KR20210148056A - 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 for improving directivity of an antenna array, a transmitting-receiving antenna system including the same, and a beam forming method performed in the transmitting-receiving antenna system. According to an embodiment of the present invention, the transmitting-receiving antenna system comprises: an antenna array consisting of a plurality of antennas; RF lenses for an antenna provided at an upper part of the antenna array and disposed to correspond to the plurality of antennas respectively; and an RF lens for an array provided at an upper part of the RF lenses for the antenna.

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 specifically, to a transmit/receive antenna system that improves directivity of an antenna array by using an RF lens.

This achievement is based on the Ministry of Science, ICT and Future Planning’s public technology-based market-linked start-up search support project (task number: 1711047948, department name: Ministry of Science, ICT and Future Planning: Ministry of Science, ICT and Future Planning: National Research Foundation, Research project name: Public technology-based market-linked start-up search support project , Research project title: High Performance Short Range Radar for Self-Driving Cars, Contribution rate: 1/1, Host institution: Korea Advanced Institute of Science and Technology, Research period: 2016.09.05 ~ 2017.02.28) It is a patent obtained through

A wireless communication system or radar includes a transmission/reception antenna system for transmitting and receiving a wireless signal. A modern transmit/receive antenna system often uses multiple antennas, and in the case of a multi-antenna-based transmit/receive antenna system, using a multiple-input multiple-output (MIMO) technology or a beamforming technology increases data transmission speed. In addition, it has many advantages such as reducing interference between devices, increasing a signal transmission distance, or increasing a signal-to-noise ratio.

Here, the transmit beamforming technology adjusts the phase and amplitude of signals transmitted from each of multiple antennas so that signals transmitted from different antennas constructively interfere or cancel each other according to directions. It is a technology that allows a transmission signal to be transmitted with directionality while causing destructive interference. The reception beamforming technology adjusts and combines the phase and amplitude of signals received from each of multiple antennas to increase reception sensitivity in a specific direction to receive directivity. The principle is the same as that of transmit beamforming. Transmission or reception beamforming is a technique that can be applied when signals transmitted or received by each antenna are stochastically highly correlated.

On the other hand, unlike beamforming technology, MIMO technology is a technology used when signals transmitted or received by each antenna are not ideally correlated with each other (stochastically uncorrelated). MIMO technology uses multiple antennas at the same time It makes it possible to obtain robust performance even in the case of changes in the channel environment by transmitting and receiving data streams or by using a diversity gain. MIMO technology tends to degrade as the correlation between the signals transmitted or received by each antenna increases.

Recently, in the field of wireless communication, research on the above-described MIMO and beamforming technology is being actively conducted as methods for efficient use of frequency resources along with exhaustion of frequency resources. These MIMO and beamforming technologies are expected to become core technologies for 5G (5G) mobile communication. In addition, as interest in advanced driver assistance systems (ADAS) and self-driving cars increases, the competition to develop better automotive radars is intensifying. Antennas are basically being introduced.

Accordingly, the following embodiments propose a technique capable of solving problems of MIMO and beamforming and improving performance in a transmit/receive antenna system having multiple antennas.

In one embodiment, in a transmit/receive antenna system having multiple antennas, a technology that can cover a wide angle with a single antenna array and solve the directivity performance degradation of the antenna array caused by the nonlinearity between the spatial frequency and the incident angle and the directivity of the antenna provides

Specifically, one embodiment transmits/receives using an RF lens device including RF lenses for antennas disposed to correspond to a plurality of antennas constituting the antenna array, respectively, and RF lenses for an array provided on top of the RF lenses for antennas An antenna system and a beamforming method are provided.

According to an embodiment, a transmit/receive antenna system for improving antenna directivity includes: an antenna array including a plurality of antennas; RF lenses for an antenna provided on an upper portion of the antenna array, wherein the RF lenses for the antenna are disposed to correspond to the plurality of antennas, respectively; and an RF lens for an array provided on top of the RF lenses for the antenna.

According to one aspect, each of the RF lenses for the antenna changes a beam shape of each of the plurality of antennas, the antenna array forms a beam within a first angular range, and the RF lens for the array includes: The directing angle of the beam of the antenna array may be refracted so that the directing angle range of the beam of the antenna array is changed from the first angle range to a second angle range wider or narrower than the first angle range.

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

According to another aspect, each of the RF lenses for the antenna refracts the rays forming the beam of each of the plurality of antennas to change the beam shape of each of the plurality of antennas within a specific angular range. can

According to another aspect, each of the RF lenses for the antenna is provided to control the focal length of the lens, so that the specific angle range can be adaptively adjusted.

According to another aspect, each of the RF lenses for the antenna may refract the rays of each of the plurality of antennas so that the gain of each of the plurality of antennas has a threshold value only within the specific angular range.

According to another aspect, the RF lenses for the antenna may be arranged to correspond to each of the plurality of antennas one-to-one.

According to another aspect, the RF lens for the array is provided to control the focal length of the lens, so that the second angle range can be adaptively adjusted.

According to an embodiment, the RF lens device provided on the antenna array including a plurality of antennas to improve directivity of the antenna array is provided on the antenna array and includes beams of each of the plurality of antennas. RF lenses for an antenna that change shape, wherein the RF lenses for the antenna are respectively disposed to correspond to the plurality of antennas; and provided above the RF lenses for the antenna, the antenna array refracts the directing angle of the beam formed within the first angular range to obtain the first directing angle range of the beam of the antenna array from the first angular range and an RF lens for the array that changes to a second angular range that is wider or narrower than the angular range.

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

According to an embodiment, an antenna array consisting of a plurality of antennas; Transmission and reception including RF lenses for an antenna provided on the upper portion of the antenna array, wherein the RF lenses for the antenna are disposed to correspond to the plurality of antennas, respectively, and an RF lens for an array provided on the upper portion of the RF lenses for the antenna A beamforming method performed in an antenna system includes changing, in each of the RF lenses for the antenna, a beam shape of each of the plurality of antennas; forming, by the antenna array, a beam within a first angular range; and in the RF lens for the array, refracting the directing angle of the beam of the antenna array such that the directing angular range of the beam of the antenna array is changed from the first angular range to a second angular range wider or narrower than the first angular range including the step of making

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

According to another aspect, the step of changing the beam shape of each of the plurality of antennas refracts rays forming a beam of each of the plurality of antennas, thereby changing the beam shape of each of the plurality of antennas. It may include changing within a specific angular range.

According to another aspect, the changing of the beam shape of each of the plurality of antennas within a specific angular range may include the plurality of antennas so that the gain of each of the plurality of antennas has a threshold value only within the specific angular range. It may be a step of refracting each ray.

In one embodiment, in a transmit/receive antenna system having multiple antennas, a technology that can cover a wide angle with a single antenna array and solve the directivity performance degradation of the antenna array caused by the nonlinearity between the spatial frequency and the incident angle and the directivity of the antenna can provide

Specifically, one embodiment transmits/receives using an RF lens device including RF lenses for antennas disposed to correspond to a plurality of antennas constituting the antenna array, respectively, and RF lenses for an array provided on top of the RF lenses for antennas An antenna system and a beamforming method may be provided.

1 is a diagram illustrating a conventional transmit/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 transmission/reception 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 oriented in the 0° direction in the ideal transmission/reception antenna system of the conventional structure.
5 is a view for explaining the gain of the antenna array according to an angle when the antenna array is oriented in a 30° direction in an ideal transmission/reception antenna system of a conventional structure.
6 is a view for explaining the gain of the antenna array according to an angle when the antenna array is oriented in a 60° direction in an ideal transmission/reception antenna system of a conventional structure.
7 is a view for explaining the gain of the antenna array according to an angle when the antenna array is oriented in a 90° direction in an ideal transmission/reception antenna system of a conventional structure.
8 is a diagram for explaining gain characteristics and directivity according to an angle of an antenna in a realistic transmission/reception antenna system having a conventional structure.
9 is a view for explaining the gain of the antenna array according to an angle when the antenna array is oriented in the 0° direction in a realistic transmission/reception antenna system having a conventional structure.
FIG. 10 is a view for explaining the gain of the antenna array according to an angle when the antenna array is oriented in a 30° direction in a realistic transmit/receive antenna system having a conventional structure.
11 is a view for explaining a gain of an antenna array according to an angle when the antenna array is oriented in a 60° direction in a realistic transmission/reception antenna system having a conventional structure.
12 is a view for explaining the gain of the antenna array according to an angle when the antenna array is oriented in a 90° direction in a realistic transmit/receive antenna system having a conventional structure.
13 is a diagram illustrating a transmission/reception antenna system according to an embodiment.
14 is a view for explaining an RF lens for an antenna included in the transmission/reception antenna system shown in FIG. 13 .
15 is a diagram for explaining a gain characteristic and directivity according to an angle of an antenna in a transmission/reception antenna system according to an embodiment.
FIG. 16 is a diagram for explaining an embodiment of an RF lens for an array included in the transmission/reception antenna system shown in FIG. 13 .
FIG. 17 is a view for explaining another embodiment of an RF lens for an array 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, 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 examples. Also, like reference numerals in each figure denote like members.

In addition, the terms (Terminology) used in this specification are terms used to properly express a preferred embodiment of the present invention, which may vary depending on the intention of a viewer or operator or a custom in the field to which the present invention belongs. Accordingly, definitions of these terms should be made based on the content throughout this specification.

Embodiments described herein relate to a transmit/receive antenna system having multiple antennas, and are disposed to correspond to a plurality of antennas constituting an antenna array, respectively, and RF lenses for antennas to change a beam shape of each of the plurality of antennas And it is provided on the upper portion of the RF lenses for the antenna to refract the directing angle of the beam formed by the antenna array within the first angular range, so that the directing angle range of the beam of the antenna array is wider or narrower than the first angular range from the first angular range By configuring the transmit/receive antenna system to include the RF lens for the array that changes to the second angular range, the nonlinearity between the spatial frequency and the incident angle and the directivity degradation of the antenna array caused by the directivity of the antenna are solved, and a single antenna array is used. To cover a wide angle.

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

1 is a diagram illustrating a conventional transmit/receive antenna system.

Referring to FIG. 1 , a 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 interval between 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, but , but not limited thereto. Hereinafter, an ideal transmission/reception antenna system and a realistic transmission/reception antenna system, which will be described below with reference to FIGS. 2 to 12, are assumed to have the same structure as in FIG.

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 transmission/reception 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 the angle of incidence. In this way, the rate of change of the phase according to space is referred to as 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 .

3 is a diagram for explaining gain characteristics and directivity according to the angle of an antenna in an ideal transmission/reception antenna system of a conventional structure, and FIG. It is a view for explaining the gain of the antenna array according to the angle of , and FIG. 5 is a view for explaining the gain of the antenna array according to the angle when the antenna array is oriented in the 30° direction in an ideal transmission/reception antenna system of a conventional structure 6 is a view for explaining the gain of the antenna array according to an angle when the antenna array is oriented in a 60° direction in an ideal transmission/reception antenna system of a conventional structure, and FIG. 7 is an ideal transmission/reception antenna system of a conventional structure , is a diagram for explaining the gain of the antenna array according to an angle when the antenna array is oriented in a 90° direction.

Referring to FIG. 3 , when the gain according to the angle of the antenna in the conventional transmit/receive antenna system, ie, the beam pattern, is expressed in a cartesian coordinate system, it is always 1 for the -90° to 90° direction range, such as 310. If it has the characteristic of phosphorus, if 310 is graphed in the polar coordinate system, it appears as 320. In this ideal case of the transmit/receive antenna system (the transmit/receive antenna system of the conventional structure), when the linear antenna array is steered in a specific direction, the gain of the antenna array according to the angle, that is, the beam pattern is shown as shown in FIGS. 4 to 7 .

Hereinafter, the beam pattern refers to a radiation pattern of an antenna or a radiation pattern of an antenna array comprising multiple antennas, and directivity refers to a degree or property of a beam pattern of an antenna or antenna array being concentrated in a specific direction. For example, directivity that can be expressed by a beam shape (beam shape) can be used as an expression of high, large, low, and the like. In this case, when the directivity is high, the beam shape is narrow, and when the directivity is low, the beam shape has a narrow relationship. Hereinafter, the beam shape is a concept including the width of the beam, and "changing the beam shape" removes energy radiation outside a certain angular range so that the width of the beam is located within a certain angular range, It means keeping the antenna gain within the angular range.

In addition, steering means that the directional antenna or the directional antenna array is directed in a desired direction.

Referring to FIG. 4 , in an ideal transmission/reception antenna system, when the antenna array is oriented in the 0° direction, the gain of the antenna array according to the angle, ie, the beam pattern, is drawn as a graph of a linear scale in a Cartesian coordinate system. When the beam pattern of 410 is drawn as a graph of a linear scale in the polar coordinate system, it appears as 420.

In this case, the beam pattern of the antenna array may be sharply formed as the number of antennas constituting the antenna array increases. However, even if the number of antennas is the same, the beam pattern has the highest directivity when the array is steered in the 0° direction, and the directivity of the beam pattern decreases as the directivity angle increases in the 90° direction or -90° direction. have This problem may occur because the relationship between the incident angle and the spatial frequency of the signal is a non-linear 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. In this case, the directing angle has the same meaning as the direction of the beam.

Referring to FIG. 5 , in an ideal transmission/reception antenna system, when the antenna array is oriented in the 30° direction, if the gain of the antenna array according to the angle, that is, the beam pattern, is drawn as a graph of a linear scale in a Cartesian coordinate system, it appears as 510, 510 If the beam pattern of is drawn as a graph of a linear scale in the polar coordinate system, it appears as 520.

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

Referring to FIG. 6, when the antenna array is oriented in the 60° direction in an ideal transmission/reception antenna system, the gain of the antenna array according to the angle, that is, the beam pattern, is drawn as a graph of a linear scale in a Cartesian coordinate system. If the beam pattern of 610 is drawn as a graph of a linear scale in the polar coordinate system, it appears as 620.

At this time, the beam pattern when the antenna array is oriented in the 60° direction has remarkably lowered directivity compared to the beam pattern described above with reference to FIG. 4 and the beam pattern described above with reference to FIG. 5 , and the -90° direction Since the gain of the antenna array with respect to R is 4.5 or more, there is a problem in that interference by a signal from an undesired direction of -90° may be greatly generated.

Referring to FIG. 7 , in an ideal transmission/reception antenna system, when the antenna array is oriented in the 90° direction, the gain of the antenna array according to the angle, i.e., the beam pattern, is drawn as a graph of a linear scale in the Cartesian coordinate system, as shown in 710, 710 When the beam pattern of is drawn as a graph of a linear scale in the polar coordinate system, it appears as 720.

Here, it is confirmed that the directivity of the beam pattern when the antenna array is directed in the 90° direction is greatly reduced, 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.

As described above, an ideal transmission/reception antenna system has been described in which the gain according to the orientation angle of the antenna is always 1 in the -90° to 90° direction range. However, in an actual wireless transmission/reception environment, the antenna itself has directivity Accordingly, the gain and directivity according to the angle of the antenna appear different from those of FIG. 3 . A detailed description thereof will be described with reference to FIG. 8 .

8 is a diagram for explaining gain characteristics and directivity according to an angle of an antenna in a realistic transmission/reception antenna system of a conventional structure, and FIG. It is a diagram for explaining the gain of the antenna array according to the angle of , and FIG. 11 is a view for explaining the gain of the antenna array according to an angle when the antenna array is oriented in a 60° direction in a realistic transmit/receive antenna system of a conventional structure, and FIG. 12 is a realistic transmit/receive antenna system of a conventional structure , is a diagram for explaining the gain of the antenna array according to an angle when the antenna array is oriented in a 90° direction.

Referring to FIG. 8 , in the conventional transmit/receive antenna system, the gain according to the orientation angle of the antenna, that is, when the beam pattern is expressed in a Cartesian coordinate system, is 1 for the 0° direction as shown in 810, and the -90° direction or the 90° direction. If it has a characteristic that gradually decreases as the angle moves to , 810 is shown as 820 when graphed in the polar coordinate system. When the linear antenna array is oriented in a specific direction in a transmission/reception antenna system (transmission/reception antenna system of a conventional structure) in this realistic case, the gain of the antenna array according to an angle, ie, a beam pattern, is shown as shown in FIGS. 9 to 12 .

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

At this time, it is confirmed that the beam pattern of the antenna array such as 920 has 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 transmission/reception antenna system, when the antenna array is oriented in the 30° direction, when the gain of the antenna array according to the angle, that is, the beam pattern, is drawn as a graph of a linear scale in a Cartesian coordinate system, it appears as 1010, 1010 When the beam pattern of is drawn as a graph of a linear scale in the polar coordinate system, it appears as 1020.

Here, it is confirmed that the gain of the antenna array when oriented in the 30° direction tends to shift slightly to the left than the gain of the antenna array described above with reference to FIG. 5 . That is, when there is directivity of the antenna itself as in a realistic transmission/reception antenna system, if the directivity angle of the antenna itself and the directivity angle of the antenna array do not match, it may have a bad influence on adjusting the directivity of the antenna array.

Referring to FIG. 11, when the antenna array is oriented in the 60° direction in a realistic transmit/receive antenna system, the gain of the antenna array according to the angle, that is, the beam pattern, is drawn as a graph of a linear scale in a Cartesian coordinate system. If the beam pattern of is drawn as a graph of a linear scale in the polar coordinate system, it appears as 1120.

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

Referring to FIG. 12, when the antenna array is oriented in the 90° direction in a realistic transmission/reception antenna system, the gain of the antenna array according to the angle, that is, the beam pattern, is drawn as a graph of a linear scale in the Cartesian coordinate system, as shown in 1210, 1210 If the beam pattern of is drawn as a graph of a linear scale in the polar coordinate system, it appears as 1220.

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

However, in mobile communication, sector antennas often have to cover 120°, and even in the case of short-range radars for autonomous vehicles, which are being actively researched recently, about 120° must be covered. However, with the conventional transmit/receive antenna system, it is impossible to cover 120° with a single antenna array as described with reference to FIGS. 8 to 12 .

Accordingly, the following embodiments propose a transmission/reception antenna system capable of solving a directional performance degradation of an antenna array and covering a wide angle with a single antenna array by including an RF lens device.

13 is a diagram illustrating a transmission/reception antenna system according to an embodiment.

Referring to FIG. 13 , the transmit/receive 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 , 1316 . ) is included. Hereinafter, it is assumed that an interval between 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, although the antenna array 1310 is described as a one-dimensional linear array as shown in the drawing, it is not limited thereto and a plurality of antennas 1311 , 1312 , 1313 , 1314 , 1315 , 1316 are two-dimensionally arranged. It may be a dimensional array. Even in this case, the RF lens device 1320 to be described later may be equally applied.

RF lens device 1320 is provided on the upper portion of the antenna array 1310, the plurality of antennas (1311, 1312, 1313, 1314, 1315, 1316) for antenna RF lenses 1321, 1322, 1323 , 1324 , 1325 , 1326 , and an RF lens 1330 for an array provided on the antenna RF lenses 1321 , 1322 , 1323 , 1324 , 1325 , 1326 .

Here, the antenna RF lenses 1321 , 1322 , 1323 , 1324 , 1325 , and 1326 may be disposed to correspond to each of 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 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 , 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 RF lens 1323 is a ₂ the beam shape of the antenna (1313), a ₃ antenna RF lens 1324 is a ₃ the beam shape of the antenna (1314), a ₄ antenna RF lens 1325 for the 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 a quantity representing the beam shape (width) of the antenna beam pattern changed by the RF lens for antenna 1321, 1322, 1323, 1324, 1325, 1326, and θ ₁ is related to the changed antenna beam pattern means parameters. A detailed description thereof will be described with reference to FIG. 14 .

At this time, each of the antenna RF lenses 1321, 1322, 1323, 1324, 1325, 1326 changes the beam shape of each of the plurality of antennas 1311, 1312, 1313, 1314, 1315, 1316, This may mean changing the directivity of each of the antennas 1311 , 1312 , 1313 , 1314 , 1315 , and 1316 (directivity of the antenna itself). Accordingly, each of the antenna RF lenses 1321 , 1322 , 1323 , 1324 , 1325 , and 1326 may be designed in consideration of the directivity of each of the plurality of antennas 1311 , 1312 , 1313 , 1314 , 1315 , 1316 . (For example, an aspherical lens or the like may be used, and more than one lens element may be used).

The antenna array 1310 forms a beam within a first angular range. At this time, the antenna array 1310 is a plurality of antennas (1311, 1312, 1313, 1314, 1315, 1316) by each of the RF lenses 1321, 1322, 1323, 1324, 1325, 1326 for the antenna, each of the modified By determining the first angular range that satisfies the constraint by the beam shape, the beam may be formed 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 ₁ may be located (φ ₁ <θ _{1 ), and a value of -φ 1} to φ _{1 that} is the first angle range may be determined. As a more specific example, the antenna array 1310 _{determines the parameter φ 1} of the first angular range forming the beam, the modified beam of each of the plurality of antennas 1311 , 1312 , 1313 , 1314 , 1315 , 1316 . As a constraint by the shape parameter θ _{1 , an expression of φ 1} =θ ₁ -(beam width of the antenna array 1310)/2 may be used. Hereinafter, the first angle range -φ ₁ to φ ₁ means a value indicating the range of the beam directing angle of the antenna array 1310 .

The RF lens 1330 for the array changes the beam direction of the antenna array 1310 from the first angle range to the second angle range wider or narrower than the first angle range. to refract In other words, the RF lens 1330 for the array may change the directional angle range of the beam of the antenna array 1310 from the first angle range to the second angle range.

For example, the RF lens 1330 for the array refracts the directing angle of the beam of the antenna array 1310 having a first angular range of _{-φ 1} to φ _{1 , so that the beam of the antenna array 1310 is -φ 2} It can be made to have a second angular range of ~φ _{2 .} Accordingly, the RF lens 1330 for the array may narrow or widen the coverage of the antenna array 1310 by refracting the beam direction of the antenna array 1310 . Hereinafter, the second angular range of -φ ₂ to φ ₂ means a value representing a range of a directing angle changed by refraction after the beam of the antenna array 1310 passes through the RF lens 1330 for the array. A 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 includes the plurality of antennas 1311, 1312, 1313, 1314, 1315, 1316, and RF lenses 1321, 1322, 1323 for antennas that change the beam shape of each. , 1324 , 1325 , 1326 , and the antenna array 1310 refract the directing angle of the beam formed within the first angular range, so that the directing angle range of the beam of the antenna array 1310 is changed from the first angular range to the second angular range By including the RF lens 1330 for the array that changes to , it is possible to solve the directivity performance degradation of the antenna array caused by the nonlinearity between the spatial frequency and the incident angle and the directivity of the antenna, and to cover a wide angle with a single antenna array. .

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

Referring to FIG. 14 , the RF lens 1400 for an antenna allows the directivity of the antenna to have the same characteristics as in FIG. 15 in an actual wireless transmission/reception environment. 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 reduces the antenna gain by dispersing the rays 1410 in a direction close to 0° among the rays forming the beam of the antenna through refraction, and forms 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 value.

15 is another method for explaining the process of FIG. 14 in which the beam shape of the antenna is changed while rays emitted from the antenna are refracted by the RF lens 1400 for the antenna, 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 1510 is drawn in the polar coordinate system, it appears as 1520. Accordingly, the RF lens 1400 for the antenna can prevent interference from an unwanted direction in the antenna.

_{A specific angular range of -θ 1} to θ ₁ in which the beam shape of the antenna described above is changed (the angular range covered by the beam of the beam pattern of the antenna) is a transmit/receive antenna to which the structure and operation of the RF lens 1400 for the above-described antenna is applied An antenna array included in the system (the transmission/reception antenna system described with reference to FIG. 13 ) may affect a constraint for determining an angular range (a first angular range) in which a beam is to be formed.

Accordingly, the RF lens 1400 for the antenna is provided to control the focal length of the lens (implemented to have a zooming function) so that a specific angular range can be adaptively adjusted, and the RF lens 1400 for the antenna is applied to the transmit/receive antenna system may adaptively adjust the first angular range in which the beam of the antenna array is formed according to a constraint by the adjusted beam shape of each of the plurality of antennas.

FIG. 16 is a diagram for explaining an embodiment of an RF lens for an array included in the transmission/reception antenna system shown in FIG. 13 .

Referring to FIG. 16 , the RF lens 1600 for an array included in the transmit/receive antenna system described above in FIG. 13 is 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 1620 of the antenna array has a directing angle range _{of -φ 2} to φ ₂ , which is a second angular range wider than _{-φ 1} to φ _{1 .} can be made 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) ( 1620), _{while covering a wider angular range than -θ 1} to θ ₁ , it is possible to prevent the problem of degradation of the directing performance occurring in the conventional beamforming from occurring.

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

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

Referring to FIG. 17 , the array RF lens 1700 included in the transmit/receive antenna system described above in FIG. 13 is 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 beam 1720 of the antenna array is in the directing angle range _{of -φ 2} to φ ₂ , which is a second angular range narrower than _{-φ 1} to φ _{1 .} can be made to have Therefore, as the beam 1720 of the antenna array after passing through the RF lens 1700 for the array becomes sharper than the beam 1710 of the antenna array before passing through the RF lens 1700 for the array, higher spatial resolution With spatial resolution, more sophisticated beam steering may be possible. This characteristic may appear as an increase in cell capacity in mobile communication, and may appear as an improved spatial resolution for target recognition in a radar system.

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

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

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

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

Specifically, each of the RF lenses for the antenna in step S1810 may refract rays forming the beam of each of the plurality of antennas to change the beam shape of each of the plurality of antennas within a specific angular range.

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

At this time, changing the beam shape of each of the plurality of antennas within a specific angular range means refracting the rays of each of the plurality of antennas so that the gain of each of the plurality of antennas has a threshold value only within a specific angular range. can

Next, in step S1820, the antenna array provided with the RF lens device forms a beam within the first angle range. In particular, the antenna array may form a beam within the determined first angular range after determining a first angular range that satisfies the constraint by the changed beam shape of each of the plurality of antennas. 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, in step S1830, the RF lens for the array included in the RF lens device is configured such that the beam direction angle range of the antenna array is changed from the first angle range to a second angle range wider or narrower than the first angle range. Deflects the direction of the beam of the array.

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

As described above, the beamforming method has been described as including three steps ( S1810 and S1830 ), but is not limited thereto, and may further include other steps.

As described above, although the embodiments have been described with reference to the limited embodiments and drawings, various modifications and variations are possible from the above description by those skilled in the art. For example, the described techniques are performed in an order different from the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (1)

A transmit/receive antenna system for improving antenna directivity, comprising:
An antenna array consisting of a plurality of antennas;
RF lenses for an antenna provided on an upper portion of the antenna array, wherein the RF lenses for the antenna are disposed to correspond to the plurality of antennas, respectively; and
The RF lens for the array provided on the upper part of the RF lenses for the antenna
A transmit/receive antenna system comprising a.

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