CN111755827A

CN111755827A - Ultra-wideband antenna based on cross laminated fractal ring structure

Info

Publication number: CN111755827A
Application number: CN202010689446.5A
Authority: CN
Inventors: 宋树祥; 潘凯; 李顺
Original assignee: Guangxi Normal University
Current assignee: Guangxi Normal University
Priority date: 2020-08-11
Filing date: 2020-08-11
Publication date: 2020-10-09

Abstract

The invention discloses an ultra-wideband antenna based on a cross laminated fractal ring structure, which comprises a dielectric substrate, a floor, a feeder line and a main radiation patch, wherein the floor is arranged on the back surface of the dielectric substrate, and the feeder line and the main radiation patch are arranged on the front surface of the dielectric substrate; the main radiation patch is composed of a plurality of main rings which are concentrically arranged, and a plurality of small rings which are in a cross laminated form and have the same size are loaded in each step of the main rings. The antenna designed by adopting the cross laminated fractal ring structure has ultra-wide working bandwidth, good radiation characteristic and stable gain, and is suitable for various wireless communication systems such as ultra-wide band and the like.

Description

Ultra-wideband antenna based on cross laminated fractal ring structure

Technical Field

The invention relates to the field of communication antennas, in particular to an ultra-wideband antenna based on a cross laminated fractal ring structure.

Background

An antenna plays an indispensable role in a wireless communication system as a device for transmitting and receiving electromagnetic wave signals. Since the 3.1-10.6GHz spectrum was classified as the civil frequency Band by the Federal Communications Commission (FCC) in 2002, the Ultra-wideband (UWB) technology has been rapidly developed with its advantages of Wide bandwidth, low power consumption, high speed, etc., and the Ultra-wideband antenna is a communication antenna based on the Ultra-wideband technology. The traditional antenna is generally a narrow-band resonant antenna, the working bandwidth is very limited, and the traditional antenna cannot adapt to the ever-increasing information flow in modern communication. The ultra-wideband system is a wireless communication system with the advantages of ultra-wideband bandwidth, high-speed transmission rate, multipath fading resistance, low energy consumption and the like, and is more suitable for modern communication modes than a narrowband communication system.

It is expected that as communication devices are developed toward portable and multi-band operation, small size and wide bandwidth will become the trend of antenna design, and more and better solutions will be developed. The fractal theory is a mathematical theory describing irregularity and discretization, is applied to the electromagnetic field, particularly to antenna design, and utilizes the attached self-similarity to enable the radiation characteristic of the antenna to be in periodic change, effectively improves the space utilization rate by utilizing the space filling performance, increases the effective electrical size of the antenna, and prolongs the surface current path of the antenna so as to reduce the size and expand the bandwidth. Fractal structures have a plurality of styles, provide a plurality of possibilities for designing novel antennas, and have great potential in future application.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the ultra-wideband antenna based on the cross laminated fractal ring structure.

In order to achieve the purpose, the invention adopts the following technical scheme:

the ultra-wideband antenna based on the cross laminated fractal ring structure comprises a dielectric substrate, a floor, a feeder line and a main radiation patch, wherein the floor is arranged on the back surface of the dielectric substrate, and the feeder line and the main radiation patch are arranged on the front surface of the dielectric substrate; the main radiation patch is composed of a plurality of main rings which are concentrically arranged, and a plurality of small rings which are in a cross laminated form and have the same size are loaded in each step of the main rings.

The antenna designed by adopting the cross laminated fractal ring structure has ultra-wide working bandwidth, good radiation characteristic and stable gain, and is suitable for various wireless communication systems such as ultra-wide band and the like.

Further, main ring be provided with 3, its radius and thickness of outside-in reduce in proper order, be first main ring, second main ring and third main ring respectively.

Furthermore, the outer diameter of each step of small ring is equal to the outer radius of the corresponding step of main ring, the number of the small rings is 3, and the outer diameters of the small rings are respectively a first small ring, a second small ring and a third small ring from large to small.

Further, two adjacent small circular rings of each step are 90 degrees out of phase.

Furthermore, the small circular ring of each step passes through the center of the main circular ring.

Further, the antenna also comprises an impedance transformation structure, wherein the impedance transformation structure is arranged between the feeder line and the main radiation patch, and the impedance transformation structure is connected with the first main ring, so that the antenna can obtain a better impedance matching effect.

Compared with the prior art, the invention has the following advantages: 1. the impedance bandwidth of the antenna is very wide; 2. the volume is small; 3. the omnidirectional radiation can be realized; 4. easy to integrate with other circuits.

Drawings

Fig. 1 is a schematic front structural view of an ultra-wideband antenna based on a cross-laminated fractal ring structure according to the present invention;

fig. 2 is a schematic diagram of a back structure of an ultra-wideband antenna based on a cross-laminated fractal ring structure according to the present invention;

fig. 3 is a return loss curve diagram of the ultra-wideband antenna based on the cross-laminated fractal ring structure;

fig. 4 is a peak gain curve diagram of the ultra-wideband antenna based on the cross-laminated fractal loop structure according to the present invention;

fig. 5 is a radiation efficiency curve diagram of the ultra-wideband antenna based on the cross-laminated fractal ring structure;

fig. 6(a) - (c) are radiation patterns of the ultra-wideband antenna based on the cross-laminated fractal ring structure at different frequency points.

Detailed Description

The invention is described in detail below with reference to the accompanying drawings:

in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "front", "back", "inside", "outside", and the like are based on the directions or positional relationships shown in the drawings, or the directions or positional relationships conventionally put in use of the products of the present invention, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed in a specific direction and operation, and thus, cannot be construed as limiting the present invention.

As shown in fig. 1-2, the ultra-wideband antenna based on the cross-laminated fractal ring structure of the present invention includes a dielectric substrate 1, a floor 2, a main radiation patch 4 and a feeder 11, and is designed in a microstrip line feeding manner as a whole. The dielectric substrate 1 is made of FR4 material with dielectric constant of 4.4 and loss tangent of 0.02, and has a rectangular surface with side length of 34mm, width of 25mm and thickness of 1.6 mm. The main radiation patch 4, the feeder line 11 and the floor 2 are all plated with copper. The floor 2 is arranged on the lower portion of the back face of the medium substrate 1, the floor 2 is a combination of a rectangle and a semi-ellipse, the width of the rectangle is 23mm, the height of the rectangle is 6mm, and the semi-minor axis of the ellipse is 4 mm. The front surface of the dielectric substrate 1 is provided with a feeder line 11 and a main radiation patch 4, and the feeder line 11 is connected to the lower end of the main radiation patch 4. The main radiation patch 4 is composed of 3 concentric main rings with the radius and thickness decreasing from outside to inside, namely a first main ring 5, a second main ring 6 and a third main ring 7. Wherein, the inner radius and the outer radius of the first main circular ring 5 are respectively 9.5mm and 11mm, and the thickness is 1.5 mm; the inner radius and the outer radius of the second main circular ring 6 are respectively 5.8mm and 6.9mm, and the thickness is 1.1 mm; the inner radius and the outer radius of the third main circular ring 7 are respectively 3mm and 3.8mm, and the thickness is 0.8 mm.

The inner diameter of each step of small ring is equal to the outer diameter of the corresponding step of main ring, the difference between every two adjacent small rings is 90 degrees, the circle center of each small ring with the difference of 180 degrees is on the same straight line, and the straight line also passes through the circle center of the main ring. The small ring of each order passes through the center of the main ring of the same order, namely the outer edge of the small ring of the same order is inscribed with the outer edge of the large ring. The small circular rings are provided with 3 types, and the outer diameters of the small circular rings are a first small circular ring 8, a second small circular ring 9 and a third small circular ring 10 from large to small. The inner radius and the outer radius of the first small circular ring 8 are respectively 4.9mm and 5.5mm, and the thickness is 0.6 mm; the inner radius and the outer radius of the second small circular ring 9 are respectively 3.05mm and 3.45mm, and the thickness is 0.4 mm; the inner radius and the outer radius of the third small circular ring 10 are respectively 1.6mm and 1.9mm, and the thickness is 0.3 mm.

In order to obtain better impedance matching effect of the antenna, an impedance change structure 3 is loaded at the joint of the feeder line 11 and the main radiation patch 4, and the upper end of the impedance change structure 3 is connected with the first main circular ring 5. The upper half of the impedance variation structure 3 is 3.26mm high and 1mm wide, and the lower half is 7.75mm high and 2.3mm wide.

The features of the present invention can be further illustrated by the results:

FIG. 3 is a graph of return loss S11, the operating frequency band of return loss S11< -10dB is 2-11GHz, and the relative bandwidth reaches 138.5%, which shows that the antenna has good impedance matching characteristics, covers the ultra-wideband spectrum range of 3.1-10.6GHz, and has ultra-wideband characteristics.

Fig. 4 is a gain curve diagram of the antenna, which has a high gain and small fluctuation in the whole working frequency band, and basically meets the radiation requirement of the ultra-wideband antenna.

Fig. 5 is a graph of the radiation efficiency of the antenna at a high value in the range of 0.83-0.97 over the entire operating frequency band, which indicates that the antenna has good energy conversion capability and good overall radiation performance.

Fig. 6(a) - (c) are antenna radiation patterns with frequencies of 4GHz, 7GHz, and 10GHz, respectively, which include a horizontal pattern E plane (XOY) and a vertical pattern H plane (YOZ), and it can be seen that the E plane radiation pattern of the antenna at each frequency point is approximately "8" shaped, and the H plane is substantially circular, so that omnidirectional radiation can be achieved, the radiation characteristics are good, and the radiation requirement of the ultra-wideband antenna is met.

Although particular embodiments of the present invention have been described and illustrated in detail, it should be noted that various changes and modifications could be made to the above-described embodiments without departing from the spirit of the invention and the scope of the appended claims.

Claims

1. The ultra-wideband antenna based on the cross laminated fractal ring structure comprises a dielectric substrate (1), a floor (2), a feeder (11) and a main radiation patch (4), and is characterized in that the floor (2) is arranged on the back of the dielectric substrate (1), and the feeder (11) and the main radiation patch (4) are arranged on the front of the dielectric substrate (1); the main radiation patch (4) is composed of a plurality of main rings which are concentrically arranged, and a plurality of small rings which are in a cross laminated form and have the same size are loaded in each step of the main rings.

2. The ultra-wideband antenna based on the cross-laminated fractal ring structure as claimed in claim 1, wherein the number of the main rings is 3, and the radius and thickness of the main rings are sequentially reduced from outside to inside, which are respectively the first main ring (5), the second main ring (6) and the third main ring (7).

3. The ultra-wideband antenna based on the cross-laminated fractal ring structure as claimed in claim 2, wherein the outer diameter of each small ring is equal to the outer radius of the corresponding main ring, the number of the small rings is 3, and the outer diameters of the small rings are from large to small, namely a first small ring (8), a second small ring (9) and a third small ring (10).

4. The ultra-wideband antenna based on a cross-laminated fractal ring structure as claimed in claim 3, wherein the two adjacent small circular rings of each step are 90 degrees out of phase.

5. The ultra-wideband antenna based on a cross-laminated fractal ring structure as claimed in claim 4, wherein the small ring of each step passes through the center of the main ring.

6. The ultra-wideband antenna based on the cross-laminated fractal ring structure as claimed in claim 5, further comprising an impedance transformation structure (3), wherein the impedance transformation structure (3) is disposed between the feed line (11) and the main radiating patch (4), and the impedance transformation structure (3) is connected to the first main ring (5).