KR102661028B1 - Multi-input multi-output radar device including antenna sub-arrays and method of operating thereof - Google Patents

Abstract

A multiple-input multiple-output radar device according to an embodiment of the present invention includes first to Pth transmitting antenna sub-arrays, a transmitting circuit, a receiving antenna array, a receiving circuit, and a control circuit. Each of the first to Pth transmission antenna sub-arrays includes first to Mth transmission antennas arranged in a row along a first direction on a substrate, and radiates transmission signals toward an object. The transmission circuit converts first baseband signals into the transmission signals based on a first control signal. The receiving antenna array includes first to Qth receiving antennas arranged in a line along the first direction and spaced apart from the first to Mth transmitting antennas on the substrate, and responds to the transmitting signals to the object. It receives reflected signals reflected from. The receiving circuit converts the reflected signals into second baseband signals based on a second control signal and performs digital beamforming on the second baseband signals to form a digital beam pattern. The control circuit generates the first and second control signals. The transmission signals are RF signals orthogonal to each other, and the reception circuit forms a virtual reception antenna array including (P * Q) virtual reception antennas based on the second baseband signals.

Description

Multiple-input multiple-output radar device including antenna sub-arrays and operating method thereof {MULTI-INPUT MULTI-OUTPUT RADAR DEVICE INCLUDING ANTENNA SUB-ARRAYS AND METHOD OF OPERATING THEREOF}

The present invention relates to a radar device, and more specifically, to a multiple-input, multiple-output radar device that reduces hardware complexity and digital signal processing.

As radar devices are used in fields such as autonomous driving systems, biometric information collection systems, and smart security systems, research on radar devices that can demonstrate high performance is actively underway. In particular, when the distance between the transmitter and receiver modules of the radar device is not far, the multi-input multi-output (MIMO) radar device can provide high azimuth resolution and can be used in a variety of fields.

In general, a multi-input, multi-output radar device is equipped with a digital-to-analog converter (DAC) and an analog-to-digital converter (ADC) for each channel to provide full digital It is implemented in a digital) manner. In this case, estimation of the position of the object can be performed simultaneously for all scanning angles within the viewing angle. However, when the multi-input, multi-output radar device as described above operates with high performance at high frequency and high resolution, digital signal throughput and hardware complexity rapidly increase.

One purpose of the present invention to solve the above problems is to provide a multi-input, multi-output radar device that reduces digital signal processing and reduces hardware complexity in an environment that operates with high performance at high frequency and high resolution.

An object of the present invention is to provide a method of operating the multi-input multi-output radar device.

In order to achieve the above object, a multiple-input multiple-output radar device according to an embodiment of the present invention includes first to Pth transmitting antenna sub-arrays (P is an integer of 2 or more), a transmitting circuit, a receiving antenna array, and a receiving antenna. It may include a circuit and a control circuit. Each of the first to Pth transmission antenna sub-arrays includes first to Mth transmission antennas (M is an integer of 2 or more) arranged in a row on a substrate along a first direction, and radiates transmission signals toward an object. can do. The transmission circuit may convert first baseband signals into the transmission signals based on the first control signal. The receiving antenna array includes first to Qth receiving antennas (Q is an integer of 2 or more) arranged in a line along the first direction and spaced apart from the first to Mth transmitting antennas on the substrate, Reflected signals reflected from the object may be received in response to transmitted signals. The receiving circuit may convert the reflected signals into second baseband signals based on a second control signal and perform digital beamforming on the second baseband signals to form a digital beam pattern. The control circuit may generate the first and second control signals. The transmission signals are radio frequency (RF) signals orthogonal to each other, and the reception circuit includes (P * Q) virtual reception antennas based on the second baseband signals. An array can be formed.

In one embodiment, the receiving circuit determines the direction of grating lobes occurring in the digital beam pattern and the null point occurring in the analog beam pattern formed by the first to Pth transmission antenna sub-arrays. The grating lobes can be offset by matching their directions.

In one embodiment, the first transmission antennas included in two adjacent transmission antenna sub-arrays among the first to P-th transmission antenna sub-arrays are spaced apart from each other by a first distance in the first direction, and the first Among the through Qth receiving antennas, two adjacent receiving antennas may be spaced apart in the first direction by a second distance different from the first distance.

In one embodiment, the first spacing may be equal to the size of the aperture of all of the first to Mth transmitting antennas, and the second spacing may be equal to the size of the aperture of all of the first to Pth transmitting antenna sub-arrays. You can.

In one embodiment, the first spacing is equal to the size of the aperture of all of the first to Qth receiving antenna arrays, and the second spacing is equal to the size of the aperture of one of the first to Pth transmitting antenna sub-arrays. It may be the same as

In one embodiment, the transmission circuit includes first to Pth beamforming units corresponding to the first to Pth transmission antenna subarrays, respectively, and each of the first to Pth beamforming units is a digital- It may include an analog converter, a mixer, and first to M phase shifters. The digital-to-analog converter may provide a corresponding one of the first baseband signals. The mixer may convert a corresponding one of the first baseband signals into a radio frequency (RF) signal. The first to Mth phase shifters may delay the phase of the RF signal by a predetermined delay amount and provide the delay to a corresponding one of the first to Mth transmission antennas.

In one embodiment, the multiple-input multiple-output radar device scans a front area centered on a reference direction perpendicular to the upper surface of the substrate to detect the object, and the receiving circuit is configured to detect the object as a result of the digital beamforming. Based on this, angle information related to the location of the object can be estimated.

In order to achieve the above object, a multiple-input multiple-output radar device according to an embodiment of the present invention includes first to Pth transmitting antenna subarrays (P is an integer of 2 or more), a transmission circuit, and first to Qth transmitting antenna subarrays. It may include receiving antenna sub-arrays, receiving circuitry, and control circuitry. Each of the first to Pth transmission antenna sub-arrays includes first to Mth transmission antennas (M is an integer of 2 or more) arranged in a row on a substrate along a first direction, and radiates transmission signals toward an object. can do. The transmission circuit may convert first baseband signals into the transmission signals based on the first control signal. Each of the first to Qth receiving antenna sub-arrays includes first to Qth receiving antennas arranged in a line along the first direction and spaced apart from the first to Mth transmitting antennas on the substrate (Q is 2) or more) and may receive reflected signals reflected from the object in response to the transmission signals. The receiving circuit may convert the reflected signals into second baseband signals based on a second control signal and perform digital beamforming on the second baseband signals to form a digital beam pattern. The control circuit may generate the first and second control signals. The transmission signals are RF signals orthogonal to each other, and the receiving circuit may form a virtual receiving antenna array including (P * Q) virtual receiving antennas based on the second baseband signals.

In one embodiment, the receiving circuit offsets the grating lobes by matching the directions of the grating lobes occurring in the digital beam pattern with the directions of null points occurring in the analog beam patterns of the first to P-th transmission antenna sub-arrays. You can do it.

In one embodiment, the first transmission antennas included in two adjacent transmission antenna sub-arrays among the first to P-th transmission antenna sub-arrays are spaced apart from each other by a first distance in the first direction, and the first The first receiving antennas included in two adjacent receiving antenna sub-arrays among the through Q-th receiving antenna sub-arrays may be spaced apart in the first direction by a second distance different from the first distance.

In one embodiment, the first spacing may be equal to the size of the aperture of all of the first to Mth transmitting antennas, and the second spacing may be equal to the size of the aperture of all of the first to Pth transmitting antenna sub-arrays. You can.

In order to achieve the above object, in the method of operating a multiple-input multiple-output radar device according to an embodiment of the present invention, by the first to Pth transmitting antenna sub-arrays (P is an integer of 2 or more), Transmission signals that are orthogonal to each other may be radiated. Each of the first to Pth transmission antenna sub-arrays may include first to Mth transmission antennas (M is an integer of 2 or more). Reflected signals reflected from the object in response to the transmission signals may be received by a reception antenna array including first to Qth reception antennas. By a receiving circuit, the reflected signals are converted into baseband signals, and a virtual receiving antenna array including (P * Q) virtual receiving antennas can be formed based on the baseband signals. Digital beamforming on the baseband signals may be performed by the receiving circuit using the virtual receiving antenna array. Angular information related to the location of the object may be estimated by a control circuit based on the results of the digital beamforming.

The multi-input multi-output radar device according to an embodiment of the present invention can reduce digital signal processing even when high performance at high frequency and high resolution is required, and reduce hardware complexity in an environment operating at a high frequency above a certain level.

In addition, the multiple-input, multiple-output radar device according to an embodiment of the present invention can obtain coherent processing gain of transmission signals, effectively detecting objects located at a distance without causing a decrease in each resolution. You can.

1 is a block diagram showing a multi-input multi-output radar device according to an embodiment of the present invention.
Figures 2 (a) and (b) are diagrams for explaining an example in which the transmission antenna sub-array set and the reception antenna array of Figure 1 are disposed on a substrate.
FIG. 3 is a diagram illustrating an example of arrangement of antennas included in each of the transmit antenna sub-array set and the receive antenna array of FIG. 1 .
FIG. 4 is a diagram illustrating an example of a first beamforming unit included in the beamforming network of FIG. 1.
FIG. 5 is a diagram illustrating an example of a first receiving unit included in the receiving circuit of FIG. 1.
FIG. 6 is a diagram illustrating an example in which the transmitting antennas included in the transmitting antenna sub-array set of FIG. 1 and the receiving antennas included in the receiving antenna array are disposed on a substrate.
FIG. 7 is a diagram illustrating an example of a virtual receiving antenna array formed in the signal processing circuit of FIG. 1.
FIG. 8 is a diagram illustrating an example in which the transmitting antennas included in the transmitting antenna sub-array set of FIG. 1 and the receiving antennas included in the receiving antenna array are arranged on a substrate.
Figure 9 is a block diagram showing a multi-input multi-output radar device according to an embodiment of the present invention.
FIG. 10 is a diagram illustrating an example in which the transmitting antennas included in the transmitting antenna sub-array set of FIG. 9 and the receiving antennas included in the receiving antenna sub-array set of FIG. 9 are disposed on a substrate.
FIG. 11 is a diagram illustrating simulation conditions for detecting objects using a multi-input multi-output radar device according to an embodiment of the present invention.
FIGS. 12, 13, and 14 are diagrams for explaining simulation results of detecting objects using the multi-input multi-output radar device of FIG. 1 under the simulation conditions of FIG. 11.
Figures 15 (a) and (b) show the directions of null points occurring in the analog beam pattern of the transmitting antenna sub-array set of Figure 1 and the directions of grating lobes occurring in the digital beam pattern formed in the receiving circuit of Figure 1. This is a drawing to explain the matching operation.
Figure 16 is a flowchart showing a method of operating a multi-input multi-output radar device according to an embodiment of the present invention.

Regarding the embodiments of the present invention disclosed in the text, specific structural and functional descriptions are merely illustrative for the purpose of explaining the embodiments of the present invention, and the embodiments of the present invention may be implemented in various forms. It should not be construed as limited to the embodiments described in.

Since the present invention can be subject to various changes and can have various forms, specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms may be used for the purpose of distinguishing one component from another component. For example, a first component may be referred to as a second component, and similarly, the second component may be referred to as a first component without departing from the scope of the present invention.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as "between" and "immediately between" or "neighboring" and "directly adjacent to" should be interpreted similarly.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the existence of a described feature, number, step, operation, component, part, or combination thereof, but are not intended to indicate the presence of one or more other features or numbers. It should be understood that this does not exclude in advance the possibility of the existence or addition of steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the present application, should not be interpreted as having an ideal or excessively formal meaning. .

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings. The same reference numerals are used for the same components in the drawings, and duplicate descriptions for the same components are omitted.

1 is a block diagram showing a multi-input multi-output radar device according to an embodiment of the present invention.

Referring to FIG. 1, a multi-input multi-output (MIMO) radar device 10 may include a transmitting device 100, a receiving device 300, and a control circuit 500.

The transmitting device 100 includes a transmitting antenna sub-array set 110 and a transmitting circuit 130, and the transmitting circuit 130 may include a beamforming network 135. The receiving device 300 includes a receiving antenna array 310 and a receiving circuit 330, and the receiving circuit 335 may include a signal processing circuit 335. Each of the transmitting device 100 and the receiving device 300 may include a plurality of antennas.

In one embodiment, the plurality of antennas may be configured in different shapes in each of the transmitting device 100 and the receiving device 300, and in another embodiment, the plurality of antennas may be configured in similar shapes. . For example, the plurality of antennas may be configured as antenna sub-arrays (or may be referred to as 'sub-array' or 'phase sub-array') in the transmitting device 100, and may be configured as a simple antenna in the receiving device 300. It may consist of an antenna array. For example, the plurality of antennas may be configured as antenna sub-arrays in both the transmitting device 100 and the receiving device 300. The multiple-input multiple-output radar device 10, in which the plurality of antennas are configured as antenna sub-arrays only in the transmitting device 100, is described with reference to FIGS. 1, 3, 4, 5, 6, and 8. The multi-input multi-output radar device 10a, in which the plurality of antennas are configured as antenna sub-arrays in both the transmitting device 100 and the receiving device 300, will be described later with reference to FIGS. 9 and 10. .

In one embodiment, the plurality of antennas disposed within the transmitting device 100 may constitute a transmitting antenna sub-array set 110, and the plurality of antennas disposed within the receiving device 300 may constitute a receiving antenna array 310. ) can be configured.

In one embodiment, the transmitting device 100, the receiving device 300, and the control circuit 500 may be implemented on one substrate, and the plurality of antennas are spaced at preset intervals along a preset direction on the substrate. It can be implemented to be spaced apart and arranged in a line. Specific examples in which the plurality of antennas are arranged in each of the transmitting device 100 and the receiving device 300 will be described later with reference to FIGS. 6, 8, and 10.

The control circuit 500 may provide an input digital signal (IS) to the transmission circuit 130 and receive an output digital signal (OS) from the reception circuit 330. The control circuit 500 may provide a first control signal (CTL1) and a second control signal (CTL2) to each of the transmitting circuit 130 and the receiving circuit 330.

The transmission circuit 130 generates first baseband signals by converting the input digital signal (IS) into an analog signal based on the first control signal (CTL1), and converts the first baseband signals into transmission signals that are high frequency signals. It can be converted to (TS). The transmission circuit 130 may provide transmission signals TS to the transmission antenna sub-array set 110 .

In one embodiment, transmission signals TS may be generated in the beamforming network 135. The beamforming network 135 may include a plurality of beamforming units, and the control circuit 500 may independently control each of the plurality of beamforming units based on the first control signal CTL1.

The transmission antenna sub-array set 110 may radiate transmission signals TS toward an object. The reception antenna array 310 may receive reflection signals (RS) reflected from the object in response to transmission signals (TS).

The receiving circuit 330 converts the reflected signals RS based on the second control signal CTL2 to generate second baseband signals, and converts the second baseband signals into an output digital signal OS, which is a digital signal. It can be converted to . The receiving circuit 330 may provide an output digital signal (OS) to the control circuit 500.

In one embodiment, the transmission signals TS may be radio frequency (RF) signals orthogonal to each other, and the reception circuit 330 may be configured as a virtual reception antenna based on the second baseband signals. A virtual receiving antenna array including: The receiving circuit 330 may form a digital beam pattern by performing digital beamforming on the second baseband signals based on the virtual receiving antenna array. More specifically, the virtual reception antenna array and the digital beam pattern are configured so that the signal processing circuit 335 included in the reception circuit 330 uses the property that the transmission signals TS are orthogonal to each other to generate the second baseband signal. The virtual reception antenna array and the digital beam pattern can be formed by separating signal components orthogonal to each other from the signal components.

In one embodiment, the receiving circuit 330 determines the direction of grating lobes occurring in the digital beam pattern and the antenna sub array set 110 (or the antenna sub array included in the transmit antenna sub array set 110). The grating lobes can be offset by matching the directions of null points occurring in the analog beam pattern formed by the arrays.

In one embodiment, analog-to-digital converters (ADC) and digital-to-analog converters are included in the transmitting device 100 and the receiving device 300, respectively. (DAC) may be implemented with fewer antennas than the number of antennas included in the transmitting device 100 and the receiving device 300.

Through the above configuration, the multi-input multi-output radar device according to an embodiment of the present invention reduces digital signal throughput even when high performance of high frequency and high resolution is required, and reduces hardware complexity in an environment operating at a high frequency above a certain level. can be reduced.

In addition, the multiple-input, multiple-output radar device according to an embodiment of the present invention can obtain coherent processing gain of transmission signals, effectively detecting objects located at a distance without causing a decrease in each resolution. You can.

Figures 2 (a) and (b) are diagrams for explaining an example in which the transmission antenna sub-array set and the reception antenna array of Figure 1 are disposed on a substrate.

In Figure 2, an example is shown in which a transmit antenna sub-array set and a receive antenna array are disposed on each of the substrates 700a and 700b. The first and second directions D1 and D2 represent directions parallel to the upper surfaces of the substrates 700a and 700b and intersect each other perpendicularly, and the third direction D3 represents a direction perpendicular to the upper surfaces of the substrates 700a and 700b.

Referring to (a) of FIG. 2, a transmitting antenna sub-array set 110a and a receiving antenna array 310a may be disposed on the substrate 700a, respectively. More specifically, each of the transmitting antenna sub-array set 110a and the receiving antenna array 310a may include a plurality of antennas, and may be parallel to the virtual line VL1 extending in the first direction D1. The plurality of antennas may be arranged on symmetrical first and second virtual lines PL1 and PL2.

Referring to (b) of FIG. 2, a transmitting antenna sub-array set 110b and a receiving antenna array 310b may be disposed on the substrate 700b, respectively. More specifically, each of the transmitting antenna sub-array set 110b and the receiving antenna array 310b may include a plurality of antennas, and a virtual line perpendicular to the virtual line VL2 extending in the second direction D2. The plurality of antennas may be disposed on the third line PL3.

In one embodiment, each of the transmit antenna sub-array sets 110a and 110b may correspond to the transmit antenna sub-array set 110 described above with reference to FIG. 1, and each of the receive antenna arrays 310a and 310b may correspond to the transmit antenna sub-array set 110 described above with reference to FIG. Each may correspond to the receiving antenna array 310 described above with reference to FIG. 1. As will be described later with reference to FIG. 9, etc., when the plurality of antennas are configured as antenna sub-arrays in the receiving device, a receiving antenna sub-array set may be placed at the location where the receiving antenna arrays 310a and 310b are placed. there is.

Since the examples shown in (a) and (b) of FIGS. 2 do not limit the form in which the transmitting antenna sub-array set and the receiving antenna array are disposed on the substrate, the transmitting antenna sub-array set and the receiving antenna array As long as the plurality of antennas included in each antenna array are arranged along the first direction D1, the relative positions between the transmitting antenna sub-array set and the receiving antenna array can be changed.

FIG. 3 is a diagram illustrating an example of arrangement of antennas included in each of the transmit antenna sub-array set and the receive antenna array of FIG. 1 .

Referring to FIG. 3, the transmission antenna sub-array set 110 may include first to P-th transmission antenna sub-arrays (P is an integer of 2 or more) 111, 113, and 115, and first to P-th transmission antenna sub-arrays 111, 113, and 115. Each of the transmission antenna sub-arrays 111, 113, and 115 may include first to Mth transmission antennas (M is an integer of 2 or more) arranged in a row along the first direction D1 on the substrate. For example, the first transmission antenna sub-array 111 may include the first to Mth transmission antennas (TA11, TA12, TA13, and TA1M), and the second transmission antenna sub-array 113 may include the first to Mth transmission antennas (TA11, TA12, TA13, and TA1M), and the second transmission antenna sub-array 113 may include the first to M It may include the M-th transmission antennas (TA21, TA22, TA23, and TA2M), and the P-th transmission antenna sub-array 115 may include the first to M-th transmission antennas (TAP1, TAP2, TAP3, and TAPM). You can.

The receiving antenna array 310 is spaced apart from the first to M transmitting antennas (TA11, TA12, TA13, TA1M, TA21, TA22, TA23, TA2M, TAP1, TAP2, TAP3, and TAPM) in the first direction (D1). It may include first to Qth reception antennas (Q is an integer of 2 or more) (RA1, RA2, RA3, and RAQ) arranged in a row along .

In one embodiment, the first transmission antennas included in two adjacent transmission antenna sub-arrays (for example, 111 and 113) among the first to P transmission antenna sub-arrays 111, 113, and 115 ( For example, TA11 and TA21 may be spaced apart by a first distance in the first direction D1, and two adjacent receiving antennas among the first to Q receiving antennas RA1, RA2, RA3, and RAQ ( For example, RA1 and RA2) may be spaced apart from each other in the first direction D1 by a second distance that is different from the first distance. The first interval and the second interval will be described later with reference to FIGS. 6 and 8.

FIG. 4 is a diagram illustrating an example of a first beamforming unit included in the beamforming network of FIG. 1.

In FIG. 4, the first to M-th transmission antennas (TA11, TA12, TA13, and TA1M) included in the first transmission antenna sub-array 111 of FIG. 3, and the first to M-th transmission antennas (TA11, TA12) , TA13 and TA1M) and a first beamforming unit 135-1 electrically connected to each other are shown.

3 and 4, the first beamforming unit 135-1 includes a digital-to-analog converter 183, a mixer 181, and first to M phase shifters 161, 163, 165, and 167. ) may include.

The digital-analog converter 183 may generate a first baseband signal BS1 based on the input digital signal and provide the first baseband signal BS1 to the mixer 181. The mixer 181 converts the first baseband signal BS1 into an RF signal, which is a high frequency signal, based on the first baseband signal BS1 and the oscillation signal FLO1, and converts the RF signal into a first to M phase It can be provided by each of the transition devices 161, 163, 165, and 167.

The first to M phase shifters (161, 163, 165, and 167) delay the phase of the RF signal by each predetermined delay amount to transmit the first to M transmit antennas (TA11, TA12, TA13, and TA1M). One of the corresponding ones can be provided.

In one embodiment, the delay amount by which each of the first to M phase shifters 161, 163, 165, and 167 delays the phase of the RF signal is the first to M transmit antennas TA11, TA12, It can be determined based on the direction of transmission signals transmitted by TA13 and TA1M), and the amount of delay can be controlled by the first control signal (CTL1) described above with reference to FIG. 1.

For convenience of explanation, only the first beamforming unit 135-1 corresponding to the first transmission antenna sub-array 111 is shown and described in FIG. 4, but the second to P-th transmission antenna sub-arrays of FIG. 3 Each of 113 and 115 may also be electrically connected to the second to P beamforming units in the same manner as the first beamforming unit 135-1. By the above configuration, the transmission circuit may include first to P beamforming units corresponding to the first to P transmit antenna sub-arrays 111, 113, and 115, respectively, and the first to P Each of the beamforming units may include a digital-to-analog converter, a mixer, and first to M phase shifters.

FIG. 5 is a diagram illustrating an example of a first receiving unit included in the receiving circuit of FIG. 1.

In FIG. 5, a first receiving antenna (RA1) included in the receiving antenna array 310 of FIG. 3 and a first receiving unit (330-1) electrically connected to the first receiving antenna (RA1) are shown.

Referring to FIGS. 3 and 5 , the first receiver 330-1 may include an analog-to-digital converter 383 and a mixer 381.

The mixer 381 converts the reflected signal into a baseband signal based on the reflected signal and the oscillation signal (FLO2) received from the first receiving antenna (RA1), and converts the baseband signal into an analog-to-digital converter 383. can be provided. The analog-to-digital converter 383 can convert the baseband signal into a digital signal.

For convenience of explanation, only the first receiving unit 330-1 corresponding to the first receiving antenna RA1 is shown and described in FIG. 5, but the second to Q receiving antennas RA2 to RAQ of FIG. 3 are shown in FIG. Each may also be electrically connected to the second to Qth receivers in the same manner as the first receiver 330-1. By the above configuration, the receiving circuit may include first to Q-th receiving units corresponding to first to Q-th receiving antennas, respectively, and each of the first to Q-th receiving units may include an analog-to-digital converter and a mixer. It can be included.

FIG. 6 is a diagram illustrating an example in which the transmitting antennas included in the transmitting antenna sub-array set of FIG. 1 and the receiving antennas included in the receiving antenna array are disposed on a substrate.

In FIG. 6, the first to Mth transmission antennas (TA11, TA12, TA13, TA1M, TA21, TA22, An example in which TA23, TA2M, TAP1, TAP2, TAP3, and TAPM) and first to Q receiving antennas (RA1, RA2, RA3, and RAQ) are disposed on a substrate is shown. Adjacent transmission antennas (for example, TA11 and TA12) among the transmission antennas included in each of the first to P transmission antenna subarrays 111, 113, and 115 are spaced apart by a preset distance DT11. Considered.

Referring to FIG. 6, first transmission antennas included in two adjacent transmission antenna sub-arrays (for example, 111 and 113) among the first to P-th transmission antenna sub-arrays 111, 113, and 115. (For example, TA11 and TA21) may be spaced apart from each other by a first distance in the first direction D1.

Among the first to Qth receiving antennas (RA1, RA2, RA3, and RAQ), two adjacent receiving antennas (for example, RA1 and RA2) have a second interval different from the first interval in the first direction (D1). It can be separated by as much.

In one embodiment, the first interval is the first to Mth transmission antennas (e.g., TA11, TA12, TA13) included in one of the first to Pth transmission antenna subarrays 111, 113, and 115. and TA1M), and the second interval may be equal to the size of the entire opening of the first to P-th transmission antenna sub-arrays 111, 113, and 115.

In one embodiment, the first interval may be determined according to [Equation 1] below, and the second interval may be determined according to [Equation 2] below.

[Equation 1]

DT12 = DT11 * M

In [Equation 1], DT12 is the first interval, and DT11 is adjacent transmission antennas (e.g. For example, TA11 and TA12) are the spacing apart, and M is the number of transmission antennas included in one of the first to Pth transmission antenna sub-arrays 111, 113, and 115.

[Equation 2]

DR1 = DT11 * M * P

In [Equation 2], DR1 represents the second interval, and DT11 represents adjacent transmission antennas among the transmission antennas included in one of the first to Pth transmission antenna sub-arrays 111, 113, and 115 ( For example, TA11 and TA12) are the spacing apart, M is the number of transmission antennas included in one of the first to Pth transmission antenna sub-arrays 111, 113, and 115, and P is the transmission antenna sub-array is the number of them.

FIG. 7 is a diagram illustrating an example of a virtual reception antenna array formed in the signal processing circuit of FIG. 1.

In FIG. 7, virtual reception antennas (VRA1, VRA2, VRA3, VRA4, ..., VRA(PxQ-1), and VRA(PxQ)) included in the virtual reception antenna array described above with reference to FIG. 1 are disposed. An example is shown.

Referring to FIGS. 6 and 7, among the virtual reception antennas (VRA1, VRA2, VRA3, VRA4, ..., VRA(PxQ-1) and VRA(PxQ)), two adjacent virtual reception antennas (e.g. , VRA1 and VRA2) may be spaced apart by a third interval.

In one embodiment, the third interval may be spaced apart from the first interval in FIG. 6 .

In one embodiment, the third interval is the first to Mth transmission antennas (e.g., TA11, TA12, TA13) included in one of the first to Pth transmission antenna subarrays 111, 113, and 115. and TA1M) may be equal to the size of the overall opening.

In one embodiment, the third interval may be determined according to Equation 3 below.

[Equation 3]

DV = DT11 * M

In [Equation 1], DV is the third interval, and DT11 is adjacent transmission antennas (e.g. For example, TA11 and TA12) are the spacing apart, and M is the number of transmission antennas included in one of the first to Pth transmission antenna sub-arrays 111, 113, and 115.

FIG. 8 is a diagram illustrating an example in which the transmitting antennas included in the transmitting antenna sub-array set of FIG. 1 and the receiving antennas included in the receiving antenna array are arranged on a substrate.

In FIG. 8, 1st to Mth transmission antennas (TA11, TA12, TA13, TA1M, TA21, TA22, An example in which TA23, TA2M, TAP1, TAP2, TAP3, and TAPM) and first to Q receiving antennas (RA1, RA2, RA3, and RAQ) are disposed on the substrate is shown. Adjacent transmission antennas (for example, TA11 and TA12) among the transmission antennas included in each of the first to P transmission antenna subarrays 111, 113, and 115 are spaced apart by a preset distance DT11. Considered.

Referring to FIG. 8, first transmit antennas included in two adjacent transmit antenna sub-arrays (for example, 111 and 113) among the first to P transmit antenna sub-arrays 111, 113, and 115. (For example, TA11 and TA21) may be spaced apart from each other by a fourth distance in the first direction D1.

Among the first to Qth receiving antennas (RA1, RA2, RA3, and RAQ), two adjacent receiving antennas (for example, RA1 and RA2) have a fifth interval different from the fourth interval in the first direction (D1). It can be separated by as much.

In one embodiment, the fourth spacing is equal to the size of the apertures of all of the first to Qth receiving antennas (RA1, RA2, RA3, and RAQ), and the fifth spacing is the same as the size of the apertures of the first to Pth transmitting antenna subarrays. It may be the same as the size of one of (111, 113, and 115) apertures.

In one embodiment, the fourth interval may be determined according to [Equation 4] below, and the fifth interval may be determined according to [Equation 5] below.

[Equation 4]

DT22 = DT11 * M * Q

In [Equation 4], DT22 is the fourth interval, and DT11 is adjacent transmission antennas (e.g. For example, TA11 and TA12) are the spacing apart, M is the number of transmitting antennas included in one of the first to P transmitting antenna sub-arrays 111, 113, and 115, and Q is included in the receiving antenna array. This is the number of receiving antennas.

.

[Equation 5]

DR2 = DT11 * M

In [Equation 5], DR2 represents the fifth interval, and DT11 represents adjacent transmission antennas among the transmission antennas included in one of the first to Pth transmission antenna sub-arrays 111, 113, and 115 ( For example, TA11 and TA12 are the spacing apart, and M is the number of transmission antennas included in one of the first to Pth transmission antenna sub-arrays 111, 113, and 115.

Transmission antennas (TA11, TA12, TA13, TA1M, TA21, TA22, TA23, TA2M, TAP1, TAP2, TAP3) included in the first to Pth transmission antenna subarrays 111, 113, and 115 shown in FIG. 8 and TAPM) and the receiving antennas (RA1, RA2, RA3, and RAQ) included in the receiving antenna array have a different separation distance from the embodiment shown in FIG. 6, the antenna generated by the embodiment of FIG. 8 A virtual receiving antenna array including virtual receiving antennas may have the same form as shown in FIG. 7. Accordingly, among the virtual receiving antennas formed according to the embodiment shown in FIG. 8, two adjacent virtual receiving antennas may be spaced apart by the third interval in FIG. 7.

Figure 9 is a block diagram showing a multi-input multi-output radar device according to an embodiment of the present invention.

Compared to the multiple-input multiple-output radar device 10 shown in FIG. 9, the multiple-input multiple-output radar device 10a shown in FIG. 9 has a plurality of devices included in the receiving device 300a as well as the transmitting device 100. Antennas are also composed of antenna sub-arrays. Hereinafter, duplicate descriptions of components having the same reference numerals as those shown in FIG. 1 will be omitted.

Referring to FIG. 9, the multiple-input multiple-output radar device 10a may include a transmitting device 100, a receiving device 300a, and a control circuit 500. The transmitting device 100 includes a transmitting antenna sub-array set 110 and a transmitting circuit 130, and the transmitting circuit 130 may include a beamforming network 135. The receiving device 300a includes a receiving antenna sub-array set 310a and a receiving circuit 330, and the receiving circuit 335 may include a signal processing circuit 335.

In one embodiment, a plurality of antennas disposed within the transmitting device 100 may constitute a transmitting antenna sub-array set 110, and the plurality of antennas disposed within the receiving device 300a may constitute a receiving antenna sub-array set ( 310a) can be configured.

FIG. 10 is a diagram illustrating an example in which the transmitting antennas included in the transmitting antenna sub-array set of FIG. 9 and the receiving antennas included in the receiving antenna sub-array set of FIG. 9 are disposed on a substrate.

In FIG. 10, the first to Mth transmission antennas (TA11, TA12, TA13, TA1M) included in each of the first to Pth transmission antenna subarrays 111, 113, and 115 included in the transmission antenna subarray set. , TA21, TA22, TA23, TA2M, TAP1, TAP2, TAP3 and TAPM), and each of the first to Qth receiving antenna subarrays 311, 313 and 315 included in the receiving antenna subarray set. An example in which 1st to Nth receiving antennas (RA11, RA12, RA13, RA1N, RA21, RA22, RA23, RA2N, RAQ1, RAQ2, RAQ3, and RAQN) are disposed on a substrate is shown.

Adjacent transmission antennas (for example, TA11 and TA12) among the transmission antennas included in each of the first to P transmission antenna subarrays 111, 113, and 115 are spaced apart by a preset distance DT31, Adjacent receiving antennas (for example, RA11 and RA12) among the receiving antennas included in each of the first to Q receiving antenna subarrays 311, 313, and 315 are spaced apart by a preset distance DR31. Considered.

Referring to FIG. 10, first transmit antennas included in two adjacent transmit antenna sub-arrays (for example, 111 and 113) among the first to P transmit antenna sub-arrays 111, 113, and 115. (For example, TA11 and TA21) may be spaced apart from each other by a sixth interval in the first direction D1.

First receiving antennas (e.g., RA11) included in two adjacent receiving antenna sub-arrays (e.g., 311 and 313) among the first to Q-th receiving antenna sub-arrays (311, 313, and 315), respectively and RA21) may be spaced apart by a seventh interval in the first direction D1.

In one embodiment, the sixth interval is the first to Mth transmission antennas (e.g., TA11, TA12, TA13) included in one of the first to Pth transmission antenna subarrays 111, 113, and 115. and TA1M), and the seventh interval may be equal to the size of the entire opening of the first to Pth transmission antenna sub-arrays 111, 113, and 115.

In one embodiment, the sixth interval may be determined according to [Equation 6] below, and the seventh interval may be determined according to [Equation 7] below.

[Equation 6]

DT32 = DT11 * M

In [Equation 6], DT32 is the sixth interval, and DT11 is adjacent transmission antennas (e.g. For example, TA11 and TA12) are the spacing apart, and M is the number of transmission antennas included in one of the first to Pth transmission antenna sub-arrays 111, 113, and 115.

[Equation 7]

DR32 = DT11 * M * P

In [Equation 7], DR32 represents the seventh interval, and DT11 represents adjacent transmission antennas among the transmission antennas included in one of the first to Pth transmission antenna sub-arrays 111, 113, and 115 ( For example, TA11 and TA12) are the spacing apart, M is the number of transmission antennas included in one of the first to Pth transmission antenna sub-arrays 111, 113, and 115, and P is the transmission antenna sub-array is the number of them.

FIG. 11 is a diagram illustrating simulation conditions for detecting objects using a multi-input multi-output radar device according to an embodiment of the present invention.

Referring to FIG. 11, the positions of the first and second objects T1 and T2 can be estimated using the multiple-input multiple-output radar device 10 of FIG. 1. A reference direction (RD) centered on the multi-input multi-output radar device 10 may be set, and in one embodiment, the reference direction (RD) is a third direction perpendicular to the upper surface of the substrate described above with reference to FIG. 1, etc. It may be direction (D3).

Each of the first and second objects T1 and T2 may be located at a distance of 10 m from the multi-input multi-output radar device 10, and the first object T1 has the reference direction RD as its center. The second object T2 may be positioned deviated 10.2 ㅀ to the left, and the second object T2 may be positioned 23.6 ㅀ to the right around the reference direction RD.

Under the above simulation conditions, a simulation was performed using the multi-input multi-output radar device 10 including four transmitting antenna sub-arrays each including four transmitting antennas, and eight receiving antennas.

FIGS. 12, 13, and 14 are diagrams for explaining simulation results of detecting objects using the multi-input multi-output radar device of FIG. 1 under the simulation conditions of FIG. 11.

In FIGS. 12, 13, and 14, simulation results using a conventional multi-input multi-output radar device under the same simulation conditions are shown.

Referring to FIGS. 11, 12, 13, and 14, the multi-input multi-output radar device 10 detects an object by scanning the front area centered on the reference direction (RD) and detects the object using a digital beam. Based on the forming result, angle information related to the location of the detected object may be estimated.

Figure 12 shows a case where the scanning angle is set to 1ㅀ, Figure 13 shows a case where the scanning angle is set to 5ㅀ, and Figure 14 shows a case where the scanning angle is set to 10ㅀ. .

Figures 15 (a) and (b) show the directions of null points occurring in the analog beam pattern of the transmitting antenna sub-array set of Figure 1 and the directions of grating lobes occurring in the digital beam pattern formed in the receiving circuit of Figure 1. This is a drawing to explain the matching operation.

FIG. 15(a) shows the results of simulation using the multiple-input multiple-output radar device 10 described above with reference to FIG. 1, and FIG. 15(b) shows the multiple-input multiple-output radar device 10 described above with reference to FIG. 9. The results of simulation performed using the multi-output radar device 10a are shown.

When the direction of the main lobe of the analog beam pattern and the direction of the main lobe of the digital beam pattern differ by about 5 ㅀ, the results of simulation using the multi-input multi-output radar device 10 (Figure 15) In (a)), the signal level of the normalized grating lobes is approximately -13 dB, and as a result of simulation using the multi-input multi-output radar device 10a ((b) of FIG. 15), the normalized grating The signal level of the lobes is approximately -27 dB.

Therefore, in a real environment, when detecting an object using the multiple-input multiple-output radar devices 10 and 10a according to an embodiment of the present invention, as described above with reference to FIG. 1, a transmit antenna sub-array set (or Before the detection, an operation of matching the directions of null points occurring in the analog beam pattern formed by the antenna subarrays included in the transmitting antenna subarray set and the direction of the grating lobes occurring in the digital beam pattern formed by the receiving circuit is performed. It must be done in advance.

Figure 16 is a flowchart showing a method of operating a multi-input multi-output radar device according to an embodiment of the present invention.

Referring to FIG. 16, transmission signals orthogonal to each other may be radiated toward the object (S100). The step S100 includes the first to Pth transmission antenna sub-arrays (P is 2) each including the first to Mth transmission antennas (M is an integer of 2 or more) described above with reference to FIGS. 1 and 3, etc. It can be performed by an integer above).

Reflected signals reflected from the object may be received in response to the transmission signals (S200). Step S200 may be performed by a receiving antenna array including the first to Qth receiving antennas described above with reference to FIGS. 1 and 3, etc.

The reflected signals are converted into baseband signals, and a virtual receiving antenna array including (P * Q) virtual receiving antennas may be formed based on the baseband signals (S300). Step S300 may be performed by the receiving circuit described above with reference to FIGS. 1 and 3, etc.

Digital beamforming on the baseband signals may be performed using the virtual reception antenna array (S400). Step S400 may be performed by the receiving circuit described above with reference to FIGS. 1 and 3, etc.

Angular information related to the location of the object may be estimated based on the results of the digital beamforming. Step S500 may be performed by the control circuit described above with reference to FIGS. 1 and 3, etc.

As described above, the multiple-input, multiple-output radar device according to an embodiment of the present invention reduces digital signal throughput even when high performance of high frequency and high resolution is required, and reduces hardware complexity in an environment operating at a high frequency above a certain level. can be reduced.

In addition, the multiple-input, multiple-output radar device according to an embodiment of the present invention can obtain coherent processing gain of transmission signals, effectively detecting objects located at a distance without causing a decrease in each resolution. You can.

The present invention can be applied to various communication devices and systems, including a multi-input multi-output radar device and/or a radar system using a multi-input multiple output radar device, and various electronic devices and systems including the same. Therefore, the present invention is applicable to a mobile phone, a smart phone, a tablet personal computer (PC), a laptop computer, a personal digital assistant (PDA), and a portable multimedia player. player; digital camera, portable game console, navigation device, wearable device, internet of things (IoT) device, internet of everything It can be usefully used in various electronic devices such as IoE devices, virtual reality (VR) devices, and augmented reality (AR) devices.

In particular, the present invention is applicable to 5G mobile communication systems (e.g., about 28 GHz, 40 GHz, etc.), military radar and communication systems (e.g., X band, Ku band, W band, etc.), and satellite communication systems (e.g. For example, Ka band, etc.), automotive radar (for example, self-driving cars) (for example, about 79 GHz, etc.), wireless power transmission (for example, about 5.8 GHz, etc.), etc. .

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can.

Claims (12)

First to Pth transmission antenna sub-arrays each including first to Mth transmission antennas (M is an integer of 2 or more) arranged in a row along a first direction on a substrate, and radiating transmission signals toward an object. (P is an integer greater than or equal to 2);
a transmission circuit that converts first baseband signals into the transmission signals based on a first control signal;
It includes first to Q receiving antennas (Q is an integer of 2 or more) arranged in a line along the first direction and spaced apart from the first to M transmitting antennas on the substrate, and responds to the transmission signals. a receiving antenna array that receives reflected signals reflected from the object;
a receiving circuit that converts the reflected signals into second baseband signals based on a second control signal and performs digital beamforming on the second baseband signals to form a digital beam pattern; and
Comprising a control circuit that generates the first and second control signals,
The transmission signals are radio frequency (RF) signals orthogonal to each other,
the receiving circuit forms a virtual receiving antenna array including (P * Q) virtual receiving antennas based on the second baseband signals,
The receiving circuit is,
The grating lobes are generated by matching the directions of the grating lobes occurring in the digital beam pattern and the directions of null points occurring in the analog beam patterns of the first to P-th transmission antenna sub-arrays. ) A multi-input multi-output radar device characterized in that it cancels out. delete According to claim 1,
The first transmission antennas included in two adjacent transmission antenna sub-arrays among the first to P-th transmission antenna sub-arrays are spaced apart by a first distance in the first direction,
Two adjacent receiving antennas among the first to Q receiving antennas are spaced apart from each other in the first direction by a second interval different from the first interval. First to Pth transmission antenna sub-arrays each including first to Mth transmission antennas (M is an integer of 2 or more) arranged in a row along a first direction on a substrate, and radiating transmission signals toward an object. (P is an integer greater than or equal to 2);
a transmission circuit that converts first baseband signals into the transmission signals based on a first control signal;
It includes first to Q receiving antennas (Q is an integer of 2 or more) arranged in a line along the first direction and spaced apart from the first to M transmitting antennas on the substrate, and responds to the transmission signals. a receiving antenna array that receives reflected signals reflected from the object;
a receiving circuit that converts the reflected signals into second baseband signals based on a second control signal and performs digital beamforming on the second baseband signals to form a digital beam pattern; and
Comprising a control circuit that generates the first and second control signals,
The transmission signals are radio frequency (RF) signals orthogonal to each other,
the receiving circuit forms a virtual receiving antenna array including (P * Q) virtual receiving antennas based on the second baseband signals,
The first transmission antennas included in two adjacent transmission antenna sub-arrays among the first to P-th transmission antenna sub-arrays are spaced apart by a first distance in the first direction,
Among the first to Qth receiving antennas, two adjacent receiving antennas are spaced apart in the first direction by a second distance different from the first distance,
The first spacing is equal to the size of the aperture of all the first to Mth transmitting antennas,
The second interval is the same as the size of the apertures of the first to Pth transmission antenna sub-arrays. First to Pth transmission antenna sub-arrays each including first to Mth transmission antennas (M is an integer of 2 or more) arranged in a row along a first direction on a substrate, and radiating transmission signals toward an object. (P is an integer greater than or equal to 2);
a transmission circuit that converts first baseband signals into the transmission signals based on a first control signal;
It includes first to Q receiving antennas (Q is an integer of 2 or more) arranged in a line along the first direction and spaced apart from the first to M transmitting antennas on the substrate, and responds to the transmission signals. a receiving antenna array that receives reflected signals reflected from the object;
a receiving circuit that converts the reflected signals into second baseband signals based on a second control signal and performs digital beamforming on the second baseband signals to form a digital beam pattern; and
Comprising a control circuit that generates the first and second control signals,
The transmission signals are radio frequency (RF) signals orthogonal to each other,
the receiving circuit forms a virtual receiving antenna array including (P * Q) virtual receiving antennas based on the second baseband signals,
The first transmission antennas included in two adjacent transmission antenna sub-arrays among the first to P-th transmission antenna sub-arrays are spaced apart by a first distance in the first direction,
Two adjacent receiving antennas among the first to Qth receiving antennas are spaced apart in the first direction by a second distance different from the first distance,
The first spacing is equal to the size of the aperture of all the first to Qth receiving antenna arrays,
The second spacing is equal to the size of an opening of one of the first to Pth transmission antenna sub-arrays. The method of claim 1, wherein the transmitting circuit:
Comprising first to Pth beamforming units corresponding to the first to Pth transmission antenna subarrays, respectively,
Each of the first to P beamforming units
a digital-to-analog converter providing a corresponding one of the first baseband signals;
a mixer that converts a corresponding one of the first baseband signals into a radio frequency (RF) signal; and
A multiple-input, multiple-output radar device comprising first to Mth phase shifters that delay the phase of the RF signal by a predetermined delay amount and provide it to a corresponding one of the first to Mth transmission antennas. . According to clause 6,
The multi-input multi-output radar device scans a front area centered on a reference direction perpendicular to the upper surface of the substrate to detect the object,
The receiving circuit is a multiple-input, multiple-output radar device characterized in that it estimates angular information related to the location of the object based on the results of the digital beamforming. First to Pth transmission antenna sub-arrays each including first to Mth transmission antennas (M is an integer of 2 or more) arranged in a row along a first direction on the substrate, and radiating transmission signals toward an object. (P is an integer greater than or equal to 2);
a transmission circuit that converts first baseband signals into the transmission signals based on a first control signal;
Each includes first to Nth receiving antennas (N is an integer of 2 or more) arranged in a line along the first direction and spaced apart from the first to Mth transmitting antennas on the substrate, and the transmission signal first to Qth receiving antenna sub-arrays (Q is an integer of 2 or more) that receive reflected signals reflected from the object in response to;
a receiving circuit that converts the reflected signals into second baseband signals based on a second control signal and performs digital beamforming on the second baseband signals to form a digital beam pattern; and
Comprising a control circuit that generates the first and second control signals,
The transmission signals are RF (radio frequency) signals orthogonal to each other,
The receiving circuit separates signals orthogonal to each other among the second baseband signals to form a virtual receiving antenna array including (P * Q) virtual receiving antennas,
The receiving circuit is,
The grating lobes are generated by matching the directions of the grating lobes occurring in the digital beam pattern and the directions of null points occurring in the analog beam patterns of the first to P-th transmission antenna sub-arrays. ) A multi-input multi-output radar device characterized in that it cancels out. delete First to Pth transmission antenna sub-arrays each including first to Mth transmission antennas (M is an integer of 2 or more) arranged in a row along a first direction on the substrate, and radiating transmission signals toward an object. (P is an integer greater than or equal to 2);
a transmission circuit that converts first baseband signals into the transmission signals based on a first control signal;
Each includes first to Nth receiving antennas (N is an integer of 2 or more) arranged in a line along the first direction and spaced apart from the first to Mth transmitting antennas on the substrate, and the transmission signal first to Qth receiving antenna sub-arrays (Q is an integer of 2 or more) that receive reflected signals reflected from the object in response to;
a receiving circuit that converts the reflected signals into second baseband signals based on a second control signal and performs digital beamforming on the second baseband signals to form a digital beam pattern; and
Comprising a control circuit that generates the first and second control signals,
The transmission signals are RF (radio frequency) signals orthogonal to each other,
The receiving circuit separates signals orthogonal to each other among the second baseband signals to form a virtual receiving antenna array including (P * Q) virtual receiving antennas,
The first transmission antennas included in two adjacent transmission antenna sub-arrays among the first to P-th transmission antenna sub-arrays are spaced apart by a first distance in the first direction,
The first receiving antennas included in two adjacent receiving antenna sub-arrays among the first to Q-th receiving antenna sub-arrays are spaced apart from each other in the first direction by a second interval different from the first interval. Output radar device. The method of claim 10, wherein the first spacing is equal to the size of the apertures of all the first to Mth transmitting antennas,
The second interval is the same as the size of the apertures of the first to Pth transmission antenna sub-arrays. The first to Pth transmission antenna sub-arrays (P is an integer of 2 or more), each of which includes the first to Mth transmission antennas (M is an integer of 2 or more), radiate transmission signals orthogonal to each other toward the object. step;
Receiving reflected signals reflected from the object in response to the transmission signals, at a reception antenna array including first to Qth reception antennas;
converting, in a receiving circuit, the reflected signals into baseband signals and forming a virtual receiving antenna array including (P * Q) virtual receiving antennas based on the baseband signals;
forming a digital beam pattern by performing digital beamforming on the baseband signals using the virtual receiving antenna array, in the receiving circuit; and
In a control circuit, estimating angular information related to the position of the object based on the results of the digital beamforming,
The receiving circuit is,
The grating lobes are generated by matching the directions of the grating lobes occurring in the digital beam pattern and the directions of null points occurring in the analog beam patterns of the first to P-th transmission antenna sub-arrays. ) A method of operating a multi-input multi-output radar device, characterized in that canceling out the