radar device

Abstract

A radar device is provided. The radar device includes a radar circuit configured to transmit a first radar signal occupying a first frequency band and a second radar signal occupying a second frequency band. The radar device includes an antenna device comprising a first group of first antennas and a second group of second antennas, and the antenna device is configured to selectively transduce the first radar signal via the first antennas but not via the second antennas, and to selectively transduce the second radar signal via the second antennas but not via the first antennas. The radar device includes a signal processing device configured to detect target reflections via a first propagation channel from the first radar signal and to detect target reflections via a second propagation channel from the second radar signal. The signal processing device is configured to jointly evaluate target reflections via the first propagation channel and target reflections via the second propagation channel to form a common virtual antenna array for determining the angular position of a target object.

Description

Technical Field

[0001] The present disclosure relates to a radar device for automotive applications, a vehicle having such a radar device, and a method for operating a radar device for automotive applications. Background Art

[0002] Radar devices are used in automotive applications to detect and locate target objects, such as other vehicles, obstacles, or lane boundaries. These target objects may be located in front of, behind, or to the side of the vehicle. Such radar devices typically include a signal generator that generates a radar signal; an antenna device that illuminates the target object with the radar signal and captures the radar signal reflected from the target object; and a signal receiver that analyzes the radar signal reflected from the target object. The information extracted from the reflected radar signal can then be used for advanced driver assistance system (ADAS) features such as emergency brake assist, adaptive cruise control, and lane change assist.

[0003] Antenna systems for automotive applications typically include several transmitting antennas and several receiving antennas. Typically, the radar circuitry is able to modify the individual signals fed to the individual transmitting antennas independently of one another, for example in terms of frequency, amplitude, or phase. Similarly, the radar circuitry is able to analyze the individual signals captured by the individual receiving antennas independently of one another. Typically, each pair of transmitting and receiving antennas defines a propagation channel for the radar signal, which runs from the respective transmitting antenna to the target object and back to the respective receiving antenna. When the individual transmitting antennas are fed with orthogonal signals that can be separated at the receiver, ensuring that each antenna receives all transmitted signals, the number of propagation channels available for signal evaluation is equal to the product of the number of transmitting antennas and the number of receiving antennas.

[0004] To determine the angular position of a target object illuminated by a radar system, the transmitting and receiving antennas are typically positioned at different locations on the antenna system. The angular position of the target object is then inferred from the phase shifts detected by the radar signals propagating along separate propagation channels. To resolve the angular position of the target object along a specific direction, the individual antennas of the radar system must be displaced relative to one another along that direction. Generally, the accuracy with which the angular position of the target object can be determined increases with the number of propagation channels, and therefore the number of available individual antennas.

[0005] Therefore, there is a need to increase the number of propagation channels that can be used to determine the angular position of a target object illuminated by a radar device. Summary of the Invention

[0006] In one aspect, the present disclosure is directed to a radar device for automotive applications, the radar device comprising: a radar circuit for transmitting and receiving radar signals; an antenna device for transducing the radar signals; and a signal processing device for processing the radar signals. The radar circuit is configured to transmit and receive a first radar signal occupying a first frequency band and a second radar signal occupying a separate second frequency band. The antenna device comprises a first set of first antennas and a second set of second antennas, and the antenna device is configured to selectively transduce the first radar signal via the first antennas but not the second antennas, and selectively transduce the second radar signal via the second antennas but not the first antennas. The signal processing device is configured to detect target reflections via a first propagation channel from the first radar signal and target reflections via a second propagation channel from the second radar signal, wherein the signal processing device is configured to jointly evaluate the target reflections via the first propagation channel and the target reflections via the second propagation channel to form a common virtual antenna array for determining the angular position of a target object illuminated by the antenna device.

[0007] The present disclosure is based on the concept that the number of propagation channels that can be used to determine the angular position of a target object can be increased by augmenting an antenna array operating in a first frequency band with antennas operating in a separate second frequency band. In other words, the propagation channels established between the antennas operating in the second frequency band are added to the propagation channels established between the antennas operating in the first frequency band. Adding the first propagation channel and the second propagation channel to form a common virtual antenna array results in an increase in the achievable angular resolution, which is inversely proportional to the number of propagation channels used and is determined by Given by , where λ is the wavelength of the radar signal, N is the number of propagation channels, d is the effective spacing of the virtual antennas of the virtual antenna array, and θ is the angular position of the target object. Additional propagation channels can, for example, be used to increase the angular resolution in azimuth and / or elevation.

[0008] The first group of first antennas and / or the second group of second antennas can each operate in a multiple-input multiple-output (MIMO) configuration, for example, wherein the first group of antennas and / or the second group of antennas each include multiple transmit antennas and multiple receive antennas. Separate first and / or second propagation channels are then defined between separate combinations of transmit antennas and receive antennas in the corresponding antenna groups.

[0009] Because the first and second antennas transduce in separate frequency bands, a first propagation channel is established only between the first antennas, and a second propagation channel is established only between the second antennas. There is no propagation channel established between one of the first antennas and one of the second antennas. At least a portion of the first antennas is arranged at a location separated from all second antennas, and at least a portion of the second antennas is arranged at a location separated from all first antennas. For example, the antenna arrangement may include a single pair of one of the first transmitting antennas and one of the second transmitting antennas, forming a first reference transmitting antenna and a second reference transmitting antenna, respectively, and a single pair of one of the first receiving antennas and one of the second receiving antennas, forming a first reference receiving antenna and a second reference receiving antenna, respectively. The first reference transmitting antenna and the second reference transmitting antenna may be arranged at the same location on the antenna arrangement, and the first reference receiving antenna and the second reference receiving antenna may be arranged at the same location on the antenna arrangement. All other first and second antennas may be arranged at separate locations relative to each other.

[0010] To separate the individual radar signals transduced by the transmit antennas after reception at the receive antennas, the individual first radar signals transduced by the transmit antennas of the first antenna group can be generated with mutually independent first separability parameters, and / or the individual second radar signals transduced by the transmit antennas of the second antenna group can be generated with mutually independent second separability parameters. The separability parameters can be, for example, phase shift keying (e.g., binary phase shift keying) or phase modulation (e.g., binary phase modulation). Alternatively, the individual transmit antennas can also use time division multiplexing (TDM) to transmit their radar signals.

[0011] The radar device may be configured to, during evaluation of target reflections by the signal processing device, transmit and receive one of the first radar signals having a separability parameter for ensuring separability between the individual first radar signals, and to transmit and receive one of the second radar signals having the same separability parameter for ensuring separability between the individual second radar signals. For example, the radar device may be configured to transmit and receive all first radar signals having a set of mutually independent separability parameters (such as mutually independent phase codes), and to transmit and receive all second radar signals having the same set of mutually independent separability parameters.

[0012] The radar device (e.g., the signal processing device and / or the radar circuitry) can also be configured to separate the first radar signal from the second radar signal by separating signals within the first frequency band from signals within the second frequency band (e.g., by using a frequency filter or a duplexer). This can enable the first radar signal and the second radar signal to be transmitted simultaneously even when only a limited number of separability parameters are available (e.g., due to hardware limitations, such as binary phase shifters used to implement quadrature phase codes on the radar signals).

[0013] Each pair of transmitting and receiving antennas within the first antenna group implements a separate first propagation channel, and each pair of transmitting and receiving antennas within the second antenna group implements a separate second propagation channel. The signal processing device can use separability parameters of individual radar signals transduced by the antennas of the corresponding groups to distinguish the individual propagation channels within different groups of antennas. The signal processing device can determine the propagation characteristics and / or reflection characteristics of the individual propagation channels by comparing the radar signals transmitted by the antennas associated with the individual propagation channels with the received radar signals and by analyzing the propagation delay introduced by the corresponding propagation channels.

[0014] The radar device can be configured as a continuous wave (CW) radar device, and the radar signal can exhibit signal modulation that is used to determine the propagation delay of individual target reflections traveling along individual propagation channels. Such signal modulation can include frequency modulation, such as a series of frequency chirps, phase modulation, etc. Thus, the radar device can be configured as a frequency modulated continuous wave (FMCW) or phase modulated continuous wave (PMCW) radar device.

[0015] When configured as an FMCW radar device, a single first radar signal may include a series of first frequency chirps across a first frequency band, and a single second radar signal may include a series of second frequency chirps across a second frequency band. The first frequency chirps and the second frequency chirps may each have a constant slope, for example, a constant decreasing slope. Alternatively, the first frequency chirps and the second frequency chirps may all exhibit the same slope.

[0016] The first radar signal and the second radar signal may be configured to simultaneously transmit and receive pulse Doppler (STARPD) signals. Utilizing these STAR PD signals, the first radar signal and the second radar signal may include a plurality of pulsed frequency sweeps over the first frequency band and the second frequency band, respectively.

[0017] The radar device can be configured to simultaneously transmit and receive individual pairs of the first and second radar signals, or all of the first and second radar signals. For example, the radar device can be configured to simultaneously transmit and receive chirp cycles (bursts) of each of the first and second radar signals, and simultaneously capture target reflections of the chirp cycles via all of the first and second propagation channels.

[0018] The signal processing device can be configured to compare, for each propagation channel, a radar signal received via a corresponding receiving antenna with a radar signal transmitted via a corresponding transmitting antenna of the propagation channel to generate a comparison signal representing a propagation delay of a target reflection via the corresponding propagation channel. The signal processing device can generate the comparison signal, for example, by mixing the received radar signal with the instantaneously transmitted radar signal to generate the comparison signal as an intermediate signal at the difference frequency between the received radar signal and the transmitted radar signal. Based on the individual comparison signals, a distance value indicating the distance to the target object can be derived for each of the first propagation channel and the second propagation channel. To this end, by performing a first Fourier transform on the comparison signal of the individual frequency chirp of the corresponding propagation channel, the comparison signal of the individual frequency chirp transmitted via the corresponding propagation channel can be mapped to a set of range bins.

[0019] Furthermore, for each range value of each propagation channel, a target velocity value can be derived. To this end, the signal processing device can be configured to map the comparison signal to a Doppler bin via a second Fourier transform, whereby, for a given range bin, a second Fourier transform is performed on the corresponding range bins of all frequency chirps transmitted via the corresponding propagation channel.

[0020] When signal processing for determining the distance and velocity values of the target object is performed separately for each propagation channel, the signal processing device also jointly evaluates the target reflections via all the first propagation channels and the second propagation channels to determine the angular position of the target object based on the difference in propagation delays exhibited by the individual target reflections when traveling through their corresponding propagation channels. In order to generate different propagation delays, the transmitting antennas and receiving antennas of each first propagation channel and the second propagation channel have a varying relative antenna spacing in the direction along which the angular position of the target object is determined. For example, the relative antenna spacing between the transmitting antenna and the receiving antenna of an individual propagation channel can increase linearly across all the first propagation channels and the second propagation channels. The virtual antennas in the common virtual antenna array composed of the first propagation channels and the second propagation channels have equal effective spacing from each other.

[0021] The signal processing device can jointly evaluate the target reflection via the first propagation channel and the second propagation channel by concatenating the comparison signal of the first propagation channel and the comparison signal of the second propagation channel before signal processing. For example, for each combined range-velocity bin, the signal processing device can perform a third Fourier transform on the concatenated comparison signal of the first propagation channel and the second propagation channel. All Fourier transforms (such as the first Fourier transform and / or the second Fourier transform and / or the third Fourier transform) can be performed as fast Fourier transforms (FFTs).

[0022] Separate signal modulations, such as a first frequency chirp and a second frequency chirp, may be cyclically repeated. The radar circuit may be configured to first generate the first radar signal and then generate the second radar signal, and the antenna device may be configured to first transduce the first radar signal and then transduce the second radar signal. When the first signal modulation and the second signal modulation are cyclically repeated, the first and second radar signals may be alternately generated by the radar circuit and subsequently transduced by the antenna device.

[0023] The radar circuitry of a radar device includes all parts of the radar device that process radar signals at the radar frequency used to illuminate a target object. Therefore, the radar circuitry constitutes the radar front end of the radar device. The radar circuitry may include a signal generator that generates the radar signal and a signal receiver that receives and measures the radar signal. The radar circuitry may be configured as a transceiver comprising a transmitter (e.g., a signal generator) and a receiver.

[0024] The radar circuit is configured to transmit, receive, or process radar signals. The radar circuit can transmit and receive radar signals by generating the radar signals at a signal generator based on at least one control signal, and / or by evaluating or measuring the radar signals at a signal receiver to generate at least one data signal. Similarly, the radar signals can be routed between the radar circuit and the antenna device by transmitting the radar signals from the radar circuit to the antenna device and / or by transmitting the radar signals from the antenna device to the radar circuit.

[0025] To generate the radar signal based on the at least one control signal, the signal generator includes one or more transmit chains. Each transmit chain is configured to convert a control signal into a transmit port signal and output the transmit port signal to a signal port of the radar circuit, which is connected to an antenna port of the antenna device. The transmit port signal generated by the transmit chain then provides the first radar signal and the second radar signal.

[0026] Each transmit chain may, for example, include a digital-to-analog converter (DAC) controlled by a control signal that controls the transmit chain, and / or one or more signal control devices that are also controlled by the control signal and that shape the transmit port signal generated by the transmit chain. Such a signal control device may, for example, be configured as a variable attenuator or amplifier, a variable phase shifter, etc. The signal generator may receive a control signal from a signal processing device of the radar device. The control signal may, for example, be a digital control signal.

[0027] In order to generate the at least one data signal based on the radar signal, the signal receiver includes one or more receiving chains. Each receiving chain is configured to receive a receiving port signal via a signal port of the radar circuit connected to the antenna port of the antenna device. Each receiving port signal provides the radar signal to the receiving chain. Each receiving chain is also configured to convert the receiving port signal into a data signal and output the data signal to the signal processing device. Each receiving chain may, for example, include an analog-to-digital converter (ADC) that samples the port signal and generates a data signal output by the receiving chain; and / or one or more signal conditioning devices (such as a low noise amplifier, a programmable filter, a mixer, etc.) that shape the port signal before sampling. The data signal representing the receiving port signal may be a digital data signal.

[0028] The radar circuit can be configured, for example, to process several independent port signals to generate several independent transmit port signals based on several independent control signals, and / or to measure several independent receive port signals to generate several independent data signals. The signal generator can then include several transmit chains, one for each transmit port signal, and / or the signal receiver can then include several receive chains, one for each receive port signal. Each transmit chain is configured to generate a separate transmit port signal based on a separate control signal, the separate control signal and the transmit port signal being independent of each other. Similarly, each receive chain is configured to measure a separate receive port signal received from the antenna arrangement and to generate a separate data signal based on the corresponding receive port signal, the separate receive port signal and the separate data signal being independent of each other.

[0029] Individual transmit chains are coupled to the antenna assembly via individual transmit ports of the radar circuit, and individual receive chains are coupled to the antenna assembly via individual receive ports of the radar circuit. Each transmit port is coupled to one of the transmit chains of the radar circuit and is schematically located between the transmit chain and the antenna assembly, while each receive port is coupled to one of the receive chains of the radar circuit and is schematically located between the receive chain and the antenna assembly. Thus, each individual transmit port of the radar circuit can be schematically located between the last signal control device of its associated transmit chain and the antenna assembly. Similarly, each receive port of the radar circuit can be schematically located between the antenna assembly and the first signal conditioning device of its associated receive chain. The transmit port and receive port constitute the signal ports of the radar circuit.

[0030] According to the present disclosure, a radar signal is defined as a signal transduced by a separate antenna of an antenna arrangement. Similarly, a port signal is defined as a signal that is routed via a separate signal port of a radar circuit and processed by a single transmit chain or a single receive chain of the radar circuit. For example, if only one antenna is connected to the signal port through which the port signal is routed, then one port signal may include a single radar signal, or, for example, if more than one antenna (such as a first antenna in the first antenna and a second antenna in the second antenna) is connected to a common signal port through which the port signal is routed, then one port signal may include several radar signals (such as a first radar signal in the first radar signal and a second radar signal in the second radar signal). In the latter case, the individual radar signals constitute separate signal parts of the port signal.

[0031] Individual port signals and / or individual radar signals may exhibit individual and mutually independent signal parameters, such as phase, amplitude, chirp, phase shift, code sequence (e.g., binary phase-shifted code), etc. The mutually independent signal parameters may constitute an orthogonal and linearly independent parameter set. The individual and mutually independent signal parameters may correspond to separability parameters that ensure separability between the individual port signals after reception, for example, for forming a virtual antenna array.

[0032] The radar circuit can be configured in an integrated circuit. The radar circuit can be configured only in this single integrated circuit, or the radar circuit can be distributed across one or more additional integrated circuits. These integrated circuits can be coupled to each other in a phase-coherent manner. For example, the integrated circuit can be configured as a monolithic microwave integrated circuit (MMIC). The individual ports of the radar circuit can be physical connection points of one or more integrated circuits in the radar circuit (e.g., an MMIC including the radar circuit). The individual ports can also be logical ports or conceptual ports, which are located, for example, at the signal line between the transmit chain and the antenna device and / or at the signal line between the receive chain and the antenna device in the radar device, wherein the individual components of the radar circuit and the antenna device are integrated on a common carrier (e.g., a common substrate).

[0033] The antenna device can convert the radar signal into electromagnetic radiation sent toward the target object radiated by the antenna device to convert the radar signal, and / or the antenna device can convert the radar signal by receiving the electromagnetic radiation scattered back by the target object and converting the received electromagnetic radiation into the radar signal. The individual antenna elements of the antenna can be connected to the corresponding signal ports of these antenna elements in the radar circuit in a conductive manner. These antenna elements can be closely coupled via conductive coupling or inductive coupling, for example. The individual antenna can be configured as a substrate integrated antenna, such as a microstrip patch antenna or a slotted substrate integrated waveguide (SIW) antenna. The individual antenna can also be configured as an end-fire antenna, a 3D antenna or a metallized plastic antenna.

[0034] A first frequency band occupied by the first radar signal and a second frequency band occupied by the second radar signal may have a frequency gap between them. The frequency gap may be equal to at least one-tenth, at least one-fifth, at least one-third, or at least half of the frequency span of the first and / or second frequency bands. The frequency gap may be equal to at most one-tenth, at most one-fifth, at most one-third, or at most half of the frequency span of the first and / or second frequency bands. Alternatively, the first frequency band may be directly adjacent to the second frequency band so that no frequency gap is present between the first and second radar signals. The first radar signal may exhibit a first frequency modulation, and the second radar signal may exhibit a second frequency modulation.

[0035] Furthermore, to jointly evaluate the first and second radar signals, the signal processing device can be configured to evaluate only the first radar signal and / or only the second radar signal individually to obtain target information accessible only to one of the first and second antenna groups, while the other is inaccessible. Such target information accessibility can be generated, for example, by different antenna parameters and / or different antenna locations of the first and second antennas that respectively transduce the first and second radar signals, such as different antenna gains and / or different signal-to-noise ratios of the received radar signals and / or different antenna fields of view and / or different polarizations. The first propagation channel formed by the first antenna group and the second propagation channel formed by the second antenna group can have different propagation channel characteristics (e.g., polarization), and / or fields of view (e.g., in elevation and / or azimuth), and / or radiation directions, and / or detection ranges, and / or signal gains.

[0036] The antenna arrangement can be configured to transduce the first radar signal with a first polarization and to transduce the second radar signal with a second polarization, wherein the second polarization is different from, for example, orthogonal to, the first polarization. Thus, a first radiated field transduced by the first antenna has the first polarization, while a second radiated field transduced by the second antenna has the second polarization.

[0037] For example, the first polarization and the second polarization may be linear polarizations, and the first radar signal or the second radar signal may be transduced using horizontal linear polarization, while the other of the first radar signal and the second radar signal may be transduced using vertical linear polarization. The first polarization and the second polarization may also be circular polarizations, and the first radar signal or the second radar signal may be transduced using left-hand circular polarization, while the other of the first radar signal and the second radar signal may be transduced using right-hand circular polarization.

[0038] Transducing the first and second radar signals using different polarizations improves isolation between a first propagation channel formed by the first radar signal and a second propagation channel formed by the second radar signal. If the antenna arrangement includes a first group of antennas and a second group of antennas, and the first group of antennas includes a first antenna for transducing the first radar signal, and the second group of antennas includes a second antenna for transducing the second radar signal, then all antennas in the first group can be transduced using a first polarization, while all antennas in the second group can be transduced using a second polarization. Consequently, all first propagation channels formed by the first group of antennas can operate using the first polarization, while all second propagation channels formed by the second group of antennas can operate using the second polarization.

[0039] When evaluating a data signal generated from a received radar signal in a signal processing device, the different polarizations of the first and second radar signals can be used, for example, to classify a detected target object. This allows the polarization characteristics of the target object to be detected and used during object classification by the signal processing device. Object classification can be performed, for example, using a machine learning algorithm that has been trained on data signals representing polarization characteristics of different training target objects.

[0040] The first antennas transducing the first radar signal may each have a first field of view, and the second antennas transducing the second radar signal may each have a second field of view different from the first field of view. The signal processing device may then be configured to jointly evaluate the first propagation channel established by the first antenna and the second propagation channel established by the second antenna only if the target object is located in a common field of view given by the intersection of the first field of view and the second field of view.

[0041] For example, the first field of view may have a first lateral extent along the transverse direction, and the second field of view may have a second lateral extent along the transverse direction, wherein the first lateral extent is greater than the second lateral extent. Additionally or alternatively, the first field of view may have a first longitudinal extent along the longitudinal direction, and the second field of view may have a second longitudinal extent along the longitudinal direction, wherein the first longitudinal extent is less than the second longitudinal extent.

[0042] This enables the radar device to perform different radar functions requiring different fields of view by evaluating only the first propagation channel or the second propagation channel, respectively. For example, the data signal from the second antenna can be used by the signal processing device for a long-range radar (LRR) function and / or adaptive cruise control and / or emergency brake assist, while the data signal from the first antenna can be used for a medium-range radar (MRR) or short-range radar (SRR) function and / or lane change assist and / or cross traffic detection and / or parking assist.

[0043] To achieve a small field of view, the second antennas may each include a plurality of antenna elements that are arranged closely adjacent to one another in a lateral direction and form a phased array that narrows the beam solid angle of the second antenna in the lateral direction. The first antennas may each include a plurality of antenna elements that form a larger beam solid angle than the antenna elements of the second antenna, for example, because the first antenna has fewer antenna elements than the second antenna.

[0044] According to the present disclosure, the antenna of an antenna device is generally formed by all of the following antenna elements: these antenna elements jointly transduce energy between the antenna's radiation field in the far field region and the antenna's associated radar signal processed by the radar circuit. Such an antenna may include a single antenna element, or the antenna may be configured as an array antenna including a group of antenna elements: the group of antenna elements forms the antenna's individual radiating components and coherently transduce energy between the radiation field and the radar signal. If the antenna is a receiving antenna, the radiation field is the incoming radiation field captured by the antenna element. If the antenna is a transmitting antenna, the radiation field is the outgoing radiation field generated by the antenna element.

[0045] The radiated field of an antenna has well-defined instantaneous field parameters in the far field of the antenna, such as phase center, frequency, and amplitude. Similarly, each antenna has antenna parameters that define the characteristics of the antenna and the radiated field of the antenna. These antenna parameters can be radiation pattern, polarization, gain, directivity, position of the phase center, or antenna position.

[0046] Individual radar signals are oscillating electromagnetic signals, such as microwave signals. The radar frequency of the radar signal can be at least 1 GHz, at least 30 GHz, at least 60 GHz, or at least 70 GHz. The radar frequency can be at most 200 GHz, at most 100 GHz, at most 85 GHz, at most 60 GHz, or at most 40 GHz. The radar frequency of the radar signal can be, for example, between 31 GHz and 37 GHz, or between 75 GHz and 85 GHz, or between 76 GHz and 81 GHz. The first frequency band of the first radar signal can be between 75 GHz and 78 GHz, for example, between 75.5 GHz and 77.5 GHz, while the second frequency band of the second radar signal can be between 79 GHz and 82 GHz, for example, between 79.5 GHz and 81.5 GHz.

[0047] A radar device can be mounted on a vehicle. The radar device can be configured as an interior radar device that captures target reflections from the vehicle's passenger compartment, or as an exterior radar device that captures target reflections from the vehicle's external environment, such as a front radar, a side radar, or a rear radar. Radar devices can be used in automotive applications to detect and locate target objects, such as other vehicles, obstacles, or lane boundaries. Such target objects may be located in front of, behind, or to the side of the vehicle.

[0048] The radar device may be part of a vehicle control system and may be connected to a control device of the vehicle control system. The control device may be configured to perform advanced driver assistance functions such as adaptive cruise control, emergency brake assist, lane change assist, or autonomous driving based on data signals received from the radar device. The control device and / or signal processing device of the radar device may be configured as a programmable logic device, such as a programmable logic controller, an FPGA, an ASIC, or a microprocessor.

[0049] According to an embodiment, the phase center of the first reference transmitting antenna in the first group of antennas coincides with the phase center of the second reference transmitting antenna in the second group of antennas, and the phase center of the first reference receiving antenna in the first group of antennas coincides with the phase center of the second reference receiving antenna in the second group of antennas.

[0050] Therefore, the first reference propagation channel established between the first reference transmit antenna and the first reference receive antenna and the second reference propagation channel established between the second reference transmit antenna and the second reference receive antenna have the same path length for all target objects. Therefore, the relative phase difference between the target reflection propagated via the first reference propagation channel operating in the first frequency band and the target reflection propagated via the second reference propagation channel operating in the second frequency band is independent of the distance traveled by the first radar signal and the second radar signal. Therefore, the differential phase shift obtained via the first reference propagation channel and the second reference propagation channel can be used to calibrate any phase difference between the first propagation channel and the second propagation channel caused by the frequency difference between the first radar signal and the second radar signal.

[0051] The first reference transmit antenna and the second reference transmit antenna may be formed by a single wideband antenna configured to transduce at both the first frequency band and the second frequency band. Similarly, the first reference receive antenna and the second reference receive antenna may be formed by a single wideband antenna configured to transduce at both the first frequency band and the second frequency band.

[0052] According to an embodiment, a signal processing device is configured to measure a phase difference between a first reference signal propagated via a first reference propagation channel established between a first reference transmit antenna and a first reference receive antenna, and a second reference signal propagated via a second reference propagation channel established between a second reference transmit antenna and a second reference receive antenna. The signal processing device is further configured to compensate for the measured phase difference when jointly evaluating target reflections via the first propagation channel and target reflections via the second propagation channel.

[0053] This compensation removes any phase shift between the first propagation channel and the second propagation channel caused by the first radar signal and the second radar signal occupying different frequency bands and having different signal characteristics. Therefore, any phase difference that is independent of the differential path length between the individual propagation channels can be removed, and the angular position of the target object can be determined with high accuracy. The phase difference can be derived from a first intermediate signal and a second intermediate signal, the first intermediate signal being generated from the first radar signal transduced via a first reference transmitting antenna and a first reference receiving antenna, and the second intermediate signal being generated from the second radar signal transduced via a second reference transmitting antenna and a second reference receiving antenna. The radar device can be configured to simultaneously transmit and / or receive the first reference signal and the second reference signal.

[0054] In addition to the phase difference caused by the different frequencies of the first and second radar signals, the signal processing device may be configured to compensate for further contributions to the overall differential phase shift between the first reference propagation channel and the second reference propagation channel.

[0055] According to an embodiment, the signal processing device is configured to compensate for an angle-dependent phase shift caused by different radiation patterns of a first reference antenna within a first frequency band and a second reference antenna within a second frequency band, and / or a distance-dependent phase shift caused by a change in the distance to the target object between a target reflection of the first reference signal and a target reflection of the second reference signal, and / or a global phase offset of the first reference signal relative to the second reference signal when generating the first reference signal and the second reference signal.

[0056] For example, due to different antenna radiation patterns of a first reference antenna operating in a first frequency band and a second reference antenna operating in a second frequency band, the total differential phase shift between the first reference signal and the second reference signal may depend on the angular position of the target object in the azimuth direction and / or the elevation direction. Therefore, the signal processing device may determine a first angle-dependent phase shift caused by the angular position of the target object along a first direction (such as the azimuth direction). and / or a second angle-dependent phase shift due to the angular position of the target object along a second direction (such as the elevation direction)

[0057] In order to determine the angle-dependent phase shift, the signal processing means may comprise a differential phase diagram derived from the radiation pattern of the first reference antenna and the radiation pattern of the second reference antenna. The differential phase diagram may comprise an angle-dependent phase shift depending on the angular position of the target object. and / or For example, the differential phase map may be stored in a memory module of the signal processing device.

[0058] Angle-dependent phase shift and / or The measurement can be performed at a test facility by measuring the angular correlation phase of the radiation patterns of the first and second reference antennas. This measurement may have been performed during a pre-calibration process for the antenna arrangement. Thus, a method for operating a radar arrangement as described herein may comprise the steps of measuring the angular correlation of the radiation patterns of the first and second reference antennas, for example, the angular correlation of the phase values of the radiation patterns of the first and second reference antennas in a first direction, such as the azimuth direction, and in a second direction, such as the elevation direction; and storing the results of these measurements in a memory module of the radar arrangement, for example, as a differential phase map.

[0059] Additionally or alternatively, for example, in the case where the radar circuit is operated in an alternating mode, the total differential phase shift may depend on the relative movement of the target object relative to the radar device between the reflection of the first reference signal and the reflection of the second reference signal. Thus, the distance between the target object and the radar device may change from the reflection of the first reference radar signal to the reflection of the second reference radar signal. The signal processing device may be configured to determine the range-dependent phase shift, for example, by performing Doppler measurements for determining the relative radial target velocity of the target object and by estimating the range difference based on the relative target velocity and the time span between the transmission of the first reference signal and the second reference signal.

[0060] Additionally or alternatively, for example, where the radar circuit operates in an alternating mode and alternately transmits and receives the first radar signal and the second radar signal, the total differential phase shift may depend on a global phase offset introduced when generating the first reference signal and the second reference signal. The global phase offset may be caused, for example, by different starting phases of at least one reference oscillator of the radar circuit used to generate the first reference signal and the second reference signal. The signal processing device may be configured to determine the global phase offset based on a time delay between the generation of the first reference signal and the second reference signal and a frequency difference between the first reference signal and the second reference signal, and optionally based on an additional phase offset of the starting phases of these signals (such as a random phase offset or a phase offset between two integrated circuits used to generate the first reference signal and the second reference signal, respectively).

[0061] The signal processing means may determine a phase shift separating phase measurements of the first reference signal and the second reference signal propagated via the first reference propagation channel and the second reference propagation channel. and / or and / or and / or Alternatively, any of these parameters may also be included in the phase difference determined based on the first reference signal and the second reference signal propagated via the first reference propagation channel and the second reference propagation channel. and / or and / or The radar device may ignore the range-dependent phase shift when simultaneously transmitting at least the first reference radar signal and the second reference radar signal. and / or global phase offset This requires less processing, provides faster results, and does not rely on the phase shifts used to establish distance correlation. and / or global phase offset predictions based on previous measurements.

[0062] The total differential phase shift between the first and second propagation channels can be compensated for by scaling the phase values of all intermediate signals obtained from the first propagation channel or the second propagation channel with a scaling factor derived from the total differential phase shift between the first reference propagation channel and the second reference propagation channel. When scaling the phase of the intermediate signal obtained from the first propagation channel, the scaling factor can be equal to the ratio of the second reference phase of the intermediate signal obtained from the second reference propagation channel to the first reference phase of the intermediate signal obtained from the first reference propagation channel. When scaling the phase of the intermediate signal obtained from the second propagation channel, the reciprocal of the scaling factor can be used. Additional phase shift can be compensated after the intermediate signal is mapped to the range bin and / or after the intermediate signal is mapped to the velocity bin.

[0063] According to an embodiment, the signal processing device is configured to determine the angular position of the target object based on the relative phase shifts between all target reflections propagated via the first propagation channel and the second propagation channel. This allows the angular position of the target object to be determined with high accuracy, because the angular resolution increases with the number of propagation channels evaluated.

[0064] According to an embodiment, the signal processing device is configured to jointly evaluate the phase values derived from all first and second propagation channels to determine the angular position of the target object, for example, by performing a common Fourier transform on the phase values. This allows the angular position of the target object to be determined with high accuracy and in a short time. Instead of jointly processing the phase values by performing a common Fourier transform, other angle-finding algorithms, such as super-resolution, can also be used to determine the angular position of the target object.

[0065] According to an embodiment, all individual transmit antennas in the first and second antenna groups are aligned with one another along a first direction, and all individual receive antennas in the first and second antenna groups are aligned with one another along the first direction. Consequently, a common virtual antenna array formed by evaluating the first and second propagation channels is also aligned along the first direction. Consequently, all phase shifts acquired during propagation through the first and second propagation channels depend on the angular position of the target object in the first direction, maximizing angular resolution along the first direction.

[0066] According to an alternative embodiment, a portion of the first antenna and / or the second antenna is distributed along a first direction, and another portion of the first antenna and / or the second antenna is distributed along a second direction, wherein the second direction is different from the first direction, for example, orthogonal to the first direction. This allows the angular position of the target object along both the first direction and the second direction to be determined simultaneously, and thus allows the separation of individual target objects based on their positions along these two directions.

[0067] According to an embodiment, the first direction is an azimuth direction relative to the ground on which the vehicle including the radar device is traveling, and the second direction is an elevation direction relative to the ground.

[0068] According to an embodiment, one of the first antennas and one of the second antennas are coupled to a common signal port of the radar circuit, the common signal port being configured to route both a first radar signal transduced via the corresponding first antenna and a second radar signal transduced via the corresponding second antenna. Routing both the first radar signal and the second radar signal via the common signal port reduces the number of signal ports required to connect the first antenna and the second antenna to the radar circuit.

[0069] The common signal port through which the first radar signal and the second radar signal are routed may be a transmit port of the radar device, and the first antenna and the second antenna may be transmit antennas of the antenna device. Alternatively, the common signal port may be a receive port of the radar device, and the first antenna and the second antenna may be receive antennas of the antenna device. For example, the first antenna coupled to the common signal port may be a first reference transmit antenna, and the second antenna coupled to the common signal port may be a second reference transmit antenna. Alternatively, the first antenna coupled to the common signal port may be a first reference receive antenna, and the second antenna coupled to the common signal port may be a second reference receive antenna.

[0070] The port signal routed via the common signal port includes: a first radar signal, which is a first signal portion occupying a first frequency band; and a second radar signal, which is a second signal portion occupying a second frequency band. Thus, the full bandwidth of the radar circuit routed via the common signal port can be shared between the first antenna and the second antenna. If the radar circuit includes an integrated circuit, the common signal port can be configured as an external connection point of the integrated circuit. Routing the first and second radar signals via the common signal port effectively doubles the number of separate antennas and propagation channels that can be addressed via the connection point forming the common signal port.

[0071] The antenna arrangement may be configured as a frequency selective antenna arrangement that transduces first radar signals occupying a first frequency band via the first antenna but not via the second antenna, and transduces second radar signals occupying a second frequency band via the second antenna but not via the first antenna.

[0072] The frequency selectivity of the antenna arrangement can be achieved, for example, by employing a frequency selective first antenna and a frequency selective second antenna that are directly and simultaneously coupled to the common signal port. The frequency selectivity can also be achieved by coupling the first antenna and the second antenna to the common signal port via a signal routing device (such as a frequency selective multiplexer) or a switching device (which selectively couples the first antenna or the second antenna to the common signal port). The switching device can be configured to selectively couple the first antenna or the second antenna to the common signal port. The switching device can be configured as a microwave switch. Frequency selectivity can also be achieved by coupling the first antenna to the common signal port via a first filter and / or coupling the second antenna to the common signal port via a second filter, wherein the first filter passes a first frequency band and blocks a second frequency band, and wherein the second filter passes the second frequency band and blocks the first frequency band.

[0073] The first antenna and the second antenna may also be coupled in series to a common signal port, with at least one frequency filter coupled between the first and second antennas. The filter may block the first radar signal and only transduce the second radar signal. The first antenna may then be configured to transduce only the first radar signal, or the first antenna may be configured to transduce both the first and second radar signals.

[0074] The antenna device may be configured to transduce only the first radar signal via the first antenna without transducing the second radar signal by suppressing transduction of the second radar signal by at least 10 dB, at least 20 dB, at least 30 dB, at least 40 dB, or at least 50 dB compared to the first radar signal. Similarly, the antenna device may be configured to transduce only the second radar signal via the second antenna without transducing the first radar signal by suppressing transduction of the first radar signal by at least 10 dB, at least 20 dB, at least 30 dB, at least 40 dB, or at least 50 dB compared to the second radar signal.

[0075] Typically, each signal port of the radar circuit can be configured as a common signal port, and each common signal port can be connected to a first antenna of the first antenna and a second antenna of the second antenna. The common signal port is then configured to route a first radar signal as a first signal component occupying a first frequency band, the first radar signal being transduced via its respective first antenna, and a second radar signal being transduced via its respective second antenna, as a second signal component occupying a second frequency band. This effectively doubles the number of antennas that can be connected to the radar circuit.

[0076] The signal processing device can be configured to separate the first radar signal and the second radar signal from the respective port signals received via the common signal port, for example, by filtering out a first frequency band to obtain the first radar signal and filtering out a second frequency band to obtain the second radar signal. Filtering can be performed by analog filtering before sampling and / or by digital filtering after sampling.

[0077] According to an embodiment, the phase center of the first antenna coupled to the common signal port coincides with the phase center of the second antenna coupled to the common signal port. The first antenna may constitute a first reference antenna and the second antenna may constitute a second reference antenna to establish a first reference propagation channel and a second reference propagation channel for determining an additional frequency-induced phase shift between the first propagation channel and the second propagation channel.

[0078] According to an embodiment, the phase center of the first antenna coupled to the common signal port is shifted relative to the phase center of the second antenna coupled to the common signal port. Thus, the first antenna and the second antenna can be used to establish a first propagation channel and a second propagation channel that exhibit a propagation delay that depends on the angular position of the target object.

[0079] Typically, the radar circuit may have a common signal port coupled to a first antenna and a second antenna having the same phase center, and one or more further common signal ports each coupled to the first antenna and the second antenna having a phase center shifted relative to each other.

[0080] According to an embodiment, at least one of the first antennas is coupled to a first integrated circuit of the radar circuit to transmit and receive its corresponding first radar signal, and at least one of the second antennas is coupled to a second integrated circuit of the radar circuit to transmit and receive its corresponding second radar signal. The first integrated circuit and the second integrated circuit may be configured to transmit the corresponding first and second radar signals simultaneously. For example, the first and second integrated circuits may have synchronous triggers for transmitting the corresponding first and second radar signals.

[0081] The first integrated circuit can be configured to transmit and receive all first radar signals, and the second integrated circuit can be configured to transmit and receive all second radar signals. The integrated circuits can be configured to transmit the first radar signal and the second radar signal simultaneously. These integrated circuits can each have a signal port for each first radar signal or second radar signal. In addition, these integrated circuits can include binary phase shifters at each transmit signal port. The phase shifters can be used to generate a separability parameter based on binary phase shift keying, and these phase shifters can use phase codes that allow the radar signals transmitted via their respective transmit signal ports to be mutually separable or orthogonal. The first integrated circuit can operate in a first frequency band, and the second integrated circuit can operate in a second frequency band.

[0082] In another aspect, the present disclosure is directed to a vehicle having a radar device according to the present disclosure. All effects and embodiments described in conjunction with the radar device also belong to the vehicle including the radar device, and vice versa.

[0083] In another aspect, the present disclosure is directed to a method for operating a radar device for automotive applications, the radar device comprising: a radar circuit for transmitting and receiving radar signals; an antenna device for transducing the radar signals; and a signal processing device for processing the radar signals, wherein the antenna device comprises a first group of first antennas and a second group of second antennas. The method comprises the following steps:

[0084] transmitting and receiving, using a radar circuit, a first radar signal occupying a first frequency band and a second radar signal occupying a second frequency band;

[0085] transducing the first radar signal via the first antenna but not via the second antenna, and transducing the second radar signal via the second antenna but not via the first antenna;

[0086] detecting, using a signal processing device, a target reflection via a first propagation channel from the first radar signal and a target reflection via a second propagation channel from the second radar signal;

[0087] By means of the signal processing device, the target reflection via the first propagation channel and the target reflection via the second propagation channel are jointly evaluated to form a common virtual antenna array for determining the angular position of the target object illuminated by the antenna device.

[0088] The method can be performed by the radar device according to the present disclosure. Therefore, all effects and embodiments described in conjunction with the radar device also belong to the method according to the present disclosure, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Exemplary embodiments and functions of the present disclosure are described herein with reference to the following schematically illustrated drawings:

[0090] Figure 1 is a radar apparatus according to the present disclosure;

[0091] Figure 2 is the arrangement of the first antenna and the second antenna of the radar device;

[0092] Figure 3 is the transmission of the first antenna and the second antenna;

[0093] Figure 4 is the port signal generated by the signal generator of the radar device;

[0094] Figure 5 The part of the radar apparatus used to determine the propagation delay of signals from individual ports;

[0095] Figure 6 is the evaluation of data signals;

[0096] Figure 7 is another embodiment of the radar apparatus according to the present disclosure;

[0097] Figure 8 is another embodiment of the radar apparatus according to the present disclosure;

[0098] Figure 9 yes Figure 7 and Figure 8 The layout of the antenna of the radar device shown;

[0099] Figure 10 yes Figure 1 An alternative arrangement of antennas for the radar apparatus shown;

[0100] Figure 11 is a method of operating a radar apparatus according to the present disclosure; and

[0101] Figure 12 A vehicle is equipped with the radar apparatus according to the present disclosure. DETAILED DESCRIPTION

[0102] Figure 1 A radar device 1 is depicted, which has a radar circuit 100, an antenna device 200, and a signal processing device 120. The radar circuit 100 includes a signal generator 105 having a first transmission chain 125 and a second transmission chain 126. The first transmission chain 125 is coupled to a first common transmission signal port 130, and the second transmission chain 126 is coupled to a second common transmission signal port 131.

[0103] The respective common transmit signal ports 130 and 131 are coupled to a first antenna 211 and a second antenna 221 of the antenna device 200. The first antenna 211 and the second antenna 221 coupled to the first common transmit signal port 130 have coincident phase centers, such that the first antenna 211 and the second antenna 221 are transduced at the same position on the antenna device 200. The first antenna 211 and the second antenna 221 coupled to the second common transmit signal port 131 have phase centers shifted relative to each other, such that the corresponding first antenna 211 and the second antenna 221 are arranged at different positions on the antenna device 200.

[0104] The first transmit chain 125 is connected to the signal processing device 120 to receive a first control signal 121, and the second transmit chain 126 is connected to the signal processing device 120 to receive a second control signal 122. Based on the first control signal 121, the first transmit chain 125 generates a first transmit port signal 10, which includes a first signal portion 11 occupying a first frequency band and a second signal portion 12 occupying a second frequency band. The first transmit port signal 10 is routed to the antenna device 200 via the first common transmit signal port 130, and the antenna device 200 is configured to transduce the first signal portion 11 of the first transmit port signal 10 into a first radar signal via a first antenna 211 coupled to the first common transmit signal port 130, and to transduce the second signal portion 12 of the first transmit port signal 10 into a second radar signal via a second antenna 221 coupled to the first common transmit signal port 130.

[0105] Based on the second control signal 122, the second transmit chain 126 generates a second transmit port signal 15, which includes a first signal portion 16 occupying the first frequency band and a second signal portion 17 occupying the second frequency band. The second transmit port signal 15 is routed to the antenna device 200 via the second common transmit signal port 131, and the antenna device 200 is configured to selectively transduce the first signal portion 16 of the second transmit port signal 15 into a first radar signal via the first antenna 211 coupled to the second common transmit signal port 131, and selectively transduce the second signal portion 17 of the second transmit port signal 15 into a second radar signal via the second antenna 221 coupled to the second common transmit signal port 131.

[0106] The individual first signal portion 11 of the first transmit port signal 10 and the individual first signal portion 16 of the second transmit port signal 15 are radiated toward the target object 3 by the individual first antenna 211, and the individual second signal portion 12 of the first transmit port signal 10 and the individual second signal portion 17 of the second transmit port signal 15 are radiated toward the target object 3 by the individual second antenna 221. The target object 3 at least partially reflects the signal portions 11 and 12 of the first transmit port signal 10 and the signal portions 16 and 17 of the second transmit port signal 15 back to the antenna arrangement 200.

[0107] At the antenna arrangement 200, first signal portions 11 and 16 occupying the first frequency band are transduced by two separate first antennas 211, and second signal portions 12 and 17 occupying the second frequency band are transduced by two separate second antennas 221. The antenna arrangement 200 is configured to selectively transduce the first signal portions 11 and 16 via the first antenna 211 but not via the second antenna 221, and to selectively transduce the second signal portions 12 and 17 via the second antenna 221 but not via the first antenna 211.

[0108] One of the first antennas 211 and one of the second antennas 221 are coupled to the first receive chain 127 of the signal receiver 110 of the radar circuit 100 via the first common receive signal port 135. Similarly, the other of the first antennas 211 and the other of the second antennas 221 are coupled to the second receive chain 128 of the signal receiver 110 via the second common receive signal port 136. The first antenna 211 and the second antenna 221 coupled to the first common receive signal port 135 have coincident phase centers, while the first antenna 211 and the second antenna 221 coupled to the second common receive signal port 136 have separated phase centers located at different positions on the antenna device 200.

[0109] The antenna arrangement 200 routes the first signal portion 21 of the first receive port signal 20 from the first antenna 211 coupled to the first common receive signal port 135 and the second signal portion 22 of the first receive port signal 20 from the second antenna 221 coupled to the first common receive signal port 135 to the first receive chain 127 via the first common receive signal port 135. The antenna arrangement 200 also routes the first signal portion 26 of the second receive port signal 25 from the first antenna 211 coupled to the second common receive signal port 136 and the second signal portion 27 of the second receive port signal 25 from the second antenna 221 coupled to the second receive signal port 136 to the second receive chain 128 via the second common receive signal port 136.

[0110] The first signal portion 21 of the first receive port signal 20 includes a portion of the first signal portion 11 of the first transmit port signal 10 and a portion of the first signal portion 16 of the second transmit port signal 15, which are received by the first antenna 211 coupled to the first common receive signal port 135. The second signal portion 22 of the first receive port signal 20 includes a portion of the second signal portion 12 of the first transmit port signal 10 and a portion of the second signal portion 17 of the second transmit port signal 15, which are received by the second antenna 221 coupled to the first common receive signal port 135.

[0111] Likewise, the first signal portion 26 of the second receive port signal 25 includes a portion of the first signal portion 11 of the first transmit port signal 10 and a portion of the first signal portion 16 of the second transmit port signal 15, which are received by the first antenna 211 coupled to the second common receive signal port 136. The second signal portion 27 of the second receive port signal 25 includes a portion of the second signal portion 12 of the first transmit port signal 10 and a portion of the second signal portion 17 of the second transmit port signal 15, which are received by the second antenna 221 coupled to the second common receive signal port 136.

[0112] First receive chain 127 generates a first radar data signal 123 representing a first port signal 20 received from first common receive signal port 135, and second receive chain 128 generates a second radar data signal 124 representing a second port signal 25 received from second common receive signal port 136. Signal receiver 110 is connected to signal processing device 120, and first radar data signal 123 and second radar data signal 124 are passed from signal receiver 110 to signal processing device 120.

[0113] use Figure 1In the illustrated radar device 1, each antenna 211, 221 is connected to the radar circuit 100 via a single signal port 130, 131, 135, 136. Individual signal portions 11, 12, 16, 17, 21, 22, 26, 27 of the port signals 10, 15, 20, 25 then constitute separate radar signals, each of which is transduced by a separate antenna 211, 221. Signal portions 11, 16, 21, 26 transduced via the first antenna 211 constitute the first radar signal, while signal portions 12, 17, 22, 27 transduced via the second antenna 221 constitute the second radar signal.

[0114] The first transmit chain 125 and the second transmit chain 126 respectively generate a first portion 11 of the first transmit port signal 10 and a first portion 16 of the second transmit port signal 15, wherein the first portions 11 and 16 have different values of the first separability parameter, and the first transmit chain and the second transmit chain respectively generate a second portion 12 of the first transmit port signal 10 and a second portion 17 of the second transmit port signal 15, wherein the second portions 12 and 17 have different values of the second separability parameter. Using the first separability parameter, the signal processing device 120 is able to separate the portion of the first signal portion 21 of the first receive port signal 20 that originates from the first portion 11 of the first transmit port signal 10 and the portion of the first signal portion 26 of the second receive port signal 25 that originates from the first portion 11 of the first transmit port signal 10 from the portion of the first signal portion 21 of the first receive port signal 20 that originates from the first portion 16 of the second transmit port signal 15 and the portion of the first signal portion 26 of the second receive port signal 25 that originates from the first portion 16 of the second transmit port signal 15. Similarly, using the second separability parameter, the signal processing device 120 separates the portion of the second signal portion 22 of the first receiving port signal 20 originating from the second portion 12 of the first transmitting port signal 10 and the portion of the second signal portion 27 of the second receiving port signal 25 originating from the second portion 12 of the first transmitting port signal 10 from the portion of the second signal portion 22 originating from the second portion 17 of the second transmitting port signal 15 and the portion of the second signal portion 27 originating from the second portion 17 of the second transmitting port signal 15.

[0115] In addition, the signal processing device 120 uses the separated frequency bands of the first signal portion 21 and the second signal portion 22 received via the first common receiving signal port 135 to separate the first signal portion 21 and the second signal portion 22 of the first receiving port signal 20, and the signal processing device 120 uses the separated frequency bands of the first signal portion 25 and the second signal portion 26 received via the second common receiving signal port 136 to separate the first signal portion 26 and the second signal portion 27 of the second receiving port signal 25.

[0116] The first antenna 211 transduces electromagnetic radiation using a first polarization, and the second antenna 221 transduces electromagnetic radiation using a second polarization orthogonal to the first polarization. For example, the first antenna 211 may transduce electromagnetic radiation using horizontal linear polarization, and the second antenna 221 may transduce electromagnetic radiation using vertical linear polarization. Vice versa, the first antenna 211 may transduce electromagnetic radiation using vertical linear polarization, and the second antenna 221 may transduce electromagnetic radiation using horizontal linear polarization.

[0117] Radar apparatus 1 establishes a total of eight different propagation channels from antenna apparatus 200 to target object 3 and back to antenna apparatus 200. Signal processing apparatus 120 is configured to separately detect target reflections propagated via the individual propagation channels and establish a virtual array in a MIMO configuration. Of the eight different propagation channels, a group of first propagation channels operates in a first frequency band, and a group of second propagation channels operates in a second frequency band.

[0118] The radar device 1 establishes the following propagation channels: a propagation channel 70 from the first antenna 211 connected to the first common transmit signal port 130 to the first antenna 211 connected to the first common receive signal port 135; a propagation channel 71 from the second antenna 221 connected to the first common transmit signal port 130 to the second antenna 221 connected to the first common receive signal port 135; a propagation channel 72 from the first antenna 211 connected to the first common transmit signal port 130 to the first antenna 211 connected to the second common receive signal port 136; and a propagation channel 73 from the second antenna 221 connected to the first common transmit signal port 130 to the second antenna 221 connected to the second common receive signal port 136.

[0119] The radar device 1 also establishes the following propagation channels: a propagation channel 74 from the first antenna 211 connected to the second common transmit signal port 131 to the first antenna 211 connected to the first common receive signal port 135; a propagation channel 75 from the second antenna 221 connected to the second common transmit signal port 131 to the second antenna 221 connected to the first common receive signal port 135; a propagation channel 76 from the first antenna 211 connected to the second common transmit signal port 131 to the first antenna 211 connected to the second common receive signal port 136; and a propagation channel 77 from the second antenna 221 connected to the second common transmit signal port 131 to the second antenna 221 connected to the second common receive signal port 136.

[0120] The set of first propagation channels operating in the first frequency band is established by the first signal portion transduced via the first antenna 211. The set of first propagation channels includes all propagation channels 70, 72, 74, and 76 established between the first antenna 211. The set of second propagation channels is established based on the second signal portion transduced via the second antenna 221. The set of second propagation channels includes all propagation channels 71, 73, 75, and 77 established between the second antenna 221.

[0121] The first transmit antenna 211 coupled to the first transmit signal port 130 constitutes a first reference transmit antenna 216, and the second transmit antenna 221 coupled to the first transmit signal port 130 constitutes a second reference transmit antenna 226. Furthermore, the first receive antenna 211 coupled to the first receive signal port 135 constitutes a first reference receive antenna 217, and the second receive antenna 221 coupled to the first receive signal port 135 constitutes a second reference receive antenna 227.

[0122] Propagation channel 70 established between first reference transmit antenna 216 and first reference receive antenna 217 constitutes first reference propagation channel 78, and propagation channel 71 established between second reference transmit antenna 226 and second reference receive antenna 227 constitutes second reference propagation channel 79. Because first reference transmit antenna 216 and second reference transmit antenna 226 coupled to first transmit signal port 130 have overlapping phase centers, and because first reference receive antenna 217 and second reference receive antenna 227 coupled to first common receive signal port 135 also have overlapping phase centers, first reference propagation channel 78 has the same path length as second reference propagation channel 79. Therefore, any differential phase shift between first radar signals 11, 21 propagating via first reference propagation channel 78 and second radar signals 12, 22 propagating via second reference propagation channel 79 is not due to the different path lengths of the respective propagation channels 70, 71. This enables determination of additional phase differences resulting from the different frequency bands of first radar signals 11, 21 and second radar signals 12, 22.

[0123] In addition to this additional phase difference due to the different frequency bands, the signal processing means 120 are further configured to determine further contributions to the total differential phase shift between the first reference propagation channel 78 and the second reference propagation channel 79. These further contributions include: an angle-dependent phase shift due to the angular position of the target object 3 in the first, i.e., azimuthal, direction; and the angle-dependent phase shift due to the angular position of the target object 3 in the second elevation direction Phase Shift and Both are caused by the difference in radiation patterns between the first reference transmitting antenna 216 and the second reference transmitting antenna 226 , and the difference in radiation patterns between the first reference receiving antenna 217 and the second reference receiving antenna 227 .

[0124] A further contribution to the total differential phase shift is the distance-dependent phase shift caused by the change in distance to the target object 3 between the target reflection of the first signal portion 11 and the target reflection of the second signal portion 12. Finally, further contributions include a global phase offset caused by different phase values of the reference oscillator of the radar circuit 100 when generating the first signal portion 11 and the second signal portion 12

[0125] Figure 1 Alternative embodiments of the radar apparatus 1 shown may include more than two transmit chains 125, 126 and common transmit signal ports 130, 131, for example, three transmit chains and three associated transmit signal ports, and more than two receive chains 127, 128 and common receive signal ports 135, 136, for example, four receive chains and four associated receive signal ports. A first antenna 211 and a second antenna 221 may be coupled to the respective signal ports, and the individual port signals routed via the individual signal ports may each include a first signal portion occupying a first frequency band and a second frequency portion occupying a second frequency band. Antenna apparatus 200 may then be configured to transduce the individual first signal portions into a first radar signal via first antenna 211 and the individual second signal portions into a second radar signal via second antenna 221. The individual first signal portions may differ from each other by at least a first separability parameter, and the individual second signal portions may differ from each other by at least a second separability parameter.

[0126] Figure 2 An exemplary layout of a first antenna 211 and a second antenna 221 on an antenna device 200 is schematically shown. The first transmitting antenna 214 and the second transmitting antenna 224 are arranged adjacent to each other along a first direction 201. Similarly, the first receiving antenna 215 and the second receiving antenna 225 are also arranged adjacent to each other along the first direction 201. The individual transmitting antennas 214 and 224 have the same position along a second direction 202 perpendicular to the first direction 201, and the individual receiving antennas 215 and 225 also have the same position along the second direction 202. Thus, when transducing within the first frequency band or the second frequency band, respectively, the positions of the individual antennas 211 and 221 are defined by their respective phase centers. These positions correspond to MIMO positions defined by different phase differences obtained when propagating through separate propagation channels 70, 71, 72, 73, 74, 75, 76, 77, 78, and 79.

[0127] The first reference receive antenna 217 and the second reference receive antenna 227 are located at a reference position 641 along the first direction 201, and the remaining receive antennas 215 and 225 are arranged adjacent to each other, with a distance 640 between them. Distance 640 may, for example, be equal to a reference radiation wavelength having a reference frequency within the first frequency band, within the second frequency band, or between the first and second frequency bands. For example, the reference frequency may be a center frequency between the first and second frequency bands. The first reference transmit antenna 216 and the second reference transmit antenna 226 are also located at a reference position 641 along the first direction 201. The remaining transmit antennas 214 and 224 are arranged adjacent to each other and spaced apart by twice the distance 640. Therefore, the spacing between the transmit antennas 214 and 224 along the first direction 201 is equal to k times the distance 640 between the receive antennas 215 and 225, where k is the number of receive antennas 215 and 225.

[0128] Along the first direction 201, the first transmitting antenna 214 and the first receiving antenna 215 are arranged on opposite sides of the reference position 641. Similarly, the second transmitting antenna 224 and the second receiving antenna 225 are arranged on opposite sides of the reference position 641 along the first direction 201. In addition, the first transmitting antenna 214 and the second transmitting antenna 224 are arranged on opposite sides of the reference position 641 along the first direction 201, and the first receiving antenna 215 and the second receiving antenna 225 are also arranged on opposite sides of the reference position 641 along the first direction 201.

[0129] The signal processing device 120 is configured to form a common virtual antenna array 650 from the individual propagation channels 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 established between the first antenna 211 and the second antenna 221 . Figure 2 Schematically depicted is a virtual antenna array 650. The virtual antenna array 650 comprises a set of first virtual antennas 601 corresponding to the first propagation channels 70,72,74,76 and a set of second virtual antennas 602 corresponding to the second propagation channels 71,73,75,77.

[0130] For each virtual antenna 601, 602, its distance from the reference position 641 along the first direction 201 corresponds to the relative distance between the transmit antenna 614, 624 and the receive antenna 615, 625 of its corresponding propagation channel 70, 71, 72, 73, 74, 75, 76, 77. Since the transmit antennas 214, 224 are spaced apart from each other by twice the distance 640 between the receive antennas 215, 225, all virtual antennas 601, 602 have an equal effective spacing 642 between them, which is equal to the distance 640.

[0131] Figure 3 The first transmission 51 of the first antenna 211 and the second transmission 52 of the second antenna 221 are shown as a function of frequency 30. The first transmission 51 exceeds the minimum transmission 42 in the first frequency band 31 between the first minimum frequency 32 and the first maximum frequency 33, and the second transmission 52 exceeds the minimum transmission 42 in the second frequency band 34 between the second minimum frequency 35 and the second maximum frequency 36.

[0132] The first minimum frequency 32 may be equal to 75.5 GHz, and the second maximum frequency 36 may be equal to 81.5 GHz.The first maximum frequency 33 may be equal to 77.5 GHz, and the second minimum frequency 35 may be equal to 79.5 GHz.

[0133] If you can Figure 3 As can be seen, the first frequency band 31 and the second frequency band 34 are separated from each other and do not overlap. Between the first frequency band 31 and the second frequency band 34, there is a frequency gap spanning the frequency between the first maximum frequency 33 and the second minimum frequency 35. Figure 1 The radar circuit 100 of the illustrated radar device 1 processes first signal portions 11, 16, 21, 26 of the port signals 10, 15, 20, 25 occupy a first frequency band 31, and second signal portions 12, 17, 22, 27 of the port signals 10, 15, 20, 25 occupy a second frequency band 34. In an alternative embodiment of the radar device 1, the frequency bands 31, 34 may be defined by two different, spaced minimum transmissions.

[0134] Figure 4 Schematically, the frequencies 30 of the first and second port signals 10, 15 generated by the signal generator 105 of the radar device 1 during time 60 are shown. The frequencies 30 of the port signals 10, 15 are repeatedly cycled through the second frequency band 34 and the first frequency band 31. Figure 4 In the exemplary embodiment shown, the frequency 30 of the port signal 10, 15 is first linearly swept from a second maximum frequency 36 to a second minimum frequency 35 in a second frequency band 34, and then linearly swept from a first maximum frequency 33 to a first minimum frequency 32 in a first frequency band 31. This cycle or burst is then repeated.

[0135] In an alternative embodiment, different frequency sweeps can be used within the first frequency band 31 and / or within the second frequency band 34. For example, the frequency 30 can be swept from a lower frequency to a higher frequency. The frequency sweep can also begin by sweeping over the first frequency band 31 instead of sweeping over the second frequency band 34.

[0136] Individual frequency sweeps within the first frequency band 31 and the second frequency band 34 constitute individual frequency chirps from which the radar circuit 100 and the signal processing device 120 deduce the propagation delays of target reflections travelling via the individual propagation channels 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 .

[0137] Because the first antenna 211 transduces within the first frequency band 31 and the second antenna 221 transduces within the second frequency band 34, the target reflections via the first propagation channels 70, 72, 74, 76 exhibit an additional phase difference relative to the target reflections via the second propagation channels 71, 73, 75, 77, wherein the additional phase difference is a frequency-induced phase difference resulting from the frequency difference between the first radar signals 11, 16, 21, 26 transduced via the first antenna 211 and the second radar signals 12, 17, 22, 27 transduced via the second antenna 221.

[0138] The signal processing device 120 is configured to determine the phase difference caused by the additional frequency when forming a common virtual antenna array 650 by jointly evaluating the target reflection via the propagation channels 70, 71, 72, 73, 74, 75, 76, 77, and compensate for the phase difference on all propagation channels 70, 71, 72, 73, 74, 75, 76, 77.

[0139] Figure 5 Schematically shown is a portion of the radar device 1 used to determine the propagation delay based on the individual frequency chirps of the port signals 15, 25 transduced via propagation channels 76, 77 established by the first antenna 211 and the second antenna 221 connected to the second transmit signal port 131 and the second receive signal port 136.

[0140] The receive port signal 25 (which includes a first signal portion 26 and a second signal portion 27 transduced via the first receive antenna 211 and the second receive antenna 221, respectively, coupled to the receive signal port 136) is received by the receive chain 127 and subsequently compared with the instantaneous transmit port signal 15 transmitted via the first antenna 211 and the second antenna 221 coupled to the common transmit signal port 131. The comparison is accomplished by mixing the receive port signal 25 with the instantaneous transmit port signal 15 using the mixing module 154. This forms an intermediate signal 152 at the difference frequency between the transmit port signal 15 and the receive port signal 25. Since the transmit port signal 15 and the receive port signal 25 include linear frequency chirps with the same slope, their frequency difference and the resulting frequency of the intermediate signal 152 are constant in time. Furthermore, the frequency of intermediate signal 152 is a measure of the distance to target object 3 from which radar signals 16, 17 were reflected, since any delay in radar signals 16, 17 acquired during propagation between radar device 1 and target object 3 increases the instantaneous frequency difference between receive port signal 25 and transmit port signal 15, and thereby increases the frequency of intermediate signal 152.

[0141] The intermediate signal 152 is measured by a measurement module 154 of the receiving chain 127. The measurement module 154 is configured as an analog-to-digital (ADC) converter and samples the intermediate signal 152 to generate a data signal 123 representing the intermediate signal 152. The data signal 123 is received by the signal processing device 120, and the signal processing device 120 evaluates the data signal 123 to determine the position and velocity of the target object 3 based on the data signal 123.

[0142] Although Figure 5 The signal evaluation for the first propagation channel 76 between the first antenna 211 and the second propagation channel 77 between the second antenna 221, which are connected to the second common transmit signal port 131 and the second common receive signal port 136, is depicted, but the radar device 1 is configured to evaluate the signals transmitted via the remaining propagation channels 70, 71, 72, 73, 74, 75 in the same manner. This means that the receive port signal 20, 25 of each propagation channel 70, 71, 72, 73, 74, 75, 76, 77 is compared with the instantaneous transmit port signal 10, 15 of the corresponding propagation channel 70, 71, 72, 73, 74, 75, 76, 77 by mixing the two corresponding port signals 10, 15, 20, 25. The resulting intermediate signal 152 is then evaluated by the signal processing device 120.

[0143] for Figure 1In the radar device 1 shown, this results in four intermediate signals 152, one for each combination of common transmit signal ports 130, 131 and common receive signal ports 135, 136. Each intermediate signal 152 represents a propagation characteristic, such as a propagation delay or phase shift, of one of the first propagation channels 70, 72, 74, 76 and one of the second propagation channels 71, 73, 75, 77. The propagation characteristics of all propagation channels 70, 71, 72, 73, 74, 75, 76, 77 are jointly evaluated by the signal processing device 120.

[0144] Figure 6 The evaluation of data signals 125 corresponding to the individual propagation channels 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 by the signal processing device 120 is schematically depicted.

[0145] The signal processing device 120 splits the intermediate signal 125 into separate signal parts, each of which corresponds to the intermediate signal of one of the propagation channels 70, 71, 72, 73, 74, 75, 76, 77. The signal processing device 120 also splits the separate signal parts into parts corresponding to the separate frequency chirps transmitted via the respective propagation channels 70, 71, 72, 73, 74, 75, 76, 77. For each propagation channel 70, 71, 72, 73, 74, 75, 76, 77, these data can be described in a first channel data matrix 700, in which the rows represent the separate chirps 710 and the columns represent the separate samples 705 of the intermediate signal 125 corresponding to the separate chirps 710.

[0146] The signal processing device 120 first processes the intermediate signals 125 corresponding to the individual propagation channels 70, 71, 72, 73, 74, 75, 76, and 77 individually by mapping the data of each individual first channel data matrix 700 into range bins 725, where the individual range bins 725 group signals reflected at the same target distance from the radar device 1. This mapping is achieved by performing a row-by-row Fourier transform 720 (i.e., FFT) on the individual first channel data matrices 700 for the propagation channels 70, 71, 72, 73, 74, 75, 76, and 77. This results in data represented by a second channel data matrix 720 for each propagation channel 70, 71, 72, 73, 74, 75, 76, and 77, which has rows that still represent the individual chirps 710 and columns that represent the individual range bins 725. A row-by-row Fourier transform 715 resolves the chirp 710 into individual frequency components, each corresponding to a particular target distance.

[0147] Subsequently, the signal processing device 120 maps the data values of the individual chirps 710 for each individual range bin 725 into velocity bins 735, where the individual velocity bins 735 group signals reflected by targets 3 having the same target velocity. The mapping is performed by performing a column-by-column Fourier transform 730 (i.e., a column-by-column FFT) on the individual second channel data matrix 720. This results in a third channel data matrix 733 having columns representing the individual range bins 725 and rows representing the individual velocity bins 735. In an alternative embodiment, compensation for the phase difference determined based on the first reference phase and the second reference phase may also be performed after the signal data is converted to velocity bins 735 via the column-by-column Fourier transform 730.

[0148] For each individual third channel data matrix 733 , the signal processing device 120 determines target detection 740 by evaluating the signal strength of the individual range bins 725 and velocity bins 735 and comparing the signal strength to the minimum signal strength indicative of a reflective target 3 having the corresponding range and velocity.

[0149] Each data entry of third channel data matrix 733 is a complex value having an amplitude and a phase. The phase of the individual entries of third channel data matrix 733 is evaluated by signal processing device 120 to determine the velocity and angular position of target object 3 that reflected radar signals 11, 12, 16, 17. However, since first radar signals 11, 16 propagated via first propagation channels 70, 72, 74, 76 and second radar signals 12, 17 propagated via second propagation channels 71, 73, 75, 77 occupy different frequency ranges, and since first radar signals 11, 16 and second radar signals 12, 17 are transmitted intermittently and received with a delay between transmissions, the phase of the entries of third channel data matrix 733 also depends on whether the corresponding radar signal 11, 12, 16, 17 was transmitted via first propagation channels 70, 72, 74, 76 between first antenna 211 or via second propagation channels 71, 73, 75, 77 between second antenna 221.

[0150] The signal processing device 120 is configured to compensate for this correlation of the phase values on the propagation channels 70, 71, 72, 73, 74, 75, 76, and 77. To this end, the signal processing device 120 first determines the phase shift obtained via the propagation channel 71 forming the first reference propagation channel 78 as a first reference phase, and determines the phase shift obtained via the propagation channel 72 forming the second reference propagation channel 79 as a second reference phase.

[0151] Since the first reference propagation channel 78 and the second reference propagation channel 79 have the same propagation path between the radar device 1 and the target object 3, any difference between the first reference phase and the second reference phase does not depend on the different distances traveled by the reference signals 11, 12, 21, 22. Instead, this phase difference is caused by the different signal characteristics of the first reference signals 11, 21 transmitted via the first reference propagation channel 78 and the second reference signals 12, 22 transmitted via the second reference propagation channel 79. In addition, this phase difference depends on the angle-dependent phase shift caused by the angular position of the target object 3 in the first, or azimuth, direction 201. and the angle-dependent phase shift due to the angular position of the target object 3 in the second elevation direction 202 Depends on the distance-dependent phase shift and global phase offset

[0152] In order to compensate for these phase differences between the signals 11, 12, 16, 17 propagated via the first propagation channels 70, 72, 74, 76 and the second propagation channels 71, 73, 75, 77, the signal processing device 120 scales the phase values of the intermediate signals obtained from the second propagation channels 71, 73, 75, 77 by the ratio of the first reference phase to the second reference phase. This effectively results in the data entries of the third channel data matrix 733 being referenced to the signal characteristics of the first radar signals 11, 16, 21, 26 occupying the first frequency band 31.

[0153] In an alternative embodiment, compensation for the phase difference determined based on the first reference phase and the second reference phase may also be performed before transforming the signal data into the velocity bin 735 through the column-by-column Fourier transform 730 .

[0154] For each individual third channel data matrix 733 , the signal processing device 120 determines target detection 740 by evaluating the signal strength of the individual range bins 725 and velocity bins 735 and comparing the signal strength to the minimum signal strength indicative of a reflective target 3 having the corresponding range and velocity.

[0155] The signal processing device 120 then determines the angular position of the target object 3 represented by the target detection 740 based on the relative phase shifts between all target reflections propagated via the first propagation channels 70, 72, 74, 76 and the second propagation channels 71, 73, 75, 77. To do this, the signal processing device 120 maps those data values corresponding to the same target detection 740 across all third channel data matrices 733 into separate angular bins, each representing a different angular position of the detected target object 3. The mapping is accomplished by performing a matrix-by-matrix Fourier transform (i.e., a matrix-by-matrix FFT). This FFT then represents an angular FFT.

[0156] Figure 7 Another embodiment of the radar device 1 according to the present disclosure is shown. So far, there is no significant difference in the description or drawings. Figure 7 The embodiment shown is in accordance with the combination Figure 1 The illustrated embodiments may be configured as disclosed, and vice versa.

[0157] Figure 7 The radar circuit 100 of the radar device 1 shown has a total of three transmit signal ports, namely, a first transmit signal port 130, a second transmit signal port 131, and another transmit signal port 133. Furthermore, the radar circuit 100 has four receive signal ports, namely, a first receive signal port 135, a second receive signal port 136, and two further receive signal ports 137. Each of the signal ports 130, 131, 133, 135, 136, 137 forms a common signal port to which the corresponding first antenna 211 and the corresponding second antenna 221 are connected.

[0158] Each of the first antenna 211 and the second antenna 221 is configured as a serially fed array antenna. Each first antenna 211 includes a set of first antenna elements 213, and each second antenna 221 includes a set of second antenna elements 223. The first antenna 211 and the second antenna 221, coupled to the first transmit signal port 130 of the radar apparatus 1, form a first reference transmit antenna 216 and a second reference transmit antenna 226, respectively, and thus have the same phase center. The first antenna 211 and the second antenna 221, coupled to the first receive signal port 135, form a first reference receive antenna 217 and a second reference receive antenna 227, respectively, and thus also have the same phase center. The antenna elements 213 of the first reference transmit antenna 216 and the antenna elements 223 of the second reference transmit antenna 226 are formed as overlapping antenna elements 213 and 223 that transduce energy in both the first frequency band 31 and the second frequency band 34. Likewise, antenna element 213 of first reference receiving antenna 217 and antenna element 223 of second reference receiving antenna 227 are formed as overlapping antenna elements 213 , 223 that transduce in both first frequency band 31 and second frequency band 34 .

[0159] The additional first antennas 211 and the additional second antennas 221 connected to the other signal ports 131, 133, 136, and 137 all have different phase centers. These antennas 211 and 221 are connected to the corresponding common signal ports 131, 133, 136, and 137 via signal routing devices 230, each of which has a first port 231 connected to the corresponding first antenna 211 and a second port 232 connected to the corresponding second antenna 221. The signal routing devices 230 are each connected to their corresponding common signal ports 131, 133, 135, 136, and 137 via a common signal line 205. The signal routing devices 230 selectively route a first signal portion of the port signal transduced via the first antenna 211 via the first port 231 and the common signal line 205, and route a second signal portion of the port signal transduced via the second antenna 221 via the second port 232 and the common signal line 205. The signal routing device 230 may be configured as a frequency dependent duplexer, a switch, or the like.

[0160] Figure 8 An alternative embodiment of the radar device 1 according to the present disclosure is shown. No differences can be drawn from the description or drawings so far. Figure 8 The embodiment shown is in accordance with the combination Figure 7 The illustrated embodiments may be configured as disclosed, and vice versa.

[0161] Figure 8 Radar circuit 100 of radar device 1 shown includes a first integrated circuit 101 and a second integrated circuit 102. Each integrated circuit 101, 102 includes a signal generator 105 and a signal receiver 110. Each signal generator 105 is connected to a first transmit port 130, a second transmit port 131, and an additional transmit port 133 of the respective integrated circuit 101, 102, and each signal receiver 110 is connected to a first receive port 135, a second receive port 136, and two additional receive ports 137 of the respective integrated circuit 101, 102. Each individual port 130, 131, 133, 135, 136, 137 constitutes a physical external connection point for the respective integrated circuit 101, 102.

[0162] First integrated circuit 101 is configured to simultaneously transmit and receive a first radar signal transduced via first antenna 211, and second integrated circuit 102 is configured to simultaneously transmit and receive a second radar signal transduced via second antenna 221. First integrated circuit 101 and second integrated circuit 102 operate simultaneously and have synchronization triggers for transmitting the first and second radar signals. Furthermore, first integrated circuit 101 and second integrated circuit 102 include phase-coherently coupled reference oscillators.

[0163] First integrated circuit 101 generates a first radar signal having a set of mutually independent phase codes as a separability parameter, while second integrated circuit 102 generates a second radar signal having the same set of mutually independent phase codes. To generate the phase codes, first integrated circuit 101 and second integrated circuit 102 include a binary phase shifter at each of signal ports 130, 131, 133, 135, 136, and 137.

[0164] First reference transmit antenna 216 and second reference transmit antenna 226, comprised of common antenna elements 213 and 214, are coupled to first transmit port 130 of first integrated circuit 101 and first transmit port 130 of second integrated circuit 102 via duplexer 240. The duplexer combines a first reference signal received from first integrated circuit 101 and occupying first frequency band 31 with a second reference signal received from second integrated circuit 102 and occupying second frequency band 34. Similarly, first reference receive antenna 217 and second reference receive antenna 227, also comprised of common antenna elements 213 and 223, are coupled to first receive port 135 of first integrated circuit 101 and first receive port 135 of second integrated circuit 102 via another duplexer 240. The duplexer 240 separates the signal component of the first reference signal from the signal component of the second reference signal, directing the signal component of the first reference signal to first receive port 135 of first integrated circuit 101 and the signal component of the second reference signal to first receive port 135 of second integrated circuit 102.

[0165] The remaining first transmit antenna 211 is individually coupled to the second transmit signal port 131 and the further transmit signal port 133 of the first integrated circuit 101, and the remaining first receive antenna 211 is also individually coupled to the second receive signal port 136 and the further receive signal port 137 of the first integrated circuit 101. Similarly, the remaining second transmit antenna 221 is individually coupled to the second transmit signal port 131 and the further transmit signal port 133 of the second integrated circuit 102, and the remaining second receive antenna 221 is individually coupled to the second receive signal port 136 and the further receive signal port 137 of the second integrated circuit 102.

[0166] Figure 9 Shown Figure 7 and Figure 8An exemplary layout of antennas 211 and 221 of radar apparatus 1 is shown. Transmit antennas 214 and 224 form a linear transmit array arranged along a first direction 201, with first and second reference transmit antennas 216 and 226 coinciding and positioned at the center of the transmit array at a reference position 641. First transmit antenna 214 is positioned along first direction 201 on a first side 605 relative to reference position 641, and second receive antenna 224 is positioned on a second side 606 relative to reference position 641. Furthermore, receive antennas 215 and 225 are arranged in a linear receive array along first direction 201, with first and second reference receive antennas 217 and 227 coinciding and positioned at reference position 641. First receive antenna 215 is positioned along first direction 201 on a second side 606 relative to reference position 641, and second receive antenna 225 is positioned on a first side 605.

[0167] The transmit antennas 214, 224 are spaced apart from each other by a distance four times greater than the distance 640 between the receive antennas 215, 225. A common virtual antenna array 650 established by the first and second propagation channels between the antennas 214, 215, 216, 226 then includes virtual antennas 601, 602 having an effective spacing 642 therebetween that corresponds to the distance 640 between the receive antennas 215, 225.

[0168] Figure 10 Schematically depicts Figure 1 The alternative arrangement of the first antenna 211 and the second antenna 221 of the radar device 1 is shown. Differences so far will now be described or will be apparent from the accompanying drawings. Figure 10 The layout shown follows the Figure 2 The layout shown can be configured as disclosed, and vice versa.

[0169] use Figure 10 In the illustrated arrangement, the first reference transmit antenna 216 and the second reference transmit antenna 226 coincide and are arranged at a reference position 641 along the first direction 201. The additional first transmit antenna 214 is displaced relative to the reference antennas 216 and 217 by a distance 640 along the first direction 201 and by another distance 645 along the second direction 202. This results in the first virtual antennas 601 of the virtual antenna array 650 being located in a single row extending along the first direction 201 and displaced relative to each other by a further distance 645 along the second direction 202. By jointly evaluating the first and second propagation channels established between the first antenna 211 and the second antenna 221, the signal processing device 120 is thus able to determine the angular position of the target object 3 along both the first and second directions 201, 202.

[0170] Using alternative embodiments of the individual radar devices 1 described herein, the first effective spacing between first virtual antennas 601 can be different from the second effective spacing between second virtual antennas 602. Additionally or alternatively, the distance between individual first receive antennas 215 can be different from the distance between individual second receive antennas 225, and / or, correspondingly, the distance between individual first transmit antennas 214 can be different from the distance between individual second transmit antennas 224. Furthermore, first transmit antennas 214 and / or first receive antennas 215 can have unequal spacings from one another. Similarly, second transmit antennas 224 and / or second receive antennas 225 can have unequal spacings from one another. Using all of these embodiments, signal processing device 120 can be configured to account for these unequal spacings or distances when constructing common virtual antenna array 650.

[0171] Figure 11 A method 400 of operating a radar device 1 according to the present disclosure is depicted. Method 400 includes the steps of transmitting and receiving radar signals by generating 405 first radar signals 11, 16 occupying a first frequency band 31 and second radar signals 12, 17 occupying a second frequency band 34 using transmit chains 125, 126 of signal generator 105 of radar circuit 100. The method then includes the steps of routing 410 radar signals 11, 12, 16, 17 to antenna device 200 via signal ports 130, 131, 133. Method 400 also includes the steps of transducing first radar signals 11, 16 and second radar signals 12, 17 using antenna device 200 by radiating 415 first radar signals 11, 16 via first transmit antenna 211 and second radar signals 12, 17 via second transmit antenna 221.

[0172] Method 400 then includes the step of transducing the radar signals by capturing 420 first radar signals 21, 26 via first receive antenna 211 of antenna arrangement 200 and capturing second radar signals 22, 27 via second receive antenna 221 of antenna arrangement 200, respectively. The method also includes the step of routing 425 radar signals 21, 22, 26, 27 from antenna arrangement 200 to radar circuit 100 via receive signal ports 135, 136, 137. Method 400 also includes the step of measuring received radar signals 21, 22, 26, 27 by generating 430 data signals 123, 124 representing radar signals 21, 22, 26, 27 received by receive chains 127, 128. The method 400 then comprises the step of detecting 440 target reflections via the first propagation channels 70, 72, 74, 76 from the first radar signals 21, 26 and detecting target reflections via the second propagation channels 71, 73, 75, 77 from the second radar signals 22, 27 using the signal processing device 120. Subsequently, the method 400 comprises the step of jointly evaluating 445 target reflections via the first propagation channels 70, 72, 74, 76 and target reflections via the second propagation channels 71, 73, 75, 77 by forming a common virtual antenna array 650 and determining the angular position of the target object 3 illuminated by the antenna device 200.

[0173] Figure 12 A vehicle 500 equipped with a radar device 1 according to the present disclosure is depicted. Figure 12 In the illustrated embodiment, radar device 1 is configured as a front radar for vehicle 1 , and the radiation field 501 of the antenna assembly of radar device 1 is directed forward of vehicle 500 . Radar device 1 is part of vehicle control system 502 of vehicle 500 and is connected to a control device 504 of vehicle control system 502 . Control device 504 is configured to execute advanced driver assistance functions such as adaptive cruise control, emergency brake assist, lane change assist, or autonomous driving based on data signals received from radar device 1 . These data signals represent the position of a target object in front of radar device 1 mounted on vehicle 500 . Control device 504 is configured to at least partially control the movement of vehicle 500 based on the data signals received from radar device 1 . To control the movement of the vehicle, control device 504 can be configured to brake, accelerate, and / or steer vehicle 500 .

[0174] Label list

[0175] 1 Radar device

[0176] 3 Target objects

[0177] 10 First sending port signal

[0178] 11 First signal part

[0179] 12 Second signal part

[0180] 15 Second sending port signal

[0181] 16 First signal part

[0182] 17 Second signal part

[0183] 20 First receiving port signal

[0184] 21 First signal part

[0185] 22 Second signal part

[0186] 25 Second receiving port signal

[0187] 26 First signal part

[0188] 27 Second signal part

[0189] 30 frequency

[0190] 31 First Band

[0191] 32 First minimum frequency

[0192] 33 First maximum frequency

[0193] 34 Second frequency band

[0194] 35 Second minimum frequency

[0195] 36 Second maximum frequency

[0196] 42 min send

[0197] 51 First Send

[0198] 52 Second Send

[0199] 60 hours

[0200] 70 Propagation Channel

[0201] 71 Propagation Channel

[0202] 72 Propagation Channel

[0203] 73 Propagation Channel

[0204] 74 Propagation Channel

[0205] 75 Propagation Channel

[0206] 76 Propagation Channel

[0207] 77 Propagation Channel

[0208] 78 First reference propagation channel

[0209] 79 Second reference propagation channel

[0210] 100 Radar Circuit

[0211] 101 First Integrated Circuit

[0212] 102 Second Integrated Circuit

[0213] 105 Signal Generator

[0214] 110 signal receiver

[0215] 120 signal processing device

[0216] 121 First control signal

[0217] 122 Second control signal

[0218] 123 First radar data signal

[0219] 124 Second radar data signal

[0220] 125 First Send Chain

[0221] 126 Second Send Chain

[0222] 127 First Receive Chain

[0223] 128 Second receive chain

[0224] 130 First sending port

[0225] 131 Second sending port

[0226] 133 Additional sending port

[0227] 135 First receiving port

[0228] 136 Second receiving port

[0229] 137 Additional receiving ports

[0230] 151 Mixing Module

[0231] 152 Intermediate Signal

[0232] 154 Measurement Module

[0233] 200 Antenna Device

[0234] 201 First Direction

[0235] 202 Second Direction

[0236] 205 public signal line

[0237] 211 First Antenna

[0238] 213 First antenna element

[0239] 214 First transmitting antenna

[0240] 215 First receiving antenna

[0241] 216 First reference transmitting antenna

[0242] 217 First reference receiving antenna

[0243] 221 Second Antenna

[0244] 223 Second antenna element

[0245] 224 Second transmitting antenna

[0246] 225 Second receiving antenna

[0247] 226 Second reference transmitting antenna

[0248] 227 Second reference receiving antenna

[0249] 230 signal routing device

[0250] 231 First Port

[0251] 232 Secondary port

[0252] 240 Duplexer

[0253] 400 Method

[0254] 405 Generate Radar Signal

[0255] 410 Routing radar signals from radar circuit to antenna assembly

[0256] 415 Radiated Radar Signal

[0257] 420 Capture radar signal

[0258] 425 Routing radar signals from antenna assembly to radar circuitry

[0259] 430 Generate Data Signal

[0260] 440 Distinguishing Propagation Channels

[0261] 445 Joint Assessment of Radar Signals

[0262] 500 vehicles

[0263] 501 Radiation Field

[0264] 502 Vehicle Control System

[0265] 504 Vehicle Control Device

[0266] 510 ground surface

[0267] 601 First Virtual Antenna

[0268] 602 Second Virtual Antenna

[0269] 605 First Side

[0270] 606 Second side

[0271] 640 Distance

[0272] 641 Reference Position

[0273] 642 effective spacing

[0274] 645 Another Distance

[0275] 650 public virtual antenna array

[0276] 700 First Channel Data Matrix

[0277] 705 samples

[0278] 710 Chirp

[0279] 715 Line-by-line Fourier transform

[0280] 720 Second Channel Data Matrix

[0281] 725 Distance Warehouse

[0282] 730 Column-by-column Fourier transform

[0283] 733 Third Channel Data Matrix

[0284] 735 Speed Warehouse

[0285] 740 detection

Claims

1. A radar device (1) for automotive applications, comprising: A radar circuit (100), the radar circuit transmitting and receiving radar signals; an antenna device (200), the antenna device transducing the radar signal; as well as A signal processing device (120), wherein the signal processing device processes the radar signal. wherein the radar circuit (100) is configured to transmit and receive a first radar signal occupying a first frequency band (31) and a second radar signal occupying a separate second frequency band (34), The antenna device (200) comprises a first group of first antennas (211) and a second group of second antennas (221). wherein the antenna arrangement (200) is configured to selectively transduce the first radar signal via the first antenna (211) but not via the second antenna (221), and selectively transduce the second radar signal via the second antenna (221) but not via the first antenna (211), wherein the signal processing device (120) is configured to detect target reflections via a first propagation channel from the first radar signal and to detect target reflections via a second propagation channel from the second radar signal, wherein the signal processing device (120) is configured to jointly evaluate target reflections via the first propagation channel and target reflections via the second propagation channel to form a common virtual antenna array (650) for determining the angular position of a target object (3) illuminated by the antenna device (200), and The signal processing device (120) is configured to determine the angular position of the target object (3) based on the relative phase shift between all target reflections propagated via the first propagation channel and the second propagation channel.

2. The radar device (1) according to claim 1, in, The phase center (301) of the first reference transmitting antenna in the first group of first antennas (211) coincides with the phase center (302) of the second reference transmitting antenna (226) in the second group of second antennas (221), and the phase center (301) of the first reference receiving antenna in the first group of first antennas (211) coincides with the phase center (302) of the second reference receiving antenna (227) in the second group of second antennas (221).

3. The radar device (1) according to claim 2, in, The signal processing device (120) is configured to measure a phase difference between a first reference signal and a second reference signal, the first reference signal being propagated via a first reference propagation channel established between the first reference transmit antenna and the first reference receive antenna, and the second reference signal being propagated via a second reference propagation channel established between the second reference transmit antenna (226) and the second reference receive antenna, The signal processing device (120) is configured to compensate for the measured phase difference when jointly evaluating the target reflection via the first propagation channel and the target reflection via the second propagation channel.

4. The radar device (1) according to claim 3, in, The signal processing device (120) is configured to compensate for: Angle-dependent phase shifts (Δφ_AZ, Δφ_EL) caused by different radiation patterns of the first reference transmit antenna and the first reference receive antenna within the first frequency band (31) and the second reference transmit antenna and the second reference receive antenna within the second frequency band (34), and / or a range-dependent phase shift (Δφ_RANGE) between a target reflection of the first reference signal and a target reflection of the second reference signal caused by a change in the distance to the target object (3), and / or When generating the first reference signal and the second reference signal, a global phase offset (Δφ_GL) of the first reference signal relative to the second reference signal.

5. The radar device (1) according to claim 1, in, The signal processing device (120) is configured to jointly evaluate the phase values derived from all first propagation channels and second propagation channels to determine the angular position of the target object (3).

6. The radar device (1) according to claim 5, in, The signal processing device (120) is configured to jointly evaluate phase values derived from all first propagation channels and second propagation channels to determine the angular position of the target object (3) by performing a common Fourier transform on the phase values.

7. The radar device (1) according to claim 1, in, All individual transmit antennas (214, 224) in the first group of first antennas (211) and the second group of second antennas (221) are aligned with each other along a first direction, and Wherein, all individual receiving antennas (215, 225) in the first group of first antennas and the second group of second antennas (221) are aligned with each other along the first direction.

8. The radar device (1) according to claim 1, in, A portion of the first antenna (211) and / or the second antenna (221) is distributed along a first direction, and another portion of the first antenna (211) and / or the second antenna (221) is distributed along a second direction, Wherein, the second direction (202) is different from the first direction.

9. The radar device (1) according to claim 8, in, The second direction (202) is orthogonal to the first direction.

10. The radar device (1) according to claim 8, in, The first direction is an azimuth direction relative to a ground surface (510) on which a vehicle (500) including the radar device (1) is traveling, The second direction (202) is an elevation direction relative to the ground surface (510).

11. The radar device (1) according to claim 1, in, A first antenna among the first antennas (211) and a second antenna among the second antennas (221) are coupled to a common signal port (130, 131, 133, 135, 136, 137) of the radar circuit (100), the common signal port (130, 131, 133, 135, 136, 137) being configured to route both the first radar signal transduced via the corresponding first antenna (211) and the second radar signal transduced via the corresponding second antenna (221).

12. The radar device (1) according to claim 11, in, The phase center (301) of the first antenna (211) coupled to the common signal port (130, 131, 133, 135, 136, 137) coincides with the phase center of the second antenna (221) coupled to the common signal port (130, 131, 133, 135, 136, 137).

13. The radar device (1) according to claim 11, in, A phase center (301) of the first antenna (211) coupled to the common signal port (130, 131, 133, 135, 136, 137) is shifted relative to a phase center of the second antenna (221) coupled to the common signal port (130, 131, 133, 135, 136, 137).

14. The radar device (1) according to claim 1, in, At least one of the first antennas (211) is connected to a first integrated circuit (101) of the radar circuit (100), the first integrated circuit being used for transmitting and receiving corresponding first radar signals, At least one second antenna in the second antennas (221) is connected to a second integrated circuit (102) of the radar circuit (100), and the second integrated circuit is used for transmitting and receiving corresponding second radar signals.

15. A vehicle (500) comprising a radar device (1) according to any one of claims 1 to 14.

16. A method (400) of operating a radar device (1) for automotive applications, the radar device (1) comprising a radar circuit (100) for transmitting and receiving radar signals; an antenna device (200) for transducing the radar signals; and a signal processing device (120) for processing the radar signals. in, The antenna device (200) comprises a first group of first antennas (211) and a second group of second antennas (221), The method (400) comprises the following steps: Using the radar circuit (100) to transmit and receive (405, 430) a first radar signal occupying a first frequency band (31) and a second radar signal occupying a second frequency band (34); transducing (415, 420) the first radar signal via the first antenna (211) but not via the second antenna (221), and transducing (415, 420) the second radar signal via the second antenna (221) but not via the first antenna (211); Detecting, by means of the signal processing device (120), a target reflection via a first propagation channel from the first radar signal and a target reflection via a second propagation channel from the second radar signal, jointly evaluating (445) target reflections via the first propagation channel and target reflections via the second propagation channel using the signal processing device (120) to form a common virtual antenna array (650) for determining the angular position of a target object (3) illuminated by the antenna device (200), The method (400) further comprises the following steps: The signal processing device (120) is used to determine the angular position of the target object (3) based on the relative phase shift between all target reflections propagated via the first propagation channel and the second propagation channel.

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