CN114843772A - Dual-frequency dual-circular-polarization high-isolation Fabry-Perot cavity MIMO antenna and processing method thereof - Google Patents
Dual-frequency dual-circular-polarization high-isolation Fabry-Perot cavity MIMO antenna and processing method thereof Download PDFInfo
- Publication number
- CN114843772A CN114843772A CN202210439776.8A CN202210439776A CN114843772A CN 114843772 A CN114843772 A CN 114843772A CN 202210439776 A CN202210439776 A CN 202210439776A CN 114843772 A CN114843772 A CN 114843772A
- Authority
- CN
- China
- Prior art keywords
- dielectric plate
- dielectric
- antenna
- dual
- fabry
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/50—Structural association of antennas with earthing switches, lead-in devices or lightning protectors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
- H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/52—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
- H01Q15/14—Reflecting surfaces; Equivalent structures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
- H01Q15/24—Polarising devices; Polarisation filters
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
- H01Q5/10—Resonant antennas
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
- H01Q5/30—Arrangements for providing operation on different wavebands
Abstract
The invention discloses a 2X 2 double-frequency double-circular-polarization high-isolation Fabry-Perot cavity multi-input multi-output antenna and a processing method, and belongs to the technical field of antennas. The antenna is formed by rotationally arranging four identical Fabry-Perot antenna units at 90 degrees. The antenna unit is composed of a feed antenna and a partial reflecting surface. The feed antenna is a hybrid structure of slot and patch. The chiral metamaterial is used as a partial reflecting surface unit to realize left-handed circularly polarized waves and right-handed circularly polarized waves. And the port isolation between adjacent antenna units is improved by introducing the broadband metamaterial wave absorber. The antenna array has the characteristics of high isolation, high gain, double frequency bands and double circular polarization, and is suitable for modern mobile communication application. The processing method comprises the following steps: preprocessing the feed antenna; processing a part of the reflecting surface; processing the wave absorber; placing a partial reflecting surface above the feed antenna to form an antenna unit; arranging the antenna units into a MIMO antenna array in a rotating way; wave absorbers are placed between the units.
Description
Technical Field
The invention relates to the technical field of antenna engineering, in particular to a dual-band dual-circular-polarization high-isolation Fabry-Perot cavity MIMO antenna.
Background
Multiple input multiple output antennas, also known as MIMO antennas. Compared with the traditional single antenna, the antenna has the capability of greatly improving the data rate and the channel capacity under the condition of not occupying extra bandwidth, and therefore, the antenna has attracted extensive attention in the field of antennas. MIMO antennas have potential applications in current and next generation wireless communication systems, sensor systems, radar and satellite communications, etc.
The MIMO antenna is widely used in the field of wireless communication and the like due to the characteristics of increasing spatial freedom, improving system performance, increasing channel capacity and the like, and the circularly polarized antenna is widely concerned due to strong anti-multipath fading capability, so that the circularly polarized MIMO antenna is widely developed. In recent years, a great deal of research has been conducted on dual-band circular polarization MIMO antennas, and the modes of implementing dual-band circular polarization can be roughly classified into three types. (1) The patch antenna method realizes circular polarization by opening orthogonal slots, circular slots, corner cuts and the like on a patch antenna and changing the distribution of current on the patch. However, such antennas are generally narrower in axial ratio bandwidth and lower in gain due to the radiation mechanism of the patch antenna itself. (2) Phase delay method: the method distributes signals into two paths of signals with equal amplitude and 90-degree phase difference through a 90-degree power divider, and excites two orthogonally polarized input ends of a dual-frequency dual-linear polarized antenna so as to form circularly polarized radiation. (3) Polarization conversion method: the conversion from linear polarized waves to circularly polarized waves is realized by loading a polarization conversion cover above the linear polarized antenna, and the conversion cover can also be used as a partial reflecting surface to realize the improvement of gain.
In summary, the conventional circularly polarized MIMO antenna has the problems of narrow axial ratio bandwidth, low gain, etc., and a future wireless communication system will need a wider axial ratio bandwidth, a higher gain, and a lower delay. Therefore, the research on the dual-frequency dual-circular polarization high-isolation MIMO antenna has practical significance.
Disclosure of Invention
At present, the published circularly polarized MIMO antenna has insufficient gain and axial ratio bandwidth, which limits the application range, or has insufficient isolation, which deteriorates the system performance and lacks practicability.
The technical problem to be solved by the invention is as follows: the partial reflecting surface is loaded, the purpose is to improve the gain of the feed antenna and realize dual-frequency polarization conversion, then the MIMO antenna is formed in an array mode, the isolation degree between each unit is improved by loading the wave absorber, the MIMO antenna working on two frequency bands in different circular polarization modes is proposed for the first time, and high isolation is realized.
The invention is realized by the following technical scheme:
a dual-frequency, dual-circular polarization and high-isolation Fabry-Perot cavity MIMO antenna comprises a feed antenna, a partial reflecting surface and a wave absorbing body. The partial reflecting surface covers the upper part of the feed antenna and is used for improving the gain of the feed antenna and realizing polarization conversion, the feed antenna and the partial reflecting surface form an antenna unit, the antenna unit is rotationally arranged at 90 degrees to form an MIMO antenna, and the wave absorber is loaded between the antenna units and is used for improving the isolation of the MIMO antenna.
Compared with the existing circularly polarized MIMO antenna, the dual-frequency, dual-circularly polarized and high-isolation Fabry-Perot cavity MIMO antenna provided by the invention has the innovative points that:
the high-gain double-frequency circularly polarized Fabry-Perot antenna is obtained by adopting a method of covering a part of reflecting surface above a feed antenna, wherein a part of reflecting surface has a high reflection coefficient and a double-frequency polarization conversion function at the same time; therefore, the electromagnetic waves are reflected for multiple times in the cavity to achieve the in-phase superposition of the electric fields, and finally part of the reflecting surface is transmitted, so that the gain of the feed antenna is enhanced, and the transmitted electromagnetic waves are radiated in a circular polarization mode to achieve polarization conversion.
The patch type feed antenna is selected, and has the advantages that the patch antenna has the structural characteristics of compact structure, easiness in processing, design, low cost and the like, so that the whole structure of the Fabry-Perot resonant cavity antenna is simple and easy to realize.
As a further description of the present invention, the second dielectric plate is introduced into the feed antenna, and the slot ground on the upper surface and the patch on the lower surface of the second dielectric plate are electrically coupled by the microstrip on the lower surface of the first dielectric, resulting in a single-feed dual-band linearly polarized antenna without affecting the overall profile of the fabry-perot antenna.
As a further description of the present invention, the portion of the reflective surface overlying the patch antenna described above comprises a single layer dielectric substrate of a two-layer printed metal structure.
As a further description of the present invention, the wave absorber loaded between the antenna units includes: the bottom layer of the fifth dielectric slab is of a circular ring structure, 4 ports are formed in the ring at intervals of 90 degrees, and the 4 ports are connected through 4 150 omega chip resistors; the bottom layer of the fourth dielectric plate is a circular ring structure, the circular ring is smaller than the circular ring of the top layer of the fifth dielectric plate, 4 ports are formed in the ring at intervals of 90 degrees, the 4 ports are connected through 4 150 omega chip resistors, the position of the opening is rotated by 45 degrees relative to the position of the opening in the upper layer of the fifth dielectric plate, 4 through holes are formed in the fourth dielectric plate, and the position of each through hole is the position where the fourth dielectric plate resistor is placed; the bottom layer of the sixth dielectric slab is fully copper-clad, the top layer of the sixth dielectric slab is a circular ring structure, 4 openings are formed in the ring at intervals of 90 degrees, and the 4 openings are connected by 4 150 omega chip resistors; the top layer of the seventh dielectric plate is in a circular ring structure, the circular ring is smaller than the circular ring of the top layer of the sixth dielectric plate, 4 ports are spaced at 90 degrees on the ring, the 4 ports are connected by 4 150 omega chip resistors, the position of the opening is rotated by 45 degrees relative to the position of the opening on the upper layer of the sixth dielectric plate, 4 through holes are formed in the seventh dielectric plate, and the position of the through holes is the position where the fourth dielectric plate resistors are placed. The sizes of the circular rings and the opening positions of the fourth dielectric plate and the seventh dielectric plate are consistent; the sizes of the circular rings and the opening positions of the fifth dielectric plate and the sixth dielectric plate are consistent. And no gap is reserved among the fourth dielectric plate, the fifth dielectric plate, the sixth dielectric plate and the seventh dielectric plate.
As a further description of the present invention, the specific structure of the feed antenna of the dual-band, dual-circular-polarization, high-isolation fabry-perot cavity MIMO antenna is as follows: the feeder line structure on the lower surface of the first dielectric slab is an SMA feed-in single microstrip line, and the tail end of the microstrip line is branched into two microstrip lines; the central part of the upper surface copper-clad structure is separated by a rectangular gap; the center of the lower surface of the second dielectric plate is coated with a rectangle. The copper feeder sequentially stacks a first dielectric plate and a second dielectric plate according to the sequence that the bottom layer is the first dielectric plate and the top layer is the second dielectric plate; the first dielectric plate and the second dielectric plate have the same thickness; the first dielectric plate and the second dielectric plate have the same dielectric constant.
As a further description of the invention, the slotted structure on the upper surface of the first dielectric substrate and the copper-clad structure on the lower surface of the second dielectric substrate are correspondingly and concentrically arranged.
As a further description of the present invention, the first dielectric substrate is provided with a plurality of fixing holes, and the second dielectric plate is provided with a plurality of fixing holes corresponding to the fixing holes of the first dielectric plate. One end of the nylon medium supporting column is fixed in the fixing hole of the first medium plate, the other end of the nylon medium supporting column is fixed in the fixing hole of the second medium plate, and the second medium plate is supported to be arranged above the ground plane.
As a further description of the present invention, the specific structure of the wave absorber of the dual-frequency dual-circular polarization fabry-perot cavity MIMO antenna is as follows: and sequentially stacking a fourth dielectric plate, a fifth dielectric plate, a sixth dielectric plate and a seventh dielectric plate according to the sequence that the bottom layer is the fourth dielectric plate, the fifth dielectric plate and the sixth dielectric plate are arranged next to the fourth dielectric plate, and the uppermost layer is the seventh dielectric plate. And then the dielectric layers are arranged in a cross shape periodically, and the length and the width of the cross shape are the sum of the thicknesses of the two ground planes and the four dielectric plates, the fifth dielectric plate, the sixth dielectric plate and the seventh dielectric plate. The thicknesses of the four dielectric plates, the fifth dielectric plate, the sixth dielectric plate and the seventh dielectric plate are the same, and the dielectric constants are the same.
As a further description of the present invention, the overall specific structure of the dual-band dual-circular polarization fabry-perot cavity MIMO antenna is as follows: and placing the first dielectric plate at the bottom, the second dielectric plate above the first dielectric plate, the third dielectric plate above the second dielectric plate, and the wave absorbing body in the air cavity between the first dielectric plate and the third dielectric plate.
In summary, the dual-frequency, dual-circular polarization and high-isolation fabry-perot cavity MIMO antenna provided by the invention adopts the antenna with the single-sided copper-clad structure, in which the microstrip feeder line on the lower surface of the first dielectric plate is simultaneously coupled with the slotted ground on the upper surface and the second dielectric plate, as the excitation source to form dual-frequency resonance; the single-layer dielectric substrate is used as a reflecting cover plate of the feed antenna, so that high gain and double circular polarization are realized; the fourth dielectric plate, the fifth dielectric plate, the sixth dielectric plate and the seventh dielectric plate form a wave absorbing body, and the isolation of the MIMO antenna is enhanced. Finally, the MIMO antenna realizes left-hand circular polarization and right-hand circular polarization at low frequency and high frequency respectively, the realized 2 standing wave ratio bandwidths are 3.6 percent and 12.6 percent, wherein the 3dB axial ratio bandwidth is 3 percent and 2 percent respectively, and the port isolation among all the units of the antenna is better than 42.2dB on the whole working frequency band; meanwhile, the cross section of the MIMO antenna is only about 1/2 of the wavelength in vacuum.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. compared with the existing double-frequency circularly polarized MIMO antenna, the invention firstly proposes that different circularly polarized waves can be radiated in two different frequency bands;
2. the invention relates to a single-layer partial reflecting surface which can realize gain improvement and double-band double-circular polarization conversion, and has higher gain and a stable directional diagram compared with the traditional double-frequency circular polarization MIMO antenna;
3. the invention has high port isolation, higher channel capacity and lower channel fading;
4. the invention has simple structure and convenient realization.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
fig. 1 is a structural cross-sectional view of a fabry-perot MIMO antenna according to embodiment 1 of the present invention.
Fig. 2 is a top view of a radiating patch of the feed antenna structure according to embodiment 1 of the present invention.
Fig. 3 is a front view of a radiation patch of a feed antenna structure according to embodiment 1 of the present invention
Fig. 4 is a three-dimensional view of a partial reflecting surface unit in embodiment 1 of the present invention.
FIG. 5 is a top view of a top metal unit of a partially reflective surface in accordance with example 1 of the present invention.
Fig. 6 is a top view of the bottom metal unit of the partial reflection surface in embodiment 1 of the present invention.
Fig. 7 is a three-dimensional view of a wave absorber unit according to example 1 of the present invention.
FIG. 8 is a top view of a wave absorber in example 1 of the present invention.
Fig. 9 is a reflection coefficient curve and a gain curve chart of the feed antenna according to embodiment 1 of the present invention under HFSS simulation.
FIG. 10 is a graph of transmission coefficient ratio and transmission phase difference of co-polarization and cross-polarization of a partially reflective surface unit in accordance with example 1 of the present invention under HFSS simulation.
FIG. 11 shows the transmission coefficients of circular polarization of a partially reflective surface unit in accordance with embodiment 1 of the present invention under HFSS simulation.
FIG. 12 is a graph of the reflection coefficient and absorption rate of the absorber unit of example 1 of the present invention under HFSS simulation.
Fig. 13 is a reflection coefficient graph of the MIMO antenna according to embodiment 1 of the present invention under HFSS simulation.
Fig. 14 is a S-parameter graph of the MIMO antenna according to embodiment 1 of the present invention under HFSS simulation.
Fig. 15 is a gain curve and an axial ratio curve of the MIMO antenna according to embodiment 1 of the present invention under HFSS simulation.
Fig. 16 shows the H-plane pattern of the MIMO antenna of embodiment 1 of the present invention at 3.4GHz under HFSS simulation.
Fig. 17 shows the E-plane pattern of the MIMO antenna of embodiment 1 of the present invention at 3.4GHz under HFSS simulation.
Fig. 18 shows the H-plane pattern of the MIMO antenna of embodiment 1 of the present invention at 6.6GHz under HFSS simulation.
Fig. 19 shows the E-plane pattern of the MIMO antenna of embodiment 1 of the present invention at 6.6GHz under HFSS simulation.
Fig. 20 shows basic steps of a dual-band dual-circular polarization fabry-perot cavity MIMO antenna design according to embodiment 1 of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
Example 1:
as shown in fig. 1, a dual-band, dual-circular polarization, high-isolation fabry-perot cavity MIMO antenna provided by the present invention includes: the feed antenna, set up the wave absorber between antenna element and the reflection apron above the feed antenna.
The feed antenna is a first dielectric substrate 3 coated with copper on two sides, a microstrip feeder line 1 is carved on the lower surface of the feed antenna, slotted copper is used as a ground plane 2 on the upper surface of the feed antenna, a second dielectric plate 4 of the feed antenna is coated with copper 5 on the lower surface of the feed antenna.
The partially reflecting surface is formed by a third dielectric plate 14 coated with copper. The bottom surface of the third dielectric substrate 14 is provided with three metal strip structures 12, and the upper surface of the third dielectric substrate 14 is provided with an I-shaped copper-clad structure 13.
Furthermore, the feed antenna adopts a microstrip to feed, the microstrip is connected with the SMA feed from the side surface, the first dielectric substrate and the second dielectric substrate are separated by a certain distance, and two working frequency bands are generated through coupling.
Further, a fourth dielectric plate 9 and a fifth dielectric plate 10 of the wave absorber are fully coated with copper 8 on the lower surface of the fourth dielectric plate 9, a circular open ring 7 on the upper surface of the fourth dielectric plate, a circular open ring 6 on the upper surface of the fifth dielectric plate 10, and a 150 Ω resistor 11.
Further, the MIMO antennas are arranged with 90 ° rotation.
As shown in fig. 3, in this embodiment, the feed line of the feed antenna is 1, the slot ground is 2, and the patch on the lower surface of the second dielectric plate is 5, so that it exhibits more free variables; in addition, the second dielectric substrate is introduced to be separated from the first dielectric substrate by a certain distance, and two working broadband are generated through microstrip coupling. By designing the impedance of the microstrip line, and by setting these variables, good impedance matching of a wide frequency band is achieved.
Further, as shown in fig. 2, the first dielectric substrate 3 is provided with a plurality of fixing holes, and correspondingly, in this embodiment, the fixing holes are respectively provided at four vertex angles of the second dielectric substrate 4, and a distance between the fixing hole and the second dielectric substrate 4 may be determined according to actual conditions, and the distance between the fixing hole and the second dielectric substrate has a very small influence on the performance of the antenna and only plays a role of supporting. One end of the nylon dielectric support column is fixedly arranged in the positioning hole in the second dielectric substrate 4, the other end of the nylon dielectric support column is fixedly arranged in the positioning hole corresponding to the first dielectric substrate 3 in the feed antenna, and then the second dielectric plate 4 is arranged above the slot ground.
Further, as shown in fig. 1, the distance between the third dielectric substrate 14 and the first dielectric plate 3 is about 1/2 of the operating wavelength of the low frequency band of the antenna.
As shown in fig. 1, a part of the reflective surface in the dual-band, dual-circular-polarization, high-isolation fabry-perot cavity MIMO antenna is a third dielectric plate 14 coated with copper. As shown in fig. 4, there are three strip-shaped metals 12 on the bottom surface of the third dielectric substrate 14; as shown in fig. 4, the upper layer is coated with an "I" type metal structure 13. As shown in fig. 5, a plurality of "I" shaped structures 13 with the same size are periodically arranged above the third dielectric plate, and as shown in fig. 6, a plurality of strip-shaped metals 12 with the same size are periodically arranged below the third dielectric plate. And the copper-clad structure 12 on the bottom surface of the third dielectric substrate 14 and the copper-clad structure 13 on the upper surface of the third dielectric substrate 14 are aligned in the center.
In this embodiment, the dielectric constant of the third dielectric substrate 14 is 3.38, and the thickness is 1.52 mm. As shown in fig. 4, the side length l of the copper-clad third dielectric substrate 14 on the bottom surface 12 1 26mm in width w 1 1.8mm and a gap g of 8.2 mm. The upper surface of the third dielectric substrate 14 is I-shapedTwo lengths d of the structure 1 Is 10.4mm and has a width d w 1.8mm, a middle length d 2 Is 16.9 mm. As shown in FIG. 5, the copper-clad structures of the third dielectric substrate 14 are arranged periodically in a plane, and the center-to-center distance p between two adjacent copper-clad structures is 26 mm.
In this embodiment, the dielectric constant of the sixth dielectric substrate 9 is 4.4, the thickness is 4mm, the dielectric constant of the seventh dielectric plate 10 is 4.4, the thickness is 4mm, the dielectric constant of the fourth dielectric substrate 17 is 4.4, the thickness is 4mm, the dielectric constant of the fifth dielectric plate 18 is 4.4, and the thickness is 4 mm.
Further, as shown in fig. 7, the lower surface of the sixth dielectric plate is fully coated with copper 8, and the side length p a Is 21mm, and the inner radius r of the metal split ring 7 on the upper surface of the sixth dielectric slab 1 Is 8.3mm and has a width w a 1mm, and opened at intervals of 90 °, the opening width s is 1mm, and a 150 Ω resistor 11 is placed at the opened position. The inner radius r of the metal split ring 6 on the upper surface of the seventh dielectric plate 2 Is 6.5mm and has a width w a 1mm, the opening position is rotated by 45 ° with respect to the ring 7 and the openings are spaced at 90 ° intervals, the opening width s is 1mm, and a 150 Ω resistor is placed at the opening position. The inner radius r of the metal split ring 15 on the lower surface of the fifth dielectric slab 1 Is 8.3mm and has a width w a 1mm, and openings at intervals of 90 °, the opening width s being 1mm, and a 150 Ω resistor being placed at the opening position. The inner radius r of the metal split ring 16 on the lower surface of the fourth dielectric plate 2 Is 6.5mm and has a width w a Which is 1mm, the opening position is rotated by 45 deg. with respect to the ring 15 and the openings are spaced at 90 deg. intervals, the opening width s is 1mm, and a 150 omega resistor is placed at the opening position.
Further, as shown in fig. 7, holes 19 are formed in the fourth dielectric plate and the seventh dielectric plate at positions where the fifth dielectric plate and the sixth dielectric plate are located. The opening positions of the ring 6 and the ring 16 are the same, the opening positions of the ring 7 and the ring 15 are the same, and the through hole punching positions of the fourth dielectric plate and the seventh dielectric plate are the same. As shown in fig. 8, the copper-clad structures of the sixth dielectric substrate 9 and the seventh dielectric substrate 10 are arranged periodically in a plane, and the center-to-center distance p between two adjacent copper-clad structures a Are all 21 mm.
In other preferred embodiments of the present invention, if other types of circuit boards are used as the third dielectric substrate 14, the dimensions of the copper metallization structures 12 and 13 of the third dielectric substrate 14 will vary according to the design theory described above, but these parameters vary depending on the dielectric constant of the third dielectric substrate 14 used.
In other preferred embodiments of the present invention, if other types of circuit boards are used for the fourth dielectric substrate 9 and the fifth dielectric plate 10, the sizes of the copper-clad structure 7 of the fourth dielectric plate 9 and the copper-clad structure 6 of the fifth dielectric plate 10 and the type of the resistor 11 are different according to the above design theory, but the variation of these parameters is related to the dielectric constants of the fourth dielectric substrate 9 and the fifth dielectric plate 10.
In summary, the dual-frequency, dual-circular polarization and high-isolation fabry-perot cavity MIMO antenna provided by the invention adopts the antenna with the single-sided copper-clad structure, in which the microstrip feeder line on the lower surface of the first dielectric plate is simultaneously coupled with the slotted ground on the upper surface and the second dielectric plate, as the excitation source to form dual-frequency resonance; the single-layer dielectric substrate is used as a reflecting cover plate of the feed antenna, so that high gain and double circular polarization are realized; the fourth dielectric plate and the fifth dielectric plate form a wave absorbing body, and the isolation of the MIMO antenna is enhanced. Finally, the MIMO antenna realizes left-hand circular polarization and right-hand circular polarization at low frequency and high frequency respectively, the realized 2 standing wave ratio bandwidths are 3.6 percent and 12.6 percent, wherein the 3dB axial ratio bandwidth is 3 percent and 2 percent respectively, and the port isolation among all the units of the antenna is better than 45dB on the whole working frequency band; meanwhile, the cross section of the MIMO antenna is only about 1/2 of the wavelength in vacuum.
As shown in fig. 9, a reflection coefficient curve and a gain curve of a feeding antenna of the dual-frequency, dual-circular polarization, high isolation fabry-perot cavity MIMO antenna according to the present invention are respectively shown, and simulation results show that the feeding antenna can achieve standing-wave ratio bandwidths of less than 2 of 3.6% and 12.6% in low-frequency and high-frequency distributions, and the gains are respectively 1.48dBi-3.46dBi and 5.65dBi-8.4dBi within a matching bandwidth.
As shown in fig. 10, it can be seen that the amplitude ratio and the phase difference of the co-polarized transmission coefficient and the cross-polarized transmission coefficient of the partial reflecting surface according to the present invention are 0.87 and 1.07 at 3.55GHz and 7GHz, respectively, and the phase difference is 90 ° and-90 °, respectively, which indicates that the linearly polarized wave is converted into the left-handed circularly polarized wave at 3.55GHz and the right-handed circularly polarized wave at 7GHz, respectively.
As shown in FIG. 11, in order to partially reflect the transmission coefficient of the linear polarized wave to the circularly polarized wave in the present invention, it can be seen that T is at 3.55GHz +y Is 0.16, T -y 0.5, the right-hand circularly polarized wave is obviously smaller than the left-hand circularly polarized wave; at 7GHz, T +y Is 0.84, T -y 0.01, so that the left-hand circularly polarized wave is suppressed and the right-hand circularly polarized wave is transmitted.
As shown in FIG. 12, in order to show the reflection coefficient and the absorption rate of the absorber of the present invention, it can be seen that the reflection coefficient is lower than-10 dB and the absorption rate is higher than 90% in the wide band range of 3-7.7 GHz.
As shown in fig. 13, the standing-wave ratio curves of the dual-band, dual-circular-polarization, high-isolation fabry-perot cavity MIMO antenna of the present invention can observe the operating bandwidths at 3.3-3.42GHz (3.6%) and 6.15-6.96GHz (12.6%).
As shown in fig. 14, for the port isolation curve of the dual-band, dual-circular polarization, high isolation fabry-perot cavity MIMO antenna of the present invention, it can be observed that the port isolation is better than 42.2dB within 3.3-3.42GHz and better than 43.6dB within 6.15-6.96 GHz.
As shown in fig. 15, for the axial ratio and gain curves of the dual-frequency, dual-circular polarization, high-isolation fabry-perot cavity MIMO antenna of the present invention, it can be observed that the 3dB axial ratio bandwidth is 3.33-3.43GHz (3%) and 6.53-6.66GHz (2%), and the gain is 5dBi-7.9dBi and 9.24dBi-10.8dBi in the low-frequency and high-frequency axial ratio bandwidths, respectively.
As shown in fig. 16, for the H-plane directional pattern of the dual-band dual-circular polarization method and high-isolation fabry-perot cavity MIMO antenna of the present invention at 3.4GHz, it can be observed that the main radiation direction is left-handed circular polarization, and the difference between the two circular polarizations is higher than 20 dB.
As shown in fig. 17, an E-plane directional pattern of the dual-band dual-circular polarization method high-isolation fabry-perot cavity MIMO antenna of the present invention at 3.4GHz can observe that the main radiation direction is left-handed circular polarization, and the difference between the two circular polarizations is higher than 20 dB.
As shown in fig. 18, for the H-plane directional pattern of the dual-band dual-circular polarization method and high-isolation fabry-perot cavity MIMO antenna of the present invention at 6.6GHz, it can be observed that the main radiation direction is right-hand circular polarization, and the difference between the two circular polarizations is higher than 20 dB.
As shown in fig. 19, it can be observed that the main radiation direction is right-hand circular polarization, and the difference between the two types of circular polarizations is higher than 20dB, for the E-plane directional pattern of the dual-band dual-circular polarization method high-isolation fabry-perot cavity MIMO antenna of the present invention at 6.6 GHz.
Fig. 20 shows a basic process for processing a dual-band, dual-circular polarization and high-isolation fabry-perot cavity MIMO antenna according to the present invention.
While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Therefore, any modification, equivalent replacement, improvement and the like made within the principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A dual-band, dual-circular-polarization, high-isolation Fabry-Perot cavity MIMO antenna, comprising: the feed antenna and the partial reflecting surface above the feed antenna are combined into a Fabry-Perot cavity antenna unit and a wave absorbing body between the antenna units.
The feed antenna is composed of a first dielectric substrate with copper-coated on both sides and a second dielectric substrate with copper-coated on one side, a microstrip feed line is carved on the lower surface of the first dielectric substrate, a metal ground plane with a slot is arranged on the upper surface of the first dielectric substrate, and the size of the metal ground is the same as that of a part of the reflecting surface. The second dielectric substrate is positioned right above the first dielectric substrate, a rectangular patch is carved on the lower surface of the second dielectric substrate, and the rectangular patch is coupled while the microstrip feeder line of the first dielectric substrate excites the slot ground, so that two resonance points are formed.
The partial reflecting surface is positioned above the feed antenna and consists of a third dielectric plate coated with copper on two sides. An I-shaped structure is carved on the upper surface of the third dielectric plate, the I-shaped structure deflects by 45 degrees, and three metal strips are carved on the lower surface.
The wave absorbing body consists of a fifth dielectric plate and a sixth dielectric plate with copper-coated double surfaces, and a fourth dielectric plate and a seventh dielectric plate with copper-coated single surfaces. The top layer of the fifth dielectric plate is fully coated with copper, the bottom layer of the fifth dielectric plate is of an open circular ring structure, and the openings are connected through resistors; the bottom layer of the fourth dielectric plate is of an open circular ring structure, the openings are connected by resistors, the fourth dielectric plate is perforated with through holes, and the through holes are the positions where the fifth dielectric plate resistors are placed; the bottom layer of the sixth dielectric plate is fully coated with copper, the top layer of the sixth dielectric plate is an open circular ring structure, and the openings are connected by resistors; the top layer of the seventh dielectric plate is an open circular ring structure, the openings are connected by resistors, the seventh dielectric plate is perforated by through holes, and the through holes are positioned at the positions where the resistors of the sixth dielectric plate are placed.
2. The dual-band, dual-circular polarization and high-isolation Fabry-Perot cavity MIMO antenna according to claim 1, wherein the specific structure of the wave absorber is as follows: the bottom layer of the fifth dielectric slab is of a circular ring structure, 4 ports are formed in the ring at intervals of 90 degrees, and the 4 ports are connected through 4 150 omega chip resistors; the bottom layer of the fourth dielectric plate is a circular ring structure, the circular ring is smaller than the circular ring of the top layer of the fifth dielectric plate, 4 ports are formed in the ring at intervals of 90 degrees, the 4 ports are connected through 4 150 omega chip resistors, the position of the opening is rotated by 45 degrees relative to the position of the opening in the upper layer of the fifth dielectric plate, 4 through holes are formed in the fourth dielectric plate, and the position of each through hole is the position where the fourth dielectric plate resistor is placed; the bottom layer of the sixth dielectric slab is fully copper-clad, the top layer of the sixth dielectric slab is a circular ring structure, 4 openings are formed in the ring at intervals of 90 degrees, and the 4 openings are connected by 4 150 omega chip resistors; the top layer of the seventh dielectric plate is in a circular ring structure, the circular ring is smaller than the circular ring of the top layer of the sixth dielectric plate, 4 ports are spaced at 90 degrees on the ring, the 4 ports are connected by 4 150 omega chip resistors, the position of the opening is rotated by 45 degrees relative to the position of the opening on the upper layer of the sixth dielectric plate, 4 through holes are formed in the seventh dielectric plate, and the position of the through holes is the position where the fourth dielectric plate resistors are placed. The sizes of the circular rings and the opening positions of the fourth dielectric plate and the seventh dielectric plate are consistent; the sizes of the circular rings and the opening positions of the fifth dielectric plate and the sixth dielectric plate are consistent. And no gap is reserved among the fourth dielectric plate, the fifth dielectric plate, the sixth dielectric plate and the seventh dielectric plate.
3. The MIMO antenna with dual-band, dual-circular polarization and high isolation Fabry-Perot cavity of claim 1, wherein the interval between the ground plane of the feed antenna and the third dielectric substrate of the partial reflecting surface is hc, the initial value is 1/2 of the operating wavelength of the antenna at the low frequency band, and the optimal gain and axial ratio bandwidth are ensured by optimizing the distance hc.
4. The MIMO antenna with dual-band, dual-circular polarization and high isolation Fabry-Perot cavity of claim 3, wherein the lower surface of the third dielectric substrate is periodically provided with strip-shaped metallic copper structures; the upper surface of the third dielectric substrate is periodically provided with a plurality of I-shaped patch structures with the same size.
5. The MIMO antenna with dual-frequency, dual-circular polarization and high isolation Fabry-Perot cavity of claim 3, wherein the fourth dielectric plate has a periodic arrangement of open rings and resistors on its lower surface; open rings and resistors are periodically arranged on the lower surface of the fifth dielectric plate; open rings and resistors are periodically arranged on the upper surface of the sixth dielectric plate, and the lower surface of the sixth dielectric plate is completely coated with copper; open rings and resistors are periodically arranged on the upper surface of the seventh dielectric plate.
6. The dual-band, dual-circular polarization, high isolation fabry-perot cavity MIMO antenna of claim 2, wherein the partially reflective surface first dielectric substrate has a dielectric constant of 3.38 and a thickness of 0.81mm, and the second dielectric substrate has a dielectric constant of 3.38 and a thickness of 0.81 mm.
7. The dual-band dual-circular polarization high-isolation Fabry-Perot cavity MIMO antenna according to claim 2, wherein the third dielectric plate has a dielectric constant of 3.38 and a thickness of 1.52mm, and the second dielectric plate has a dielectric constant of 3.38 and a thickness of 0.5 mm.
8. The dual-band, dual-circular polarization and high isolation fabry-perot cavity MIMO antenna of claim 2, wherein the fourth dielectric plate has a dielectric constant of 4.4 and a thickness of 4mm, and the fifth dielectric plate has a dielectric constant of 4.4 and a thickness of 4 mm.
9. A method for processing a dual-frequency, dual-circular polarization and high-isolation Fabry-Perot cavity MIMO antenna is characterized by comprising the following steps:
step 1: placing a partial reflecting surface above the feed antenna to form an antenna unit;
step 2: arranging the antenna units into a MIMO antenna array in a rotating way;
and step 3: wave absorbers are added between the units.
10. The method as claimed in claim 8, wherein the first dielectric substrate is provided with a plurality of fixing holes, the second dielectric substrate is provided with a plurality of fixing holes corresponding to the holes of the first dielectric substrate, one end of the nylon dielectric support column is fixedly disposed in the fixing hole of the first dielectric plate, the other end of the nylon dielectric support column is fixedly disposed in the fixing hole of the second dielectric plate, and the second dielectric plate is supported and disposed above the slotted metal ground. A partial reflecting surface is arranged above the feed antenna, the partial reflecting surface and the partial reflecting surface form an antenna unit, and the antenna unit is arranged by rotating 90 degrees to form a 2 x 2 MIMO antenna. The specific method for placing the wave absorber comprises the following steps: the wave absorbing bodies form a cross-shaped array and are arranged among the four antenna units for fixing the feed source antenna and the partial reflecting surface, and the partial reflecting surface is supported and arranged right above the feed antenna.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210439776.8A CN114843772A (en) | 2022-04-25 | 2022-04-25 | Dual-frequency dual-circular-polarization high-isolation Fabry-Perot cavity MIMO antenna and processing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210439776.8A CN114843772A (en) | 2022-04-25 | 2022-04-25 | Dual-frequency dual-circular-polarization high-isolation Fabry-Perot cavity MIMO antenna and processing method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114843772A true CN114843772A (en) | 2022-08-02 |
Family
ID=82565711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210439776.8A Pending CN114843772A (en) | 2022-04-25 | 2022-04-25 | Dual-frequency dual-circular-polarization high-isolation Fabry-Perot cavity MIMO antenna and processing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114843772A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117498026A (en) * | 2023-12-29 | 2024-02-02 | 南京信息工程大学 | Method for decoupling micro-strip antenna array of Fabry-Perot resonant cavity |
-
2022
- 2022-04-25 CN CN202210439776.8A patent/CN114843772A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117498026A (en) * | 2023-12-29 | 2024-02-02 | 南京信息工程大学 | Method for decoupling micro-strip antenna array of Fabry-Perot resonant cavity |
| CN117498026B (en) * | 2023-12-29 | 2024-04-02 | 南京信息工程大学 | Method for decoupling micro-strip antenna array of Fabry-Perot resonant cavity |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111052504B (en) | Millimeter wave antenna array element, array antenna and communication product | |
| Zhang et al. | Dual-band structure reused antenna based on quasi-elliptic bandpass frequency selective surface for 5G application | |
| US10978812B2 (en) | Single layer shared aperture dual band antenna | |
| CN112072294B (en) | Broadband low-profile high-isolation dual-circular-polarization two-dimensional wide-angle scanning sparse array | |
| CN113097716B (en) | Broadband circularly polarized end-fire antenna adopting substrate integrated waveguide technology | |
| CN114256626B (en) | Dual-frequency dual-circular polarization efficient common-caliber flat antenna | |
| Nahar et al. | Survey of various bandwidth enhancement techniques used for 5G antennas | |
| CN114156659B (en) | Broadband common-caliber dipole array of Sub-6GHz and millimeter wave frequency bands | |
| CN113555697A (en) | Circular polarization high-gain antenna based on folding plane reflective array technology | |
| KR20050117316A (en) | Microstrip stack patch antenna using multi-layered metallic disk and a planar array antenna using it | |
| CN115528424A (en) | Wide-beam dual-circular-polarization super-surface antenna unit, implementation method and phased array antenna | |
| Parthasarathy et al. | Design of linear 2× 2 array using substrate-integrated-waveguide patch antenna for 28GHz mm-wave applications | |
| CN111541031B (en) | Broadband low-profile transmission array antenna and wireless communication equipment | |
| CN113690584A (en) | Millimeter wave wide-angle scanning phased-array antenna based on substrate integrated ridge waveguide | |
| Jagtap et al. | Gain and bandwidth enhancement of circularly polarized MSA using PRS and AMC layers | |
| CN114843772A (en) | Dual-frequency dual-circular-polarization high-isolation Fabry-Perot cavity MIMO antenna and processing method thereof | |
| US4660047A (en) | Microstrip antenna with resonator feed | |
| CN116404414A (en) | Microwave/millimeter wave double-frequency broadband common-caliber antenna with multiplexing structure | |
| CN110931968A (en) | Low cross polarization millimeter wave microstrip flat plate array antenna | |
| CN115939782A (en) | W-band rotary type circularly polarized magnetoelectric dipole antenna array | |
| CN113708046A (en) | Miniaturized broadband circular polarization three-dimensional printing mixed dielectric resonator antenna | |
| Guo et al. | A K-/Ka-band planar shared-aperture beam-scanning array with a high-isolation for the emerging mm-Wave shared-aperture terminals | |
| Kakhki et al. | Magneto-electric dipole antenna loaded with meta-lens for beamforming and dual-beam radiation applications | |
| CN115911869B (en) | Millimeter wave wide bandwidth angle scanning antenna and antenna array based on three-function electric wall | |
| Kumar et al. | Cavity-Backed Slot Loaded Substrate Integrated Waveguide Self-Diplexing Antenna for C Band Applications |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |