Radar transceiver for radar signals and radar instrument

Abstract

A radar transceiver for radar signals, having a frequency-selective radar transmitting unit and / or a frequency-selective radar receiving unit, the frequency-selective radar transmitting unit comprising: a digital-to-analog converter for converting broadband digital signals provided for all transmitting channels into analog transmitting signals, a signal modulator that modulates a signal carrier by means of an analog transmission signal output by the digital-to-analog converter to generate a modulated transmission signal, at least one frequency selective component that distributes the transmission signal modulated by the signal modulator to a plurality of transmission channels as radar signal radiation; the frequency-selective radar receiving unit comprises at least one frequency-selective component for combining a received radar signal comprising a plurality of receiving channels, a signal demodulator for demodulating the radar signal combined by the frequency-selective component by means of a signal carrier to produce a demodulated received signal, and at least one analog-to-digital converter that samples the received signal demodulated by the signal demodulator to generate a digital received signal.

Description

Technical Field

[0001] This invention relates to a radar transceiver for radar signals, and more particularly to a sensor concept for radar instruments with wideband digital signal generation and frequency-selective TX / RX behavior. Background Technology

[0002] Radar detects objects using electromagnetic or radio waves. In addition to measuring distance, radar can also detect the angle and relative speed to moving objects.

[0003] DE 10 2013 222 963 A1 relates to a radar antenna including a main radiator, a waveguide element, and a lens, wherein the waveguide element is configured and arranged between the main radiator and the lens such that the cross-sectional area of ​​the waveguide element on the side facing the main radiator is smaller than the cross-sectional area of ​​the waveguide element on the opposite side, away from the main radiator. Importantly, the main radiator is configured as an edge-transmitting antenna, and the waveguide element is configured and arranged to cooperate with the edge-transmitting antenna such that the waveguide element overlaps with the edge-transmitting antenna on its upper and opposite lower sides at its end facing the edge-transmitting antenna.

[0004] DE112018001287T5 relates to a radar technology that uses a frequency modulation method to measure distance or relative velocity. This improves range resolution while preventing signal-to-noise ratio degradation. The radar circuit includes a signal generation unit that generates a transmitted signal for transmitting a wave; a modulation control unit that controls the frequency modulation of the transmitted signal; a receiver-side circuit unit that detects a signal based on the difference frequency between the received signal and the transmitted signal; and a signal processing unit that performs analysis processing based on the detected signal and calculates the distance and relative velocity.

[0005] DE 10 2019 201 374 A1 relates to a method for operating multiple radar sensors in a radar network, wherein each transmitted FMCW radar signal is preceded by a CW signal containing binary encoded information about the transmission parameters and / or other information of the transmitting radar sensor. In a preferred configuration, each radar sensor receives a corresponding CW signal with information about the transmission parameters of other radar sensors in the radar network, processes this information, and matches its own transmission parameters to those of other radar sensors upon identification of a match, thus deviating from the matching of transmission parameters of other radar sensors. This method enables multiple radar sensors to operate without interference in a radar network and can also be used for multi-static radar systems.

[0006] DE102022205109A1 relates to an electronic device that may include a standing wave ratio (VSWR) sensor disposed on an radio frequency transmission line between a signal generator and an antenna. The VSWR sensor collects VSWR measurements of radio frequency signals transmitted by the signal generator through the transmission line. Control circuitry logic can identify changes in the VSWR measurement over time and compare these changes to a threshold to determine whether an external object near the antenna is living or inanimate. If the external object is living, the control circuitry logic can reduce the maximum transmit power level of the antenna; if the external object is inanimate, it can maintain or increase the maximum transmit power level. This can be used to maximize the wireless performance of the electronic device while ensuring that the device complies with legal limits for radio frequency energy exposure. Summary of the Invention

[0007] According to the first aspect, the present invention realizes a radar transceiver for radar signals, having a frequency-selective radar transmitting unit and / or a frequency-selective radar receiving unit. The frequency-selective radar transmission unit of the radar transceiver includes: A digital-to-analog converter is constructed to convert broadband digital signals provided for all transmission channels into analog transmission signals. A signal modulator that modulates a carrier signal to generate a modulated transmission signal using an analog transmission signal output from the digital-to-analog converter; and At least one frequency-selective component is configured to distribute the transmitted signal modulated by the signal modulator to a plurality of transmit (TX) channels for radar signal radiation; and The frequency-selective radar receiving unit of the radar transceiver equipment includes: At least one frequency-selective component is configured to combine received radar signals comprising multiple receive (RX) channels; A signal demodulator that demodulates radar signals combined by the frequency-selective components using a signal carrier to generate a demodulated received signal; and At least one analog-to-digital converter is configured to sample the received signal demodulated by the signal demodulator to generate a digital received signal.

[0008] In the device of this invention, instead of setting up a converter for each TX channel as in broadband digital radar, a single signal source (DAC) is used, which is distributed to multiple TX channels via a frequency-selective TX path / TX antenna. This allows for frequency division multiplexing (FDM) using a single signal source (DAC).

[0009] Unlike implementing N wideband TX and / or RX channels, the radar transceiver device of the present invention preferably requires only a single TX and / or RX channel.

[0010] In the radar transceiver device for radar signals of the present invention, signal distribution is preferably achieved through passive components.

[0011] According to the requirements, in the radar transceiver for radar signals of the present invention, instead of the TX path, the RX path can also be implemented in such a way that only one wideband analog-to-digital converter is needed. Furthermore, both paths (TX side and RX side) of the radar transceiver can be implemented simultaneously in a frequency-selective manner.

[0012] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the frequency selective component has a frequency selective antenna.

[0013] This provides a space-saving and efficient way to achieve frequency selectivity.

[0014] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the frequency selective antenna has a frequency selective microstrip antenna, a frequency selective waveguide antenna, or a frequency selective reflector antenna.

[0015] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the frequency-selective microstrip antenna has a frequency-selective patch antenna having a different phase center for each frequency in one dimension.

[0016] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the frequency-selective microstrip antenna has a frequency-selective helical antenna having a different phase center for each frequency in two dimensions.

[0017] Advantageous for implementing the radar transceiver apparatus of the present invention is that the transmitting / receiving elements, particularly the frequency-selective antenna, have a frequency-dependent phase center, which can be repeated periodically or aperiodically. The phase center can be frequency-dependent in all three spatial dimensions.

[0018] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the phase center is periodically repeated in the frequency domain.

[0019] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the phase center is realized non-periodically in the frequency domain.

[0020] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the frequency-selective microstrip antenna has a frequency-selective antenna with a log-periodic arrangement.

[0021] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the frequency selective component has a frequency selective signal filter.

[0022] These are preferably constructed to be passive and allow for a simple and space-saving implementation of frequency selectivity.

[0023] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the frequency selective component has a frequency selective active component.

[0024] This could be a signal amplifier. It also allows for a simple and space-saving implementation of frequency selectivity.

[0025] In one possible embodiment of the radar transceiver device for radar signals of the present invention, the signal modulator is configured to perform FMCW modulation of the signal carrier.

[0026] FMCW modulation provides a precise method for distance measurement and can provide detailed information about the target object through its continuous modulation and frequency variations.

[0027] In one possible embodiment of the radar transceiver device for radar signals of the present invention, a local oscillator is provided, which generates the signal carrier.

[0028] This provides a frequency-stable signal carrier, thereby improving the accuracy of angle and distance estimation.

[0029] The present invention also provides a radar instrument having radar transceiver equipment according to the first aspect of the invention and a signal processing unit for estimating the angle and / or distance of a target object. Attached Figure Description

[0030] Possible embodiments of the radar transceiver for radar signals of the present invention will now be described in more detail with reference to the accompanying drawings. The drawings show: Figure 1 A schematic block diagram illustrating one possible implementation of the radar transceiver device for radar signals according to the present invention is shown. Figure 2A The illustration shows a system concept with a frequency-selective transmitting antenna in one possible embodiment of the radar transceiver for radar signals according to the present invention; Figure 2BThe illustration shows a system concept for representing a frequency-selective signal transmission path in another possible embodiment of the radar transceiver for radar signals according to the present invention; Figure 3 A schematic representation of a frequency-selective patch antenna with different phase centers for each frequency in one dimension is shown. Figure 4 A schematic representation of a frequency-selective helical antenna with different phase centers at each frequency in two dimensions is shown. Figures 5A-5D The signal spectrum is shown to illustrate the functionality of possible embodiments of the radar transceiver for radar signals according to the present invention. Detailed Implementation

[0031] A radar transceiver device 1 for radar signals according to the present invention includes a frequency-selective radar transmitting unit 2 and / or a frequency-selective radar receiving unit 3, such as... Figure 1 As shown schematically in the diagram.

[0032] The frequency-selective radar transmitting unit 2 of the radar transceiver 1 includes a digital-to-analog converter (DAC) 2A, which is configured to convert broadband digital signals provided for all transmission channels into analog transmission signals.

[0033] The frequency-selective radar transmitting unit 2 of the radar transceiver 1 also has a signal modulator 2B, which modulates a signal carrier to generate a modulated transmitting signal by means of the analog transmitting signal output by the digital-to-analog converter (DAC) 2A.

[0034] The frequency-selective radar transmitting unit 2 of the radar transceiver device 1 has at least one frequency-selective component 2C, which is configured to distribute the transmitted signal modulated by the signal modulator 2B to a plurality of transmit (TX) channels for radar signal radiation.

[0035] In one possible embodiment of the present invention, the radar transceiver 1 for radar signals according to the present invention further includes a frequency-selective radar receiving unit 3.

[0036] The frequency-selective radar receiving unit 3 of the radar transceiver device 1 has at least one frequency-selective component 3C, which is configured to combine received radar signals including multiple receive (RX) channels.

[0037] The frequency-selective radar receiving unit 3 of the radar transceiver 1 also has a signal demodulator 3B, which demodulates the radar signal combined by the frequency-selective component 3C by means of a signal carrier to generate a demodulated received signal.

[0038] The frequency-selective radar receiving unit 3 of the radar transceiver device 1 also has at least one analog-to-digital converter (ADC) 3A, which is configured to sample the received signal demodulated by the signal demodulator 3B to generate a digital received signal.

[0039] In one possible embodiment of the radar transceiver device 1 of the present invention, the frequency selective components 2C and 3C have frequency selective antennas.

[0040] Figure 2A An example implementation of radar transceiver 1 is shown, which has a frequency-selective antenna 2C disposed on the transmitting side, which receives a modulated signal from a modulator 2B. The modulated signal may optionally be amplified by a signal amplifier A (amplifier).

[0041] exist Figure 2A In the illustrated implementation example, the transmitting unit 2 is frequency-selective, while the receiving side 3 is conventionally constructed. Each of the M receiving antennas Rx1 to RxM provides a broadband signal to a demodulator, which demodulates the broadband signal and provides it to the associated analog-to-digital converter (ADC) via a low-pass filter (LP). The ADC samples the low-pass filtered demodulated signal and outputs the sampled value to the signal processing unit (SVE).

[0042] Figure 1 and Figure 2A The frequency-selective antenna 2C of the radar transceiver 1 shown can be implemented differently, and for example has a frequency-selective microstrip antenna, a frequency-selective waveguide antenna, or a frequency-selective reflector antenna.

[0043] exist Figure 2A In one possible implementation of the radar transceiver device 1 of the present invention, the frequency-selective microstrip antenna 2C has a frequency-selective patch antenna having a different phase center PZ for each frequency in one dimension, such as... Figure 3 As shown schematically in the diagram.

[0044] exist Figure 2A In another possible implementation of the radar transceiver device 1 of the present invention, the frequency-selective microstrip antenna 2C has a frequency-selective helical antenna with different phase centers PZ for each frequency in two dimensions, such as... Figure 4 As shown schematically in the diagram.

[0045] In one possible embodiment of the radar transceiver device 1 of the present invention, the phase center PZ is repeatedly realized periodically or non-periodically in the frequency domain.

[0046] In another possible embodiment of the radar transceiver device 1 of the present invention, the frequency-selective microstrip antenna 2C has a frequency-selective antenna with a log-periodic arrangement.

[0047] In another possible embodiment of the radar transceiver device 1 for radar signals of the present invention, the frequency selective component has a frequency selective signal filter, such as... Figure 2B As shown.

[0048] Figure 2B This illustration shows a possible implementation of the radar transceiver device 1 of the present invention, wherein frequency selectivity is achieved on the transmitting side 2 through the allocation of signal paths and the setting of a frequency-selective bandpass filter (BP) 2C. Additionally, a signal amplifier A (amplifier) ​​may optionally be provided.

[0049] In another possible embodiment of the radar transceiver device 1 for radar signals of the present invention, the frequency selective components 2C and 3C have frequency selective active components, in particular signal amplifiers.

[0050] In one possible embodiment of the radar transceiver device 1 for radar signals according to the present invention, the signal modulator 2B is configured to perform FMCW modulation of the signal carrier ST. In another possible embodiment of the radar transceiver device 1 for radar signals according to the present invention, a local oscillator 4 is provided, which generates the signal carrier ST.

[0051] In FMCW modulation (Frequency Modulated Continuous Wave), the signal carrier ST generated by oscillator 4 is modulated. The signal carrier ST in radar transceiver 1 is a high-frequency signal, serving as the basis for radar measurements. It is a continuous wave that is transmitted and received in the radar system to obtain information about distant objects. The frequency f of the signal carrier ST is very high, typically in the gigahertz (GHz) range, to enable the capture of fine details of the target object. FMCW is a modulation technique in which the frequency f of the continuous carrier signal ST varies over time. The modulation is continuous, rather than pulsed as in traditional radar systems.

[0052] The carrier signal ST is altered through frequency modulation. The carrier signal ST is a continuous sinusoidal signal with a specific center frequency. The frequency f of the carrier signal ST changes linearly or non-linearly over a specific time period.

[0053] This can be achieved by increasing the frequency (linear frequency modulation) or by frequency modulation over a period of time. In one possible implementation, the frequency f of the signal carrier ST increases linearly over a fixed time interval, i.e., within the so-called linear frequency modulation period (in the case of linear FMCW modulation).

[0054] FMCW modulation enables radar instruments to measure the range and velocity of a target. The process involves transmitting an FMCW signal, in which a continuous, frequency-modulated carrier wave is transmitted. The transmitted FMCW signal illuminates the target object and is reflected. The radar instrument receives the reflected signal and compares it to the transmitted signal. The frequency difference between the transmitted and received signals (the so-called beat signal frequency) is used to calculate the target object's range and velocity.

[0055] In an FMCW radar instrument with radar transceiver 1, the signal carrier ST has a continuous high-frequency signal generated by a local oscillator (LO) 4, which is modulated by modulator 2B using a varying frequency (FMCW). This modulation allows the radar instrument to obtain information about the distance and velocity of a target object by analyzing the time offset and frequency shift of the reflected signal. FMCW technology provides a precise method for distance measurement and can provide detailed information about the target object through its continuous modulation and frequency variation.

[0056] Wideband digital radar sensors are not yet commercially available. Traditionally, each transmit channel (TX) requires a DAC to generate an analog modulated signal for the modulator 2B, which significantly increases complexity as the number of TX channels / antennas increases. This is achieved by utilizing frequency-selective components (e.g., in...) Figure 2A , 2B In the implementation shown, frequency selectivity is achieved on the transmitting side, which avoids this.

[0057] The radar transceiver device 1 of the present invention comprises a DAC / ADC, an amplifier, a mixer, a filter, and an antenna, and can perform frequency selectively in various ways. Here, each component in the TX and / or RX paths can contribute to frequency selectivity, such as... Figures 5A-5D As shown schematically in the diagram.

[0058] Figures 5A-5D An example of the possible frequency behavior of the TX / RX path of the radar transceiver device 1 of the present invention is shown, having three frequency bands FB1, FB2, and FB3.

[0059] Figure 5A The ideal frequency selectivity behavior with three frequency bands FB1, FB2, and FB3 is shown.

[0060] Figure 5B This demonstrates the actual (non-ideal) behavior with a non-ideal frequency band FB.

[0061] Figure 5C The frequency band FB is shown to have a periodic distribution, while Figure 5D The frequency band FB is shown to be non-periodic.

[0062] The frequency selectivity behavior can be, for example, periodic ( Figure 5C ) or non-periodic ( Figure 5D This is repeated, so that multiple parts of a broadband signal can be radiated through the same path.

[0063] However, it is advantageous for the radar transceiver device 1 of the present invention to implement the transmitting / receiving elements, especially the frequency-selective antenna 2C, to have a frequency-dependent phase center PZ, which can be repeated periodically or aperiodically. The phase center PZ can be frequency-dependent in all spatial dimensions.

[0064] Frequency selectivity can be achieved on the transmitting side (TX) and / or receiving side (RX) of the radar transceiver device 1 of the present invention.

[0065] Possible implementations for use on the transmitting side (TX) of the frequency selective radar transceiver device 1 of the present invention will now be described in more detail.

[0066] The frequency-selective radar transmitting unit 2 of the radar transceiver device 1 has at least one frequency-selective component 2C, which is configured to distribute the transmitted signal modulated by the signal modulator 2B to a plurality of transmit (TX) channels for radar signal radiation.

[0067] In one possible embodiment of the radar transceiver device 1 of the present invention, the frequency selective component 2C of the frequency selective radar transmitting unit 2 has a frequency selective antenna. The frequency selective antenna 2C may, for example, be a frequency selective microstrip antenna, a frequency selective waveguide antenna, or a frequency selective reflector antenna.

[0068] In one possible embodiment of the radar transceiver device 1 of the present invention, the frequency-selective microstrip antenna 2C has a frequency-selective patch antenna having a different phase center PZ for each frequency f in one dimension, such as... Figure 3 As shown schematically in the diagram.

[0069] In another possible embodiment of the radar transceiver device 1 of the present invention, the frequency-selective microstrip antenna 2C has a frequency-selective helical antenna having different phase centers for each frequency f in two dimensions, such as... Figure 4 As shown schematically in the diagram.

[0070] In one possible embodiment of the radar transceiver device 1 of the present invention, the phase center PZ is repeatedly implemented periodically or aperiodically in the frequency domain. In the frequency-selective antenna 2C, a broadband signal is applied to the antenna structure. Frequency-dependent phase centers PZ are generated by the geometry of the antenna structure, and each phase center radiates a different portion of the broadband transmitted signal into the channel.

[0071] For the implementation of the radiating element, the following antenna structures can be used in different embodiments of the radar transceiver device 1 of the present invention: - Microstrip antenna: • Linear patch arrays with different center frequencies (see...) Figure 3 ) • A spiral antenna-like arrangement (see...) Figure 4 ) • Planar logarithmic periodic arrangement • The stacked patches are arranged in a similar manner, with each patch having a significantly different resonant frequency (varying in the z-direction, extending the field of view in a direction with a very large azimuth shift (Winkelablagen)). - Waveguide antennas, such as arrangements of waveguide slot radiators with varying slot dimensions (slot length, slot width). - A reflector antenna with frequency-selective reflectivity in different regions of the reflector.

[0072] Figure 3 A frequency-selective patch antenna 2C with different phase centers PZ for each frequency f is shown. Figure 3 The patch antenna shown is a microstrip antenna. In one possible implementation, the patch antenna consists of conductive patches applied to a dielectric and can be mounted on a grounded backplane. The frequency-selective patch antenna 2C is envisioned to exhibit different characteristics at different frequencies f. This can be achieved by using different geometries and materials that affect the antenna's resonant frequency. Furthermore, multiple patch elements can be arranged in a specific pattern to produce a selective frequency response.

[0073] The phase center PZ of an antenna is the point from which electromagnetic waves appear to radiate. For an ideal antenna, the phase center PZ is the same at all frequencies f. However, in practice, the phase center PZ may vary with frequency f. Figure 3 The patch antenna 2C shown is frequency selective and has different phase centers PZ for different frequencies f. This means that the point at which the wave radiates varies with frequency f. This can be influenced by the design of antenna 2C.

[0074] Figure 4 This paper demonstrates a frequency-selective helical antenna with different phase centers PZ at each frequency f in two dimensions. A helical antenna is a broadband antenna with a helical structure. Its characteristics include the ability to operate over a wide frequency range while providing constant impedance and directional characteristics. Helical antennas are suitable for applications requiring high bandwidth.

[0075] Frequency selectivity means that antenna 2C responds differently at different frequencies f. The phase center PZ of the antenna is the point from which electromagnetic waves appear to radiate. If the antenna has different phase centers for different frequencies f, then the point from which the wave radiates changes with frequency. Figure 4 The frequency-selective helical antenna shown is configured in such a way that it exhibits different radiation characteristics at different frequencies. This antenna structure can be achieved through the design of the helical geometry and the antenna surface.

[0076] Figure 4 The helical antenna shown is preferably composed of conductive materials arranged in a helical structure. This structure can be an Archimedean spiral, a logarithmic spiral, or other shapes. The characteristic of a spiral is that different frequencies f resonate at different points on the spiral. This causes the phase center PZ to vary with frequency f. Figure 4 In the frequency-selective helical antenna shown, the phase center PZ can be different in two dimensions (x and y). This means that the position where the wave radiates can vary along the x-axis and y-axis, depending on the frequency f.

[0077] In another possible alternative embodiment of the radar transceiver device 1 for radar signals of the present invention, the frequency selective components 2C, 3C have frequency selective signal filters.

[0078] Figure 2B This illustrates a possible implementation of the radar transceiver device 1 of the present invention, which uses a signal filter, particularly a passive bandpass filter (BP), to achieve frequency selectivity on the transmitting side. When using a filter to achieve frequency selectivity, the broadband signal is distributed onto multiple frequency-selective parallel TX paths, such as... Figure 2B The illustrated implementation example shows parallel Tx paths radiating through individually controlled antennas Tx1 to TxN. This results in different phase centers PZ for different frequency components. The filter structure can be implemented, for example, using microstrip technology (e.g., hairpin filters, stub pin filters), as a waveguide (e.g., a coupled-cavity filter with an iris), or classically as a lumped element. Depending on the implementation, the signal filter can be located on other physical components of device 1. When implemented as a waveguide, it is suitable, for example, to integrate the structure into a waveguide antenna.

[0079] In another possible embodiment of the radar transceiver device 1 of the present invention, frequency selectivity can also be dynamically and tunably set by active components. Thus, for example, frequency behavior can be switched during measurement, thereby generating additional path combinations (classically: more MIMO channels). This can be achieved in one possible embodiment of the radar transceiver device 1 of the present invention via varactor diodes, RF-MEMS, or tunable liquid crystal capacitors. Combinations of various frequency-selective active components are possible.

[0080] The system of the present invention, or the radar transceiver device 1 of the present invention, can in principle be divided into a transmit (TX) path 2 and a receive (RX) path 3. Each path 2, 3 includes, for example, a DAC / ADC, an amplifier, a mixer, a filter, and an antenna. Frequency selectivity can be achieved simultaneously in TX path 2, RX path 3, or both paths 2, 3 of the radar transceiver device 1.

[0081] The reduction in the number of physically existing channels applies to the affected paths respectively. For the TX path of radar transceiver 1, the number of parallel TX channels is reduced; for the RX path of radar transceiver 1, the number of parallel RX channels is reduced; for the combined variant of radar transceiver 1, both parallel TX and RX channels are reduced.

[0082] When implementing frequency selectivity within the radar transceiver 1 for radar signals according to the present invention on the transmitting side, such as Figure 2A , 2B As shown, TX path 2 is constructed to be frequency selective, such that a broadband signal from, for example, a single signal source 2A (e.g., a DAC) is distributed across multiple TX antenna phase centers PZ. This frequency selectivity allows the location of the radiated signal energy to be inferred at the receiver and angular estimation to be applied to it. This can be achieved, for example, through correlation, Fourier transform, or AI-supported methods.

[0083] When implementing frequency selectivity within the radar transceiver 1 for radar signals according to the present invention on the receiving side, the RX path 3 is constructed to be frequency selective. Wideband TX signals from one or more signal sources are received, combined, and sampled by means of at least one analog-to-digital converter (ADC) through a frequency selective structure having a frequency-dependent phase center (e.g., an antenna). Through frequency selectivity, the receiver can allocate the received signal energy to a position for the TX signal and apply angle estimation to it.

[0084] In the case of a dual-frequency selective combination, i.e., when both the transmitting side 2 and the receiving side 3 are implemented, signal evaluation via the signal processing unit (SVE) presents unique challenges. Due to the dual-frequency selectivity, not every TX phase center can be received by every RX phase center. This means that, regarding angle estimation, full MIMO operation cannot be achieved without using frequency converters in the path. For example, the TX and RX phase centers can be configured to have the same frequency, thus achieving 1:1 transmission (classically: multiple SISO channels), or overlapped, such that, for example, one TX phase center corresponds to multiple RX phase centers, and vice versa (classically: multiple SIMO / MISO channels). Furthermore, in addition to angle estimation, distance estimation can be performed based on all received frequencies, which improves the overall bandwidth and thus improves range resolution.

[0085] As a special variant, the TX or RX antenna can be implemented as a frequency-scanning antenna, which allows for selective manipulation of single or multiple frequencies, such as for shielding clutter reflections from other directions, while broadband manipulation illuminates the entire field of view.

[0086] A frequency selectivity estimation method based on the radar transceiver device 1 of the present invention can be performed. For angle estimation, MIMO methods can be used, which are based on the fact that each RX can allocate the received signal to a uniquely determinable TX. Then, methods such as DML, correlation, Fourier transform, or correlation methods are applied to this. In cases of sharp frequency selectivity, these methods can be used in the radar transceiver device 1 of the present invention.

[0087] When implementing the radar transceiver device 1 of the present invention, it is possible that the signals cannot be clearly separated from each other (see...). Figure 5B Furthermore, the phase centers PZ may smoothly transition to each other, such that each frequency f has its own phase center PZ. Therefore, matched signal evaluation is required in this case. One possible implementation is, for example, the maximum likelihood method, where the received signal is compared with a calibrated measurement for each incident angle. Alternatively, angle estimation can be achieved through training using AI-supported algorithms.

[0088] Alternatively, due to the broadband nature of the signal generation, predistortion can also be performed, which optimizes the coupling factor between phase centers PZ so that the signal can be explicitly assigned to a single phase center PZ again. Predistortion can be implemented analytically or AI-supported.

[0089] Due to frequency selectivity, it may be possible that the full signal bandwidth is not available for evaluation at the receiver (RX). Therefore, it is also possible that multiple RX paths (or TX paths) are evaluated together with respect to their RX signal bandwidth. This improves range resolution. Because the evaluation may involve the influence of different TX / RX phase centers, a common range and angle evaluation may be required, estimating both the angle and range simultaneously.

Claims

1. A radar transceiver (1) for radar signals, the radar transceiver having a frequency-selective radar transmitting unit (2) and / or a frequency-selective radar receiving unit (3). in, The frequency-selective radar transmitting unit (2) has: The digital-to-analog converter (2A) of the radar transceiver device (1) is configured to convert broadband digital signals provided for all transmission channels into analog transmission signals; A signal modulator (2B) modulates a signal carrier to generate a modulated transmission signal by means of an analog transmission signal output from the digital-to-analog converter (2A); as well as At least one frequency selective component (2C) is configured to distribute the transmitted signal modulated by the signal modulator (2B) to a plurality of transmit (TX) channels for radar signal radiation; and The frequency-selective radar receiving unit (3) of the radar transceiver device (1) has the following features: At least one frequency selective component (3C) configured to combine received radar signals comprising multiple receive (RX) channels; A signal demodulator (3B) demodulates a radar signal combined by the frequency selective component using a signal carrier to generate a demodulated received signal. as well as At least one analog-to-digital converter (3A) is configured to sample the received signal demodulated by the signal demodulator (3B) to generate a digital received signal.

2. The radar transceiver for radar signals according to claim 1, wherein, The frequency-selective component has a frequency-selective antenna.

3. The radar transceiver for radar signals according to claim 2, wherein, The frequency-selective antenna may be a frequency-selective microstrip antenna, a frequency-selective waveguide antenna, or a frequency-selective reflector antenna.

4. The radar transceiver for radar signals according to claim 3, wherein, The frequency-selective microstrip antenna has the following frequency-selective patch antenna: the frequency-selective patch antenna has a different phase center for each frequency in one dimension.

5. The radar transceiver for radar signals according to claim 3, wherein, The frequency-selective microstrip antenna has the following frequency-selective spiral antenna: the frequency-selective spiral antenna has a different phase center for each frequency in two dimensions.

6. The radar transceiver for radar signals according to claim 3 or 4, wherein, The phase center (PZ) is realized periodically or aperiodically in the frequency domain.

7. The radar transceiver for radar signals according to claim 3, wherein, The frequency-selective microstrip antenna has a frequency-selective antenna with a logarithmic periodic arrangement.

8. The radar transceiver for radar signals according to claim 1, wherein, The frequency-selective component has a frequency-selective signal filter.

9. The radar transceiver for radar signals according to claim 1, wherein, The frequency-selective component has a frequency-selective active component.

10. The radar transceiver for radar signals according to any one of claims 1 to 9, wherein, The signal modulator is configured to perform FMCW modulation on the signal carrier.

11. A radar transceiver for radar signals according to any one of claims 1 to 10, wherein a local oscillator (LO) is provided, the local oscillator generating the signal carrier.

12. A radar instrument having a radar transceiver (1) according to any one of claims 1 to 11 and a signal processing unit (SVE) for estimating the angle and / or distance of a target object.

Images