RU2695934C1 - Mimo antenna array with wide viewing angle - Google Patents

Abstract

FIELD: radio equipment.

SUBSTANCE: group of inventions relates to radio engineering. MIMO antenna array comprises a first group of antenna elements and a second group of antenna elements, wherein the first group of antenna elements includes several active antenna elements, as well as passive antenna elements, wherein antenna elements of first group are arranged so that to generate radiation pattern having depression in central part of diagram, wherein second group of antenna elements includes several active antenna elements, as well as passive antenna elements, wherein antenna elements of second group are arranged in such a way as to form radiation pattern having a projection in central part of diagram, wherein if the first group comprises transmitting antenna elements as active antenna elements, the second group comprises receiving antenna elements as active antenna elements, and vice versa.

EFFECT: high resolution, simple design, high compactness of the MIMO antenna array.

7 cl, 13 dwg

Description

Technical field

The present invention relates to radio engineering, and, more specifically, to a wide-angle MIMO scanning antenna array.

State of the art

Radar (radar) systems MIMO (Multiple Input Multiple Output - multiple input, multiple output) - a system consisting of several receiving and several transmitting antennas. Moreover, each transmitting antenna in such a system emits an arbitrary signal independently of other transmitting antennas. Each receiving antenna can receive these signals. A field of N transmitting antennas and a field of M receiving antennas mathematically leads to a virtual field of N · M antenna elements and the same increase in the size of the virtual aperture of the MIMO array.

MIMO radar systems can be used to improve spatial resolution and provide significantly improved noise immunity. Improved signal to noise ratio also increases the likelihood of target detection.

At present, radar systems are widely used in various industries, including military equipment, communications, vehicles, etc. For example, a radar system, such as a 3D / 4D radar, is a key component in car navigation. The main characteristic of a 3D radar is to detect the direction of the object in the azimuthal (horizontal) plane or elevation (vertical) plane, as well as determining the speed of the object and the distance to the object. In turn, the 4D radar is able to track the direction of the object both in the azimuthal plane and in the elevation plane, along with determining the speed of the object and the distance to the object.

Modern automotive radar systems operate in various modes, such as SRR (short-range application - range less than 30m-50m), MRR (middle-range application - range less than 70m-100m) and LRR (long-range application - range less than 150m-200m). In order to increase resolution for SRR and MRR solutions, modern radar systems use the MIMO approach for digital beamforming to detect direction to the target.

For applications in automotive radar systems, especially in SRR mode, it is necessary to provide a wide field of view (FoV) of the radar system in the azimuth plane. For example, to detect objects in front of (or behind) a vehicle, two antenna arrays are currently installed on the bumper of the vehicle, each of which has a viewing angle of 90 °, providing a total viewing angle of about 180 °. This approach is explained by the fact that in antenna arrays having a viewing angle of more than 90 °, parasitic petals appear in the radiation pattern, which significantly reduces the energy efficiency of such antenna arrays.

It is worth noting that the viewing angle of a MIMO radar having N transmitters (or receivers) and M receivers (or transmitters) is determined by the angular directions in which the gain of the envelope of the scanning beam of the MIMO antenna array decreases by 3 dB relative to the maximum gain in the field of view, and the level the gain of the envelope of the scanning beam of the MIMO antenna array is defined as:

и

- диаграмма направленности излучения каждого из N передатчиков и каждого из М приемников, θ -угол направления на объект в азимутальной плоскости. Where

and

- radiation pattern of each of the N transmitters and each of the M receivers, θ is the angle of direction to the object in the azimuthal plane.

Side lobes are the lobes (local maxima) of the far field radiation pattern, which are not the main lobe

Spurious lobes are side lobes that, due to the spatial overlap effect, become much larger in amplitude and approach the level of the main lobe for phased array antennas.

The prior art solution US 20170331178 A1, revealing the structure of the antenna with a wide beam, which includes a first substrate, a second substrate located on the lower surface of the first substrate, a microstrip antenna layer located on the upper surface of the first substrate and including many microstrip antennas connected in the form of a strip, a plurality of spurious elements located symmetrically on two sides of the microstrip antennas with an interval between them, and the length of the spurious element is less than the length microstrip antenna, a grounding layer located between the first substrate and the second substrate, and a supply line layer located on the lower surface of the second substrate. When using a parasitic element to improve the beam width with half the power, the visibility range of the vehicle’s radar system is increased. However, this document does not disclose an increase in the viewing angle for the antenna array, in particular for the MIMO antenna array.

. Это приводит к ухудшению разрешения на 60% по сравнению с традиционной фазированной решеткой с расстоянием

. Кроме того, данное решение направлено только на классическую фазированную решетку и не раскрывает повышение угла обзора для антенной решетки MIMO.In the article “Dual-Band Wide-Angle Scanning Phased Array Composed of SIW-Cavity Backed Elements” by You-Feng Cheng, Xiao Ding, etc. (see IEEE, Transactions on Antennas and Propagation, Volume: 66, Issue: 5, May 2018) An aperiodic dual-band phased array with wide-angle scanning is disclosed. As the main element of the grating, a cavity-closed antenna with an integrated integrated waveguide (SIW) is used, which has a wide beam at a frequency of 4.8 and 5.8 GHz. The phased array contains eight sublattices with a uniformly distributed arrangement, and each sublattice is located in a symmetrical structure. Theoretical and optimization methods in which the main rays of the sublattice and the full lattice coincide, and the maximum side lobe of the full lattice indicates zero sublattice, are proposed to reduce the side lobes. Based on optimized results, the main beam of a phased array can scan from -75 ° to + 75 ° in both frequency ranges, and the array supports beam coverage with a level of -3 dB from -86 ° to + 86 ° in the low-frequency range and from -82 ° up to + 82 ° in a high range, respectively. However, a wide FoV in this solution is achieved due to the close arrangement of the radiating elements: 16 elements with an aperture of 5λ give the average distance between the elements

. This leads to a 60% lower resolution compared to a traditional phased array with distance

. In addition, this solution is aimed only at the classical phased array and does not reveal an increase in the viewing angle for the MIMO antenna array.

In the article “Planar Phased Array with Wide-angle Scanning Performance Based on Image Theory” by Ren Wang, Bing-Zhong Wang, etc. (see IEEE, Transactions on Antennas and Propagation, Volume: 63, Issue: 9, September 2015) disclosed a broadband antenna and a flat phased array with wide-angle scanning characteristics based on image theory. To solve the problem of wide-angle scanning, a summarizing assessment of the main types of carrier-based antennas is given, and the types of antennas available for wide-angle scanning arrays are indicated. The article proposes a wide-angle scanning grating with grounding of an artificial magnetic conductor (AMC). The direction of the main beam of the grating can vary from -89 ° to 90 ° in the H plane with a gain fluctuation of less than 3 dB, and the scanning width with a level of 3 dB can cover the range from -105 ° to 105 °. However, in this solution, FoV expansion is achieved through the use of an additional layer of grounded artificial magnetic conductor (AMC), which increases the complexity of the PCB structure (printed circuit board) and worsens the matching parameters of the antenna elements due to the need for coordination with AMC. In addition, this solution is aimed only at the classical phased array and does not reveal an increase in the viewing angle for the MIMO antenna array.

Thus, in the prior art there is a need for a simple, compact and inexpensive MIMO antenna array having a wide viewing angle and high resolution.

SUMMARY OF THE INVENTION

The present invention is directed to solving at least some of the above problems.

The present invention provides an MIMO antenna array comprising a first group of antenna elements and a second group of antenna elements, the first group of antenna elements including several active antenna elements as well as passive antenna elements, the antenna elements of the first group being arranged so as to form a diagram radiation directivity having a depression in the central part of the diagram, i.e. in each row of the antenna array containing the antenna elements of the first group, between the active antenna elements of the first group of elements there is at least one passive antenna element, the active antenna elements of the first group in a row located in accordance with one of the following options:

- one passive antenna element is located between the active antenna element and the next active antenna element on the one hand and one passive antenna element is located between the active antenna element and the next active antenna element on the other side;

- one passive antenna element is located between the active antenna element and the next active antenna element on the one hand, and two passive antenna elements are located between the active antenna element and the next active antenna element on the other side;

- two passive antenna elements are located between the active antenna element and the next active antenna element on the one hand and two passive antenna elements are located between the active antenna element and the next active antenna element on the other side;

- one passive antenna element is located between the active antenna element and the next active antenna element on the one hand and several passive antenna elements are located on the other side;

- two passive antenna elements are located between the active antenna element and the next active antenna element on the one hand and several passive antenna elements are located on the other side;

moreover, the second group of antenna elements includes several active antenna elements, as well as passive antenna elements, and the antenna elements of the second group are arranged so as to form a radiation pattern having a protrusion in the Central part of the diagram, i.e. in each row of the antenna array containing the antenna elements of the second group, at least two active antenna elements of the second group of elements are adjacent without any passive antenna elements between them, and if the first group contains transmitting antenna elements as active antenna elements, then the second group contains receiving antenna elements as active antenna elements, and vice versa.

Active antenna element - an antenna element having a coordinated electrodynamic connection (or feeder connection) with a receiver or transmitter.

A passive antenna element (also known as a secondary emitter) does not have feeder communication with a receiver or transmitter. It can be shorted to ground (short circuit mode), or not connected to earth at all (idle mode).

, где λ - длина электромагнитной волны частотного диапазона активного антенного элемента.According to one embodiment of the antenna array in each row of the antenna array, the distance between the phase centers of the elements is

where λ is the electromagnetic wavelength of the frequency range of the active antenna element.

According to another embodiment of the antenna array, the passive antenna elements are identical to the active antenna elements in type of antenna elements and / or size.

According to another embodiment of the antenna array, the passive antenna elements differ from the active antenna elements in at least the type of antenna elements and / or size.

According to another embodiment of the antenna array, the passive antenna elements have different sizes.

According to another embodiment of the antenna array, elements are connected to the passive antenna elements in which the phase of the re-emitted signal raids.

According to another embodiment of the antenna array, the active antenna elements and passive antenna elements are selected from the group consisting of the following: patch antennas, slot antennas, dipoles.

The present invention provides a simple and compact MIMO antenna array with a wide viewing angle and high resolution.

Brief Description of the Drawings

The invention is further explained in the description of the preferred embodiments of the invention with reference to the accompanying drawings, in which:

In FIG. 1 shows the principle of operation of a portion of an antenna array containing a radiating antenna element and several passive elements, according to one embodiment of the present invention.

Figure 2 shows the effect of adding passive elements to the radiating element.

Figure 3 shows the simulation results of the radiation pattern of the emitting element and passive elements.

Figure 4 shows embodiments of various configurations of antenna elements in the antenna array.

Figure 5 shows the principle of formation of the final radiation pattern of the antenna array MIMO.

Figure 6 shows the location options of the active antenna elements and passive elements in the group No. 1 of the elements of the antenna array MIMO.

Figure 7 shows examples of the location of the elements of group No. 2 of the elements of the antenna array MIMO.

On Fig shows an example of the layout of part of the MIMO antenna array containing elements of group No. 1 and group No. 2.

Figure 9 shows examples of radiation patterns for elements of group No. 1.

Figure 10 shows examples of radiation patterns for various layout options for elements of group No. 2.

Figure 11 shows the formation of the resulting radiation pattern by elements of group No. 1 and group No. 2.

12 shows a possible implementation of a MIMO antenna array (4Tx X 8Rx) in accordance with the present invention.

On Fig shows the radiation pattern of the MIMO antenna array in accordance with the present invention in different frequency ranges.

Detailed description

, где λ - длина электромагнитной волны частотного диапазона излучающего элемента (обычно равна

, где

соответствует минимальной частоте в полосе, а

соответствует максимальной частоте в полосе).According to the present invention, the FoV of the radiating antenna element (also known as the primary radiator) is increased by adding several rows of passive antenna elements (hereinafter referred to as passive elements) identical to the radiating antenna element (hereinafter referred to as radiating element), the distance between the phase centers of the elements being

where λ is the electromagnetic wavelength of the frequency range of the radiating element (usually equal

where

corresponds to the minimum frequency in the band, and

corresponds to the maximum frequency in the band).

The use of passive elements identical to radiating elements makes it possible to unify and simplify the production process of both these elements themselves and of the antenna array containing these elements.

Alternatively, passive elements may have a form factor different from the radiating element.

, то разность фаз между пассивными элементами и излучающим элементом будет

, где n=1, 2... 3 и обозначает ряд пассивного элемента. Таким образом, нечетные пассивные элементы будут действовать как противофазные элементы к излучающему элементу; а четные пассивные элементы будут действовать как синфазные элементы. Если пассивный элемент из n-го ряда переизлучает часть P_n электромагнитной энергии излучающего элемента, то амплитуда формы сигнала n-го ряда пассивных элементов может быть рассчитана как: A_n=P_n*A₀, где A₀ - амплитуда сигнала излучающего элемента.The increase in FoV is achieved due to the reflection by passive elements of a part of the electromagnetic energy emitted by the radiating element. If the distance

, then the phase difference between the passive elements and the radiating element will be

, where n = 1, 2 ... 3 and denotes the row of the passive element. Thus, the odd passive elements will act as antiphase elements to the radiating element; and even passive elements will act as in-phase elements. If a passive element from the nth row re-emits a part P _{n of the} electromagnetic energy of the radiating element, then the amplitude of the waveform of the nth row of passive elements can be calculated as: A _n = P _n * A ₀ , where A ₀ is the signal amplitude of the radiating element.

In this embodiment, the interaction of passive elements with a radiating (transmitting) antenna element is considered, however, said passive elements can similarly function in conjunction with a receiving antenna element.

The resulting configuration (radiating elements + passive elements) will act as an array with 2N + 1 elements, in accordance with the following formula:

where Evlaa is the total field of the virtual linear antenna array (vlaa - Virtual Linear Antenna Array), A ₀ is the amplitude of the signal of the radiating element, N is the number of rows of passive elements on one side of the radiating element (2 * N is the total number of passive elements), n is the number of the passive element (and n = 1 for the passive element closest to the active element), P _n is the part of the electromagnetic energy of the emitting element reradiated by the nth passive element; d is the distance between the phase centers of the elements, k _o is the wave number; ϕ is the angular coordinate of the radiation pattern of the element.

An increase in the number of passive elements leads to an increase in the FoV radiation pattern of the radiating element and to a decrease in the variation in the gain level of the resulting radiation depending on the angular coordinate of the radiation pattern.

Next, with reference to FIG. 2, the effect of adding passive elements to the radiating element is demonstrated.

In FIG. 2a shows a radiation pattern of a single emitting element. There are no passive elements (N = 0), therefore, the radiating element has a standard radiation pattern of one antenna element, the viewing angle of which is of the order of ~ 80 °.

On figb shows the radiation pattern in the case of N = 1. In this case, one passive element (odd elements) are symmetrically located on both sides of the radiating element. Wherein:

Two passive elements act as antiphase elements for the radiating element and suppress the maximum radiation pattern of the central radiating element. For example, if P ₁ = -15dB, then the resulting radiation at an angle of 0 ° will deteriorate by -2.45 dB, compared with the case when N = 0. However, the angle of view of the radiation pattern at the level of -3dB increases and reaches 120 °.

Figure 2c shows the radiation pattern in the case of N = 2. In this case, two passive elements (odd and even elements) are symmetrically located on both sides of the radiating element. Wherein:

Two odd passive elements act as antiphase elements relative to a radiating element with an emission amplitude P ₁ , while two even passive elements act as in-phase elements with an emission amplitude P ₂ . Common-mode passive elements will compensate for the effect of out-of-phase passive elements: increase minima and suppress radiation maxima. This leads to a wider viewing angle up to 130 °.

Figure 3 shows the simulation results of the radiation pattern of the emitting element and passive elements when n varies from 1 to 6.

With an increase in the number of passive elements, the frequency of oscillations of the radiation pattern becomes higher, the amplitude of the oscillations decreases, and FoV when it reaches a certain number of passive elements practically ceases to expand.

In the example shown in FIG. 3, when n = 0 (see FIG. 3a), the FoV of the radiation of the radiating element at a level of -3dB is about 80 °. In the case where n = 1 (see FIG. 3b), the FoV increases to 122 °. In the case where n = 2 (see FIG. 3c), the FoV increases to 130 °. In the case where n = 3 (see FIG. 3d), the FoV increases to 136 °. In the case where n = 4 (see Fig. 3d), the FoV increases to 138 °. Between the cases when n = 5 and n = 6 there is practically no difference, and the FoV is about 140 ° (see Fig. 3e).

The resulting radiation pattern of the antenna array is obtained by adding the above radiation patterns of the individual elements.

In general, the formula for calculating the radiation pattern of a radiating element together with passive elements takes the following form:

- коэффициент, который определяет часть излучаемой антенным элементом мощности, переизлучаемую n-ым пассивным элементом,

- характерный размер пассивного элемента в азимутальном направлении,

- расстояние между фазовыми центрами излучающего элемента и n-го пассивного элемента,

- частота сигнала,

- волновое сопротивление при частоте

. Для пассивного элемента

. Для соседнего излучающего элемента

и он будет поглощать до 90% энергии.where the index "+" indicates passive elements on the left side of the radiating element, and the index "-" indicates passive elements on the right side,

- a coefficient that determines the part radiated by the antenna element power reradiated by the n-th passive element,

- the characteristic size of the passive element in the azimuthal direction,

- the distance between the phase centers of the radiating element and the n-th passive element,

- signal frequency,

- wave impedance at a frequency

. For passive element

. For adjacent radiating element

and it will absorb up to 90% of energy.

, то разность фаз между этими элементами будет отличаться от

.It should be noted that if the distance between the phase centers of neighboring elements will differ from

, then the phase difference between these elements will differ from

.

and

, например, посредством изменения размеров пассивных элементов, расстояния между пассивными элементами или частоты сигнала, позволяет регулировать результирующую диаграмму направленности излучения.In general, management

and

, for example, by changing the size of the passive elements, the distance between the passive elements or the signal frequency, allows you to adjust the resulting radiation pattern.

Depending on the application scenarios, the configuration of the antenna elements in the antenna array can vary significantly. Embodiments of various configurations of antenna elements in the antenna array are shown in FIG. 4.

On figa shows the layout of the antenna array containing a number of radiating elements, and on both sides of each of the radiating elements symmetrically located passive elements identical to the radiating element. Such an antenna array is used to increase the gain and decrease FoV in the direction perpendicular to the direction of expansion of FoV, i.e., for example, in the case of expanding FoV in the horizontal direction using this arrangement, the FoV in the vertical direction narrows. This arrangement can be used in automotive radar systems used for navigation.

On figb shows the layout of the antenna array containing one radiating element, and on both sides of the radiating element symmetrically located passive elements, and passive elements have different widths. The various widths of the passive elements make it possible to align the resulting radiation pattern of such an arrangement. At the same time, this arrangement allows you to expand FoV. This arrangement can be used in communication devices (for example, a base station of the 5G communication standard) or in cars (when installed on an external bumper).

On figv shows the layout of the antenna array containing a number of radiating elements, and on both sides of each of the radiating elements symmetrically located passive elements, and passive elements have different widths. 4a, such an antenna array is used to increase the gain and decrease FoV in the direction perpendicular to the direction of expansion FoV. Similarly to the arrangement of FIG. 4b, the different widths of the passive elements allow alignment of the resulting radiation pattern of such an arrangement. This arrangement can also be used in communication devices or in cars.

On Figg shows the layout of the antenna array containing a number of radiating elements, with passive elements symmetrically located on both sides of each of the radiating elements, and the number of passive elements for each radiating element is different. Such an antenna array is used to increase the gain and decrease FoV in the direction perpendicular to the direction of expansion FoV. Moreover, a different number of passive elements makes it possible to provide different FoV depending on the direction of the beam. This arrangement can also be used in 5G communication devices or in car navigation.

On fig.4d shows the layout of the antenna array containing one radiating element, and passive elements are located only on one side of the radiating element. This allows you to reduce the size of the antenna array in cases where the symmetry of the radiation is not important. Such an arrangement may find application in communication devices of the 5G standard, for example.

Figure 4e shows the layout of an antenna array containing a series of radiating elements, the passive elements being located only on one side of the radiating elements. In this case, passive elements can have a different width. Alternatively, passive elements can be located on two sides of the radiating elements, but the passive elements on one side of the radiating element are different from passive elements on the other side of the radiating element. This arrangement allows you to adjust the radiation pattern, as well as increase the gain and reduce FoV in the direction perpendicular to the direction of expansion FoV. Such an arrangement may find application in communication devices of the 5G standard, for example.

According to one embodiment, the radiating elements and the passive elements are identical in type of antenna elements and are, for example, patch antennas. However, according to an alternative embodiment, said elements may be in the form of a slot antenna, dipole, etc. According to another embodiment, the passive elements may be made different from the radiating element. In this case, various combinations of such elements are possible: a patch antenna as a radiating element and slot antennas as passive elements, a slot antenna as a radiating element and a patch antenna as passive elements, a dipole as a radiating element and slot antennas as passive elements etc.

According to another alternative embodiment of the invention, the phase of the signal re-emitted by the passive elements can be controlled by connecting the elements in which the phase incurs to said passive elements. The length of such elements in which the phase incurs (strip line, microstrip line, etc.) determines the phase of the reradiated signal.

The MIMO antenna array consists of two groups of elements: group No. 1, containing active antenna elements, designated as T, and passive antenna elements, as well as group No. 2, containing active antenna elements, designated as R, and passive antenna elements. It should be noted that if group No. 1 contains transmitters as active antenna elements, then group No. 2 contains receivers as active antenna elements, and vice versa.

The envelope of the scanning beam of the MIMO antenna array is determined in accordance with equation (1). In accordance with equation (1), the resulting radiation pattern (and, therefore, FoV) of the MIMO antenna array is defined as the product of the sum of the radiation patterns of the transmitting elements and the sum of the radiation patterns of the receiving elements.

) активных элемента требуется, чтобы MIMO решетка функционировала согласно своему определению. При этом рядом стоящие активные элементы, не переизлучают, а поглощают излучение соседнего элемента на больших углах, то есть взаимно уменьшают (ослабляют) усиление на больших углах, формируя выступ в центре диаграммы направленности излучения и приводя к снижению FoV. Это означает, что каждый раз диаграмма направленности излучения элементов R будет иметь выступ в центре диаграммы, что снижает FoV. Для формирования широкого FoV требуется сформировать два типа диаграммы направленности от элементов T и R, причем диаграмма направленности элементов T должна иметь впадину в центре, а диаграмма направленности элементов R должна иметь выступ в центре (или наоборот). Геометрическое усреднение этих диаграмм направленности компенсирует выступ и впадину и увеличивает FoV (см. фиг.5).According to the configuration of the MIMO antenna array, at least two antenna elements R must be adjacent. Two adjacent (

) active elements requires that the MIMO lattice function as defined. In this case, adjacent active elements do not reemit, but absorb the radiation of the neighboring element at large angles, i.e. mutually reduce (weaken) the gain at large angles, forming a protrusion in the center of the radiation pattern and leading to a decrease in FoV. This means that each time the radiation pattern of elements R will have a protrusion in the center of the diagram, which reduces FoV. To form a wide FoV, it is required to form two types of radiation patterns from the elements T and R, and the radiation pattern of the elements T must have a depression in the center, and the radiation pattern of the elements R must have a protrusion in the center (or vice versa). The geometric averaging of these radiation patterns compensates for the protrusion and the cavity and increases the FoV (see figure 5).

To form such a wide radiation pattern, the MIMO antenna array must satisfy several conditions:

. Также между активными антенными элементами расположен по меньшей мере один пассивный элемент. При этом, каждый активный антенный элемент может характеризоваться посредством пяти вариантов (см. фиг.6):1. Elements of group No. 1 contain several active antenna elements (transmitting or receiving) and several passive elements, and the distance between the phase centers of each active antenna element and passive elements is

. Also between the active antenna elements is at least one passive element. In this case, each active antenna element can be characterized by five options (see Fig.6):

- Option 1 (type “a” element): one passive element is located between the active antenna element and the next (adjacent) active antenna element on the one hand and one passive element is located between the active antenna element and the next active antenna element on the other hand;

- Option 2 (type “b” element): one passive element is located between the active antenna element and the next active antenna element on the one hand and two passive elements are located between the active antenna element and the next active antenna element on the other side;

- Option 3 (type “c” element): two passive elements are located between the active antenna element and the next active antenna element on the one hand and two passive elements are located between the active antenna element and the next active antenna element on the other side;

- Option 4 (element of type "d"): one passive element is located between the active antenna element and the next active antenna element on one side and several passive elements are located on the other side (edge case);

- Option 5 (element of type “e”): two passive elements are located between the active antenna element and the next active antenna element on the one hand and several passive elements are located on the other side (edge case).

This arrangement of the elements of group No. 1 provides the formation of a radiation pattern of the elements of this group having a depression in the central part of the diagram.

It should be noted that for the formation of a wide radiation pattern in a certain plane (in this case, in the horizontal plane), it is important to place the antenna elements in this plane (their location in the horizontal row of the antenna array). The relative arrangement of antenna elements in adjacent rows will primarily affect the radiation pattern along other directions. In this case, this can be neglected. Thus, in the present invention, the location of the antenna elements in each horizontal row of the antenna array is determined only by the desired radiation pattern of this antenna array in the horizontal plane.

For example, to form a wide FoV group of No. 1 elements, the following combinations of the above options are possible:

- if Y = 2, then d = 2 and a, b, c, e = 0;

- if Y = 3, then b = d = e = 1 and a, c = 0;

- if Y≥4, then b≥1, c≥0, a≥0, 2≥d≥0, 2≥e≥0,

where Y is the number of active antenna elements in group No. 1, and a, b, c, d, e is the number of elements from Y corresponding to options 1, 2, 3, 4, and 5, respectively.

. При этом по меньшей мере два активных антенных элемента расположены на расстоянии

без каких-либо пассивных элементов между ними. Такая компоновка элементов группы №2 обеспечивает формирование диаграммы направленности излучения элементов данной группы, имеющей выступ в центральной части диаграммы.2. Elements of group No. 2 contain several (≥2) active antenna elements (receiving or transmitting) and several passive elements, and the distance between the phase centers of each active antenna element and passive elements is

. At the same time, at least two active antenna elements are located at a distance

without any passive elements between them. This arrangement of the elements of group No. 2 provides the formation of a radiation pattern of the elements of this group having a protrusion in the central part of the diagram.

Examples of the arrangement of elements of group No. 2 are shown in Fig.7.

One of the layout options of the part of the MIMO antenna array containing elements of group No. 1 and group No. 2 is shown in Fig. 8. In this arrangement, Y = 8: a = 2; b is 2; c = 2; d = 2; e = 0.

As can be seen from Fig.9, the elements of group No. 1, located in accordance with Option 1, form a radiation pattern having a deep depression in the center of the diagram. Elements of group No. 1, located in accordance with Option 2, in which two passive elements on the one hand are compensated by one passive element on the other hand, form a radiation pattern having an even area in the center of the diagram. Elements of group No. 1, located in accordance with Option 3, form a radiation pattern having a protrusion in the center of the cavity of the diagram. Elements located in accordance with Options 4 and 5 can be located on the edges of the antenna array and are preferably used with a small number of elements. Option 1 - Option 3 (<4).

The best option for arranging elements of group No. 1 is the case when the number of elements in Option 1 is equal to the number of elements in Option 3 for any number of elements in Option 2.

As can be seen from figure 10, possible layout options for elements of group No. 2 form radiation patterns having a protrusion in the center of the diagram.

As can be seen from Fig. 11, the resulting radiation pattern is formed from the radiation pattern of the elements of group No. 1 having a depression and the radiation pattern of the elements of the group No. 2 having a protrusion. In this case, the resulting radiation pattern has a wide FoV.

12 shows a possible implementation of a MIMO antenna array (4Tx X 8Rx), in accordance with the present invention.

The present invention can be used in a wide frequency range. For example, when used in automotive radar systems in the SRR (77-81 GHz), MRR I (77-79 GHz), MRR II (79-81 GHz) modes, the MIMO antenna array in accordance with the present invention exhibits an FoV increase of up to about 140 ° (cm Fig. 13).

The present invention is implemented within the framework of standard PCB technology, i.e. the wide-angle MIMO antenna array in accordance with the present invention is implemented on the upper layer of the PCB, without requiring the use of additional elements (lenses, etc.) to expand the FoV and without causing structural complexity compared to a conventional PCB.

Thus, the present invention provides a simple, compact and inexpensive MIMO antenna array with a wide viewing angle and high resolution.

MIMO antenna arrays according to the present invention can find application in radar systems of vehicles, including autonomous vehicles used for navigation. It is worth noting that one MIMO antenna array in accordance with the present invention having an FoV of about 140 ° can replace two traditional antenna arrays having an FoV of about 90 ° each and currently used in vehicles for detecting objects in front (or behind) of a vehicle . Thus, the total number of radars in vehicles can be reduced, which entails a reduction in power consumption, simplification of the installation and adjustment process, etc.

In addition, the present invention can be used in wireless communication systems of promising 5G and WiGig standards, as well as in IoT (Internet of Things - “Internet of Things”). Moreover, the present invention can be used both in base stations and in antennas of mobile terminals. In this case, the present invention provides the possibility of creating an ultra-wide-angle base station.

When used in robotics, you can use the proposed antenna array to detect / avoid obstacles.

The present invention may also find application in wireless power transmission systems such as LWPT (long-distance wireless power transfer) of all types: external / internal, automobile, mobile, etc. This ensures high power transmission efficiency in any scenario.

It should be understood that although in this document to describe various elements, components, areas, layers and / or sections, terms such as "first", "second", "third" and the like can be used, these elements, components , areas, layers and / or sections should not be limited to these terms. These terms are used only to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section may be called a second element, component, region, layer or section without departing from the scope of the present invention. In the present description, the term "and / or" includes any and all combinations of one or more of the corresponding items listed.

The functionality of the element indicated in the description or claims as a single element can be implemented in practice through several components of the device, and vice versa, the functionality of the elements indicated in the description or claims as several separate elements can be implemented in practice through a single component.

Embodiments of the present invention are not limited to the embodiments described herein. Specialist in the field of technology based on the information set forth in the description and knowledge of the prior art will become apparent and other embodiments of the invention, not beyond the essence and scope of this invention.

The elements mentioned in the singular do not exclude the plurality of elements, unless specifically indicated otherwise.

One skilled in the art will appreciate that the spirit of the invention is not limited to a particular software or hardware implementation, and therefore, any software and hardware known in the art may be used to implement the invention. So hardware can be implemented in one or more specialized integrated circuits, digital signal processors, digital signal processing devices, programmable logic devices, user programmable gate arrays, processors, controllers, microcontrollers, microprocessors, electronic devices, and other electronic modules configured to carry out the functions described in this document, a computer or a combination of the above.

Although exemplary embodiments have been described and shown in the accompanying drawings, it should be understood that such embodiments are merely illustrative and not intended to limit the broader invention, and that the present invention should not be limited to the particular arrangements and structures shown and described, since various other modifications may be apparent to those skilled in the art.

The features mentioned in the various dependent claims, as well as the embodiments disclosed in various parts of the description, can be combined to achieve beneficial effects, even if the possibility of such a combination is not explicitly disclosed.

Claims (17)

1. The MIMO antenna array containing the first group of antenna elements and the second group of antenna elements, moreover, the first group of antenna elements includes several active antenna elements, as well as passive antenna elements, moreover, the antenna elements of the first group are arranged so as to form a radiation pattern having a depression in the central part of the diagram, i.e. in each row of the antenna array containing the antenna elements of the first group, between the active antenna elements of the first group of elements there is at least one passive antenna element, the active antenna elements of the first group in a row located in accordance with one of the following options: - one passive antenna element is located between the active antenna element and the next active antenna element on the one hand, and one passive antenna element is located between the active antenna element and the next active antenna element on the other side; - one passive antenna element is located between the active antenna element and the next active antenna element on the one hand, and two passive antenna elements are located between the active antenna element and the next active antenna element on the other side; - two passive antenna elements are located between the active antenna element and the next active antenna element on the one hand, and two passive antenna elements are located between the active antenna element and the next active antenna element on the other side; - one passive antenna element is located between the active antenna element and the next active antenna element on the one hand, and several passive antenna elements are located on the other side; - two passive antenna elements are located between the active antenna element and the next active antenna element on the one hand, and several passive antenna elements are located on the other side; moreover, the second group of antenna elements includes several active antenna elements, as well as passive antenna elements, moreover, the antenna elements of the second group are positioned so as to form a radiation pattern having a protrusion in the central part of the diagram, i.e. in each row of the antenna array containing the antenna elements of the second group, at least two active antenna elements of the second group of elements are located nearby without any passive antenna elements between them, moreover, if the first group contains transmitting elements as active antenna elements, then the second group contains receiving elements as active antenna elements, and vice versa. 2. The antenna array according to claim 1, in which in each row of the antenna array the distance between the phase centers of the elements is

where λ is the electromagnetic wavelength of the frequency range of the active antenna element. 3. The antenna array according to any one of claims 1, 2, in which the passive antenna elements are identical to the active antenna elements in type of antenna elements and / or size. 4. The antenna array according to any one of claims 1, 2, in which the passive antenna elements differ from the active antenna elements, at least in type of antenna elements and / or size. 5. The antenna array according to any one of claims 1, 2, in which the passive antenna elements have different sizes. 6. The antenna array according to any one of claims 1, 2, in which elements are connected to the passive antenna elements, in which the phase of the reradiated signal occurs. 7. The antenna array according to any one of claims 1 to 5, in which the active antenna elements and passive antenna elements are selected from the group consisting of the following: patch antennas, slot antennas, dipoles.

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