CN211980886U - Leaky-wave edge-emitting array antenna based on parallel double lines - Google Patents

Abstract

The utility model discloses an array antenna is penetrated on leaky wave limit based on parallel double-line, including setting up a pair of parallel double-wire on the medium base plate, the wherein one end of double-wire is provided with the feed mouth, and the SMA coaxial joint is connected by the gradual change line to the feed mouth, and double-wire's other end short circuit ground connection, the periodic alternative equidistance in double-wire both sides distributes the radiating element that a plurality of structures are the same. The utility model provides an antenna that exists among the prior art be difficult to the problem of the limitation of miniaturization and high section.

Description

Leaky-wave edge-emitting array antenna based on parallel double lines

Technical Field

The utility model belongs to the technical field of mobile communication, microwave teletransmission, concretely relates to leaky-wave edge-emitting array antenna based on parallel double-line.

Background

With the rapid development of wireless communication systems, the communication rate is gradually increased. The operating bandwidth, the number of channels, and the signal-to-noise ratio determine the channel capacity of the communication. Meanwhile, the requirements of people for communication distance and communication equipment are higher and higher. In order to realize effective transmission of long-distance signals, higher standards are put forward on the size, efficiency, directivity and the like of the new generation antenna. The planar leaky-wave array antenna can meet the performance parameters of the antenna, and is an important research direction.

The electrical performance of an antenna, which is an important device for transceiving electromagnetic waves at the frontmost end of a wireless communication system, directly affects the overall performance of the communication system, for example: return loss and effective radiation gain. Therefore, wide impedance bandwidth and high efficiency, high gain array antennas are key devices in wireless communication systems. Although the conventional antenna technology has been developed, most of the antenna designs have limitations of difficulty in miniaturization and high profile. The single-layer plane leaky-wave antenna has the advantages of small volume, easiness in manufacturing and low cost.

A planar single-layer leaky-wave antenna array has been extensively studied as a microwave antenna with a wide range of applications, and has advantages of high gain, high efficiency, simple structure, and easy manufacture. It is often used in several ways: 1. a community broadband wireless access antenna; 2. the high gain characteristic is very beneficial to long-distance signal transmission; 3. the array antenna is scanned.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an array antenna is penetrated on leaky wave limit based on parallel double-line has solved the problem that the antenna that exists is difficult to the limitation of miniaturization and high section among the prior art.

The utility model discloses the technical scheme who adopts is, based on the leaky wave limit of parallel double-line and penetrates array antenna, including setting up a pair of parallel double-wire on the medium base plate, the wherein one end of double-wire is provided with the feed mouth, and the SMA coaxial joint is connected by the gradual change line to the feed mouth, and double-wire's other end short circuit ground connection, the same radiating element of a plurality of structures is distributed in the periodic replacement equidistance in double-wire both sides. The radiation unit has the specific structure that: the double-wire feed type antenna comprises a bottom layer dipole unit and an upper layer dipole unit which are connected with a double-wire feed through a connecting wire, wherein the bottom layer dipole unit is printed on the bottom layer of a dielectric substrate, the upper layer dipole unit is printed on the upper layer of the dielectric substrate, and the directions of the bottom layer dipole unit and the upper layer dipole unit are opposite. And a director is arranged at a quarter wavelength away from the front end of the radiation unit. The director is a three-row metal strip with a length less than the antenna arm length of the radiating element.

The utility model is also characterized in that,

and the distance between two adjacent radiation units on the opposite sides of the double-lead is 0.5 times of the wavelength.

The beneficial effects of the utility model are that, the leaky wave limit based on parallel double-line penetrates the surface electric field energy amplitude distribution of array antenna, and the energy is mainly concentrated on the transmission line, and the effect through the dipole unit is with energy radiation to the space, and the introduction of director can obtain the coupling of a little energy, strengthens the holistic directionality of antenna at a certain degree, improves the gain. The directivity of the antenna can be effectively improved in the vicinity of the operating frequency. In addition, the array antenna can realize higher radiation efficiency in a broadband range, high-gain pencil-shaped beams are formed on the side part of the transmission line by the antenna, and the shapes of the two beams are approximately consistent.

Drawings

Fig. 1 is a schematic diagram of the whole structure of a leaky-wave edge-emitting antenna array of the utility model;

FIG. 2 is a block diagram of a parallel transmission line supported by a dielectric substrate;

FIG. 3 is a diagram of radiating dipole elements on both sides of a parallel transmission line;

FIG. 4 is a diagram of a quasi-yagi antenna formed by multiple directors;

FIG. 5 is a graph of gain curves versus results for an array antenna with and without directors;

FIG. 6(a) is an antenna far field pattern of an array edge-fire antenna under E-plane;

FIG. 6(b) is the antenna far field pattern of the array edge-fire antenna in the H-plane;

fig. 7 is a return loss plot for an array antenna.

In the figure, 1 is a feed port, 2 is a bottom layer dipole unit, 3 is a director, 4 is an upper layer dipole unit, 5 is a dielectric substrate, and 6 is a double-lead.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

The utility model discloses array antenna is penetrated on leaky wave limit based on parallel double-line, the structure is shown in figure 1, including setting up a pair of parallel double-wire 6 on dielectric substrate 5, the wherein one end of double-wire is provided with feed mouth 1, and feed mouth 1 is connected SMA coaxial joint by the gradual change line, and double-wire's other end short circuit ground connection, 6 both sides of double-wire are periodically replaced the equidistance and are distributed the same radiating element of a plurality of structures.

As shown in fig. 3, the specific structure of the radiation unit is as follows: the double-wire dipole antenna comprises a bottom layer dipole unit 2 and an upper layer dipole subunit 4 which are in feed connection with a double-wire 6 through connecting wires, wherein the connecting wires are perpendicular to the double-wire 6, the bottom layer dipole unit 2 is printed on the bottom layer of a dielectric substrate 5, the upper layer dipole subunit 4 is printed on the upper layer of the dielectric substrate 5, and the directions of the bottom layer dipole unit 2 and the upper layer dipole subunit 4 are opposite.

The wavelength of 0.5 times of the distance between two adjacent radiating units on the opposite sides of the double-wire 6 effectively reduces the coupling effect between the array elements and improves the radiating efficiency of the antenna.

A director 3 is arranged one quarter wavelength away from the front end of the radiation unit.

The directors 3 are three rows of metal strips with a length smaller than the antenna arm length of the radiating element, and multiple directors are placed as shown in fig. 4, so that the antenna gain can be effectively enhanced.

In order to make full use of the high gain of plane leaky-wave antenna array and the advantage of easily integrated processing, based on the structure and the performance of above-mentioned leaky-wave antenna, the utility model discloses on the technical basis of the design of traditional plane leaky-wave antenna, use parallel double-wire to carry out the series-feed radiation array unit, and antenna element selects to be classic half-wave dipole antenna. Energy transmission is respectively obtained from two sides of the parallel double lines through the coupling effect of the dipole units on the transmission lines, and then the energy is radiated to the space through the half-wave symmetrical array. The antenna units are periodically and alternately arranged on two sides of the transmission line, and the distance between every two adjacent units is 0.5 times of the guided wave wavelength. Two radiation arms of the dipole antenna unit are respectively printed on the upper side and the lower side of the dielectric substrate. Benefit from the design of traditional microstrip yagi antenna before, the utility model discloses introduced multiple metal strip and acted as the director, made it constitute accurate yagi antenna, improved the effective gain of whole array antenna to a certain extent. The single-layer medium structure can effectively reduce the height of the whole section, is simple to process, saves the manufacturing cost and is easy to produce.

The utility model discloses antenna body model is as the series feed structure of the double-wire shown in fig. 1, and energy coupling effect through radiating element makes its radiation pattern before change into transmission, state of radiation on one side. In addition, the introduction of the dipole unit has little influence on the reflection coefficient of the whole port of the antenna, and S11< -10dB is realized in the ultra-wide band range. The short circuit grounding is carried out on the tail end of the transmission line, the standing wave distribution of energy in the transmission line can be realized, and compared with the port matching state, the radiation efficiency of the antenna is improved, and the integral gain of the antenna array is further enhanced. The antenna array inputs energy through a single coaxial feed SMA joint, and a gradient line is introduced between an interface and a parallel double-lead to achieve the aim of impedance matching. Fig. 1 is an overall structure diagram of an antenna, in which antenna units are arranged parallel to an array axis, and edge-emitting antenna arrays with the same radiation pattern are formed on both sides of a transmission line.

Radio frequency signals are fed through the coaxial SMA, equal-amplitude and opposite-phase periodic fringe electric field distribution is formed at two ends of the transmission line, and the other port is in short circuit grounding. As shown in FIG. 2, the amplitude of the electric field at the two side edges of the transmission line has a periodic antinode, node, and transmits TEM waves.

The structure is optimized through a three-dimensional simulation software HFSS, the energy amplitude distribution of the surface electric field of the array antenna is obtained, the energy is mainly concentrated on a transmission line, the energy is radiated to the space through the action of a dipole unit, the coupling of a small amount of energy can be obtained through the introduction of a director, the integral directivity of the antenna is enhanced to a certain degree, and the gain is improved. Fig. 5 shows a comparison of gain curves with and without directors, which effectively improves the directivity of the antenna in the vicinity of the operating frequency. In addition, the array antenna can realize higher radiation efficiency in a wide frequency band range. Fig. 6 and 7 are far field patterns and return loss curves of the ports, respectively, of the array antenna. The antenna forms a high-gain pencil-shaped beam at the side part of the transmission line, and the shapes of the two beams are approximately consistent.

Figure 5 compares the gain of the design antenna with frequency with and without the director structure. As can be seen from fig. 5, the gain curves of the antenna in both cases with and without the director structure are generally consistent, which also illustrates that the main radiation pattern of the antenna is unchanged after the director is added. Meanwhile, the peak value of the antenna gain appears near the working frequency point, and the design concept is met. After the unit is introduced by combining the design principle of the yagi antenna, the gain change can be obviously seen near the working frequency point, and the gain amplitude can be effectively improved by about 2 dB. By increasing the number of director structures placed in parallel, the gain will increase, but too much number will result in an antenna with an overall lateral dimension that is too large. Thus increasing the radiation directivity by a reasonable choice of 3 metal strips as directors.

Fig. 6(a) is the E-plane pattern of the antenna array and (b) is the corresponding H-plane pattern. Because the radiating units are periodically and alternately arranged along the two ends of the parallel transmission line, the directional diagram of the array antenna is obtained as edge-emitting bidirectional radiation by combining the directional diagram characteristics of the dipole antenna. The array of groups on the E surface forms a pencil-shaped wave beam, and a plurality of side lobes appear on the directional diagram of the E-surface of the array due to the excitation of the surface wave. Furthermore, the beam shapes on both sides are approximately centrosymmetric, which is caused by the alternating arrangement of the antenna radiation elements. (b) The H-plane directional diagram in the (1) has stronger symmetry and is in a '8' shape. The designed antenna is not arrayed on the H-plane, so that the beam width is obviously larger than that of the E-plane.

FIG. 7 is a variation curve of return loss of the antenna with frequency, S11 is lower than-10 dB in the ultra-wideband range of 2-12GHz, and the antenna has a broadband characteristic. Dipoles are alternately introduced at both ends of the parallel transmission line, and are placed at a wavelength of about 1/4 from the parallel transmission line by the leads to form radiation. Because the connected dipoles radiate energy, the transmission performance of the transmission line is not influenced, so that the transmission line forms a mode of transmitting and radiating simultaneously, and further, the reflection echo is small, and the good standing wave characteristic in a broadband is obtained.

Claims (2)

1. Array antenna is penetrated on leaky wave limit based on parallel double-line, its characterized in that, including a pair of parallel double-wire (6) of setting on dielectric substrate (5), wherein one end of double-wire is provided with feed mouth (1), and SMA coaxial joint is connected by the gradual change line in feed mouth (1), and the other end short circuit ground of double-wire, the same radiating element of a plurality of structures of double-wire (6) both sides periodicity alternative equidistance distribution, the radiating element concrete structure is: include through the connecting wire with bottom dipole unit (2) and upper dipole subelement (4) that twin-wire (6) feed is connected, bottom dipole unit (2) are printed at dielectric substrate (5) bottom, and upper dipole subelement (4) are printed on dielectric substrate (5) upper strata, and bottom dipole unit (2) and upper dipole subelement (4) opposite direction, distance be provided with director (3) at the quarter wavelength of radiating element front end, director (3) are for length is less than the triplex row metal strip of radiating element's antenna arm length.

2. The leaky-wave edge-emitting array antenna based on the parallel twin lines as claimed in claim 1, wherein adjacent two of said radiating elements on opposite sides of said twin lines (6) are spaced apart by 0.5 times a wavelength.

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