CN111224225B - A Compact Double Dipole Driver and Quasi-Yagi Antenna Using the Driver - Google Patents

Abstract

The invention discloses a compact double dipole driver, which relates to the communication field, and comprises a cylindrical dielectric resonator, a split resonator ring and a dielectric substrate, and the dielectric substrate is located between the cylindrical dielectric resonator and the split resonator ring. The cylindrical dielectric resonator is located above the dielectric substrate, and the cylindrical dielectric resonator and the split resonant ring are arranged facing each other. The invention also discloses a quasi Yagi antenna using the compact double dipole driver, including a cylindrical dielectric resonator, a split resonator ring, a dielectric substrate, a coplanar stripline and a concave ground plane, the coplanar stripline The printing is arranged on the top surface of the dielectric substrate, the split resonant ring is arranged on the bottom surface of the dielectric substrate, and the concave ground plane is arranged on the bottom surface of the dielectric substrate. The invention has the advantages that the bandwidth of the antenna is improved because the operating frequencies of the two dipoles are close. And it makes it possible to obtain a stable high gain within the wide operating frequency band of the antenna.

Description

A Compact Double Dipole Driver and Quasi-Yagi Antenna Using the Driver

technical field

The invention relates to the field of communication antennas, in particular to a compact double dipole driver and a quasi Yagi antenna using the driver.

Background technique

In the prior art, with the rapid development of modern communication systems, the quasi-Yagi antenna, as a kind of end-fire antenna, has attracted widespread attention due to its advantages of simple structure, light weight, and easy array formation. In the prior art, many methods are adopted to improve its performance, mainly focusing on two aspects: widening of bandwidth and increasing of gain. In traditional quasi-Yagi antenna designs, the most commonly used drivers are λ ₀ /2 electric dipoles with different shapes, where λ ₀ is the wavelength in free space. In order to expand the working bandwidth, there are feed baluns with different structures in the prior art. However, due to the limited radiation bandwidth of the driver, the gain of the antenna fluctuates greatly, and the end-fire gain in the low frequency range of the working frequency band is only about 4dBi, or even lower. In order to solve this problem, in the prior art, multiple dipoles of different lengths are used to feed in series, so as to obtain wider bandwidth and stable medium gain, but this will lead to a significant increase in the longitudinal length, and at the same time give the director Introduction and design bring difficulties, so it is difficult to further increase the gain. There is also a microstrip patch magnetic dipole in the prior art, which can enhance the bandwidth and increase the gain by combining the basic TE110 mode and the high-order TE310 mode. But this method will lead to a large increase in the lateral size of the antenna, and even the width of the driver itself is greater than 1.5λ ₀ .

Contents of the invention

The technical problem to be solved by the present invention is how to make the compact double dipole driver obtain stable high gain in the working broadband of the antenna and how to widen the bandwidth. Aiming at the above technical problems to be solved, the present invention provides a compact A double dipole driver and a quasi-Yagi antenna using the driver.

In order to solve the above technical problems, the technical solution of the present invention is: a compact double dipole driver, including a cylindrical dielectric resonator, a split resonator ring and a dielectric substrate, and the dielectric substrate is located between the cylindrical dielectric resonator and the split resonator ring Between, the cylindrical dielectric resonator is located above the dielectric substrate, and the cylindrical dielectric resonator and the split resonator ring are arranged facing each other.

Further, the body radius of the cylindrical dielectric resonator is 4.25mm, and the radius of the split resonator ring is 5.3mm.

Further, the split resonant ring has a width of 0.3 mm.

Further, the body of the cylindrical dielectric resonator is provided with two symmetrically arranged metal strips, the two metal strips are arranged in parallel, and the width of the two metal strips on the cylindrical dielectric resonator body is 1.7 mm. The width of the two metal strips located outside the body of the cylindrical dielectric resonator is 0.9mm, and the distance between the two metal strips is 1.4mm.

Further, the dielectric substrate is a dielectric substrate with a square cross section.

Another object of the present invention is to provide a quasi-yagi antenna applying a compact double dipole driver as described above, comprising a cylindrical dielectric resonator, a split resonator ring, a dielectric substrate, a coplanar stripline and a concave ground The coplanar stripline is printed on the top surface of the dielectric substrate, the split resonator ring is arranged on the bottom surface of the dielectric substrate, and the concave ground plane is arranged on the bottom surface of the dielectric substrate.

Preferably, the concave ground plane is a planar reflector with a concave arc, and the concave arc depth of the concave ground plane is 8.4mm.

Preferably, the distance between the concave arc bottom of the concave ground plane and the lower edge of the split resonant ring is 11.4 mm.

Preferably, the distance between the bottom of the concave arc of the concave ground plane and the common center of the split resonator ring and the cylindrical dielectric resonator is 15.65 mm.

Preferably, the distance between the upper edge of the concave ground plane and the common center of the split resonator ring and the cylindrical dielectric resonator is 7.25 mm.

With the above technical solution, since the driver is composed of a magnetic dipole and a folded electric dipole, the two poles are respectively made of a cylindrical dielectric resonator and a split resonator ring, and the ring dielectric resonator and the split resonator ring are made of The overlapping method is respectively fixed on the top and the bottom of the substrate, and the working frequencies of the two dipoles are close to each other, thereby improving the bandwidth of the antenna. At the same time, since the two dipoles have similar radiation characteristics, a stable high gain is obtained within the wide operating frequency band of the antenna.

Description of drawings

Fig. 1 is the structural representation of compact double dipole driver among the present invention;

Fig. 2 is the schematic diagram of the three-dimensional structure of the quasi Yagi antenna of the present invention;

Fig. 3 is the cross-sectional view of the top structure of the quasi Yagi antenna in the present invention;

Fig. 4 is the electric field distribution of DR in the present invention under the TE _01δ mode frequency f _d and the current distribution diagram of S ₁₁ and ε _r1 of SRR under the high-order mode frequency f _s ;

Fig. 5 is the electric field distribution of DR in the present invention under the TE _{01 δ} mode frequency f _d and the current distribution diagram of S ₁₁ and the crack width s of SRR under the high-order mode frequency f _s of SRR;

Fig. 6 is the simulated value figure of _S11 and gain of antenna;

Fig. 7 is the simulated radiation pattern on the electric field and magnetic field plane with the antenna frequency being 9.22GHz;

Fig. 8 is the simulated radiation pattern on the electric field and magnetic field plane with the antenna frequency of 10.1 GHz.

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted here that the descriptions of these embodiments are used to help understand the present invention, but are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not constitute a conflict with each other.

Example 1

Referring to Fig. 1, this specific embodiment discloses a compact double dipole driver, including a cylindrical dielectric resonator 1, a split resonator ring 2 and a dielectric substrate 3, and the dielectric substrate 3 is located between the cylindrical dielectric resonator 1 and the split resonator ring 2 Between them, the cylindrical dielectric resonator 1 is located above the dielectric substrate 3 , and the cylindrical dielectric resonator 1 and the split resonator ring 2 are arranged facing each other.

Preferably, the body radius of the cylindrical dielectric resonator 1 is 4.25 mm, which is cylindrical, and the radius of the split resonator ring 2 is 5.3 mm. And the width of the split resonator ring 2 is 0.3 mm. The parameters of the cylindrical dielectric resonator 1 are ε _r1 =38, t=1.0mm, and tanδ ₁ =0.00015.

Preferably, the body of the cylindrical dielectric resonator 1 is provided with two symmetrically arranged metal strips 11, 12, the two metal strips 11, 12 are arranged in parallel, and the two metal strips 11, 12 are located on the body of the cylindrical dielectric resonator 1 The width is 1.7mm, the width of the two metal strips 11, 12 located outside the body of the cylindrical dielectric resonator 1 is 0.9mm, and the distance between the two metal strips 11, 12 is 1.4mm. Preferably, the dielectric substrate 3 is a dielectric substrate 3 with a square cross section. The parameters of the substrate are ε _r1 =3.55, h=20mil, and tanδ ₁ =0.0027.

Since the driver is composed of a magnetic dipole and a folded electric dipole, the two poles are respectively made of a cylindrical dielectric resonator and a split resonator ring. Since the operating frequencies of the two dipoles are close, the antenna is improved bandwidth. At the same time, since the two dipoles have similar radiation characteristics, a stable high gain is obtained within the wide operating frequency band of the antenna.

Example 2

Referring to Fig. 2 and Fig. 3, this specific embodiment discloses a kind of quasi-yagi antenna applying the compact double dipole driver in embodiment 1, including cylindrical dielectric resonator 1, split resonator ring 2, dielectric substrate 3, The coplanar stripline 4 and the concave ground plane 5, the coplanar stripline 4 is printed on the top surface of the dielectric substrate 3, the split resonator ring 2 is arranged on the bottom surface of the dielectric substrate 3, and the concave ground plane 5 is arranged on the dielectric substrate 3 on the underside.

Preferably, the concave ground plane 5 is a planar reflector with a concave arc, and the depth of the concave arc of the concave ground plane 5 is 8.4 mm.

Preferably, the distance between the bottom of the concave arc of the concave ground plane 5 and the lower edge of the split resonator ring 2 is 11.4 mm.

Preferably, the distance between the bottom of the concave arc of the concave ground plane 5 and the common center of the split resonator ring 2 and the cylindrical dielectric resonator 1 is 15.65 mm.

Preferably, the distance between the upper edge of the concave ground plane 5 and the common center of the split resonator ring 2 and the cylindrical dielectric resonator 1 is 7.25 mm.

Preferably, the coplanar stripline 4 is used as a balanced transmission line, which is printed on top of the substrate and used as a feeder. In addition, the concave ground plane 5 serves as a reflector.

In the following, the performance simulation of the antenna in the above-mentioned embodiment will be performed with reference to the accompanying drawings 4-8.

The dominant mode of the cylindrical dielectric resonator is the TE _01δ mode, and its resonant frequency is mainly determined by the parameters ε _r1 , t and r ₁ of the DR. Its electric field is shown in Figures 4 and 5, distributed according to a ring and tangent to the xz plane. It can be known that the TE _01δ mode can be excited by the coplanar stripline and radiate as a magnetic dipole (J _m =-n×E) along the y-axis. At the same time, the bottom SRR surrounds the cylindrical DR and is directly below it, constituting a double-dipole driver with a substantially increased size. The design utilizes SRRs operating in higher-order modes, and the current distribution at the SRRs at the higher-order mode frequency _fs is also shown in Figures 4 and 5. From the observation, the SRR can be regarded as a folded electric dipole whose polarization direction is along the x-axis. It can be confirmed that a compact double dipole driver has been constructed by combining the above arrangement with the structure of Embodiment 1. According to the electric field and current distributions in Figures 4 and 5, these two dipoles have similar radiation characteristics and can be reflected by the concave surface to achieve endfire radiation. Therefore, the two ohms of the driver disclosed in Embodiment 1 have similar radiation characteristics and can be reflected by the concave surface to achieve end-fire radiation.

Figures 4 and 5 show the simulated reflection coefficient S11 of the designed antenna. We can know that the TE _01δ model of DR produces a lower resonance frequency, while the SRR produces a higher resonance frequency. As shown in the figure, with the increase of ε _r1 , the lower frequency shifts down, and at the same time, the higher frequency decreases with a small increase in the effective permittivity of the SRR; while when the slot width s of the SRR decreases Hours, that is, as the length of the SRR decreases, the higher frequencies rise sharply, while the lower frequencies remain unchanged. Due to the double dipole radiation, the antenna gain remains stable within the operating frequency band.

Figure 6 shows the simulated values of S ₁₁ and gain of the designed antenna, where the dotted line is S ₁₁ and the solid line is the gain. The simulated impedance bandwidth under the condition of S ₁₁ <-10dB is 1.1GHz (11.43%). Figures 7-8 depict the simulated radiation patterns in the electric and magnetic planes at frequencies of 9.22 and 10.1 GHz, respectively. The front-to-rear ratio is always greater than 10dB. The occupied area of the double dipole driver is only πr ² =0.1λ ₀ ² , where the solid line represents the main polarization and the dashed line represents the cross polarization. Therefore, the antenna designed in the above-mentioned embodiment 2 has a relatively wide bandwidth, and the antenna obtains a stable high gain within its working wide frequency band.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions and modifications to these embodiments still fall within the protection scope of the present invention.

Claims (9)

1. A compact dual dipole driver, characterized by: the resonator comprises a cylindrical dielectric resonator (1), an open resonant ring (2) and a dielectric substrate (3), wherein the dielectric substrate (3) is positioned between the cylindrical dielectric resonator (1) and the open resonant ring (2), the cylindrical dielectric resonator (1) is positioned above the dielectric substrate (3), and the cylindrical dielectric resonator (1) and the open resonant ring (2) are arranged oppositely; the cylindrical dielectric resonator is characterized in that two metal strips (11, 12) which are symmetrically arranged are arranged on the body of the cylindrical dielectric resonator (1), the two metal strips (11, 12) are arranged in parallel, the width of each metal strip (11, 12) on the body of the cylindrical dielectric resonator (1) is 1.7mm, the width of each metal strip (11, 12) on the body of the cylindrical dielectric resonator (1) is 0.9mm, and the distance between the two metal strips (11, 12) is 1.4mm.

2. A compact dual dipole driver according to claim 1, wherein: the radius of the body of the cylindrical dielectric resonator (1) is 4.25mm, and the radius of the split resonant ring (2) is 5.3mm.

3. A compact dual dipole driver according to claim 1, wherein: the width of the split resonant ring (2) is 0.3mm.

4. A compact dual dipole driver according to claim 1, wherein: the dielectric substrate (3) is a dielectric substrate (3) with a square section.

5. A quasi-yagi antenna using the compact dual-dipole driver as claimed in any one of claims 1-4, wherein: the split-type coaxial dielectric resonator comprises a cylindrical dielectric resonator (1), an open resonant ring (2), a dielectric substrate (3), a coplanar strip line (4) and a concave grounding plane (5), wherein the coplanar strip line (4) is printed on the top surface of the dielectric substrate (3), the open resonant ring (2) is arranged on the bottom surface of the dielectric substrate (3), and the concave grounding plane (5) is arranged on the bottom surface of the dielectric substrate (3).

6. The quasi-yagi antenna of claim 5, wherein: the concave ground plane (5) is a plane reflector with a concave circular arc, and the depth of the concave circular arc of the concave ground plane (5) is 8.4mm.

7. The quasi-yagi antenna of claim 6, wherein: and the distance between the concave arc bottom of the concave grounding plane (5) and the lower edge of the opening resonant ring (2) is 11.4mm.

8. The quasi-yagi antenna of claim 7, wherein: and the distance between the concave arc bottom of the concave grounding plane (5) and the common circular center of the split resonant ring (2) and the cylindrical dielectric resonator (1) is 15.65mm.

9. The quasi-yagi antenna of claim 8, wherein: and the distance between the upper edge of the concave grounding plane (5) and the concentric centers of the split resonant ring (2) and the cylindrical dielectric resonator (1) is 7.25mm.

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