阅读说明：本技术 一种基于介质谐振器的微流体频率可重构准八木天线 (Micro-fluid frequency reconfigurable quasi-yagi antenna based on dielectric resonator ) 是由 陈建新 黄叶鑫 朱文婷 唐世昌 王雪颖 杨玲玲 于 2020-08-12 设计创作，主要内容包括：本发明涉及基于介质谐振器的微流体频率可重构准八木天线,包括：介质基板、反射器、驱动单元、差分馈电网络,和至少一对基于天线中心线对称布置的竖向贯穿驱动单元和介质基板的绝缘管,通过向绝缘管内注入液体以调节天线的工作频率,其中,对称绝缘管的注液状态一致,所述注液状态包括两种：注满液体和未注液体。本发明首次提出了一种采用工作在高阶TE<Sub>3<I>δ</I>1</Sub>模式介质谐振器的频率可重构准八木天线。根据TE<Sub>3<I>δ</I>1</Sub>模式的电场分布,选择电场较强处作为贯穿介质谐振器的四个空气孔位置来加载绝缘管,以获得较大的频率调谐范围。通过依次在对称的绝缘管里注入纯净水,可以有效地调节天线的工作频率。(The invention relates to a micro-fluid frequency reconfigurable quasi-yagi antenna based on a dielectric resonator, which comprises: the antenna comprises a dielectric substrate, a reflector, a driving unit, a differential feed network and at least one pair of insulating tubes which are symmetrically arranged based on the central line of the antenna and vertically penetrate through the driving unit and the dielectric substrate, wherein the working frequency of the antenna is adjusted by injecting liquid into the insulating tubes, the liquid injection states of the symmetrical insulating tubes are consistent, and the liquid injection states comprise two types: filled with liquid and not filledA liquid. The invention firstly provides a method for working at high-order TE δ 31 The frequency of the mode dielectric resonator can reconstruct the quasi-yagi antenna. According to TE δ 31 And in the mode electric field distribution, the position with a stronger electric field is selected as the position of four air holes penetrating through the dielectric resonator to load the insulating tube, so that a larger frequency tuning range is obtained. The working frequency of the antenna can be effectively adjusted by injecting purified water into the symmetrical insulating tubes in sequence.)

1. A microfluidic frequency reconfigurable quasi-yagi antenna based on a dielectric resonator comprises: the dielectric resonator comprises a dielectric substrate (1), a reflector (2), a driving unit (6) and a differential feed network for directly feeding the driving unit (6), wherein the driving unit (6) is a rectangular dielectric resonator, and the dielectric resonator is characterized in that: the antenna comprises at least one pair of insulating tubes (5) which are symmetrically arranged based on the center line of a dielectric resonator and vertically penetrate through a driving unit (6) and a dielectric substrate (1), and the operating frequency of the antenna is adjusted by injecting liquid into the insulating tubes (5), wherein the liquid injection states of the symmetrical insulating tubes (5) are consistent, and the liquid injection states comprise two types: filled with liquid and not filled with liquid.

2. The dielectric resonator-based microfluidic frequency reconfigurable quasi-yagi antenna of claim 1, wherein: the insulating tube (5) is a Teflon tube, and injected liquid is purified water.

3. The dielectric resonator-based microfluidic frequency reconfigurable quasi-yagi antenna of claim 1, wherein: four insulating tubes (5) are arranged, and the four insulating tubes (5) are arranged on the dielectric resonator TE at intervals along the x-axis direction _δ31The mode electric field is stronger area to obtain larger frequency tuning range.

4. The dielectric resonator-based microfluidic frequency reconfigurable quasi-yagi antenna of claim 1, wherein: the differential feed network is a pair of feed microstrip lines which are transited from the differential microstrip line (4) to the coplanar strip line (3), the drive unit (6) is directly fed with excitation, and the ground of the differential microstrip line (4) is used as a reflector (2).

5. The dielectric resonator-based microfluidic frequency reconfigurable quasi-yagi antenna of claim 1, wherein: the front end of the coplanar strip line (3) is embedded under the driving unit (6), and the width of the coplanar strip line (3) is adjustedw ₂Exposed length of coplanar strip line (3)l ₂And the length of the coplanar strip line (3) embedded below the driving unit (6)l ₃And realizing impedance matching.

6. The dielectric resonator-based microfluidic frequency reconfigurable quasi-yagi antenna of claim 1, wherein: the substrate (1) is a printed circuit board, the reflector (2) is printed on the lower surface of the printed circuit board, and the differential feed network for feeding is printed on the upper surface of the printed circuit board.

7. The dielectric resonator-based microfluidic frequency reconfigurable quasi-yagi antenna of claim 1, wherein: the differential feed network comprises two feed microstrip lines which are arranged in parallel, each feed microstrip line comprises a differential microstrip line (4) arranged right above the reflector (2) and a coplanar strip line (3) arranged between the driving unit (6) and the differential microstrip line (4), the end part of the coplanar strip line (3) extends into the space between the driving unit (6) and the dielectric substrate (1) to realize direct feed of the driving unit (6), and the differential microstrip line (4) and the coplanar strip line (3) are symmetrically arranged along the central line of the driving unit (6).

8. The dielectric resonator-based microfluidic frequency reconfigurable quasi-yagi antenna of claim 1, wherein: the distance from the top surface of the insulating tube (5) to the upper surface of the driving unit (6) is not less than 3 mm; the distance from the bottom surface of the insulating tube (5) to the dielectric substrate (1) is not less than 3 mm.

Technical Field

The invention relates to the technical field of wireless communication, in particular to a micro-fluid frequency reconfigurable quasi-yagi antenna based on a dielectric resonator.

Background

As a key device for implementing signal transmission and reception, a frequency reconfigurable antenna plays an important role in a high-performance multi-radio frequency communication platform, and has received extensive attention from researchers. To date, various methods of frequency tuning have been developed, including electrical tuning and mechanical tuning. The former is mainly realized by semiconductor diodes or electrical switches, and the tuning mechanism has high robustness in operation and technical maturity. However, they also suffer from a number of disadvantages, such as low radiation efficiency (due to losses in parasitic resistance of the diodes) and low power capacity (due to electrical breakdown of the diodes and switches). To solve this problem, in recent years, mechanical tuning using liquid metals or microfluidics has been a good choice. Among them, pure water is popular because of its low price and easy availability. Its usage can be divided into two categories: one is that pure water placed in a container is directly used as a dielectric resonator as a radiator; another is to change the effective dielectric constant of the antenna by sequentially injecting purified water into the tube under the patch.

The quasi-yagi antenna is a typical end-fire antenna, and has the advantages of simple structure, light weight, strong directivity, easy array formation and the like. The driver is usually designed with half-wavelength electric dipoles, which inevitably leads to ohmic losses. And as the operating frequency increases, this problem becomes more severe. To solve this problem, oneDielectric resonators with surface currents close to zero are more suitable for high frequency applications. In the article 'X-band magnetic dipole quasi-yagi antenna based on dielectric resonator', a quasi-yagi antenna working at TE is involved _δ11A dielectric resonator quasi-yagi antenna under a fundamental mode. The quasi-yagi electric dipole antenna has higher gain than a traditional quasi-yagi electric dipole antenna, has high efficiency of more than 90% in an X wave band, but adopts fixed working frequency and is not adjustable.

Disclosure of Invention

The invention aims to: the defects of the prior art are overcome, and the micro-fluid frequency reconfigurable quasi-yagi antenna based on the dielectric resonator is provided, and the working frequency of the micro-fluid frequency reconfigurable quasi-yagi antenna is adjustable.

In order to achieve the above object, the present invention provides a microfluidic frequency reconfigurable quasi-yagi antenna based on a dielectric resonator, which includes: the dielectric resonator comprises a dielectric substrate, a reflector, a driving unit and a differential feed network for directly feeding the driving unit, wherein the driving unit is a rectangular dielectric resonator, and the dielectric resonator is characterized in that: the antenna comprises at least one pair of insulating tubes which are symmetrically arranged based on the center line of a dielectric resonator and vertically penetrate through a driving unit and a dielectric substrate, wherein the insulating tubes are filled with liquid to adjust the working frequency of the antenna, the filling states of the symmetrical insulating tubes are consistent, and the filling states comprise two types: filled with liquid and not filled with liquid.

Furthermore, the reconfigurable quasi-yagi antenna is provided with four insulation tubes, wherein the insulation tubes are arranged on the dielectric resonator TE along the x-axis direction _δ31The mode electric field is stronger to obtain a larger frequency tuning range.

The invention firstly provides a method for working at high-order TE _δ31The frequency of the mode dielectric resonator can reconstruct the quasi-yagi antenna. According to TE _δ31The electric field distribution of the mode reasonably selects the positions of four air holes penetrating through the dielectric resonator to load the tube. By sequentially injecting purified water into the tubes, the operating frequency of the antenna can be effectively adjusted. In order to verify the method, an X-band antenna example is designed, and the simulation result is well matched with the test result. The results show thatIn the frequency tuning range using higher order TE _δ31Mode, the antenna without the additional director still has higher gain (more than 8.7 dBi) while maintaining the high radiation efficiency characteristic of the dielectric resonator antenna.

Drawings

The invention will be further described with reference to the accompanying drawings.

Fig. 1 is a perspective view of a microfluidic frequency-reconfigurable quasi-yagi antenna based on a dielectric resonator.

Fig. 2 is a schematic diagram of a micro-fluidic frequency-reconfigurable quasi-yagi antenna structure based on a dielectric resonator.

FIG. 3-a shows a pair of insulation tubes in different positions, TE _δ31The frequency of the pattern versus b trend graph.

FIG. 3-b shows a pair of insulation tubes in different positions, TE _δ31The frequency of the pattern versus the trend of w.

FIG. 4 is | S for simulation (solid line) and test (dashed line) of an antenna of an embodiment of the present invention₁₁The | graph.

Fig. 5-a is an E-plane pattern for simulation (solid line) and test (dashed line) of an antenna of an embodiment of the present invention in a "0000" state (full insulator tube empty).

Fig. 5-b is an H-plane pattern for simulation (solid line) and test (dashed line) of an antenna of an embodiment of the present invention in the "0000" state (full insulator tube empty).

Fig. 5-c is an E-plane pattern for simulation (solid line) and testing (dashed line) of an antenna of an embodiment of the present invention in a "1111" state (full water injection into the insulator).

Fig. 5-d is an H-plane pattern for simulation (solid line) and test (dashed line) of an antenna of an embodiment of the present invention in the "1111" state (full water injection in the insulator).

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

Referring to fig. 1 and fig. 2, the microfluidic frequency reconfigurable quasi-yagi antenna based on the dielectric resonator is shown in the embodiment of the invention. The antenna of the embodiment of the invention comprises: the device comprises a dielectric substrate 1, a reflector 2, a driving unit 6 and a differential feed network for directly feeding the driving unit 6. The driving unit 6 is arranged on the top layer of the dielectric substrate 1 and performs differential feeding through a differential feeding network. In order to realize coplanar strip line feeding, a pair of equal-amplitude and opposite-phase radio frequency signals are respectively transmitted along two metal microstrip lines (a differential feeding network which is formed by a pair of feeding strip lines which are transited from a differential microstrip line 4 to a coplanar strip line 3). Due to coplanar strip lines and TE _δ31The electric field distribution directions of the modes are consistent, so that high-order TE can be well excited _δ31Mode(s). The front end of the coplanar strip line 3 is embedded below the driving unit 6 by adjusting the width of the coplanar strip line 3w ₂Exposed length of coplanar strip 3l ₂And the length of the coplanar strip line 3 embedded under the driving unit 6l ₃Better impedance matching can be obtained. At the same time, the ground of the differential microstrip line 4 printed on the bottom of the substrate serves as a reflector 2 to achieve end-fire radiation.

As shown in the figure, the antenna of this embodiment has two pairs (four) of insulating tubes 5 (teflon tubes) which are symmetrically arranged based on the center line of the antenna and vertically penetrate through the driving unit 6 and the dielectric substrate 1, and the operating frequency of the antenna is adjusted by injecting purified water (or other liquid) into the insulating tubes 5, wherein the injection states of the symmetrical insulating tubes 5 are consistent, and the injection states include two types: filled with liquid and not filled with liquid.

TE of rectangular dielectric resonator _δ31The electric field of the mode is tangential to the x-z plane. By operating at higher levels of TE _δ31The dielectric resonator in the mode is used as a magnetic dipole driver, and higher gain can be obtained. Because the pure water is a high dielectric constant material ( _wr81) it can be used to partially change the effective dielectric constant of the dielectric resonator. Meanwhile, the effective dielectric constant has a direct relationship with the electric field of the corresponding mode. Therefore, will fourThe insulating tubes 5 are arranged at intervals along the x-axis direction in a region with a strong electric field, so that a large frequency tuning range can be obtained.

To facilitate the study of how the position of the insulating tube controls the frequency tuning range, a pair of tubes was used for experimental analysis as shown in fig. 3 a. First, the center lines of the two insulating tubes in the x-axis direction are gradually separated (w= 0), by distance 2bTo indicate. FIG. 3a depicts TE _δ31Frequency of mode relative tob(distance from center of insulating tube to vertical center line of dielectric resonator) in whichf _w/oAndf _wrespectively indicating that the dielectric resonator is in TE when there is no water or water in the tube _δ31The frequency of the mode(s),Δf=f _w/o-f _wrepresenting the frequency tuning range between these two states.bAs the increase starts from 1.2mm,Δfwith followingbIs increased and approximately atbWhen = 3.3mmΔfReaches a maximum value and then isbAround 8.4mm the next peak is reached. Secondly, inbIn the case of = 3.3mm, the two tubes are gradually moved from the lower edge to the upper edge of the dielectric resonator, i.e., from the lower edge to the upper edge of the dielectric resonatorw= 3.8mm tow= 3.8 mm. FIG. 3b depicts TE _δ31Frequency of mode relative tow(distance from the center of the insulating tube to the transverse center line of the dielectric resonator),wwhen the value is not less than 0, the reaction time is not less than 0,Δfhas a maximum value, and followswIncrease of absolute valueΔfGradually decreases. As can be seen,Δfand the dielectric resonator is in TE _δ31The distribution of the electric field strength in the mode is consistent.

In order to verify the proposed concept, the quasi-yagi antenna using the dielectric resonator as shown in fig. 1 and fig. 2 is designed and implemented, in the present embodiment, the driving unit 6 is a rectangular dielectric resonator, and the relative dielectric constant is_r= 45, thicknessh=1.2 mm, loss tangent tan= 0.00019, the dielectric substrate 1 is a Rogers RO4003 type plate with a relative dielectric constant of_rThickness of = 3.55t= 0.508 mm and loss tangent tan= 0.0027. The dimensions in fig. 1, 2 are as follows:sw=58mm,sl=56.4mm,dl=20mm,dw=7.6mm,b ₁=3.3mm,b ₂=8.4mm,d ₁=2mm,d ₂=1.5mm,g=0.8mm,l ₁=20mm,l ₂=8.8mm,l ₃=2.2mm,w ₁=1.2mm,w ₂=1.5mm，hw=10 mm. The distance from the top surface of the insulating tube to the top surface of the dielectric resonator is 3.8mm, and the distance from the first surface of the insulating tube to the top surface of the dielectric resonator to the lower surface of the dielectric substrate 1 is 4.492 mm. It is recommended that the height of the insulating tube exposed out of the dielectric resonator is not less than 3mm, and the height of the insulating tube exposed out of the lower surface of the dielectric substrate 1 is not less than 3 mm. The water injection state of the insulating pipe is represented by 1 and 0, the water injection state of the insulating pipe is described by 1, and the water injection state of the insulating pipe is described by 0. Therefore, the proposed frequency reconfigurable antenna has four symmetric states, "0000", "1001", "0110", and "1111".

FIG. 4 shows the reflection coefficient | S for the above four state simulation and test₁₁L. By sequentially injecting purified water into the tube, the center frequency of the antenna can be tuned from 8.99 to 8.695GHz, and the test results are shown in table 1.

TABLE 1

Status of state	0000	1001	0110	1111
					Center frequencyf 0 (GHz)	8.990	8.850	8.825	8.695
Bandwidth (MHz)	270	270	270	270
					Gain (dBi)	8.70	8.77	8.75	8.71
Radiation efficiency (%)	90.25	92.79	93.02	94.26

From the test results, the measured bandwidth (| S)₁₁|<10 dB), gain and radiation efficiency are all approximately constant values within the frequency tuning range. It is worth noting that the antenna radiation efficiency can reach more than 90% due to the use of the dielectric resonator as the driver and the micro-fluid tuning technology, and meanwhile, the high-order TE is adopted _δ31Mode, high gain (greater than 8.7 dBi) for the antenna.

Fig. 5-a to 5-d show radiation patterns of the E-plane and the H-plane corresponding to two states ("0000" and "1111") of 8.99GHz and 8.695GHz, respectively. In the figure, the curve close to the center corresponds to cross polarization, the curve close to the outer ring corresponds to main polarization, wherein the solid line is a simulation result, and the dotted line is a test result. The result shows that the tested E-plane and H-plane radiation patterns are stable in the end-fire direction and well matched with the simulation result. Cross polarization below-20 dB and front-to-back ratio better than 10dB can be observed in the ± 30 ° beam range.

In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention.