CN214706241U - 1.8GHz miniaturized fractal antenna - Google Patents

Abstract

The utility model discloses a 1.8GHz miniaturized fractal antenna, FR-4 dielectric board that is 36.7mm including length and width, and FR-4 dielectric board substrate upper surface covers there is the fractal radiation copper sheet, 50 omega microstrip feed line, banded microstrip feed copper thin slice and radiation ground copper thin slice, FR-4 dielectric board upper surface evenly is equipped with radiation ground copper thin slice all around, be equipped with the fractal radiation copper sheet in the radiation ground copper thin slice, and radiation ground copper thin slice one side central point puts and is equipped with wide 3.04 mm's ground plate, be equipped with the rectangle copper thin slice that length and width are 8.8mm and 2.3mm respectively in this ground plate, rectangle copper thin slice one end and big tangent copper thin slice round connection, the central point of big tangent copper thin slice circle puts and is equipped with the radius and is 8.2mm quartic iteration fractal copper thin slice, the utility model discloses a miniaturization and the high gain of antenna, can be applied to wireless communication, Radio frequency identification, microwave energy wireless transmission and the like.

Description

1.8GHz miniaturized fractal antenna

Technical Field

The utility model relates to an antenna structure technical field specifically is a miniaturized fractal antenna of 1.8 GHz.

Background

With the rapid development of electronic science technology, the application of wireless communication technology and derivatives thereof in real life is more and more extensive; with the continuous improvement of the technology, higher requirements and strict parameter indexes are provided for the antenna which is indispensable in wireless communication; meanwhile, in the present day that the electronic equipment technology is continuously developed forward, no matter in civil wireless communication equipment or military wireless communication equipment, under the precondition of high communication quality, a wireless communication system is required to have the performance of broadband and miniaturization at the same time, so in recent years, research hotspots in the antenna field are focused on miniaturization broadband antennas; along with continuous requirements of people on indexes such as antenna size, receiving efficiency and the like, more and more novel antennas are produced, and a microstrip antenna is one of the antennas; the microstrip antenna has the remarkable characteristics of small weight, low section, compact structure and the like; on the other hand, microstrip antennas also have their own drawbacks, such as lower gain, etc., compared to other types of antennas.

The bandwidth and the gain are two most basic factors for determining the performance of the antenna, the broadband characteristic is favorable for the antenna to be suitable for more occasions, and the high-gain characteristic is favorable for saving energy required by signal transmission; the broadband antenna has high transmission rate of antenna radiation signals and large system capacity, can improve the anti-multipath interference capability and gain, can greatly reduce the power of transmitted signals, and can greatly increase the signal transmission distance.

However, the prior art has the following defects:

1. in the prior art, the energy received by an antenna cannot be processed in an optimal state, so that the energy can be transmitted with high gain.

2. The structure of the antenna in the prior art is too single to provide a wider passband, so that the performance of the antenna cannot reach the optimal state.

3. In the prior art, the miniaturization and integration of the antenna are difficult to realize.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to overcome current defect, other antennas of this antenna comparison possess littleer size, relatively lower return loss and higher gain, can effectively solve the problem in the background art.

In order to achieve the above object, the utility model provides a following technical scheme: a1.8 GHz miniaturized fractal antenna comprises an FR-4 dielectric plate with the length and the width of 36.7mm, and the upper surface of the FR-4 dielectric board substrate is covered with a parting radiation copper sheet, a 50 omega microstrip feed line, a strip microstrip feed copper sheet and a radiation grounding copper sheet, the periphery of the upper surface of the FR-4 dielectric substrate is uniformly provided with a radiation grounding copper sheet, a parting radiation copper sheet is arranged in the radiation grounding copper sheet, the side length of the parting radiation copper sheet is of a square structure of 26.6mm, the center of one side of the radiation grounding copper sheet is provided with a grounding plate with the width of 3.04mm, rectangular copper sheets with the length and width of 8.8mm and 2.3mm are arranged in the grounding plate, the distance between each rectangular copper sheet and the two sides of the grounding plate is 0.37mm, one end of each rectangular copper sheet is connected with a large tangent copper sheet circle, the radius of the large tangent copper sheet circle is 10.1mm, and four iteration fractal copper sheets with the radius of 8.2mm are arranged at the center of the large tangent copper sheet circle.

Furthermore, the parting radiation copper sheet, the strip microstrip feed copper sheet and the radiation grounding copper sheet are positioned on the same plane.

Further, the length L of the parting radiation copper sheet is

Wherein h represents the thickness of the dielectric layer, wherein_reffIs the effective dielectric constant of the FR-4 dielectric substrate.

Compared with the prior art, the beneficial effects of the utility model are that: this 1.8GHz miniaturized fractal antenna's bandwidth is 180MHz, and return loss minimum reaches-44 dB, and this 1.8GHz miniaturized fractal antenna's gain direction is bidirectional, and maximum gain reaches 2.35dB, the utility model discloses a miniaturization and the high gain of antenna can be applied to fields such as wireless communication, radio frequency identification and microwave energy wireless transmission.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 shows the specific parameters of the structure of the present invention;

fig. 3 is a schematic diagram of a fractal structure of a four-iteration fractal copper sheet of the present invention;

FIG. 4 is a return loss plot of a 1.8GHz miniaturized fractal antenna simulated by HFSS antenna simulation software;

fig. 5 shows radiation patterns of a 1.8GHz miniaturized pattern antenna in the XOY plane and the YOZ plane simulated by HFSS antenna simulation software.

In the figure: the radiation grounding copper sheet comprises a 1 radiation grounding copper sheet, a 2-type radiation copper sheet, a 3-large tangent copper sheet circle, a 4-time iteration fractal copper sheet, a 5-grounding plate and a 6-rectangular copper sheet.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-5, the present invention provides a technical solution: a1.8 GHz miniaturized fractal antenna comprises an FR-4 dielectric plate with the length and the width of 36.7mm, and the upper surface of the FR-4 dielectric board substrate is covered with a parting radiation copper sheet, a 50 omega microstrip feed line, a strip microstrip feed copper sheet and a radiation grounding copper sheet, the periphery of the upper surface of the FR-4 dielectric substrate is uniformly provided with a radiation grounding copper sheet, a parting radiation copper sheet is arranged in the radiation grounding copper sheet, the side length of the parting radiation copper sheet is of a square structure of 26.6mm, the center of one side of the radiation grounding copper sheet is provided with a grounding plate with the width of 3.04mm, rectangular copper sheets with the length and width of 8.8mm and 2.3mm are arranged in the grounding plate, the distance between each rectangular copper sheet and the two sides of the grounding plate is 0.37mm, one end of each rectangular copper sheet is connected with a large tangent copper sheet circle, the radius of the large tangent copper sheet circle is 10.1mm, and four iteration fractal copper sheets with the radius of 8.2mm are arranged at the center of the large tangent copper sheet circle.

The core part of the utility model is the design of the fractal radiation copper sheet, and the size of the metal antenna patch of the miniaturized fractal antenna, the size and the thickness of the medium substrate are theoretically estimated when the microstrip antenna is designed, so that the relevant parameter requirement suitable for the design of the 1.8GHz frequency band can be quickly and accurately found in the simulation experiment; therefore, the following explains the theoretical calculation method of each data parameter of the microstrip antenna by taking a rectangular microstrip antenna as an example.

The theoretical design method of the microstrip antenna is adopted, the microstrip is used for feeding, and the theoretical design method comprises the following steps:

the microstrip antenna is designed according to the conventional theoretical design method of the rectangular microstrip antenna, and the width W of a patch of the microstrip antenna is

In the formula (1), f0 represents the resonant frequency of the antenna, ε r represents the relative dielectric constant, and c represents the speed of light. The resonant frequency f0 of the antenna is 1.8 GHz.

The length L of the radiating patch is

In the formula (3), h represents the dielectric layer thickness, where ε reff is the effective dielectric constant of the substrate.

In order to reduce the influence of surface wave radiation on the antenna performance, the thickness of the dielectric substrate should satisfy the following theoretical calculation formula

fm is the highest frequency of operation of the microstrip antenna.

The microstrip antenna can be equivalently analyzed as an RLC resonant circuit. C is the equivalent capacitance between radiation paster and the earth plate, XL is the equivalent inductance, and L is the equivalent inductance. The input impedance Zin of the antenna is

In the formula (6): QT is the quality factor of the resonant circuit.

A reflection parameter Γ of

According to the formula (8), the return loss S11 and the standing wave ratio σ VSWR of the antenna can be calculated as follows:

S₁₁＝20lg|Γ| (8)

the rectangular microstrip antenna uses a microstrip line for feeding, and after the length and the width of the rectangular patch are determined, standard impedance of 50 omega is generally added into the microstrip antenna.

FIG. 3 is a return loss diagram of a 1.8GHz miniaturized fractal antenna simulated by HFSS antenna simulation software, and it can be known from the diagram that the bandwidth of the 1.8GHz miniaturized fractal antenna is 180MHz, the minimum value of the return loss reaches-44 dB, and the frequency band matching performance reaches the design requirement.

Fig. 4 is a radiation pattern of the 1.8GHz miniaturized fractal antenna simulated by HFSS antenna simulation software on the XOY plane and the YOZ plane, and it can be known from the figure that the gain direction of the 1.8GHz miniaturized fractal antenna is bidirectional, the maximum gain reaches 2.35dB, and both the directivity and the gain reach the design requirements.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (3)

1. A1.8 GHz miniaturized fractal antenna comprises an FR-4 dielectric plate with the length and the width of 36.7mm, and the upper surface of the FR-4 dielectric board substrate is covered with a parting radiation copper sheet, a 50 omega microstrip feed line, a strip microstrip feed copper sheet and a radiation grounding copper sheet, the periphery of the upper surface of the FR-4 dielectric sheet is uniformly provided with a radiation grounding copper sheet, a parting radiation copper sheet is arranged in the radiation grounding copper sheet, the side length of the parting radiation copper sheet is of a square structure of 26.6mm, the center of one side of the radiation grounding copper sheet is provided with a grounding plate with the width of 3.04mm, rectangular copper sheets with the length and width of 8.8mm and 2.3mm are arranged in the grounding plate, the distance between each rectangular copper sheet and the two sides of the grounding plate is 0.37mm, one end of each rectangular copper sheet is connected with a large tangent copper sheet circle, the radius of the large tangent copper sheet circle is 10.1mm, and four iteration fractal copper sheets with the radius of 8.2mm are arranged at the center of the large tangent copper sheet circle.

2. The 1.8GHz miniaturized diversity antenna of claim 1, characterized in that: the parting radiating copper sheet, the strip microstrip feed copper sheet and the radiating grounding copper sheet are positioned on the same horizontal plane.

3. The 1.8GHz miniaturized diversity antenna of claim 1, characterized in that: the length L of the parting radiation copper sheet is

Wherein h represents the thickness of the dielectric layer, wherein_reffIs the effective dielectric constant of the FR-4 dielectric substrate.

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