CN104183912B - A kind of miniaturized dual-band monopole antenna based on metamaterial unit - Google Patents

Abstract

The invention discloses a miniaturized dual-band monopole antenna based on a metamaterial unit, which belongs to the technical field of antennas. The structure of the antenna includes a radiating part, a dielectric substrate, a ground plate and a feeder; the radiating part includes a metal strip and a metal ring, and the metal ring is at the top of the metal strip, which is formed by a rectangular ring broken from the middle and then recessed inward ; The thickness of the dielectric substrate is uniform, above the substrate is the radiation part, below is the ground plate and a metal ring of the same size, and the metal ring is located directly below the metal ring of the radiation part; the width of the ground plate is the same as that of the dielectric The width of the substrate is the same, and the height is shorter than the length of the dielectric substrate; the feeder includes an inner core wire and a shielding layer, the inner core is connected to the bottom of the radiation part, and the shielding layer is connected to the grounding plate. The antenna has good impedance matching and radiation gain, and can be arbitrarily adjusted to other operating frequency bands through size changes, and can be widely used in wireless communication systems such as WLAN and WiMAX.

Description

A Miniaturized Dual-Band Monopole Antenna Based on Metamaterial Elements

technical field

The invention belongs to the technical field of antennas for wireless communication terminals, and relates to a miniaturized dual-band monopole antenna based on a metamaterial unit.

Background technique

At present, with the development of wireless communication technology and the rise of various communication standards, the functions of wireless communication products are becoming more and more complex and diverse, and generally can support different communication standards in multiple frequency bands. At the same time, the internal circuits of wireless communication products are also more complex. In the design of wireless terminals, there is less and less space reserved for antennas, while the functional requirements for antennas are becoming more and more diverse and demanding.

In the market, there are many types of wireless products, and users have more choices when choosing products. Users' requirements for wireless products are not only satisfied with their performance, but also have high requirements for the appearance of products. Most users tend to buy wireless products that are small in size and easy to carry. Therefore, both the technology and the market require wireless devices to develop in the direction of miniaturization. The high integration of circuits can keep up with the demand for miniaturization of wireless devices, and the size of antennas often becomes the bottleneck of reducing the size of wireless products. In recent years, metamaterial antennas have become a research hotspot in the field of radio frequency engineering. With the development of research on the application of metamaterials, more and more researchers use metamaterials to design antennas to achieve the miniaturization, omnidirectionality, and high efficiency of antennas, and the research work in this field has made great progress. More scientific research results.

Contents of the invention

In view of this, the object of the present invention is to provide a miniaturized dual-band monopole antenna based on a metamaterial unit. Two symmetrical electric resonant rings are added to the pole antenna, and the two rings are respectively etched on the front and back of the dielectric plate. The antenna after loading the loop can ensure that the antenna can obtain lower resonance frequency and higher gain under the premise of low profile.

To achieve the above object, the present invention provides the following technical solutions:

A miniaturized dual-band monopole antenna based on a metamaterial unit, the structure of which includes a radiating part, a dielectric substrate, a ground plate and a feeder;

The radiating part includes a metal strip and a metal ring, the metal ring is on the top of the metal strip, and it is formed by a rectangular ring broken from the middle and then recessed inward, and there is a certain gap between the concave metal strips;

The thickness of the dielectric substrate is uniform, the radiating part is above the substrate, the grounding plate and a metal ring of the same size are located below the substrate, and the metal ring is located directly below the metal ring of the radiating part;

The width of the grounding plate is the same as the width of the dielectric substrate, and the height is shorter than the length of the dielectric substrate;

The feeder includes an inner core wire and a shielding layer, the inner core is connected to the bottom end of the radiation part, and the shielding layer is connected to the grounding plate.

Further, the length L4 of the two metal rings is 8.9-9.5mm, the width W4 is 8.9-9.5mm, the inner length L5 of the ring is 3-3.2mm, the inner width W6 is 3-4mm, and the metal width W5 of the ring is 0.3-0.8mm, L6 is 0.6-1mm.

Further, the thickness of the dielectric substrate is 0.6-1.2 mm.

Further, the length of the middle part of the metal strip of the radiation part is: L2 is 7.5-8.5 mm, the width is: W2 is 1.6-2 mm; the length of the lower end part is: L3 is 9.9-10.9 mm, and the width is: W3 is 0.8 -1.2mm.

Further, the length L1 of the dielectric substrate is 28-32mm, the width W1 is 12-16mm, the thickness of the dielectric plate is 0.6-1mm, and the relative dielectric constant of the material is between 4-5.

Further, the height of the metal ground plate is smaller than the length of the dielectric substrate, and its length L7 is 9-13 mm.

The beneficial effect of the present invention is that: the antenna described in the present invention has the following advantages: the addition of the metamaterial electric resonance ring reduces the resonant frequency point of the antenna, and a lower resonant frequency point appears, so that the antenna has two resonances Peak, and ensure that the original bandwidth of the antenna does not change; the antenna has good impedance matching and radiation gain; through size changes, the working frequency band of the antenna can be adjusted arbitrarily, and can be widely used in WLAN, WiMAX and other wireless communication systems.

Description of drawings

In order to make the purpose, technical scheme and beneficial effect of the present invention clearer, the present invention provides the following drawings for illustration:

Fig. 1 is the overall structural diagram of the metamaterial monopole antenna of the present invention;

Figure 2 is a top view of the antenna;

Figure 3 is a bottom view of the antenna;

Fig. 4 is the curve diagram of the variation of reflection coefficient with frequency obtained by simulation;

Figure 5 is the simulated radiation pattern of the antenna in the xy plane and xz plane, the dotted line represents the cross-polarization pattern, and the solid line represents the coplanar polarization pattern; sub-figures (a), (b), (c) , (d) respectively represent the xy plane at the frequency of 2.3GHz, the xz plane at the frequency of 2.3GHz, the xy plane at the frequency of 3.3GHz, and the radiation pattern of the xz plane at 3.3GHz;

Among them, 1-microstrip feeder, 2-metal floor, 3-monopole antenna, 4-upper metamaterial ring, 5-lower metamaterial ring, 6-dielectric substrate, 7-SMA interface.

detailed description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 is the overall structural diagram of the metamaterial monopole antenna of the present invention, Fig. 2 is the plan view of this antenna, Fig. 3 is the bottom view of this antenna, with reference to Fig. 1, 2 and 3, a monopole antenna described in the present invention A metamaterial miniaturized dual-band monopole antenna includes a microstrip line 1, a metal floor 2, a monopole antenna 3, an upper metamaterial ring 4, a lower metamaterial ring 5, a dielectric substrate 6 and an SMA interface 7. The upper surface of the dielectric substrate 6 is a radiating part, which is composed of a microstrip line 1, a monopole antenna 3 and a metamaterial ring 4. The metamaterial ring 4 is at the top of the monopole antenna, and the ring 4 is formed by a broken rectangular ring in the middle. And then formed a depression inward. The upper and lower ends of the monopole antenna 3 are respectively connected to the metamaterial electric resonant ring 4 and the microstrip line 1; the microstrip line 1 is connected to the inner conductor of the SMA interface 7; the metal floor 2 is connected to the outer conductor of the SMA interface 7 The lower surface of the dielectric substrate 6 includes a metal floor 2 and a metamaterial ring 5;

The dielectric substrate 6 is a thin cuboid, whose length is represented by L1 and width by W1. The material used is FR4 epoxy resin board with a relative permittivity of 4.4, a relative permeability of 1.0, and a loss tangent of 0.02. The thickness of the copper grounding plate, the metal radiation strip and the metal feeder arranged on the upper and lower surfaces of the dielectric substrate are the same.

The metamaterial electrical resonant rings 4 and 5 have a gap in the middle respectively, and are bent and extended for a section to the inside. Such a design can effectively adjust the matching degree of the antenna and the microstrip line 1, and the metamaterial electrical resonance on the lower surface The ring 5 can further reduce the resonant frequency of the antenna, thereby further realizing the miniaturization of the antenna. The width of the inwardly bent and extended metal wires of the metamaterial electric resonant rings 4 and 5 is not consistent with the other wire widths of the rings, and the inwardly bent section is wider than the surrounding parts of the rings.

After completing the above initial design, use the high-frequency electromagnetic simulation software HFSS14.0 to conduct simulation experiments. The simulation research shows that the size of the metamaterial ring has a great influence on the resonant frequency of the antenna, and the parameters obtained through the HFSS optimization function are the best. Dimensions are shown in Table 1.

Table 1 The optimal size table of each parameter of the present invention

In addition: the thickness of the copper clad metal on the surface of the dielectric substrate is 0.017mm, and the thickness of the dielectric substrate is 0.8mm.

According to the above parameters, HFSS is used to simulate and calculate the invented antenna, and the reflection coefficient curve of the antenna and the radiation pattern of the antenna are obtained.

Fig. 4 is a simulation graph of the reflection coefficient of the present invention. It can be seen from the figure that there are two resonant frequency points, which are 2.3GHz and 3.3GHz. Under the condition of |S ₁₁ |<-10dB, the impedance bandwidth frequency ranges of the antenna are 2.22-2.38GHz and 3.15-3.48GHz respectively, and the total impedance bandwidth sum is 490MHz.

Figure 5 is the radiation pattern of the xy plane and the xz plane, the dotted line represents the cross polarization pattern, and the solid line represents the coplanar polarization pattern. According to Figures (a) (c) and (b) (d), it can be seen that the radiation patterns of the antenna at 2.3GHz and 3.3GHz are very stable, and the cross-polarization is very small. At the same time, the radiation pattern of the antenna on the xz plane is approximately circular and has good omnidirectionality. The gains at the 2.2GHz and 3.3GHz frequencies are -0.45dBi and 1.85dBi respectively. For pole antennas, such gain values already belong to the current high category.

Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that it can be described in terms of form and Various changes may be made in the details without departing from the scope of the invention defined by the claims.

Claims (6)

1. a miniaturized dual-band monopole antenna based on metamaterial unit, it is characterised in that: include radiant section, medium Substrate, earth plate and feeder line；

Described radiant section includes a bonding jumper and a becket, and becket is on the top of bonding jumper, and it is by fracture between therefrom Straight-flanked ring caves in formation the most inward；

Described dielectric substrate thickness is uniform, is radiant section above medium substrate, lower section be earth plate and one same big Little becket, and this becket is positioned at the position directly below of radiant section becket；Above and below described medium substrate Becket bend inwards the peripheral portion of line width becket to be wider than extended；

The width of described earth plate is as the width of medium substrate, and the length of aspect ratio medium substrate is little；

Described feeder line includes that internal core wire and screen layer, inner core are connected with the bottom of radiant section, and screen layer is connected with earth plate Connect.

A kind of miniaturized dual-band monopole antenna based on metamaterial unit the most according to claim 1, its feature exists In: length L4 of said two becket is 8.9-9.5mm, and width W4 is 8.9-9.5mm, and interior length L5 of ring is 3-3.2mm, Insied width W6 is 3-4mm, metal width W5 of ring be 0.3-0.8mm, L6 be 0.6-1mm.

A kind of miniaturized dual-band monopole antenna based on metamaterial unit the most according to claim 1, its feature exists In: the thickness of described medium substrate is 0.6-1.2mm.

A kind of miniaturized dual-band monopole antenna based on metamaterial unit the most according to claim 1, its feature exists A length of in: the stage casing part of the bonding jumper of described radiant section: L2 is 7.5-8.5mm, and width is: W2 is 1.6-2mm；Under End portion is a length of: L3 is 9.9-10.9mm, and width is: W3 is 0.8-1.2mm.

A kind of miniaturized dual-band monopole antenna based on metamaterial unit the most according to claim 1, its feature exists In: length L1 of medium substrate is 28-32mm, and width W1 is 12-16mm, and the thickness of dielectric-slab is 0.6-1mm, material relative Dielectric constant is between 4-5.

A kind of miniaturized dual-band monopole antenna based on metamaterial unit the most according to claim 1, its feature exists In: the length of the aspect ratio medium substrate of described metal ground plate is little, and its length L7 is 9-13mm.