CN202503102U - Compact High Isolation Ultra Wideband Dual Band Antenna - Google Patents

Abstract

The utility model discloses a compact ultra-wideband dual-waveband antenna with high isolation. The compact ultra-wideband dual-waveband antenna with high isolation comprises an antenna substrate (1) and three radiating elements, wherein the three radiating elements and the substrate (1) are in the same horizontal plane, the three radiating elements are placed side by side, and the bottom surface of the substrate (1) serves as a ground plane; a first radiating element (3) consists of an L-shaped metal strip and a semicircular metal block which are connected with each other; a second radiating element (4) consists of an S-shaped metal strip and a rectangular metal block which are connected with each other; a third radiating element (5) consists of an L-shaped metal strip and an elliptic metal block which are connected with each other; the first radiating element (3) and the third radiating element (5) are symmetrically arranged on two sides of the second radiating element (4) respectively; and feed ends of the three radiating elements are connected with the substrate respectively. A double-feed three-radiating-element antenna technique is adopted, so that the antenna can work at two wavebands, the coupling degree is less than -15dB (the corresponding isolation is greater than 15dB), the standing-wave ratio is less than 2, the gain is about 4dBi, and the antenna efficiency is greater than 65 percent.

Description

Compact High Isolation Ultra Wideband Dual Band Antenna

technical field

The utility model relates to a novel high-isolation ultra-wideband dual-band antenna, in particular to a compact high-isolation ultra-wideband dual-band antenna, which belongs to the field of planar inverse F antennas.

Background technique

With the miniaturization and miniaturization of electronic devices, and the application of spread spectrum and frequency hopping technologies, higher and higher requirements are put forward for the broadband and miniaturization of communication equipment. UWB (ul-tra wide band, ultra-wideband) communication has many advantages such as large communication capacity, good confidentiality, low average power density, and strong anti-multipath interference ability. It is an important development direction of communication systems in the 21st century. Its development is also A corresponding ultra-wideband antenna technology is required. Ultra-wideband antenna design is a main research direction of ultra-wideband communication technology, and it has a wide range of applications in wireless communication, wireless access, electronic countermeasures and other systems.

Traditional ultra-wideband antennas such as logarithmic periodical antennas, equiangular helical Archimedes spiral antennas, etc., have complex feed network designs and large sizes, which do not meet the miniaturization requirements of low-power short-distance personal communication applications for ultra-wideband antennas. And the phase center is not fixed, and there will be serious distortion when it is applied to transmit short pulse signals in time domain in the pulse radio system.

The inverse F antenna has a small mass, a planar structure that is easy to integrate, and the antenna frequency band can cover multiple communication frequency bands, which can reduce the number of antennas required by the communication system, thereby reducing the system cost, and is conducive to the electromagnetic compatibility of the system. Therefore, compared with the traditional UWB antenna, the inverse-F antenna has great research prospects and practical significance.

Wireless LAN based on IEEE802.11 standard allows free wireless connection in LAN environment using unlicensed 2.4GHz or 5.3GHz radio frequency band. In practical applications, the 2.4GHz band is often crowded, so a dual-band ultra-wideband working antenna is proposed. This type of antenna can work in the 2.4GHz and 5.3GHz bands at the same time, which greatly improves the capacity and quality of wireless communication in the LAN. However, due to the almost double frequency difference between the 5.3GHz and 2.4GHz bands, the dual-band antenna has strong mutual coupling, which often causes the antenna to fail to work normally under the dual-band conditions at the same time. At present, an antenna with two radiating elements is generally designed to work in the 5.3GHz and 2.4GHz bands respectively. In order to improve the isolation, the distance between the two radiation elements is usually increased, but this greatly increases the size of the antenna, and the standing wave ratio coefficient is relatively large. Therefore, designing a compact UWB dual-band antenna with high isolation is the key to solve this problem.

Utility model content

The technical problem to be solved by the utility model is to provide a compact ultra-wideband antenna capable of working in dual bands (2.4GHz and 5.3GHz) under high isolation (<-15dB).

The utility model adopts the following technical solutions for solving the above-mentioned technical problems:

A compact high-isolation dual-band ultra-wideband antenna includes an antenna substrate and three radiating elements placed side by side in the same horizontal plane as the substrate, and the bottom surface of the substrate is used as a ground plane; wherein the first radiating element consists of a L An S-shaped metal strip is connected to a semicircular metal block, and the semicircular metal block is the radiation end of the first radiating element; the second radiating element is composed of an S-shaped metal strip connected to a rectangular metal block, and the rectangular metal The block is the radiating end of the second radiating element; the third radiating element is composed of an L-shaped metal strip connected to an elliptical metal block, and the elliptical metal block is the radiating end of the third radiating element; the first radiating element and the second radiating element The three radiating elements are respectively arranged symmetrically on both sides of the second radiating element, and the feeding ends of the three radiating elements are respectively connected to the substrate.

Further, a compact high-isolation dual-band ultra-wideband antenna of the present invention, the first radiating element works in the 2.4GHz band, the third radiating element works in the 5.3GHz band, and the second radiating element works in the 4.2GHz band band.

Further, a compact high-isolation dual-band ultra-broadband antenna of the present invention, the antenna substrate is made of metal material, with a thickness of 0.2mm~0.5mm, two symmetrically arranged on both sides of the edge of the substrate Shaft cable welding fixing points.

Further, a compact high-isolation dual-band ultra-broadband antenna of the present invention, the first radiating element and the second radiating element are fed by a coaxial cable and share a feeding end, and the feeding end is located at the first The junction of the L-shaped metal strip of the radiating element and the S-shaped metal strip of the second radiating element.

Further, in a compact high-isolation dual-band ultra-wideband antenna of the present invention, the third radiating element is fed by a coaxial cable, and the feeding end is located between the L-shaped metal strip forming the third radiating element and the The junction of oval metal blocks.

Compared with the prior art by adopting the above technical scheme, the utility model has the following technical effects:

The utility model adopts the antenna technology of three radiating elements, and its compact structure enables the entire UWB antenna to work in dual bands (2.4GHz and 5.3GHz), the isolation degree is less than -15dB, the standing wave ratio is less than 2, the gain is about 4dBi, and the antenna efficiency is greater than 65%.

Description of drawings

Figure 1 is a schematic plan view of a dual-band UWB antenna.

Fig. 2 is a schematic diagram of the planar structure of the antenna substrate.

FIG. 3 is a schematic diagram of the planar structure of the radiation elements 3 and 4 .

FIG. 4 is a schematic diagram of the planar structure of the radiation element 5 .

FIG. 5 is a curve diagram of S parameters in the case that the feeding terminals of the radiating elements 3 and 4 are P1 ports, and the feeding terminals of the radiating element 5 are P2 ports.

FIG. 6 is a graph of the standing wave ratio in the case that the feeding terminals of the radiating elements 3 and 4 are P1 ports, and the feeding terminals of the radiating element 5 are P2 ports.

Detailed ways

Below in conjunction with accompanying drawing, the technical scheme of the utility model is described in further detail:

As shown in FIG. 1 , the UWB antenna of the present invention includes an antenna substrate 1 and three radiating elements placed side by side in the same horizontal plane as the substrate 1 , wherein the feeding ends of the three radiating elements are respectively connected to the substrate.

Wherein, the radiation element 3 is composed of an L-shaped metal strip connected with a semicircular metal block, and the semicircular metal block is the radiation end of the radiation element 3 . The radiation element 4 is composed of an S-shaped metal strip connected to a rectangular metal block, and the rectangular metal block is the radiation end of the radiation element 4 . The radiation element 5 is composed of an L-shaped metal strip connected with an oval metal block, and the oval metal block is the radiation end of the radiation element 5 .

Through the special design of the structure of each radiating element, the current distribution on the surface of the radiating element can be effectively improved, and then the radiation field distribution excited by the surface current can be improved, thereby improving the isolation of the antenna in the two operating bands. In addition, different radiation element structural designs form different radiation impedances, which in turn can reduce the standing wave ratio of the antenna in the working band.

The radiating element 3 and the radiating element 5 are symmetrically arranged on both sides of the radiating element 4, so that the isolation between the radiating element 3 and the radiating element 5 can be improved and the standing wave ratio thereof can be reduced.

The antenna substrate 1 can be made of metal materials such as copper plate and aluminum plate, with a thickness of 0.2 mm to 0.5 mm. The coaxial cable welding fixing points 2 are located on both sides of the edge of the substrate 1, and the bottom surface of the substrate is used as a ground plane.

Referring to Figure 2 and Figure 3, the radiation element 3 and the radiation element 4 are made of the same material as the substrate 1, and the specific implementation can be made on a whole metal material plate through a wire cutting process or a laser cutting process as shown in Figure 2 and Figure 2. 3 shows the pattern.

Referring to Fig. 3, the radiating element 3 and the radiating element 4 share a feed, which can make the radiation excited by the surface current distribution formed by the radiating element 3 and the radiating element 4 and the radiation excited by the surface current distribution formed by the radiating element 5 have more High isolation, the feed adopts coaxial cable, and the feed end is located at 6 as shown in Figure 1.

Referring to FIG. 4 , the radiation element 5 is fed by a coaxial cable, and the feed end is located at position 7 as shown in FIG. 1 .

The introduction of the radiating element 4 interferes with the mutual coupling between the radiating element 3 and the radiating element 5, thereby increasing the isolation between the two bands of 2.4 GHz and 5.3 GHz.

Figure 5 shows the S-parameter simulation curves in the case where the feeding terminals of radiating elements 3 and 4 are P1 ports and the feeding terminals of radiating element 5 are P2 ports. It can be seen from the figure that the radiating elements 3, 4, and 5 The mutual S12 (coupling degree) is less than -15dB in the 2.4GHz~2.5GHz band, 4.2GHz~4.75GHz band and 5.15GHz~5.825GHz band.

Figure 6 shows the simulation curve of the standing wave ratio parameter in the case where the feeding end 6 of the radiating elements 3 and 4 is the P1 port and the feeding end 7 of the radiating element 5 is the P2 port. It can be seen from the figure that the radiating element The standing wave ratio coefficients among 3, 4, and 5 are all less than 2.0 in the 2.4GHz~2.5GHz band, 4.2GHz~4.75GHz band and 5.15GHz~5.825GHz band.

Claims (5)

1. A compact high-isolation dual-band ultra-wideband antenna, characterized in that it includes an antenna substrate (1), and three radiating elements placed side by side in the same horizontal plane as the substrate (1), and the substrate (1) The bottom surface of is used as the ground plane; among them, The first radiating element (3) is composed of an L-shaped metal strip connected to a semicircular metal block, and the semicircular metal block is the radiating end of the first radiating element (3); The second radiating element (4) is composed of an S-shaped metal strip connected to a rectangular metal block, and the rectangular metal block is the radiating end of the second radiating element (4); The third radiating element (5) is composed of an L-shaped metal strip connected to an elliptical metal block, and the elliptical metal block is the radiating end of the third radiating element (5); The first radiating element (3) and the third radiating element (5) are respectively arranged symmetrically on both sides of the second radiating element (4), and the feeding ends of the three radiating elements are respectively connected to the substrate. 2. A compact high-isolation dual-band ultra-wideband antenna according to claim 1, characterized in that: the working band of the first radiating element (3) is 2.4GHz, and the third radiating element (5) works The frequency band is 5.3GHz, and the working frequency band of the second radiation element (4) is 4.2GHz. 3. A compact high-isolation dual-band ultra-wideband antenna according to claim 1, characterized in that: the antenna substrate (1) is made of metal material with a thickness of 0.2mm~0.5mm and is located on the substrate ( Two coaxial cable welding fixing points (2) are arranged symmetrically on both sides of the edge of 1). 4. A compact high-isolation dual-band ultra-wideband antenna according to claim 1, characterized in that: the first radiating element (3) and the second radiating element (4) are fed by a coaxial cable and A feed end is shared, and the feed end is located at the junction (6) between the L-shaped metal strip of the first radiating element (3) and the S-shaped metal strip of the second radiating element (4). 5. A compact high-isolation dual-band ultra-wideband antenna according to claim 1, characterized in that: the third radiating element (5) is fed by a coaxial cable, and the feeding end is located at the The junction (7) between the L-shaped metal strip of the three radiation elements (5) and the oval metal block.

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