KR20200055646A - Mimo antenna array with wide field of view - Google Patents

Abstract

Disclosed is a MIMO antenna array having a wide field of view. According to one embodiment, the antenna array comprises: a first group including first antenna elements arranged to form a first concave center radiation pattern; and a second group including second antenna elements arranged to form a second convex center radiation pattern. The first antenna elements and the second antenna elements include active elements and dummy elements, respectively.

Description

MIMO ANTENNA ARRAY WITH WIDE FIELD OF VIEW

The embodiments below relate to an MIMO antenna array with a wide field of view.

A multiple input multiple output (MIMO) radar system consists of multiple receive and multiple transmit antennas. In addition, each transmit antenna in the system emits arbitrary waveforms independently of the other transmit antennas. Each receiving antenna can receive these signals. The field of the N transmit antennas and the field of the M receive antennas can mathematically result in the size of the virtual field of N · M antenna elements and the virtual aperture of the same increased MIMO array. MIMO radar systems can be used to improve spatial resolution and greatly improve immunity to interference. By improving the signal-to-noise ratio, the probability of target detection can also be increased.

Currently, radar systems are widely used in various industries such as military equipment, communications, and vehicles. For example, 3D / 4D radar systems are a key component of automotive navigation. The main feature of the 3D radar is to detect the direction of an object in one of azimuth (horizontal) and altitude (vertical) planes, and determine the object's speed and distance to the object. On the other hand, the 4D radar can track the direction of the object in both azimuth and altitude planes and determine the speed of the object and the distance to the object.

According to one embodiment, the antenna array includes a first group including first antenna elements arranged to form a first concave radiation pattern; And a second group including second antenna elements arranged to form a second convex center radiation pattern.

는 능동 소자에 의해 방사되는 전자기 파의 파장이다.The first antenna elements and the second antenna elements may include active elements and dummy elements, respectively. The active elements and the dummy elements may have the same form factor. A distance between phase centers of elements adjacent to each other among the elements including the active elements and the dummy elements is *? * / 2,

Is the wavelength of the electromagnetic wave emitted by the active element.

The first antenna elements may include first active elements and first dummy elements, and at least one of the first dummy elements may be disposed between the first active elements. The second antenna elements may include second active elements and second dummy elements, and at least two of the second active elements may be disposed adjacent to each other.

The active elements and dummy elements of the first antenna elements may be arranged according to at least one of the following cases. 1) a first case in which one dummy element is disposed between an active element and a next active element on one side, and a first case in which one dummy element is placed between an active element and the next active element on the other side, 2) one dummy element on one side A second case in which a dummy element is disposed between the active element and the next active element, and two dummy elements on the other side are disposed between the active element and the next active element, 3) two dummy elements on one side and the next active element A third case in which two dummy elements are arranged between the active element and the next active element on the other side, 4) one dummy element is arranged between the active element and the next active element on one side, A fourth case in which a plurality of dummy elements are arranged on the other side, and 5) A fifth case in which two dummy elements on one side are disposed between the active element and the next active element, and a plurality of dummy elements on the other side.

The first radiation pattern and the second radiation pattern are combined with each other, so that the field of view of the array antenna can be increased. When the first group includes transmitting elements as active elements, the second group may include receiving elements as active elements, and when the first group includes receiving elements as active elements, the second group Can include transmitting elements as active elements.

According to another embodiment, the array antenna includes an active element that emits electromagnetic waves; And at least one dummy element having the same form factor as the active element and disposed on one side or both sides of the active element.

/2이고,

는 상기 전자기 파의 파장이다.The distance between the phase centers of elements adjacent to each other among the elements including the active element and the at least one dummy element is

/ 2,

Is the wavelength of the electromagnetic wave.

The at least one dummy element may include at least one inverse dummy element and at least one in-phase dummy element, and the at least one inverse dummy element re-emits some of the energy of the electromagnetic wave based on the electromagnetic wave. The electromagnetic wave can be suppressed, and the at least one in-phase dummy element can amplify the electromagnetic wave by reradiating another part of the energy of the electromagnetic wave based on the electromagnetic wave.

When the at least one dummy element includes a plurality of dummy elements, a first dummy element closest to the active element among the plurality of dummy elements may correspond to the inverse dummy element, and the plurality of dummy elements The second dummy element close to the active element after the first dummy element may correspond to the in-phase dummy element.

The maximum radiation pattern of the active element can be suppressed by at least one dummy element, and the field of view of the array antenna can be increased. The active element may correspond to a transmitting element or a receiving element.

1 shows the principle of operation of a portion of an antenna array including a radiating antenna element and a plurality of dummy elements according to an embodiment.
2 shows the effect of adding a dummy element to a radiating element.
3 shows simulation results of radiation patterns of radiation elements and dummy elements.
4 shows an embodiment of various configurations of antenna elements in an antenna array.
5 shows the principle of forming the final radiation pattern of the MIMO array.
6 shows examples of arrangement of elements in group # 1 of elements of the MIMO array.
7 shows examples of arrangement of elements in group # 2 of elements of the MIMO array.
8 shows an exemplary configuration of a portion of a MIMO array comprising elements of Group # 1 and Group # 2.
9 shows examples of the radiation pattern for the elements of group # 1.
10 shows examples of radiation patterns for devices in group # 2.
11 shows the formation of the resulting radiation pattern of the elements of Group # 1 and Group # 2.
12 shows a possible implementation of a MIMO array (4Tx X 8Rx) according to an embodiment.
13 shows radiation patterns of MIMO arrays according to embodiments in different frequency bands.

The specific structures or functions disclosed below are merely exemplified for the purpose of describing the technical concepts, and may be implemented in various other forms unlike the disclosure below, and do not limit the embodiments of the present specification.

Terms such as first or second may be used to describe various components, but these terms should be understood only for the purpose of distinguishing one component from other components. For example, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the term "include" is intended to designate that a feature, number, step, action, component, part, or combination thereof described is present, one or more other features or numbers, steps, actions, It should be understood that the existence or addition possibilities of components, parts or combinations thereof are not excluded in advance.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined herein. Does not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The same reference numerals in each drawing denote the same members.

1 shows the principle of operation of a portion of an antenna array including a radiating antenna element and a plurality of dummy elements according to an embodiment.

The antenna array according to the embodiment may be applied to various applications such as a communication antenna and a vehicle radar. For example, modern automotive radar systems include short-range radar (SRR) for short-range applications with coverage less than 30m-50m, middle-range radar (MRR) for medium-range applications with coverage less than 70m-100m, and 150m- It can operate in a variety of modes, such as long-range radar (LRR) for long-range applications with coverage less than 200m. In order to increase the resolution of SRR and MRR, the latest radar system can apply MIMO to digital beamforming to find the direction to the target.

For applications in automotive radar systems, especially for the SRR mode, a wide field of view (FoV) of the radar system needs to be provided in the azimuth plane. For example, to detect the front (or rear) object of a vehicle, two antenna arrays are currently mounted on the vehicle bumper, each array having a field of view of 90 degrees, thereby providing a total field of view of about 180 degrees. have. Parasitic lobes appear in the radiation pattern of the antenna array having a viewing angle of 90 degrees or more, thereby reducing energy efficiency of the antenna array.

The field of view of the MIMO radar with N transmitters (or receivers) and M receivers (or transmitters) is determined by the angular directions in which the gain of the scanning beam envelope of the MIMO array is reduced by 3dB compared to the maximum. Can be determined. The gain of the scanning beam envelope of the MIMO array is determined as follows.

및

은 모든 N개의 송신기 및 모든 M개의 수신기의 방사 패턴이며, θ는 방위면에서 물체의 각도이다. 사이드 로브(side lobe)는 메인 로브가 아닌 원시야상(far field pattern)의 로브(로컬 최대 값)이다. 격자 로브(grating lobe)는 공간 앨리어싱 효과(spatial aliasing effect)로 인해 진폭이 실질적으로 커지고 위상 배열 안테나의 메인 로브의 레벨에 근접하는 사이드 로브이다.here

And

Is the radiation pattern of all N transmitters and all M receivers, and θ is the angle of the object in the azimuth. The side lobe is not the main lobe but the far field pattern lobe (local maximum). The grating lobe is a side lobe whose amplitude is substantially large due to the spatial aliasing effect and approaches the level of the main lobe of the phased array antenna.

로 나타낼 수 있다. 여기서, λ_max는 대역 내 최소 주파수에 대응하고, λ_min은 대역 내 최대 주파수에 대응한다.According to embodiments, the field of view (FoV) of a radiating antenna element (hereinafter referred to as a “radiating element” and may also be referred to as a primary radiator) is a dummy antenna element (hereinafter referred to as a “pile”) Can be increased by adding several rows of elements (referred to as “dummy elements”). The distance between the phase centers of the devices may be d ~ λ / 2. Where λ is the length of the electromagnetic wave of the bandwidth of the radiating element. In general, λ

Can be represented as Here, λ _max corresponds to the minimum frequency in the band, and λ _min corresponds to the maximum frequency in the band.

The dummy elements can be the same as the radiating elements. For example, dummy elements may have the same form factor as active elements (eg, radiating elements). The use of the same dummy elements as the radiating elements makes it possible to integrate and make the process of manufacturing the elements themselves and the antenna array containing these elements simpler. Alternatively, the dummy element may have a different form factor than the active element.

At least one dummy element may be disposed on one side or both sides of the active element. FoV may be increased by dummy elements reflecting a portion of the electromagnetic energy emitted by the emitting elements. When the distance is d to λ / 2, the phase difference between the dummy elements and the radiating element is nπ. n = 1, 2, 3,… , N, and represents the column index of the dummy element. Therefore, the dummy element of the odd index can act as an antiphase element of the radiating element, and the dummy element of the even index can act as an in-phase element. The former may be referred to as an inverse dummy element, and the latter may be referred to as an in-phase dummy element.

The reversed-phase dummy element may re-radiate a part of the energy of the electromagnetic wave based on the electromagnetic wave emitted by the active element to suppress the electromagnetic wave, and the in-phase dummy element may emit electromagnetic wave based on the electromagnetic wave emitted by the active element. It is possible to amplify the electromagnetic wave by re-radiating another part of the energy. When the d-th element in the n-th column reradiates P _n which is a part of the electromagnetic energy of the radiating element, the amplitude of the waveform in the n-th column of the dummy element may be calculated as A _n = P _n * A ₀ . A ₀ means the amplitude of the signal of the radiating element.

In this embodiment, the interaction of the dummy elements with the radiating (transmitting) antenna element is considered, but the dummy elements may function in a similar manner to the receiving antenna element. The radiating antenna element and the receiving antenna element may be collectively referred to as active elements.

The resulting configuration (radiation element + dummy element) can operate as an array with 2N + 1 elements according to the equation below.

Where Evlaa is the entire field of the virtual linear antenna array, A ₀ is the amplitude of the signal of the radiating element, and N is the number of dummy elements on one side of the radiating element. vlaa stands for Virtual Linear Antenna Array. The total number of dummy elements on both sides is 2 * N. n is an index of the dummy element, and the position (column) of the dummy element can be specified. For the dummy element closest to the active element, n = 1. P _n is part of the electromagnetic energy of the radiating element re-emitted by the n-th dummy element, d is the distance between the phase centers of the elements, k _o is the wave number, and φ is the element's radiation pattern. It is an angular coordinate.

Increasing the number of dummy elements can increase the FoV of the radiation pattern of the radiation element according to the angular coordinates of the radiation pattern, and reduce fluctuations in the gain level of the resulting radiation.

2 shows the effect of adding a dummy element to a radiating element.

2A shows the radiation pattern of a single radiation element. Since there is no dummy element (N = 0), the radiating element has a standard radiation pattern for a single antenna element and has a field of view of about 80 degrees.

2B shows the radiation pattern when N = 1. Here, one dummy element (odd element) is symmetrically arranged on both sides of the radiating element. This can be expressed as the following equation.

The two dummy elements act as an inverse element to the radiating element, and can suppress the maximum radiation pattern of the radiating element. For example, when P1 = -15dB, the resulting radiation at 0 degree is reduced by -2.45dB compared to the case where N = 0. However, in this case, the field of view of the radiation pattern at the -3dB level increases, which reaches about 120 degrees.

2C shows a radiation pattern when N = 2. Here, two dummy elements (odd elements and even elements) are symmetrically arranged on both sides of the radiating element. This can be expressed as the following equation.

The two odd dummy elements can act as inverse elements with radiation amplitude P ₁ , while the two even dummy elements can act as in-phase elements with radiation amplitude P ₂ . The in-phase dummy element can compensate for the influence of the inverse dummy element. Therefore, the minimum value of radiation can be increased, and the maximum value can be suppressed. As a result, the viewing angle can be extended up to 130 degrees.

3 shows simulation results of radiation patterns of radiation elements and dummy elements. Referring to FIG. 3, as the number of dummy elements increases, the vibration frequency of the radiation pattern increases, the amplitude of vibration decreases, and when a specific number of dummy elements is reached, FoV hardly expands.

The simulation results of the radiation pattern in FIG. 3 indicate a case where n = 0 to n = 6. In the case of -3dB level when n = 0, the FoV of the radiation of the radiating element is about 80 degrees. When n = 1, FoV increases to about 122 degrees. When n = 2, FoV increases to about 130 degrees. When n = 3, FoV increases to about 136 degrees. When n = 4, FoV increases to about 138 degrees. When n = 5 and n = 6, there is practically no difference, and FoV is about 140 degrees.

The resulting radiation pattern can be obtained by synthesizing the radiation pattern of each individual element of the antenna array. In general, the equation for calculating the radiation pattern of the radiation element together with the dummy element is as follows.

Here, "+" represents the dummy element on the left side of the radiating element and "-" represents the dummy element on the right side. P _n (x _n , d _n , w, z _n ) is a coefficient that defines which portion of the power radiated by the radiating antenna element is radiated by the n-th dummy element. x _n is the characteristic size of the dummy element in the azimuthal direction, d _n is the distance between the phase center of the radiating element and the nth dummy element, w is the signal frequency, and z _n is the wave resistance at frequency w. For dummy devices, z _n = ∞. In the case of adjacent radiating elements, it is z _n ~ 50 Ohm, and absorbs energy up to 90%.

When the active elements and the dummy elements are collectively referred to as elements, the distance between phase centers of elements adjacent to each other (which may be simply referred to as adjacent elements) may be λ / 2. It should be noted that if the distance between the phase centers of adjacent elements is different from λ / 2, the phase difference between these elements will be different from π. In general, the resulting radiation pattern can be adjusted by controlling P _n ⁺ and P _n ⁻ . For example, the size of the dummy element, the distance between the dummy elements, or the signal frequency may be changed for the control of P _n ⁺ and P _n ⁻ .

4 shows an embodiment of various configurations of antenna elements in an antenna array. The configuration of the antenna elements in the antenna array can vary greatly depending on the application scenario.

Fig. 4A shows an array of antenna arrays including a row of radiating elements, wherein the same dummy elements as the radiating elements are arranged symmetrically on both sides from each radiating element. This antenna array can be used to increase the gain and decrease the FoV in a direction perpendicular to the extension of the FoV. For example, when extending the FoV in the horizontal direction, using this arrangement, the FoV is narrowed in the vertical direction. This arrangement can be used in automotive radar systems for navigation.

4B shows an array of antenna arrays including one radiating element, wherein the dummy elements are arranged symmetrically on both sides from the radiating elements, and the dummy elements have different widths. The different widths of the dummy elements can equalize the resulting radiation pattern of this arrangement. In addition, this arrangement makes it possible to extend the FoV. This arrangement can be used in communication devices (eg 5G base stations) or automobiles (when mounted on an external bumper).

4C shows the configuration of an antenna array comprising a row of radiating elements, wherein the dummy elements are arranged symmetrically on both sides of each radiating element, and the dummy elements have different widths. Similar to the arrangement of Figure 4A, the antenna array can be used to increase the gain and decrease the FoV in a direction perpendicular to the extension of the FoV. Similar to the arrangement of Fig. 4b, different widths of the dummy elements can equalize the resulting radiation pattern of this arrangement. This arrangement can also be used in communication devices or automobiles.

4D shows an array of antenna arrays comprising a row of radiating elements, wherein the dummy elements are arranged symmetrically on either side from each radiating element, and the number of dummy elements for each radiating element is different. The antenna array can be used to increase the gain and decrease the FoV in a direction perpendicular to the extension of the FoV. In this case, different numbers of dummy elements provide different FoVs according to beam directions. This arrangement can be used for 5G communication devices or automotive navigation.

4E shows an array of antenna arrays comprising one radiating element, wherein the dummy element is arranged only on one side of the radiating element. This arrangement can be utilized when radiation symmetry is not important, and the size of the antenna array can be reduced according to this arrangement. This arrangement can be applied, for example, to 5G communication devices.

4F shows an array of antenna arrays comprising a row of radiating elements, wherein the dummy element is arranged only on one side of the radiating element. In this case, the dummy elements may have different widths. Alternatively, the dummy element may be arranged on two sides of the radiating element, but the dummy element on one side of the radiating element is configured differently from the dummy element on the other side of the radiating element. This configuration can adjust the radiation pattern, increase the gain in the direction perpendicular to the extension of the FoV and reduce the FoV. This arrangement can be applied, for example, to 5G communication devices.

According to one embodiment, the radiating element and the dummy element may be of the same type, for example a patch antenna. However, according to an alternative embodiment, the elements may be slot antennas, dipoles, and the like. According to another embodiment, the dummy element may be different from the radiating element. In addition, other combinations of these devices are possible. For example, it is a patch antenna as a radiating element, a slot antenna as a dummy element, a slot antenna as a radiating element and a patch antenna as a dummy element, a dipole as a radiating element, and a slot antenna as a dummy element.

According to another alternative embodiment, the phase of the signal re-emitted by the dummy element can be controlled by further connecting elements corresponding to a phase taper to the dummy element. For example, these elements may include strip lines, micro strip lines, etc., and the length of these elements may define the phase of the re-emitted signal.

5 shows the principle of forming the final radiation pattern of the MIMO array.

Referring to FIG. 5A, the MIMO array may be composed of two device groups, such as group # 1 (denoted by T) and group # 2 (denoted by R), which include active devices and dummy devices, respectively. If the transmitting element (transmitter) is included in the group # 1 (T) as an active element, the receiving element (receiver) may be included in the group # 2 (R) as the active element. Conversely, if the receiving element is included as an active element in group # 1 (T), the transmitting element may be included as an active element in group # 2 (R).

Referring to FIG. 5B, a process of forming the final radiation pattern of the MIMO array is illustrated. The scanning beam envelope of the MIMO array can be determined by Equation (1). According to Equation 1, the resulting radiation pattern and FoV of the MIMO array may be determined as a product of the sum of the radiation patterns of the transmitting elements and the radiation patterns of the receiving elements.

According to the MIMO array configuration, at least two antenna elements (eg, receiving antenna elements) may be disposed adjacent to each other. By definition, two adjacent (eg, λ / 2 apart) active elements may be required to provide MIMO array functionality. Any one of the adjacent active elements can absorb the other radiation at a greater angle without re-emission. For example, adjacent active devices can reduce or attenuate mutual gain at a large angle to form a convex radiation pattern and reduce FoV. This may mean that the emission pattern of the elements of group # 2 (R) is convexly formed at the center each time to reduce FoV.

In order to form a wide FoV, two types of radiation patterns can be formed from the elements of group # 1 (T) and group # 2 (R). Recess patterns having a concave center may be formed by the antenna elements of the group # 1 (T), and radiation patterns having a convex center may be formed by the antenna elements of the group # 2 (R). Conversely, it is also possible that concentric convex radiation patterns are formed by the antenna elements of group # 1 (T), and concave radiation patterns are concave by the antenna elements of group # 2 (R). As shown in FIG. 5, through geometric averaging of the radiation patterns, a concave shape radiation pattern and a convex shape radiation pattern may be synthesized to increase FoV.

6 shows examples of arrangement of active elements and dummy elements in group # 1 of elements of the MIMO array. MIMO arrays can meet several conditions to form a wide radiation pattern.

The elements of group # 1 may be composed of a number of active elements (send or receive), and a number of dummy elements with a distance of ~ λ / 2 from the phase centers of all active and dummy elements. At this time, at least one dummy element may be provided between the active elements. All antenna elements can be implemented in any of the following five cases. The five cases below are shown in FIG. 6.

1) Case 1 ("a" type element): One dummy element is arranged between the active element and the next (adjacent) active element on one side, and one dummy element is located between the active element and the next active element on the other side. Deployed;

2) Case 2 ("b" type element): one dummy element on one side is disposed between the active element and the next active element, and on the other side two dummy elements are placed between the active element and the next active element;

3) Case 3 ("c" type element): Two dummy elements on one side are disposed between the active element and the next active element, and on the other side two dummy elements are placed between the active element and the next active element;

4) Case 4 ("d" type element): One dummy element is arranged between the active element and the next active element on one side, and a plurality of dummy elements are arranged on the other side (edge case);

5) Case 5 ("e" type element): Two dummy elements on one side are disposed between the active element and the next active element, and a plurality of dummy elements are placed on the other side (edge case).

This arrangement of the elements in group # 1 can ensure a concentric radiation pattern.

In order to form a wide radiation pattern in a plane (in this case, a horizontal plane), it can be important to place an antenna element in this plane (in a horizontal row of arrays). The relative arrangement of antenna elements in adjacent columns can mainly affect radiation patterns in different directions. These effects can be neglected through the cases. Accordingly, in embodiments, the arrangement of antenna elements in each horizontal column of the antenna array can be determined in consideration of only the required radiation pattern of this antenna array in the horizontal plane.

For example, in order to form a wide FoV of a group # 1 device, a combination of the following cases is possible.

1) Y = 2: d = 2, a = b = c = e = 0;

2) Y = 3: b = d = e = 1, a = c = 0;

3) Y≥4: b≥1, c≥0, a≥0, 2≥d≥0, 2≥e≥0.

Here, Y is the number of active elements in group # 1, and a, b, c, d, and e are the number of active elements in cases 1 to 5, respectively.

7 shows examples of arrangement of elements in group # 2 of elements of the MIMO array. The elements of Group # 2 consist of a number of active elements (receiving or transmitting) and a number of dummy elements with a distance of ~ λ / 2 between the phase centers of all active antenna and dummy elements. Also, at least two active elements are spaced at a distance of ~ λ / 2, and there may be no dummy element between them. In other words, at least two of the active elements may be disposed adjacent to each other. This arrangement of the elements of group # 2 can ensure a center-convex radiation pattern.

8 shows a partial arrangement of a MIMO array including elements of Group # 1 and Group # 2. In the array of group # 1, Y = 8, a = 2, b = 2, c = 2, d = 2, e = 0.

9 shows examples of the radiation pattern for the elements of group # 1. As illustrated in FIG. 9, elements of group # 1 arranged as case 1 may form a deeply concave radiation pattern. If there are many elements of Case 1 without compensation by the elements of Case 3, the degree of concave may be too large. Therefore, it may be desirable that the number of cases 1 and 3 are matched with each other.

The elements of group # 1 arranged as case 2, in which two dummy elements arranged on one side are compensated by one dummy element arranged on the other side, may form a radiation pattern having a flat area in the center.

The elements of group # 1 arranged as case 3 may form a convex shape at the center of the concave shape of the radiation pattern. When there are many elements in Case 3 without compensation by elements in Case 1, the convex shape existing in the center of the concave shape may be too large. Therefore, it may be desirable that the number of cases 1 and 3 are matched with each other.

Elements arranged as in cases 4 and 5 may be disposed at an edge or corner of the antenna array, and are used as fewer devices (eg, less than 4) compared to cases 1 to 3 It may be desirable.

One of the best arrangements of the elements in group # 1 may include the number of elements in case 1 equal to the number of elements in case 3. In this case, the number of elements in case 2 can be arbitrarily selected.

10 shows examples of radiation patterns for devices in group # 2. As shown in Fig. 10, possible cases for the arrangement of the elements of group # 2 can form a convex centered radiation pattern.

11 shows the formation of the resulting radiation pattern of elements of Group # 1 and Group # 2. As can be seen in FIG. 11, the resulting radiation pattern can be formed from the radiation pattern of the elements of group # 1 containing concave shapes and the radiation pattern of the elements of group # 2 containing convex shapes. Thereby, the resulting radiation pattern can have a wide FoV.

12 shows a possible implementation of a MIMO array (4Tx X 8Rx) according to an embodiment. Referring to FIG. 12, the MIMO array includes active elements Tx _i and Rx _j and dummy elements. i indicates the index of the transmitting element, and indicates the index of the receiving element. Adjacent elements are arranged at a distance of d. 13 shows radiation patterns of MIMO arrays according to embodiments in different frequency bands. Embodiments can be used in a variety of wide frequency bandwidths. Referring to FIG. 13, when used in an automotive radar system in SRR (77-81 GHz), MRR I (77-79 GHz), and MRR II (79-81 GHz) modes, the MIMO array of the embodiments has a FoV of about 140 It shows the increase in road.

Embodiments can be implemented within the framework of standard PCB technology. For example, the wide-angle MIMO antenna array according to the embodiments does not require additional elements (lenses, etc.) to expand FoV, and can be implemented on the top layer of the PCB without complicating the structure compared to conventional PCBs. Can be. Thus, embodiments can provide a simple, compact and inexpensive MIMO array with a wide viewing angle and high resolution.

The MIMO array according to the embodiments may be applied to a radar system of a vehicle including an autonomous vehicle used for navigation. One MIMO array according to embodiments having a FoV of about 140 degrees replaces two conventional antenna arrays each having a FoV of about 90 degrees each currently used in the vehicle to detect objects in front (or rear) of the vehicle. can do. Therefore, by reducing the total number of radars in the vehicle, it is possible to reduce power consumption and simplify the installation and tuning process.

In addition, the embodiments can be used in an evolved 5G and WiGig standard wireless communication system and the Internet of Things (IoT). In this case, the embodiments can be used for both the antenna of the base station and the mobile terminal. In this case, embodiments may be used to design an ultra-wide angle base station. When used in robotics, the antenna array of embodiments can be used to detect / avoid obstacles.

Embodiments can also be applied to all types of wireless power transmission systems (eg, outdoor / indoor, automotive, mobile, etc.) such as long-distance wireless power transfer (LWPT). In addition, high power transmission efficiency can be ensured in all scenarios.

The embodiments described above may be implemented by hardware components, software components, and / or combinations of hardware components and software components. For example, the devices, methods, and components described in the embodiments include, for example, a processor, a controller, an Arithmetic Logic Unit (ALU), a digital signal processor, a microcomputer, and a field programmable gate (FPGA). Arrays, Programmable Logic Units (PLUs), microprocessors, or any other device capable of executing and responding to instructions can be implemented using one or more general purpose computers or special purpose computers. The processing device may perform an operating system (OS) and one or more software applications running on the operating system. In addition, the processing device may access, store, manipulate, process, and generate data in response to the execution of the software. For convenience of understanding, a processing device may be described as one being used, but a person having ordinary skill in the art, the processing device may include a plurality of processing elements and / or a plurality of types of processing elements. It can be seen that may include. For example, the processing device may include a plurality of processors or a processor and a controller. In addition, other processing configurations, such as parallel processors, are possible.

The software may include a computer program, code, instruction, or a combination of one or more of these, and configure the processing device to operate as desired, or process independently or collectively You can command the device. Software and / or data may be interpreted by a processing device, or to provide instructions or data to a processing device, of any type of machine, component, physical device, virtual equipment, computer storage medium or device. , Or may be permanently or temporarily embodied in the transmitted signal wave. The software may be distributed over networked computer systems, and stored or executed in a distributed manner. Software and data may be stored in one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, or the like alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiments or may be known and usable by those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs, DVDs, and magnetic media such as floptical disks. -Hardware devices specifically configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language code that can be executed by a computer using an interpreter, etc., as well as machine language codes produced by a compiler. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

As described above, although the embodiments have been described with limited drawings, those skilled in the art can apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order than the described method, and / or the components of the described system, structure, device, circuit, etc. are combined or combined in a different form from the described method, or other components Alternatively, even if substituted or substituted by equivalents, appropriate results can be achieved.

Claims (15)

A first group comprising first antenna elements arranged to form a first concave radiation pattern; And
A second group comprising second antenna elements arranged to form a second convex center radiation pattern
Antenna array comprising a. According to claim 1,
The first antenna elements and the second antenna elements each include active elements and dummy elements,
Antenna array. According to claim 2,
The active elements and the dummy elements have the same form factor,
Antenna array. According to claim 2,
Among the elements including the active elements and the dummy elements, a distance between phase centers of elements adjacent to each other is λ / 2, and λ is a wavelength of electromagnetic waves emitted by the active element,
Array antenna. According to claim 1,
The first antenna elements include first active elements and first dummy elements,
At least one of the first dummy elements is disposed between the first active elements,
Array antenna. According to claim 1,
The second antenna elements include second active elements and second dummy elements,
At least two of the second active elements are disposed adjacent to each other,
Array antenna. According to claim 1,
The active elements and dummy elements of the first antenna elements are arranged according to at least one of the following cases,
1) a first case in which one dummy element is disposed between the active element and the next active element on one side, and one dummy element is disposed between the active element and the next active element on the other side,
2) a second case in which one dummy element is arranged between the active element and the next active element on one side, and two dummy elements are arranged between the active element and the next active element on the other side,
3) a third case in which two dummy elements on one side are disposed between the active element and the next active element, and on the other side two dummy elements are placed between the active element and the next active element,
4) a fourth case in which one dummy element is disposed between the active element and the next active element on one side, and a plurality of dummy elements are disposed on the other side, and
5) a fifth case in which two dummy elements are arranged between the active element and the next active element on one side, and a plurality of dummy elements are arranged on the other side,
Array antenna. According to claim 1,
The first radiation pattern and the second radiation pattern are combined with each other to increase the field of view of the array antenna,
Array antenna. According to claim 1,
When the first group includes transmitting elements as active elements, the second group includes receiving elements as active elements,
When the first group includes receiving elements as active elements, the second group includes transmitting elements as active elements,
Antenna array. An active element that emits electromagnetic waves; And
At least one dummy element having the same form factor as the active element and disposed on one side or both sides of the active element.
Array antenna comprising a. The method of claim 10,
A distance between phase centers of elements adjacent to each other among the elements including the active element and the at least one dummy element is λ / 2, and λ is a wavelength of the electromagnetic wave,
Array antenna. The method of claim 10,
The at least one dummy element includes at least one inverse dummy element and at least one in-phase dummy element,
The at least one inverse dummy element suppresses the electromagnetic wave by reradiating a part of the energy of the electromagnetic wave based on the electromagnetic wave,
The at least one in-phase dummy element amplifies the electromagnetic wave by re-emitting another portion of the energy of the electromagnetic wave based on the electromagnetic wave,
Array antenna. The method of claim 12,
When the at least one dummy element includes a plurality of dummy elements,
The first dummy element closest to the active element among the plurality of dummy elements corresponds to the inverse dummy element,
Among the plurality of dummy elements, a second dummy element close to the active element after the first dummy element corresponds to the in-phase dummy element,
Array antenna. The method of claim 10,
The maximum radiation pattern of the active element is suppressed by at least one dummy element, and the field of view of the array antenna is increased.
Array antenna. The method of claim 10,
The active element corresponds to a transmitting element or a receiving element,
Array antenna.

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