to the short end of the trapezoidal radiation unit 4 connected by parallel sides;

The rectangular metal patch 5, the rectangular insulating dielectric substrate 1 and the rectangular annular metal grounding plate 2 together form a feed port; the four trapezoidal radiating elements 4 are closely and symmetrically placed on the rectangular insulating dielectric substrate 1 as four radiating elements of the antenna. The upper surface to reduce the size of the antenna; two pairs of differential feed ports are placed orthogonally to increase the differential isolation of the antenna; X-shaped metal strips 6, floor slits 8 and patch slits 9 are used to improve the antenna single isolation in the feed state.

The beneficial effect of the present invention is that: the antenna is made of a double-sided copper-clad dielectric substrate, and the overall structure can be realized by using traditional PCB technology with low cost; compared with the prior art, the antenna not only satisfies Working under high isolation, it can also work normally in single-feed state, which greatly improves the application range of the antenna, reduces the use conditions, and is convenient for users; the volume is small, the feeding method is simple, and it can be perfectly Covering the ultra-wideband frequency band, it has high use value.

Description of drawings

Fig. 1 is the overall schematic diagram of the antenna structure of the present invention;

FIG. 2 is a schematic front view of the antenna structure of the present invention;

Fig. 3 is a schematic diagram of the back of the antenna structure of the present invention;

Fig. 4 is S11 curve emulation and test result under differential mode excitation condition of the present invention;

Fig. 5 is the coupling coefficient result between adjacent ports under the differential mode excitation condition of the present invention;

Fig. 6 is S11 curve simulation and test result under the single-feed excitation condition of the present invention;

Fig. 7 is the coupling coefficient result between each port under the single-feed excitation condition of the present invention;

Fig. 8 is a radiation pattern diagram of the present invention at low frequency, medium frequency and high frequency.

detailed description

The present invention will be described in more detail below in conjunction with the accompanying drawings and embodiments.

A high-isolation double-working state dual-polarization ultra-wideband MIMO antenna, its overall structure schematic diagram is shown in Figure 1, the front and back schematic diagrams of the antenna structure are shown in Figure 2 and Figure 3 respectively, including a rectangular insulating dielectric substrate 1, The radiation surface, the rectangular ring-shaped metal ground plate 2 and the rectangular patch 3; the radiation surface includes four trapezoidal radiation units 4, four rectangular metal patches 5 and X-shaped metal strips 6; the rectangular ring-shaped metal ground The four sides of the floor 2 are respectively provided with rectangular small holes 7 of the same size; the diagonal position of the rectangular annular metal grounding plate 2 is provided with a floor slit 8; the diagonal position of the rectangular patch 3 is provided with a sticker sheet slit 9;

The radiating surface is located on the upper surface of the rectangular insulating dielectric substrate 1, and the rectangular annular metal ground plate 2 and the rectangular patch 3 are located on the lower surface of the rectangular insulating dielectric substrate 1; the size and shape of the four trapezoidal radiating units 4 are exactly the same and placed symmetrically with each other; the size and shape of the four rectangular metal patches 5 are exactly the same and placed symmetrically with each other; one end of each rectangular metal patch 5 is located at the edge of the rectangular insulating dielectric substrate 1, and the other end is connected to the short end of the trapezoidal radiation unit 4 connected by parallel sides;

The rectangular metal patch 5, the rectangular insulating dielectric substrate 1 and the rectangular annular metal grounding plate 2 together form a feed port; the four trapezoidal radiation units 4 are closely and symmetrically placed on the upper surface of the rectangular insulating dielectric substrate 1 to reduce the size of the antenna. Two pairs of differential feed ports are placed orthogonally to increase the differential isolation of the antenna. In theory, the differential isolation can be infinite and dual polarization can be obtained; the rectangular patch 3 and the rectangular hole 7 are used to adjust the frequency band of the antenna left and right offset; in order to make the antenna work normally under the single-feed state, the X-shaped metal strip 6, the floor slit 8 and the patch slit 9 can be used to improve the isolation of the antenna under the single-feed state;

The parameters of the antenna described in this embodiment are: L=32mm, h=0.508mm, Wf=1mm, Lc=2mm, Wc=3mm, Lf=2.9mm, Wg=0.1mm, L1=7.7mm, W1=2mm, W2=9.5mm, Li=26.1mm, L2=9mm, Wp=0.1mm. The proposed antenna is made of a dielectric substrate with a relative dielectric constant of 2.2 and a thickness of 0.508mm. ^The material is Rogers5880(tm).

The differential mode S11 parameter curve of the antenna is shown in Figure 4, and the -10dB bandwidth in the differential mode working state is 2.95GHz-11.1GHz; the S11 parameter curve of the single-feed mode is shown in Figure 6. The requirements of S11<-10dB are met in the range of 12GHz. Under differential mode excitation conditions, the coupling coefficients of adjacent ports are shown in Figure 5, which can reach below -45dB, and the isolation is very high; the coupling coefficients in single-feed mode are shown in Figure 7, and are also lower than the -15dB requirement. It can be seen that the present invention can work normally under two kinds of working states, and realizes the dual-state working property. The radiation pattern of the antenna at low, medium and high frequencies is shown in Figure 8. The E plane presents an 8-shaped radiation characteristic, and the H plane exhibits omnidirectional radiation.

In summary, the antenna described in the present invention can perfectly cover the 3.1-10.6GHz ultra-broadband frequency band and has a dual-state working property, works in a differential mode state, has very high isolation, and can work normally in a single-feed state . Furthermore, the feeding method of the antenna is simple, and the size of the antenna is obviously smaller than that of the same type of antenna. The invention has simple structure, easy processing and excellent antenna performance, and is very suitable for application in ultra-wideband communication systems.

Claims (4)

1. A dual-polarized ultra-broadband MIMO antenna with high isolation and dual working conditions is characterized in that it includes a rectangular insulating dielectric substrate (1), a radiation surface, a rectangular ring-shaped metal ground plate (2) and a rectangular patch (3) The radiating surface includes four trapezoidal radiating units (4), four rectangular metal patches (5) and X-shaped metal strips (6); the four sides of the rectangular annular metal grounding plate (2) are respectively opened with Rectangular small holes (7) of the same size; the diagonal position of the rectangular annular metal grounding plate (2) has a floor slit (8); the diagonal position of the rectangular patch (3) has a patch slit (9); The radiation surface is located on the upper surface of the rectangular insulating dielectric substrate (1), and the rectangular annular metal ground plate (2) and the rectangular patch (3) are located on the lower surface of the rectangular insulating dielectric substrate (1); the four trapezoidal The size and shape of the radiating units (4) are identical and placed symmetrically with each other; the size and shape of the four rectangular metal patches (5) are identical and placed symmetrically with each other; one end of each rectangular metal patch (5) is located on a rectangular insulating dielectric substrate At the edge of (1), the other end is connected with the short parallel side of the trapezoidal radiation unit (4). 2. the high-isolation dual-working state dual-polarization ultra-wideband MIMO antenna according to claim 1 is characterized in that, the rectangular metal patch (5), the rectangular insulating dielectric substrate (1) and the rectangular ring-shaped metal junction The floor (2) together constitutes a feeding port; four trapezoidal radiating elements (4) are closely and symmetrically placed on the upper surface of a rectangular insulating dielectric substrate (1) as four radiating elements of an antenna; two pairs of differential feeding ports are placed orthogonally, Increase the differential isolation of the antenna; the X-shaped metal strip (6), the floor slit (8) and the patch slit (9) are used to improve the isolation of the antenna in a single-feed state. 3. The high-isolation dual-working state dual-polarization ultra-wideband MIMO antenna according to claim 1, characterized in that the material used for the rectangular insulating dielectric substrate (1) is Rogers 5880. 4. high isolation degree according to claim 1 dual working state dual polarization ultra-wideband MIMO antenna, is characterized in that, described rectangular annular metal ground plate (2), rectangular patch (3), trapezoidal radiation unit ( 4), the four rectangular metal patches (5) and the X-shaped metal strip (6) are all made of copper with a thickness of 0.0175mm.