KR20190108092A - Rf lens apparatus for improving directivity of antenna array and transmitting-receiving antenna system including the same - Google Patents

Abstract

Disclosed are an RF lens apparatus improving directivity of an antenna array, a transception antenna system including the RF lens apparatus, and a beamforming method performed in the transception antenna system. According to one embodiment of the present invention, the transception antenna system comprises: an antenna array configured with a plurality of antennas; antenna RF lenses provided on an upper part of the antenna array, wherein the antenna RF lenses are disposed to correspond to the plurality of antennas, respectively; and an array RF lens provided on an upper part of the antenna RF lenses.

Description

RF LENS APPARATUS FOR IMPROVING DIRECTIVITY OF ANTENNA ARRAY AND TRANSMITTING-RECEIVING ANTENNA SYSTEM INCLUDING THE SAME

The following description relates to a transmit / receive antenna system having multiple antennas, and more particularly, to a transmit / receive antenna system that improves the directivity of an antenna array by using an RF lens.

This achievement was supported by the Ministry of Science, ICT and Future Planning, and the support project for linking entrepreneurship in the market based on public technology. , Research Title: High Performance Short Range Radar for Self-Driving Cars, Contribution Rate: 1/1, Organizer: Korea Advanced Institute of Science and Technology, Research Period: 2016.09.05 ~ 2017.02.28 It is a patent obtained through.

The wireless communication system or the radar includes a transmission and reception antenna system for transmitting and receiving wireless signals. Modern transmit / receive antenna systems often use multiple antennas. In the case of multi-antenna-based transmit / receive antenna systems, multiple-input multiple-output (MIMO) technology or beamforming technology increases data transmission speed. It has many advantages such as reducing the interference between devices, increasing the transmission distance of the signal, increasing the signal-to-noise ratio, and the like.

Here, the transmission beamforming technique adjusts the phase and amplitude of a signal transmitted from each of the multiple antennas so that signals transmitted from different antennas may be constructively interfered or canceled with each other according to directions. It is a technique that causes a transmission signal to be transmitted with directivity while causing destructive interference. Receive beamforming technology is a technology that adjusts the phase and amplitude of a signal received from each of the multiple antennas and combines them to increase the reception sensitivity in a specific direction so that they can be received with directivity. The principle is the same as for transmit beamforming. Transmit or receive beamforming is a technique that can be applied when signals transmitted or received by each antenna are highly correlated with each other (stochastically highly correlated).

On the other hand, unlike the beamforming technique, the MIMO technique is used when the signals transmitted or received from each antenna are ideally correlated (stochastically uncorrelated), and the MIMO technique uses multiple antennas simultaneously. By transmitting and receiving data streams, or by using diversity gain, robust performance can be obtained even in a channel environment change. MIMO technology tends to degrade as the correlation between signals transmitted or received at each antenna increases.

Recently, in the field of wireless communication, the MIMO and beamforming techniques described above have been actively studied as methods for efficient use of frequency resources together with exhaustion of frequency resources. Such MIMO and beamforming technologies are expected to be the core technologies for 5G mobile communication. In addition, as interest in the Advanced Drier Assistance System (ADAS) and self-driving cars has increased, competition for the development of higher performance automotive radars has become more intense. Antennas are basically being introduced.

Therefore, the following embodiments propose a technique that can solve the problems of MIMO and beamforming and improve the performance in a transmit / receive antenna system having multiple antennas.

One embodiment of the present invention provides a technique for solving a deterioration in the directivity performance of an antenna array caused by nonlinearity between spatial frequencies and incident angles and the directivity of an antenna in a transmit / receive antenna system having multiple antennas, and covering a wide angle with a single antenna array. To provide.

Specifically, one embodiment is a transmission and reception using an RF lens device including an RF lens for the antenna disposed to correspond to each of the plurality of antennas constituting the antenna array and the array RF lens provided on the antenna RF lenses An antenna system and a beamforming method are provided.

According to one embodiment, a transceiver antenna system for improving antenna directivity includes: an antenna array consisting of a plurality of antennas; Antenna RF lenses provided on the antenna array, wherein the antenna RF lenses are disposed to correspond to the plurality of antennas, respectively; And an array RF lens provided on the antenna RF lenses.

According to one aspect, each of the antenna RF lenses, the shape of the beam of each of the plurality of antennas, the antenna array, forming a beam within a first angle range, the array RF lens, The directivity angle of the beam of the antenna array may be refracted such that the directivity angle range of the beam of the antenna array is changed from the first angle range to a second angle range that is wider or narrower than the first angle range.

According to another aspect, the antenna array may determine the first angle range that satisfies the constraint caused by the changed beam shape of each of the plurality of antennas.

According to another aspect, each of the RF lens for the antenna, by refracting the rays forming the beam of each of the plurality of antennas to change the shape of the beam of each of the plurality of antennas within a specific angle range Can be.

According to another aspect, each of the RF lens for the antenna, it is provided to control the lens focal length can adaptively adjust the specific angle range.

According to another aspect, each of the antenna RF lenses may be able to refrac the ladle of each of the plurality of antennas such that the gain of each of the plurality of antennas has a threshold only within the specific angle range.

According to another aspect, the antenna RF lenses may be disposed to correspond one-to-one with the plurality of antennas, respectively.

According to another aspect, the array RF lens may be provided to control the lens focal length to adaptively adjust the second angle range.

According to an embodiment, the RF lens device provided on the antenna array consisting of a plurality of antennas to improve the directivity of the antenna array, is provided on the antenna array, the beam of each of the plurality of antennas RF lenses for antennas changing shape, wherein the RF RF lenses are arranged to correspond to the plurality of antennas, respectively; And an upper portion of the RF lenses for the antenna, the refractive angle of the beam formed by the antenna array within the first angle range is refracted so that the directivity angle range of the beam of the antenna array is changed from the first angle range. And an RF lens for the array that changes to a second angle range that is wider or narrower than the angle range.

According to an aspect, the first angle range may be determined as a value that satisfies a constraint caused by a changed beam shape of each of the plurality of antennas.

According to one embodiment, an antenna array consisting of a plurality of antennas; Antenna RF lenses provided on the antenna array, wherein the antenna RF lenses are disposed so as to correspond to the plurality of antennas, respectively, and the transceiver RF lens provided on the antenna RF lenses. A beamforming method performed in an antenna system includes: changing the beam shape of each of the plurality of antennas in each of the RF lenses for the antenna; The antenna array forming a beam within a first angular range; And in the array RF lens, refracting the directing angle of the beam of the antenna array such that the directing angle range of the beam of the antenna array is changed from the first angle range to a second angle range that is wider or narrower than the first angle range. It comprises the step of.

According to one aspect, forming the beam within the first angular range may include determining the first angular range that satisfies a constraint caused by a modified beam shape of each of the plurality of antennas. .

According to another aspect, changing the beam shape of each of the plurality of antennas, refracting the rays forming the beam of each of the plurality of antennas, thereby reducing the beam shape of each of the plurality of antennas It may include the step of changing within a certain angle range.

According to another aspect, the step of changing the beam shape of each of the plurality of antennas within a specific angle range, the plurality of antennas such that the gain of each of the plurality of antennas has a threshold only within the specific angle range It may be the step of refracting each ladle.

One embodiment of the present invention provides a technique for solving a deterioration in the directivity performance of an antenna array caused by nonlinearity between spatial frequencies and incident angles and the directivity of an antenna in a transmit / receive antenna system having multiple antennas, and covering a wide angle with a single antenna array. Can be provided.

Specifically, one embodiment is a transmission and reception using an RF lens device including an RF lens for the antenna disposed to correspond to each of the plurality of antennas constituting the antenna array and the array RF lens provided on the antenna RF lenses An antenna system and a beamforming method can be provided.

1 is a view showing a conventional transmit and receive antenna system.
2 is a diagram illustrating a relationship between a spatial frequency and an incident angle.
3 is a diagram for explaining gain characteristics and directivity according to an angle of an antenna in an ideal transmit / receive antenna system having a conventional structure.
4 is a view for explaining the gain of the antenna array according to the angle when the antenna array is directed in the 0 ° direction in the ideal transmit and receive antenna system of the conventional structure.
FIG. 5 is a diagram for describing gain of an antenna array according to an angle when an antenna array is directed in a 30 ° direction in an ideal transmit / receive antenna system having a conventional structure.
FIG. 6 is a diagram for explaining gain of an antenna array according to an angle when an antenna array is directed in a 60 ° direction in an ideal transmit / receive antenna system having a conventional structure.
FIG. 7 is a diagram for describing gain of an antenna array according to an angle when an antenna array is directed in a 90 ° direction in an ideal transmit / receive antenna system having a conventional structure.
FIG. 8 is a diagram for describing gain characteristics and directivity according to an angle of an antenna in a conventional transmit / receive antenna system having a conventional structure.
FIG. 9 is a diagram for describing gain of an antenna array according to an angle when the antenna array is oriented in the 0 ° direction in a realistic transmit / receive antenna system having a conventional structure.
FIG. 10 is a diagram for describing gain of an antenna array according to an angle when the antenna array is directed in a 30 ° direction in a realistic transmit / receive antenna system having a conventional structure.
FIG. 11 is a diagram for describing gain of an antenna array according to an angle when the antenna array is directed in a 60 ° direction in a realistic transmit / receive antenna system having a conventional structure.
FIG. 12 is a diagram for describing gain of an antenna array according to an angle when the antenna array is directed in a 90 ° direction in a realistic transmit / receive antenna system having a conventional structure.
13 is a diagram illustrating a transmit / receive antenna system according to an embodiment.
FIG. 14 is a diagram illustrating an RF lens for an antenna included in the transmission / reception antenna system shown in FIG. 13.
FIG. 15 illustrates a gain characteristic and directivity according to an angle of an antenna in a transmit / receive antenna system according to an embodiment.
FIG. 16 is a view for explaining an embodiment of an array RF lens included in the transmit / receive antenna system shown in FIG. 13.
17 is a view for explaining another embodiment of an array RF lens included in the transmit / receive antenna system shown in FIG. 13.
18 is a flowchart illustrating a beamforming method in a transmit / receive antenna system according to an embodiment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or limited by the embodiments. Also, like reference numerals in the drawings denote like elements.

In addition, terms used in the present specification are terms used to properly express preferred embodiments of the present invention, which may vary depending on the intention of the viewer, the operator, or customs in the field to which the present invention belongs. Therefore, the definitions of the terms should be made based on the contents throughout the specification.

Embodiments described herein relate to a transmit / receive antenna system having multiple antennas, which are arranged to correspond to the plurality of antennas constituting the antenna array, respectively, and the antenna RF lenses for changing the beam shape of each of the plurality of antennas. And refracting the directing angle of the beam formed by the antenna array within the first angle range provided on the antenna RF lenses to widen or narrow the directing angle range of the beam of the antenna array from the first angle range to the first angle range. By constructing a transmit / receive antenna system to include an array RF lens that changes to a second angular range, it solves the degradation of the directivity performance of the antenna array caused by the nonlinearity between the spatial frequency and the incident angle and the directivity of the antenna, resulting in a single antenna array. Make sure to cover a wide angle.

Hereinafter, a transmission / reception antenna system having multiple antennas means a system for transmitting and receiving signals, including an antenna array including a plurality of antennas as multiple antennas. In addition, the present invention is described by way of example for the reception beamforming technique in the transmission and reception antenna system for convenience of description, but is not limited thereto and may be equally applicable to the MIMO transmission and reception technique as well as the transmission beamforming technique. . In addition, hereinafter, the antenna array is described as being a one-dimensional linear array, but is not limited thereto and may be extended to the two-dimensional array.

1 is a view showing a conventional transmit and receive antenna system.

Referring to FIG. 1, the conventional transmit / receive antenna system has a structure including a linear antenna array 100 including a plurality of antennas A ₀ , A ₁ , A ₂ , A ₃ , A ₄ , A ₅ . . At this time, it is assumed that the spacing of the plurality of antennas A ₀ , A ₁ , A ₂ , A ₃ , A ₄ , A _{5 in the} linear antenna array 100 is a half wavelength (λ / 2) of the carrier frequency. However, it is not limited thereto. Hereinafter, an ideal transmit / receive antenna system and a realistic transmit / receive antenna system described below with reference to FIGS. 2 to 12 are assumed to have a structure as illustrated in FIG. 1.

2 is a diagram illustrating a relationship between a spatial frequency and an incident angle.

When a signal is received by the linear antenna array in the transmit / receive antenna system of the conventional structure described above with reference to FIG. 1, the signals received by each of the plurality of antennas constituting the linear antenna array have different phase values according to incident angles. The rate of change of phase according to space is called a spatial frequency, and the spatial frequency has a nonlinear relationship with the incident angle of the signal as shown in the graph 200 of FIG. 2.

FIG. 3 is a diagram for describing gain characteristics and directivity according to an angle of an antenna in an ideal transmit / receive antenna system having a conventional structure, and FIG. 4 is an ideal transmit / receive antenna system having a conventional structure when the antenna array is oriented in a 0 ° direction. 5 is a view for explaining the gain of the antenna array according to the angle of, Figure 5 is a view for explaining the gain of the antenna array according to the angle when the antenna array is directed in the 30 ° direction in the ideal transmit and receive antenna system of the conventional structure 6 is a view for explaining the gain of the antenna array according to the angle when the antenna array is directed in the 60 ° direction in the ideal transmit and receive antenna system of the conventional structure, Figure 7 is an ideal transmit and receive antenna system of the conventional structure , Antenna angle according to the angle when the antenna array is oriented in the 90 ° direction. A diagram for explaining the gain thereof.

Referring to FIG. 3, in a transmission / reception antenna system having a conventional structure, a gain according to an angle of an antenna, that is, a beam pattern in a Cartesian coordinate system is always 1 for a range of -90 ° to 90 °, such as 310. If it has a phosphorus property, 310 is graphed in a polar coordinate system and appears as 320. In such an ideal case of a transmission / reception antenna system (a conventional transmission / reception antenna system), when the linear antenna array is steered in a specific direction, the gain, that is, the beam pattern, of the antenna array according to the angle is shown as shown in FIGS. 4 to 7.

Hereinafter, the beam pattern refers to the radiation pattern of the antenna or the radiation pattern of the antenna array consisting of multiple antennas, the directivity (directivity) refers to the degree or nature that the beam pattern of the antenna or antenna array is concentrated in a specific direction. For example, the directivity that can be represented by a beam shape (beam shape) can be used as an expression such as high, large, or low. At this time, if the directivity is high, the beam shape is narrow. If the directivity is low, the beam shape is narrow. Hereinafter, the beam shape is a concept including the beam width, "changing the beam shape" is to remove the energy radiation outside the angular range so that the beam width is within a certain angular range, This means keeping the antenna gain within the angular range.

Steering also means directing the directing angle of the directional antenna or the directional antenna array in the desired direction.

Referring to FIG. 4, in an ideal transmit / receive antenna system, when the antenna array is oriented in the 0 ° direction, the gain of the antenna array according to the angle, that is, the beam pattern, is plotted on a linear scale in a rectangular coordinate system, and 410 and If the beam pattern of 410 is plotted on a linear scale in the polar coordinate system, it is shown as 420.

In this case, the beam pattern of the antenna array may have a higher directivity as the number of antennas constituting the antenna array increases, and may be sharply formed. However, even if the number of antennas is the same, the beam pattern when the array is steered in the 0 ° direction is the highest in directivity, and the beam pattern becomes inferior as the direction is 90 ° or -90 °. Have This problem may occur because the relationship between the incident angle and the spatial frequency of the signal is a nonlinear relationship as shown in FIG. 2.

Hereinafter, a steering angle means an angle or direction in which energy radiation of an antenna having directivity or an antenna array having directivity is concentrated. At this time, the directing angle has the same meaning as the direction of the beam.

Referring to FIG. 5, in an ideal transmit / receive antenna system, when the antenna array is oriented in the 30 ° direction, the gain of the antenna array according to the angle, that is, the beam pattern, is plotted as a graph of linear scale in a rectangular coordinate system, is shown as 510. The beam pattern of the graph is plotted on a linear scale in polar coordinates as shown in 520.

Here, although the beam pattern when the antenna array is directed in the 30 ° direction is slightly inferior to the beam pattern described above with reference to FIG. 4, it is confirmed that the beam pattern maintains relatively good directivity.

Referring to FIG. 6, in an ideal transmit / receive antenna system, when the antenna array is oriented in a 60 ° direction, when the gain of the antenna array according to an angle, that is, the beam pattern is plotted on a linear scale in a rectangular coordinate system, may be represented as 610. The beam pattern of 610 is plotted on a linear scale in the polar coordinate system and appears as 620.

At this time, the beam pattern when the antenna array is directed in the 60 ° direction is noticeably lowered in directivity than the beam pattern described with reference to FIG. 4 and the beam pattern described with reference to FIG. 5, and the -90 ° direction. Since the gain of the antenna array with respect to is greater than 4.5, there is a problem that interference by signals from the -90 ° direction, which is not an unwanted direction, can be greatly generated.

Referring to FIG. 7, in an ideal transmit / receive antenna system, when the antenna array is oriented in a 90 ° direction, the gain of the antenna array according to an angle, that is, the beam pattern, may be represented as a graph of linear scale in a rectangular coordinate system, as shown in 710. The beam pattern of is plotted on a linear scale graph in polar coordinates as 720.

Here, it is confirmed that the beam pattern when the antenna array is directed in the 90 ° direction is greatly inferior in directivity, and there is a problem in that a signal received from the 90 ° direction and a signal received from the −90 ° direction cannot be distinguished.

In the above description, the transmission / reception antenna system of the ideal case in which the gain according to the antenna's directivity angle is always 1 in the -90 ° to 90 ° direction range has been described, but in the actual wireless transmission / reception environment, the gain characteristic of the antenna itself also has directivity. As a result, gain and directivity according to the angle of the antenna are different from those of FIG. 3. Detailed description thereof will be described with reference to FIG. 8.

FIG. 8 is a diagram for explaining gain characteristics and directivity according to an angle of an antenna in a conventional transmit / receive antenna system of the conventional structure, and FIG. 9 is a diagram of a conventional transmit / receive antenna system in a conventional transmit / receive antenna system when the antenna array is directed in a 0 ° direction. 10 is a view for explaining the gain of the antenna array according to the angle of, Figure 10 is a view for explaining the gain of the antenna array according to the angle when the antenna array is directed in the 30 ° direction in a realistic transmitting and receiving antenna system of a conventional structure 11 is a view for explaining the gain of the antenna array according to the angle when the antenna array is directed in the 60 ° direction in the conventional transmitting and receiving antenna system of the conventional structure, Figure 12 is a realistic transmitting and receiving antenna system of the conventional structure Antenna according to the angle when the antenna array is aimed at 90 ° A diagram illustrating the gain of the X-rays.

Referring to FIG. 8, in a conventional transmit / receive antenna system, a gain according to an antenna's directing angle, that is, a beam pattern in a rectangular coordinate system is 1 for a 0 ° direction as shown in 810 and a -90 ° direction or 90 ° direction. If 810 has a characteristic that gradually decreases as the angle is moved, 810 is graphed in the polar coordinate system and appears as 820. In this realistic case, when the linear antenna array is directed in a specific direction in a transmission / reception antenna system (a conventional transmission / reception antenna system), a gain, that is, a beam pattern, of the antenna array according to an angle is shown as shown in FIGS. 9 to 12.

Referring to FIG. 9, in a realistic transmit / receive antenna system, when the antenna array is oriented in the 0 ° direction, the gain of the antenna array according to the angle, that is, the beam pattern, is represented as a graph of linear scale in a rectangular coordinate system as shown in 910. The beam pattern of is plotted on the linear scale in the polar coordinate system and it is shown as 920.

At this time, it is confirmed that the beam pattern of the antenna array such as 920 has a greater directivity than the beam pattern described above with reference to FIG. 4, because the directivity angle of the antenna itself matches the directivity angle of the antenna array.

Referring to FIG. 10, in a realistic transmit / receive antenna system, when the antenna array is oriented in the 30 ° direction, the gain of the antenna array according to the angle, that is, the beam pattern, is plotted on a linear scale in a rectangular coordinate system, as shown in 1010. The beam pattern of the graph is plotted on a linear scale in polar coordinates as shown in 1020.

Here, it is confirmed that the gain of the antenna array tends to be shifted slightly to the left of the gain of the antenna array described above with reference to FIG. 5 when directed in the 30 ° direction. That is, when there is a directivity of the antenna itself, such as a realistic transmission and reception antenna system, if the directivity angle of the antenna itself and the directivity angle of the antenna array do not coincide, it may adversely affect adjusting the directivity direction of the antenna array.

Referring to FIG. 11, in a realistic transmit / receive antenna system, when the antenna array is directed in a 60 ° direction, the gain of the antenna array according to the angle, that is, the beam pattern, is plotted on a linear scale in a rectangular coordinate system as shown in 1110, 1110. The beam pattern of the graph is plotted on a linear scale in polar coordinates as shown in 1120.

At this time, it is confirmed that the beam pattern when the antenna array is directed in the 60 ° direction is not properly formed by the directivity of the antenna itself.

Referring to FIG. 12, in a realistic transmit / receive antenna system, when the antenna array is oriented in the 90 ° direction, the gain, that is, the beam pattern, of the antenna array according to the angle is plotted on a linear scale in a rectangular coordinate system, as shown in 1210. The beam pattern of the graph is plotted on a linear scale in polar coordinates as shown in 1220.

When beamforming is performed in such a realistic transmit / receive antenna system, due to the directivity of the antenna itself, when the beam directing angle of the antenna array is increased, the beamforming performance is severely degraded. In addition, since the transmission and reception antenna system of the conventional structure does not solve the above problem, there is a disadvantage that the directing angle of the beam pattern of the antenna array is limited to an angle range much narrower than 120 °.

However, in the case of mobile communication, the sector antenna is often required to cover 120 °, and in the case of a near field radar for autonomous driving, which has been actively studied recently, it should cover about 120 °. However, it is impossible to cover 120 ° with a single antenna array as described with reference to FIGS.

Therefore, the following embodiments include an RF lens device, thereby solving the degradation of the directivity performance of the antenna array, and proposes a transmission and reception antenna system that can cover a wide angle with a single antenna array.

13 is a diagram illustrating a transmit / receive antenna system according to an embodiment.

Referring to FIG. 13, the transceiver antenna system 1300 according to an embodiment includes an antenna array 1310 and an RF lens device 1320 including a plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316. ). Hereinafter, it is assumed that the interval of the plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316 in the antenna array 1310 is a half wavelength (λ / 2) of the carrier frequency, but is not limited thereto. . In addition, the antenna array 1310 is described as a one-dimensional linear array as shown, but is not limited to this, but a plurality of antennas 1311, 1312, 1313, 1314, 1315, 1316 are arranged in two dimensions It may be a dimensional array. Even in this case, the RF lens device 1320 to be described later may be equally applied.

The RF lens device 1320 may be provided on the antenna array 1310 and disposed to correspond to the plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316, respectively, for the RF lenses 1321, 1322, and the like. 1323, 1324, 1325, and 1326, and an array of RF lenses 1330 provided on the antenna RF lenses 1321, 1322, 1323, 1324, 1325, and 1326.

The antenna RF lenses 1321, 1322, 1323, 1324, 1325, and 1326 may be disposed in a one-to-one correspondence with the plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316, respectively. For example, A ₀ antenna RF lens 1321 is arranged on the upper portion of the A ₀ antenna (1311), A ₁ antenna RF lens 1322 for may be placed on top of the A ₁ antenna 1312. Similarly, the RF lenses 1323, 1324, 1325, and 1326 for the remaining antennas may be disposed to correspond one-to-one to the remaining antennas 1313, 1314, 1315, and 1316, respectively.

Each of the antenna RF lenses 1321, 1322, 1323, 1324, 1325, and 1326 may change a beam shape of each of the plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316. For example, A ₀ antenna RF lens 1321 is a beam shape of the A ₁ antenna 1312, a beam shape of the A ₀ antenna (1311), A ₁ antenna RF lens (1322) for, A ₂ antenna for The RF lens 1323 has a beam shape of the A ₂ antenna 1313, the RF lens 1324 for an A ₃ antenna has a beam shape of an A ₃ antenna 1314, and the RF lens 1325 for an A ₄ antenna has an A _4. the beam shape of the antenna (1315), for RF lens a ₅ antenna 1326 is capable of changing the beam shape of the antenna a ₅ (1316), each with ₁ ~ θ ₁ -θ. Hereinafter, 2 * θ ₁ is an amount representing the beam shape (width) of the antenna beam pattern changed by the RF lens 1321, 1322, 1323, 1324, 1325, and 1326 for the antenna, and θ ₁ is related to the changed antenna beam pattern. It means a parameter. Detailed description thereof will be described with reference to FIG. 14.

In this case, it is understood that each of the antenna RF lenses 1321, 1322, 1323, 1324, 1325, and 1326 changes the beam shape of each of the plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316. This may mean changing the directivity (directivity of the antenna itself) of each of the antennas 1311, 1312, 1313, 1314, 1315, and 1316. Accordingly, each of the antenna RF lenses 1321, 1322, 1323, 1324, 1325, and 1326 may be designed in consideration of the self-directivity of each of the plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316. (As an example, an aspherical lens or the like may be used, and one or more lens elements may be used).

Antenna array 1310 forms a beam within a first angle range. In this case, the antenna array 1310 is modified by each of the plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316 by the RF lenses 1321, 1322, 1323, 1324, 1325, and 1326 for each antenna. By determining the first angular range that satisfies the constraint by the beam shape, it is possible to form the beam within the determined first angular range. For example, the antenna array 1310 includes a plurality of antennas (1311, 1312, 1313, 1314, 1315, 1316) of ~ φ ₁ -φ each of the first angular range in the beam shape changed in ₁ ~ θ ₁ -θ The value of -φ ₁ to φ ₁ which is the first angle range can be determined such that ₁ is located (φ ₁ <θ ₁ ). More specifically, for example, the antenna array 1310 determines the modified beam of each of the plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316 in determining the parameter φ ₁ of the first angular range that forms the beam. As a constraint by the shape parameter θ ₁ , an equation of φ ₁ = θ _1- (beam width of the antenna array 1310) / 2 can be used. Hereinafter, a first angle range of -φ ₁ to φ ₁ means a value representing a range of a directing angle of a beam of the antenna array 1310.

The array RF lens 1330 has a beam angle of the beam of the antenna array 1310 so that the beam angle of the beam of the antenna array 1310 is changed from a first angle range to a wider or narrower second angle range. Refraction In other words, the array RF lens 1330 may change the direction angle range of the beam of the antenna array 1310 from the first angle range to the second angle range.

For example, the array RF lens 1330 refracts the directing angle of the beam of the antenna array 1310 having a first angle range of -φ ₁ to φ ₁ , so that the beam of the antenna array 1310 is -φ _2. It is possible to have a second angle range of φ ₂ . Accordingly, the array RF lens 1330 may narrow or widen the coverage of the antenna array 1310 by refracting the beam angle of the beam of the antenna array 1310. Hereinafter, a second angle range of -φ ₂ to φ ₂ means a value indicating a range of the orientation angles changed by refraction after the beam of the antenna array 1310 passes through the array RF lens 1330. Detailed description thereof will be described with reference to FIGS. 16 to 17.

As such, the transmit / receive antenna system 1300 according to an embodiment may include RF lenses 1321, 1322, and 1323 for antennas for changing the beam shape of each of the plurality of antennas 1311, 1312, 1313, 1314, 1315, and 1316. , 1324, 1325, 1326, and the antenna array 1310 refracts the directing angle of the beam formed within the first angle range, thereby reducing the directing angle range of the beam of the antenna array 1310 from the first angle range to the second angle range. By including the RF lens 1330 for the array to be changed to, it is possible to solve the degradation of the directivity performance of the antenna array caused by the non-linearity between the spatial frequency and the incident angle and the directivity of the antenna, it is possible to cover a wide angle with a single antenna array .

FIG. 14 is a diagram illustrating an RF lens for an antenna included in the transmit / receive antenna system illustrated in FIG. 13, and FIG. 15 illustrates a gain characteristic and directivity according to an angle of an antenna in a transmit / receive antenna system according to an embodiment. It is for the drawing. Hereinafter, the antenna RF lens 1400 described with reference to FIG. 14 represents each of the antenna RF lenses included in the transceiver antenna system described above with reference to FIG. 13.

Referring to FIG. 14, the antenna RF lens 1400 has the directivity of the antenna in an actual wireless transmission / reception environment as shown in FIG. 15. More specifically, the RF antenna lens 1400 is for the shape of the antenna beam by refraction of rays (ray) to form the beam of the antenna (for example, θ ₁ -θ ₁ ~) an angle range can be changed into.

For example, the RF lens 1400 for the antenna may reduce the antenna gain by dispersing the ladle 1410 in a direction close to 0 ° among the ladles forming the beam of the antenna through refraction, and forming the beam of the antenna. the ladle of the ray direction close to 90 ° of 1420 by focusing through a refractive, and change the shape of the antenna beam into -θ ₁ ~ θ _1, the gain of the antenna range of an angle (-θ ₁ ~ θ ₁ Can only have a threshold.

FIG. 15 illustrates the process of FIG. 14 in which the beam shape of the antenna is changed by refraction of the rays radiated from the antenna by the antenna RF lens 1400, and as a result, shows the changed beam pattern of the antenna. have. In this case, the gain characteristic always having a value of 0 for large direction has a constant threshold value, smaller than the direction or θ ₁ -θ _1, regardless of the direction in the -θ ₁ ~ θ ₁ as shown in 1510 of the antenna If you draw 1510 in polar coordinates, it looks like 1520. Accordingly, the antenna RF lens 1400 may prevent interference from an unwanted direction in the antenna.

The specific angle range (angle range covered by the beam of the antenna beam pattern) of -θ ₁ to θ ₁ in which the beam shape of the antenna described above is changed is a transmission / reception antenna to which the structure and operation of the above-described antenna RF lens 1400 are applied. The antenna array included in the system (transceive antenna system described with reference to FIG. 13) may affect constraints that determine the angular range (first angular range) in which the beam is to be formed.

Accordingly, the antenna RF lens 1400 is provided to control the lens focal length (implemented to have a zooming function) to adaptively adjust a specific angular range, and a transmission / reception antenna system to which the antenna RF lens 1400 is applied. Can adaptively adjust the first angle range in which the beam of the antenna array is formed according to the constraint by the adjusted beam shape of each of the plurality of antennas.

FIG. 16 is a view for explaining an embodiment of an array RF lens included in the transmit / receive antenna system shown in FIG. 13.

Referring to FIG. 16, the array RF lens 1600 included in the transmission / reception antenna system described above with reference to FIG. 13 has a first angle range of −φ ₁ to φ _{1 in} a situation where φ ₁ <θ ₁ <φ ₂ . By refracting the directing angle of the beam 1610 of the antenna array having the directing angle range, the beam angle of the beam array 1620 is a second angle range of -φ ₂ to φ ₂ wider than -φ ₁ to φ _1. It can be to have. Thus, the arrays oriented angle of the beam 1610 of the previous antenna array to go through the RF lens 1600, but included in the -θ ₁ ~ θ _1, the beam of the antenna array after passed through the RF Lens Arrays (1600) ( The directivity angle of 1620 may cover a wider angle range than −θ ₁ to θ ₁ , but may prevent a problem of deterioration of the directivity performance generated in the conventional beamforming.

The operation of the array RF lens 1600 may be performed by the array RF lens 1600 controlling the lens focal length to be short. That is, the array RF lens 1600 is provided to control the lens focal length (implemented to have a zooming function) to adaptively adjust the second angle range in which the first angle range is changed.

17 is a view for explaining another embodiment of an array RF lens included in the transmit / receive antenna system shown in FIG. 13.

Referring to FIG. 17, the array RF lens 1700 included in the transmission / reception antenna system described above with reference to FIG. 13 may have a first angle range of −φ ₁ to φ _{1 in} a situation where φ ₁ <θ ₁ <φ ₂ . By refracting the directing angle of the beam 1710 of the antenna array having the directing angle range, the directing angle range of -φ ₂ to φ ₂ , in which the beam 1720 of the antenna array is a second angle range narrower than -φ ₁ to φ ₁ It can be to have. Thus, as the beam 1720 of the antenna array after passing through the array RF lens 1700 becomes sharper than the beam 1710 of the antenna array before passing through the array RF lens 1700, higher spatial resolution is achieved. With spatial resolution, more sophisticated beam steering can be enabled. This characteristic can be seen as an increase in cell capacity in mobile communications and as an improved spatial resolution for object recognition in radar systems.

The operation of the array RF lens 1700 may be performed by controlling the lens focal length of the array RF lens 1700. That is, the array RF lens 1700 is provided to control the lens focal length (implemented to have a zooming function) to adaptively adjust the second angle range in which the first angle range is changed.

18 is a flowchart illustrating a beamforming method in a transmit / receive antenna system according to an embodiment.

Referring to FIG. 18, the beamforming method according to an embodiment may be mainly performed by the transmit / receive antenna system (in particular, an RF lens apparatus) described above with reference to FIGS. 13 to 17.

In operation S1810, each of the antenna RF lenses included in the RF lens device may change a beam shape of each of the plurality of antennas.

Specifically, in step S1810, each of the RF lenses for the antenna may refract the rays forming the beams of each of the plurality of antennas, thereby changing the beam shape of each of the plurality of antennas within a specific angle range.

In addition, each of the antenna RF lens is provided to control the lens focal length can be adaptively adjusted to a specific angle range.

In this case, changing the beam shape of each of the plurality of antennas within a specific angle range may mean refracting the rays of each of the plurality of antennas such that the gain of each of the plurality of antennas has a threshold only within the specific angle range. Can be.

Subsequently, in step S1820, the antenna array including the RF lens device forms a beam within the first angle range. In particular, the antenna array may determine a first angular range that satisfies the constraint due to the changed beam shape of each of the plurality of antennas, and then form a beam within the determined first angular range. For example, a plurality of antennas, each beam shape has been changed by -θ ₁ ~ θ ₁ in the step (S1810), the antenna array at step (S1820) is -φ ₁ that satisfy the constraints of the φ ₁ <θ ₁ - determining a first angle φ ₁ to the range, and it is possible to form a beam in a first angle range of ₁ - φ ₁ -φ.

Then, the array RF lens included in the RF lens device in step S1830, the antenna so that the directional angle range of the beam of the antenna array is changed from the first angle range to a second angle range that is wider or narrower than the first angle range. Refract the directing angle of the beams of the array.

In other words, in step S1830, the array RF lens may change the directing angle of the beam of the antenna array from the first angle range to the second angle range.

Although the beamforming method has been described as including three steps S1810 and S1830, the beamforming method is not limited thereto or may further include other steps.

Although the embodiments have been described by the limited embodiments and the drawings as described above, various modifications and variations are possible to those skilled in the art from the above description. For example, the described techniques may be performed in a different order than the described method, and / or components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different form than the described method, or other components. Or even if replaced or substituted by equivalents, an appropriate result can be achieved.

Therefore, other implementations, other embodiments, and equivalents to the claims are within the scope of the claims that follow.

Claims (1)

In the transceiver antenna system for improving the antenna directivity,
An antenna array composed of a plurality of antennas;
Antenna RF lenses provided on the antenna array, wherein the antenna RF lenses are disposed to correspond to the plurality of antennas, respectively; And
Array RF lens provided on the antenna RF lenses
Transmitting and receiving antenna system comprising a.

Images