阅读说明：本技术 一种微带准八木天线 (Microstrip quasi-yagi antenna ) 是由 李高升 申婉婷 潘少鹏 冯杨 陈攀 于杰 贺佳港 于 2020-07-22 设计创作，主要内容包括：本申请涉及一种微带准八木天线。所述天线包括：双面微带准八木天线以及加载在双面微带准八木天线上的引向器；引向器包括：矩形贴片和直角微带线；矩形贴片加载在双面微带准八木天线的激励极子末端；矩形贴片用于拓展波束宽度,以及实现波束偏转；直角微带线与矩形贴片的外侧直角呈间隙配合安装；直角微带线用于进一步拓展波束宽度,以及提高天线的增益。采用本方法能够实现波束偏转引向的条件下,大大缩小了微带准八木天线的尺寸。(The application relates to a microstrip yagi antenna. The antenna includes: the dual-side microstrip yagi antenna comprises a dual-side microstrip quasi-yagi antenna and a director loaded on the dual-side microstrip quasi-yagi antenna; the director includes: a rectangular patch and a right-angle microstrip line; the rectangular patch is loaded at the tail end of an excitation pole of the double-sided microstrip quasi-yagi antenna; the rectangular patch is used for expanding the beam width and realizing beam deflection; the right-angle microstrip line and the right angle of the outer side of the rectangular patch are installed in clearance fit; the right-angle microstrip line is used for further expanding the beam width and improving the gain of the antenna. By adopting the method, the size of the microstrip quasi-yagi antenna is greatly reduced under the condition of beam deflection and direction guiding.)

1. A microstrip quasi-yagi antenna, the antenna comprising:

the dual-side microstrip yagi antenna comprises a dual-side microstrip quasi-yagi antenna and a director loaded on the dual-side microstrip quasi-yagi antenna;

the director includes: a rectangular patch and a right-angle microstrip line;

the rectangular patch is loaded at the tail end of an excitation pole of the double-sided microstrip quasi-yagi antenna; the rectangular patch is used for expanding the beam width and deflecting the beam;

the right-angle microstrip line and the right angle of the outer side of the rectangular patch are installed in a clearance fit manner; the right-angle microstrip line is used for improving the gain of the antenna.

2. The antenna of claim 1, wherein the front side of the dual-sided microstrip quasi-yagi antenna comprises: an excitation pole and a microstrip line;

the microstrip line comprises a first microstrip line and a second microstrip line, one end of the first microstrip line is connected with the excitation pole, and the other end of the first microstrip line is connected with the second microstrip line.

3. The antenna of claim 2, wherein the width of the first microstrip line is less than the width of the second microstrip line.

4. The antenna of claim 1, wherein the back side of the dual-sided microstrip quasi-yagi antenna comprises: the symmetrical excitation pole, the microstrip line and the grounding plate;

the symmetric excitation pole is symmetric with the excitation pole.

5. The antenna of claim 1, wherein the ground plane is one-half the length of the dielectric substrate.

Technical Field

The application relates to the technical field of antennas, in particular to a microstrip quasi-yagi antenna.

Background

With the rapid development of wireless communication technology, antennas, which are the most basic components of wireless communication technology, are increasingly optimized and improved. Such as some highly directional Local Positioning Systems (LPS), wireless sensor networks, and some scenarios in fifth generation mobile communication technologies, which are now more and more widely used, require an antenna type with strong directivity and compact or small size. The microstrip quasi-yagi antenna can meet the requirement, and is formed by combining a yagi antenna with strong directionality, high gain and large volume and a microstrip antenna with a low section and easy processing. The advantages of the microstrip quasi-yagi antenna and the microstrip quasi-yagi antenna are combined, the bandwidth is wide, array combination is facilitated, and the application range of the microstrip quasi-yagi antenna is greatly expanded.

Generally, a microstrip quasi-yagi antenna is an end-fire antenna formed by arranging an excitation element (generally a folded element), a passive reflector and a plurality of passive directors in parallel. Typically the director will be slightly shorter than one half wavelength, the excitation array will be equal to one half wavelength and the reflector will be slightly longer than one half wavelength. The director is capacitive to the sensing signal due to the wavelength being shorter than one half, the current leads the voltage by 90 °. The phase of the radiated signal lags by 90 degrees after passing through a path of a quarter wavelength, so that the radiated signal and the radiated signal are just counteracted, the radiated signal is in the same phase state, and the signal energy is effectively enhanced after the radiated signal and the radiated signal are superposed. The reflector is just opposite to the director, so that the signal energy is weakened, and the microstrip quasi-yagi antenna realizes the characteristics of strong directivity and high gain. In recent years, many researchers have conducted studies on microstrip quasi-yagi antennas, mainly for the purpose of reducing the size of the antenna and improving the performance, such as ultra-wideband, high front-to-back ratio, low end-firing angle, implementation of bandpass filter response, and innovative design of the antenna structure, such as sector, loop, and floor and reflector integration. In order to achieve quasi-endfire wireless communications, i.e., with the main lobe beam of the antenna between the endfire and broadside directions, the maximum gain beam pointing direction needs to be adjusted. Generally, the yagi antenna adopts a mode of arranging by means of directors at a quarter-wavelength interval along a radiation direction to realize beam deflection and direction guiding, so that the size of the whole microstrip quasi-yagi antenna is relatively large.

Disclosure of Invention

In view of the above, there is a need to provide a microstrip quasi-yagi antenna capable of solving the problem of large antenna size caused by beam deflection.

A microstrip quasi-yagi antenna, the antenna comprising:

the dual-side microstrip yagi antenna comprises a dual-side microstrip quasi-yagi antenna and a director loaded on the dual-side microstrip quasi-yagi antenna;

the director includes: a rectangular patch and a right-angle microstrip line;

the rectangular patch is loaded at the tail end of an excitation pole of the double-sided microstrip quasi-yagi antenna; the rectangular patch is used for expanding the beam width and deflecting the beam;

the right-angle microstrip line and the right angle of the outer side of the rectangular patch are installed in a clearance fit manner; the right-angle microstrip line is used for further expanding the beam deflection angle and improving the gain of the antenna.

In one embodiment, the front side of the dual-sided microstrip quasi-yagi antenna comprises: an excitation pole and a microstrip line; the microstrip line comprises a first microstrip line and a second microstrip line, one end of the first microstrip line is connected with the excitation pole, and the other end of the first microstrip line is connected with the second microstrip line.

In one embodiment, the width of the first microstrip line is smaller than that of the second microstrip line, so that the antenna structure and the general 50 Ω SMA head are matched in impedance.

In one embodiment, the back side of the dual-sided microstrip quasi-yagi antenna comprises: the symmetrical excitation pole, the microstrip line and the grounding plate; the symmetric excitation pole is symmetric with the excitation pole.

In one embodiment, the length of the grounding plate is one half of that of the dielectric substrate.

According to the microstrip quasi-yagi antenna, the rectangular patch and the right-angle microstrip line are introduced, so that the beam width can be expanded, beam deflection is realized, and the gain of the antenna can be improved. And the director formed by combining the rectangular patch and the right-angle microstrip line has small volume, thereby greatly reducing the size of the microstrip quasi-yagi antenna.

Drawings

FIG. 1 is a schematic diagram of a front side of a microstrip quasi-yagi antenna according to an embodiment;

FIG. 2 is a schematic diagram of the back side of a microstrip quasi-yagi antenna in one embodiment;

FIG. 3 is a schematic block diagram of three antennas in one embodiment;

FIG. 4 is a graph comparing simulated curves and patterns for an S11 simulation for three antennas in one embodiment;

FIG. 5 is a graph comparing current distributions of two antennas in one embodiment;

FIG. 6(a) is a graph illustrating reflectance curves obtained by adjusting the length of a strap director in one embodiment;

FIG. 6(b) is a graph illustrating reflectance curves obtained by adjusting the spacing between a strip director and a rectangular director in one embodiment;

FIG. 7 is a graph illustrating the reflection coefficient and the maximum gain obtained by varying the side length of a rectangular director in one embodiment;

FIG. 8(a) is a schematic diagram of the gain of the microstrip quasi-yagi antenna with frequency variation according to an embodiment;

FIG. 8(b) is a graph of overall efficiency of a microstrip quasi-yagi antenna as a function of frequency for one embodiment;

FIG. 9(a) is a main polarization pattern in the xz plane and yz plane in one embodiment;

fig. 9(b) is a cross-polar pattern in the xz-plane and yz-plane in one embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In one embodiment, as shown in fig. 1, there is provided a microstrip quasi-yagi antenna comprising:

the dual-side microstrip yagi antenna comprises a dual-side microstrip quasi-yagi antenna and a director loaded on the dual-side microstrip quasi-yagi antenna; the director includes: a rectangular patch and a right-angle microstrip line; the rectangular patch is loaded at the tail end of an excitation pole of the double-sided microstrip quasi-yagi antenna; the rectangular patch is used for expanding the beam width and realizing beam deflection; the right-angle microstrip line and the right angle of the outer side of the rectangular patch are installed in clearance fit; the right-angle microstrip line is used for further expanding the beam deflection angle and improving the gain of the antenna. It is worth mentioning that the fitting means

In the microstrip quasi-yagi antenna, the rectangular patch and the right-angle microstrip line are introduced, so that the beam width can be expanded, the beam deflection angle can be increased, and the gain of the antenna can be improved.

And the director formed by combining the rectangular patch and the right-angle microstrip line has small volume, thereby greatly reducing the size of the microstrip quasi-yagi antenna.

In one embodiment, the front side of the dual-sided microstrip quasi-yagi antenna comprises: an excitation pole and a microstrip line; the microstrip line comprises a first microstrip line and a second microstrip line, one end of the first microstrip line is connected with the excitation pole, and the other end of the first microstrip line is connected with the second microstrip line.

In another embodiment, the width of the first microstrip line is smaller than the width of the second microstrip line for impedance matching.

In one embodiment, as shown in fig. 2, the back side of the double-sided microstrip quasi-yagi antenna includes: the symmetrical excitation pole, the microstrip line and the grounding plate; the symmetric excitation pole is symmetric with the excitation pole.

In another embodiment, the length of the ground plate is one half of the dielectric substrate, and the ground plate also acts as a reflector, further improving directivity.

The advantageous effects of the present invention will be described below with reference to specific examples.

As shown in fig. 3, the diagram shows 3 kinds of antennas, the first is a simple double-sided microstrip quasi-yagi antenna without a director, the second is to add a rectangular patch on its excitation pole, and the third is to add a right-angle microstrip line on the basis of the second antenna.

Figure 4 shows simulated reflection coefficients for three antennas and xz plane pattern contrast at 5.8 GHz. It has been observed that by adding directors, the impedance matching is improved, but the corresponding bandwidth is reduced. The bandwidth of the antenna 2 is 5.2 to 6.2GHz, and the bandwidth of the antenna 3 is 5.3 to 6 GHz. At the resonant frequency point of 5.8GHz, the beam pattern is regulated and controlled by the director, the maximum radiation direction is deflected to-5 degrees of the antenna 2 from the direction of 4 degrees of the antenna 1, the angle of the antenna 3 is enlarged to-25 degrees, and obvious beam deflection is realized.

Fig. 5 shows the current distribution of the proposed microstrip quasi-yagi antenna ii and antenna iii, which has a maximum current distribution near the corner of the meander-strip director for the rectangular patch, and a coupled current flow in the opposite direction to the rectangular patch edge, compared to the antenna ii without meander-strip director. Therefore, the size and position of the strip director have great influence on the impedance bandwidth and the directional diagram of the antenna, and the impedance matching and the beam deflection angle can be realized by adjusting the strip director.

In order to further explore the characteristics and design principles of the proposed antenna, the director section key parameters are discussed. The reflection coefficient curve obtained by adjusting the length (Lr) of the strip director is shown in fig. 6 (a). It can be seen that as the length (Lr) of the strip director increases, the frequency at which the minimum of the S11 curve is located shifts to the left, i.e. the resonance frequency point gradually decreases. Meanwhile, the influence on the impedance bandwidth is large, and the impedance bandwidth is reduced along with the continuous increase of Lr. The reflectance curve obtained by varying the spacing (Dr) between the strip directors and the rectangular directors is shown in fig. 6 (b). It can be seen that as the spacing (Dr) between the directors increases, the resonant frequency points decrease continuously, but the magnitude of the decrease is small and has little effect.

The reflection coefficient obtained by varying the side length (Lp) of the rectangular director and the maximum gain are plotted in fig. 7. As the side length (Lp) of the rectangular director is gradually increased, the resonance frequency point is reduced, and the impedance matching degree is improved. Lp has little influence on gain, and the higher Lp is, the higher gain is; however, at 5.8GHz, when Lp is 8.5mm, the gain is the maximum, so that Lp takes 8.5mm as the final value.

Fig. 8(a) is a curve of the gain and the overall efficiency of the microstrip quasi-yagi antenna changing with frequency, the gain can be kept above 4.5dBi within the range of 5.3-6.0 GHz of the whole impedance bandwidth, the working efficiency of the antenna is more than 87%, and the efficiency reaches the maximum value of 98% at 5.8 GHz. The pattern of the xz plane at frequencies of 5.4GHz, 5.6GHz, 5.8GHz, and 6GHz, respectively, is shown in fig. 8 (b). The pattern remains substantially constant throughout the impedance bandwidth, with a maximum gain of 4.72dBi and a maximum beam pointing direction of-45 °. Meanwhile, it can be seen that the back lobe level gradually increases with increasing frequency, and the reason for this is analyzed to be that when the beam deflection angle increases, the suppression effect of the reflector located right behind on the back lobe beam is weakened. Fig. 9(a) and 9(b) are the main and cross-polarization patterns in the xz-plane and yz-plane, respectively, and it can be seen that the cross-polarization level in the xz-direction is below-19 dB, while the cross-polarization level in the yz-direction increases to-8 dB due to the smaller floor size. The 3dB beam width is 97 degrees and 157 degrees in the xz direction and the yz direction respectively, the director formed by the rectangular patch and the strip microstrip line can be found to realize the effect of widening the beam, and the device can be applied to wide-range and wide-angle wireless transmission and communication.

In conclusion, the rectangular patch director greatly expands the beam width and the bent strip microstrip line can regulate and control the beam deflection angle, reduce the size of the whole antenna and improve the antenna gain. Compared with the director formed by long and thin strips with the wavelength of about 1/4 and equal intervals in the traditional microstrip quasi-yagi antenna, the beam width of a wider angle and the flexibly regulated beam angle can be realized, and the size of the whole antenna director is greatly reduced, so that the miniaturized microstrip quasi-yagi antenna is further realized.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.