阅读说明：本技术 一种无巴伦的平面准八木滤波天线 (Balun-free planar quasi-yagi filtering antenna ) 是由 涂治红 何青蓉 于 2020-06-15 设计创作，主要内容包括：本发明公开了一种无巴伦的平面准八木滤波天线,包括第一介质基板和第二介质基板,第一介质基板位于第二介质基板上方；第一介质基板的上表面设置有引向器、两个偶极子辐射贴片和反射器,该两个偶极子辐射贴片位于引向器和反射器之间,通过引向器和反射器的辐射作用使得两个偶极子辐射贴片能够产生端射方向的辐射；第二介质基板的上表面设置有阶跃阻抗谐振器,其下表面设置有金属地板,阶跃阻抗谐振器由穿过第二介质基板和金属地板的同轴探针进行馈电,通过阶跃阻抗谐振器耦合激励第一介质基板上的引向器、两个偶极子辐射贴片和反射器。本发明具有较好的端射特性和滤波功能,带内增益稳定,且有较好的带外抑制水平,结构简单,面积小。(The invention discloses a balun-free planar quasi-yagi filtering antenna which comprises a first dielectric substrate and a second dielectric substrate, wherein the first dielectric substrate is positioned above the second dielectric substrate; the upper surface of the first dielectric substrate is provided with a director, two dipole radiation patches and a reflector, the two dipole radiation patches are positioned between the director and the reflector, and the two dipole radiation patches can generate radiation in an end-fire direction through the radiation effect of the director and the reflector; the upper surface of the second dielectric substrate is provided with a step impedance resonator, the lower surface of the second dielectric substrate is provided with a metal floor, the step impedance resonator is fed by a coaxial probe penetrating through the second dielectric substrate and the metal floor, and the director, the two dipole radiation patches and the reflector on the first dielectric substrate are excited through coupling of the step impedance resonator. The invention has better end-fire characteristic and filtering function, stable in-band gain, better out-of-band rejection level, simple structure and small area.)

1. A balun-free planar quasi-yagi filtering antenna comprises two dielectric substrates, namely a first dielectric substrate and a second dielectric substrate, wherein the first dielectric substrate is positioned above the second dielectric substrate; the method is characterized in that: the upper surface of the first dielectric substrate is provided with a director, two dipole radiation patches and a reflector, the two dipole radiation patches are positioned between the director and the reflector, and the two dipole radiation patches can generate radiation in an end-fire direction through the radiation effect of the director and the reflector; the upper surface of the second dielectric substrate is provided with a step impedance resonator, the lower surface of the second dielectric substrate is provided with a metal floor, the step impedance resonator is fed by a coaxial probe penetrating through the second dielectric substrate and the metal floor, and the director, the two dipole radiation patches and the reflector on the first dielectric substrate are excited through coupling of the step impedance resonator.

2. The balun-free planar quasi-yagi filter antenna as claimed in claim 1, wherein: the step impedance resonator is an E-type step impedance resonator.

Technical Field

The invention relates to the technical field of filtering antennas, in particular to a balun-free planar quasi-yagi filtering antenna.

Background

In a wireless communication system, as 5G communication starts to be used commercially, the performance requirement on an antenna is higher and higher, a miniaturized antenna receives more and more attention, and a filter antenna is widely applied due to the integrated design of a filter and an antenna; the microstrip quasi-yagi antenna has the characteristics of high gain, anti-interference capability and directional radiation. In the existing quasi-yagi filtering antenna, an active dipole is mainly excited, and a balun structure is needed for carrying out balance-unbalance conversion; and there are some antennas whose filtering function is mainly realized by adding filtering structure units with band-pass/band-stop characteristics, which all make the antenna structure more complicated. The end-fire performance of the quasi-yagi antenna is combined with the filtering characteristics of the filtering antenna, so that the design of the balun-free planar quasi-yagi filtering antenna has great research significance.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a simple and reliable plane quasi-yagi filtering antenna without balun, which excites each radiating unit through coupling and utilizes the filtering characteristic of each unit resonance to ensure that the antenna has better end-fire characteristic and filtering function.

In order to achieve the purpose, the technical scheme provided by the invention is as follows: a balun-free planar quasi-yagi filtering antenna comprises two dielectric substrates, namely a first dielectric substrate and a second dielectric substrate, wherein the first dielectric substrate is positioned above the second dielectric substrate; the upper surface of the first dielectric substrate is provided with a director, two dipole radiation patches and a reflector, the two dipole radiation patches are positioned between the director and the reflector, and the two dipole radiation patches can generate radiation in an end-fire direction through the radiation effect of the director and the reflector; the upper surface of the second dielectric substrate is provided with a step impedance resonator, the lower surface of the second dielectric substrate is provided with a metal floor, the step impedance resonator is fed by a coaxial probe penetrating through the second dielectric substrate and the metal floor, and the director, the two dipole radiation patches and the reflector on the first dielectric substrate are excited through coupling of the step impedance resonator.

Further, the step impedance resonator is an E-type step impedance resonator.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. compared with the existing quasi-yagi filtering antenna, the quasi-yagi filtering antenna has the advantages that the balance-unbalance conversion function is realized by coupling the excitation radiation unit without a balun structure of the traditional quasi-yagi antenna, and the quasi-yagi filtering antenna without the balun is realized.

2. Compared with the existing quasi-yagi filtering antenna, the feed part and each radiation unit of the antenna can be a resonator structure unit, and the filtering function is realized by utilizing the filtering characteristic of the resonator.

3. Compared with the existing quasi-yagi filtering antenna, due to the effect of the cross-coupling structure, the antenna of the invention generates a radiation zero point, has a better out-of-band suppression level, and has an out-of-band suppression level of about 18dB and a stable in-band gain of about 6dBi according to the result of electromagnetic simulation, and can be applied to frequency bands of sub-6GHz (3.4-3.6GHz), WiMAX (3.5GHz) and the like in 5G communication.

4. Compared with the existing quasi-yagi filtering antenna, the antenna of the invention has the advantages of simple design structure, small area, easy processing and low cost.

Drawings

Fig. 1 is a side view of an antenna of the present invention.

Fig. 2 is a top view of a first dielectric substrate.

Fig. 3 is a top view of a second dielectric substrate.

Fig. 4 is a bottom view of the second dielectric substrate.

Fig. 5 is a graph of S11 for HFSS simulation of the antenna of the present invention.

FIG. 6 is a graph showing HFSS simulation gain curves for the antenna of the present invention.

Fig. 7 shows the main planar radiation pattern of the inventive antenna HFSS simulated at 3.5 GHz.

Detailed Description

The present invention will be further described with reference to the following specific examples.

Referring to fig. 1 to 4, the balun-free planar quasi-yagi filter antenna provided in this embodiment includes two dielectric substrates, namely a first dielectric substrate a and a second dielectric substrate b, where the first dielectric substrate a is located above the second dielectric substrate b, a director 1, two dipole radiation patches 2 and 3, and a reflector 4 are disposed on an upper surface of the first dielectric substrate a, the two dipole radiation patches 2 and 3 are located between the director 1 and the reflector 4, and the two dipole radiation patches 2 and 3 can generate radiation in an end-fire direction through radiation effects of the director 1 and the reflector 4; the upper surface of the second dielectric substrate b is provided with an E-type stepped impedance resonator 5, the lower surface of the second dielectric substrate b is provided with a metal floor 6 (two rectangular grooves are etched, and the two rectangular grooves have the effect of improving the gain in the antenna end-fire direction), the E-type stepped impedance resonator 5 is fed by a coaxial probe 7 penetrating through the second dielectric substrate b and the metal floor 6, and couples and excites the director 1, the two dipole radiation patches 2 and 3 and the reflector 4 on the first dielectric substrate a through an air layer between the first dielectric substrate a and the second dielectric substrate b.

In this embodiment, the feeding portion and each radiating element of the antenna may be a resonator structure element, which utilizes the filtering characteristics of the resonator itself, so that the antenna has a filtering function. The first dielectric substrate a and the second dielectric substrate b are made of RO4003C, the relative dielectric constant of the first dielectric substrate a and the relative dielectric constant of the second dielectric substrate b are 3.38, the loss tangent of the first dielectric substrate b is 0.0027, the processing technology of the first dielectric substrate a is mature, the cost is low, the yield is high, the manufacturing process is simple, and the requirement of the quasi-yagi filter antenna on low manufacturing cost can be met.

In this embodiment, the overall size of the antenna is 40 x 3.548mm³. Quasi eight planes without balun for the present embodiment by HFSS softwareThe wood filter antenna is subjected to verification simulation. As shown in fig. 5, a curve of simulation results of S11 parameters (input port return loss) of the antenna in the frequency range of 2-5GHz is given; the frequency band of less than or equal to-10 dB of S11 is 3.25-3.78 GHz, and the relative bandwidth is 15.08%. As shown in FIG. 6, a simulation curve of the gain in the positive x-axis radial direction is shown, the maximum gain is 6.5dBi, and the out-of-band rejection level can reach 18 dB. As shown in fig. 7, the main plane radiation pattern is given at 3.5GHz, and it can be seen from fig. 7 that the antenna has an end-fire performance. Therefore, simulation results show that the balun-free planar quasi-yagi filtering antenna has the advantages of good end-fire characteristic and filtering function, stable in-band gain, good out-of-band rejection level, simple structure and small area, can meet the requirements of sub-6GHz (3.4-3.6GHz), WiMAX (3.5GHz) and other frequency bands applied to the existing 5G communication, and is worthy of popularization.

The above-mentioned embodiments are merely preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, so that the changes in the shape and principle of the present invention should be covered within the protection scope of the present invention.