Automobile radar test method and radiation detector

Abstract

The embodiment of the invention relates to an automobile radar test method and a radiation detector. The radiation detector is positioned at a distance from the radar device and / or the radome. And obtaining a reference value of the radiation power. A radar signal radiated by a radar device is received by a radiation detector. A radiation power is determined based on the received radar signal. Information about radio frequency attenuation of the radome is derived from the radiation power by using the reference value. In addition, a radiation detector and a test arrangement are described.

Description

Technical Field

[0001] The invention relates to a radiation detector and a method for testing a vehicle radar, in particular in a workshop and during an annual inspection. The invention also relates to a test arrangement. Background Art

[0002] Modern vehicles include advanced driver assistance systems (ADAS) that rely on radar devices, also called radar sensors, which are usually located behind a radar-transparent component (radome), such as a bumper or radome. The radar device and the radome together form a radar system.

[0003] Regularly checking the functionality of ADAS is very important, especially for autonomous vehicles (also called self-driving vehicles). If a vehicle needs to visit a repair shop due to a bump or scratch in the area of ​​the radar installation, the repair shop staff needs to find out whether the advanced driver assistance system is still functional or damaged.

[0004] Currently, radar transparent parts (radomes) are replaced or damage is attempted to be repaired. After a repair, such as a new coating on a bumper, it is a challenge to determine whether the functionality of the radar system has been preserved in the process.

[0005] Known systems capable of measuring the attenuation of a radome (e.g. a bumper or a radome) have disadvantages including, for example, that the radome has to be disassembled. In addition, known systems require increased knowledge of radio frequency (RF) technology to evaluate the results obtained when performing RF measurements. Obviously, it cannot be assumed that the personnel of a garage have such knowledge.

[0006] Furthermore, there is no test system for the complete system including the radar unit and the radome (ie bumper / radome). Instead, a feedback loop from the radar unit is required.

[0007] The object of the present invention is to provide a method for determining the functionality of a radar system and a radiation detector which are simple and particularly user-friendly. Summary of the invention

[0008] The following summary of the disclosure is intended to introduce in simplified form various concepts that will be further described in the detailed description section provided below. This summary is neither intended to represent essential features of the disclosure nor should this summary be used to help determine the scope of the claimed subject matter.

[0009] The present invention provides a method for testing the radio frequency (RF) attenuation of a radome. The method comprises the following steps:

[0010] -Provide radiation detectors;

[0011] - positioning the radiation detector at a distance relative to the radar device and / or the radome;

[0012] - obtain a reference value of the radiated power;

[0013] - receiving, by the radiation detector, a radar signal radiated by the radar device, wherein the radar signal passes through the radome;

[0014] - determining the radiated power based on the received radar signal; and

[0015] - deriving information about the radio frequency attenuation of the radome from the radiated power determined by using the reference value.

[0016] The present invention also provides a radiation detector for testing radio frequency (RF) attenuation. The radiation detector comprises an electronic circuit. The radiation detector can be positioned at a distance relative to the radome and / or the radar device. The radiation detector is configured to receive at least one radar signal radiated by the radar device, wherein the radar signal passes through the radome. The radiation detector is further configured to determine the radiation power based on the received radar signal. The radiation detector is further configured to derive information about the RF attenuation of the radome from the radiation power by using a reference value of the radiation power.

[0017] The main idea of ​​the invention is to provide a system and a method which can be used to determine whether a repair of a part of a radar system (e.g. a bumper and / or a radome) was successful, provided that the functionality of an Advanced Driver Assistance System (ADAS), such as Automatic Cruise Control (ACC), Blind Spot Detection, Lane Change Assist and similar systems, is not impaired by the repair. Furthermore, it can be verified whether it is necessary to replace the corresponding component with respect to the functionality of the ADAS. For example, it can be checked whether scratches impair the functionality of the ADAS. Furthermore, it can be checked whether a repair of a part (e.g. (further) painting) impairs the functionality. Impairment of functionality can be derived from radio frequency attenuation.

[0018] The system and method according to the present disclosure also allow checking the functionality of the radar system, for example as part of an end-of-line test or a regular inspection, such as an annual inspection or more precisely a mileage-related inspection.

[0019] The validation can be performed on assembled vehicles, i.e. vehicles equipped with a radar system comprising a radar unit and a radome. Thus, it is not necessary to dismantle the radome, e.g. a bumper, if the paint on the outer surface of the radome is updated. The solution is cost-effective and can be used without RF technical knowledge, since the results obtained can be classified into two categories, e.g. "fail" and "pass".

[0020] Furthermore, the number of permissible repaints of the corresponding vehicle component (i.e. the radome) need not be restricted, since the repair shop can determine whether the advanced driver assistance system is still functional. Of course, the corresponding verification can also be carried out during regular inspections (e.g. annual vehicle inspections).

[0021] Furthermore, it is ensured that the attenuation test of the radome can be performed based on real radar signals, ie radar signals that would be radiated by the vehicle's radar device. In other words, the present disclosure does not rely on a signal generator that generates an artificial signal corresponding to a real radar signal.

[0022] The radar device may be a radar device implemented or to be implemented in the vehicle. However, the radar device may also be a separately formed radar device that operates in the same frequency range as the radar device implemented or to be implemented. The radar device may operate, for example, at 77 GHz (with a bandwidth of 5 GHz), 24 GHz (with a bandwidth of 200 MHz or 4 GHz) or 120 GHz (with a bandwidth of more than 20 GHz).

[0023] The radar device is in particular a vehicle radar device or a vehicle radar sensor. The vehicle may be, for example, a motor vehicle (such as a car or a truck), a watercraft (such as a ship or a boat), or an aircraft (such as an airplane or a drone).

[0024] The radar device may be part of an advanced driver assistance system (ADAS). As mentioned above, examples of ADAS are adaptive cruise control (ACC), blind spot monitoring, lane centering or lane change assistance.

[0025] The reference value of the radiation power may be the power radiated only by the radar device, or it may be the radiation power of a radar unit including the radar device and the radome, ie, the radiation power of the radar device attenuated by the radome when the radar signal passes through the radome.

[0026] In other words, if the reference value is the radiated power of the radar unit comprising the radar device and the radome, the reference value relates in particular to the power which is initially radiated by the radar device and which is subsequently attenuated by the radome.

[0027] Usually, a reference value for the radiated power can be (previously) measured or more precisely theoretically obtained.

[0028] Deriving information about the radio frequency attenuation of the radome may include converting the (actual) radiated power P rad The reference value of the radiated power P ref (e.g. a previously measured radiated power or more precisely a theoretical value). In particular, the following relationship holds true:

[0029] P rad >Pref -a tol

[0030] Among them, a tol is a suitable tolerance value. As an example, the tolerance value may be 2 dB. However, the tolerance value may also be 0 dB, especially at the reference value P of the radiated power. ref The system changes have been taken into account.

[0031] The reference value of the radiated power may be equivalent isotropic radiated power (EIRP), such as maximum EIRP or average EIRP. Which calculation method is optimal may depend on the operating characteristics of the radar device. For example, maximum EIRP may be particularly advantageous for frequency modulated continuous wave (FMCW) radars, while average EIRP may be more advantageous for pulse-based radars.

[0032] According to one aspect, the method may further comprise the step of determining at least one attenuation metric of the radome. The attenuation metric may be used as an indicator providing insights into the state of the radome. In practice, the determined attenuation metric may be compared with a reference value provided by a threshold value (provided by the vehicle manufacturer) or on a data sheet of the radome. Thus, it may be determined whether the radome is functional in terms of radio frequency attenuation.

[0033] At least one attenuation metric of the radome may be frequency and / or temperature dependent. Valuable additional information about the attenuation properties of the radome may thus be provided. In particular, the power of the radar signal received by the radiation detector may be measured in a frequency-dependent manner. Additionally or alternatively, an environmental parameter such as temperature may be varied during the power measurement to obtain corresponding parameter-dependent measurement data (e.g. temperature-dependent power).

[0034] The method may further comprise the step of comparing the determined attenuation measure of the radome with a threshold attenuation value. Thus, a quantification of the radome state may be provided and compliance with predefined criteria may be checked. In particular, the method further comprises obtaining a threshold attenuation value.

[0035] The threshold attenuation value may be, for example, greater than 1 dB, 2 dB, or 2.5 dB. The threshold attenuation value may be less than 6 dB, 7 dB, or 8 dB. As an example, the threshold attenuation value may be 5 dB or 3 dB.

[0036] If the reference value is only the reference radiation power P of the radar device ref , then the following relationship holds:

[0037] P rad >P ref -a thr (1)

[0038] Among them, Prad is the (actual) radiated power, P ref is the reference radiated power (i.e., reference value), and a thr is the threshold attenuation value of the radar cover. The threshold attenuation value can be the reference attenuation value a ref and the corresponding appropriate tolerance value a tol sum:

[0039] a thr =a ref +a tol

[0040] Furthermore, the (actual) radiated power P can be calculated by rad With reference radiated power P ref The attenuation measure a of the radome is determined by the difference between the radiated power measured previously or more precisely the theoretical reference value calc :

[0041] a calc =P ref -P rad

[0042] By measuring the attenuation calc With this definition, relation (1) becomes:

[0043] a thr >a calc

[0044] Thus, the method may comprise checking the determined attenuation metric a calc Is it less than the threshold attenuation value a? thr .

[0045] As an example, if the radiated power being calculated is the equivalent isotropic radiated power (EIRP), then the following relationship holds:

[0046] EIRP calc >EIRP ref -a ref -a tol

[0047] Among them, EIRP calc represents a determined EIRP (eg, a maximum EIRP), calculated based on radar signals received by the radiation detector (eg, based on measurements actually performed); EIRP ref is the reference EIRP of the radar device, for example, an obtained reference value of EIRP (for example, maximum EIRP). ref is the reference (RF) attenuation value of the radome, a tolis a suitable tolerance value. As an example, the tolerance value may be 2 dB. The tolerance value may also be 0 dB, especially when system variations have been taken into account in the reference attenuation value.

[0048] The attenuation values ​​referred to herein are specifically "one-way" attenuation values. The "two-way" attenuation value (taking into account that the radar wave passes through the radome twice) can be calculated by multiplying the "one-way" value expressed in dB by 2.

[0049] According to one aspect, the method may further comprise the step of outputting a result indicating whether the radome has passed or failed an attenuation test during which information about the radio frequency attenuation of the radome was determined. Thus, particularly accessible information about the state of the radome may be provided. This information is directly derivable, or rather interpretable without RF technical expertise.

[0050] The results may be output on a graphical user interface (GUI) configured to visualize the results. In particular, the visualization of the results may also show for non-RF professionals (in addition to RF professionals) whether the radome passed or failed the corresponding test due to the determined RF attenuation, for example in words such as "pass" or "fail", via traffic light symbols "red", "yellow" or "green". Additionally or alternatively, the results may be signaled by dedicated sounds for pass and fail, respectively, or may be sent as a digital message, for example via an Ethernet connection.

[0051] According to another aspect, the method may further comprise the step of providing a signal guide between the radar device and the radiation detector. Providing a signal guide may help to position the radar device and / or the radome at a distance relative to the radiation detector. The signal guide may in particular be a spacer, i.e. a structure that ensures that the components of the system are arranged at the end points of the signal guide so that the components have a distance relative to each other.

[0052] The signal guide may be at least partially (electromagnetically) hollow to allow RF radiation to pass through the signal guide.The signal guide may, for example, have a tubular shape.

[0053] The signal guide provides the advantage that a user can position the radar device and / or radome relative to the radiation detector without having to perform range and / or azimuth measurements. Furthermore, the signal guide can ensure that unforeseen changes in relative position after initial positioning can be immediately noticed and mitigated. The signal guide reduces the risk of error and increases the reliability of the method.

[0054] Additionally or alternatively, a laser rangefinder or a conventional measuring tool (eg a ruler) may be used to position the radar device and / or the radome at the distance.In the case of laser distance measurement, the measured distance may be fed back (in particular automatically) to the radiation detector.

[0055] The signal guide may include an absorber structure. The absorber structure in particular includes a radiation absorbing material for absorbing incident RF radiation. The absorber structure has the advantage that unwanted RF signals, for example caused by reflections, can be absorbed. Thus, unwanted RF signals can be prevented from reaching the radiation detector, thereby improving the measurement accuracy.

[0056] The absorber structure may be positioned on an inner wall of the signal guide. In particular, the signal guide may be an absorber tube, ie a tube comprising the absorber structure.

[0057] The radiation detector is in particular an RF radiation detector.The radiation detector may be a broadband radiation detector.

[0058] The radiation detector may be configured for performing time-gated measurements, in particular for performing time-gated spectral analysis.

[0059] The radome may be, for example, a radome or a bumper of a vehicle, for example a bumper with an integrated radome.

[0060] In particular, when the radome is in the assembled state, the relative position of the radar device and the radome is fixed. Therefore, the positioning of the radar device and the radome relative to the radiation detector can be performed simultaneously. The radome in the assembled state is particularly understood to mean that the radome is installed to cover the radar device.

[0061] The radiation detector may be located at a distance relative to the vehicle equipped with the radar device and the radome. Thus, information about the state of the radome, in particular about the functionality of the vehicle's ADAS, may be obtained without disassembling the radar system.

[0062] A reference value of the radiated power (e.g., the maximum EIRP of the radar device) may be obtained, for example, from a storage medium, a data sheet, or an instruction manual of the radar device (e.g., manually entered from a data sheet or an instruction manual). The reference value may also be obtained from a database of a test provider or a radiation detector provider, for example, from a storage medium of the radiation detector. For example, a suitable reference value power may be provided by the manufacturer of a vehicle including the radar device and the radome.

[0063] The advantage in this case is that no reference measurements are required and therefore no disassembly of the radome is required. The method is therefore particularly user-friendly and time- and cost-efficient.

[0064] The radiation detector can be configured to obtain a reference value, such as a maximum EIRP radiated by the radar device via an interface of the vehicle. The interface can be wired or wireless. The radiation detector can be connected to an automotive Ethernet of the vehicle to obtain the reference value.

[0065] Additionally or alternatively, reference values ​​(eg radiated EIRP values) may be obtained by performing reference measurements or normalized measurements without the radome. The reference measurements may involve free space (power) measurements.

[0066] Typical values ​​for the maximum radiated EIRP may be at least 10 or 20 dBm. The value may be at most 30, 55 or 60 dBm. As an example, the value may be 25 dBm.

[0067] According to one aspect, the radome may be a repaired radome, wherein the radio frequency attenuation of the radome is determined after the radome has been repaired. Repairing the radome in particular comprises corresponding (re)painting and / or coating of the radome. Thus, it is verified whether the repair has any effect on the radio frequency attenuation of the radome.

[0068] The radiated power (eg, maximum EIRP) may be calculated based on the received power measured by the radiation detector and the distance-dependent free space path loss.

[0069] The measured power (i.e. received power) may be frequency and / or temperature dependent, since the attenuation properties of the radome may depend on these parameters. Therefore, the calculated radiated power may also be frequency and / or temperature dependent. In particular, the calculation also takes into account the conversion gain of the receiver chip of the radiation detector.

[0070] In particular, the following relationship holds:

[0071] P calc =P meas -g conv +FSPL.

[0072] As mentioned above, P calc represents the (calculated) radiated power (e.g. the maximum EIRP of a radiation detector), which is calculated based on the received radar signal. meas is the received power measured by the radiation detector (especially in a frequency-dependent manner). g conv is the conversion gain of the receiver chip of the radiation detector and specifically includes all losses on the receiver chain to the receiver chip. FSPL is the free space path loss which depends on the distance between the radiation detector and the radar device radiating the radar signal, where specifically the following relationship holds:

[0073] FSPL = 20log 10(4πd / λ).

[0074] Therein, d is the distance between the radar device and the radiation detector, in particular the distance between the antennas of the radar device and the radiation detector, and λ is the wavelength of the radar signal.

[0075] As an example, a signal frequency of 76.5 GHz at a distance of 0.5 m results in FSPL = 64.1 dB. At a distance of 0.55 m, the result is FSPL = 64.9 dB. Therefore, when assuming a distance uncertainty of 5 cm at a target distance of 50 cm, the measurement uncertainty may be 0.8 dB. In particular, the target distance may be equal to the length of the signal guide as described herein. The mentioned distance uncertainty may at least partially originate from the unknown position of the radar device, in particular its sensor. However, the position may be known and can therefore be taken into account in the definition of the distance. In this case, the corresponding measurement uncertainty disappears.

[0076] The (calculated) radiated power (eg EIRP) determined from the radiation measurement of the radome in the assembled state may in particular be understood as the (calculated) radiated power, eg EIRP, of the complete radar unit comprising the radar device and the radome.

[0077] For example, the radiation detector may be configured to determine the attenuation of the frequency varying signal.

[0078] The radar device may be part of an advanced driver assistance system (ADAS).

[0079] In particular, the radiation detector comprises a receiving antenna.The radiation detector may be a broadband radiation detector.

[0080] The radome may be, for example, a radome or a bumper of a vehicle.

[0081] According to one aspect, a testing arrangement is provided. The testing arrangement comprises a radiation detector as described herein and further comprises a signal guide.

[0082] The signal guide may have a length greater than, for example, 15 cm, 20 cm or 30 cm. The length may be less than, for example, 70 cm, 80 cm or 85 cm. As an example, the signal guide may have a length of 50 cm.

[0083] According to one aspect, the radiation detector may further comprise a storage medium comprising calibration data of the radiation detector. In particular, the calibration data is obtained during manufacture of the radiation detector.

[0084] The calibration data may be frequency resolved. Frequency resolved calibration data is particularly beneficial if the radar device uses only a limited portion of the radar bandwidth. As an example, the radar bandwidth may be 5 GHz.

[0085] According to one aspect, the calibration data may include calibration data for each polarization (eg, horizontal polarization and / or vertical polarization).

[0086] The calibration data may include calibration data for different temperatures.

[0087] The radiation detector may include a graphical user interface (GUI) configured to visualize a result indicating whether the radome has passed or failed an attenuation test during which information about the RF attenuation of the radome is determined. Since the GUI provides the results in an intuitive manner, no RF technical knowledge is required because the obtained results may be classified into two categories, such as "fail" and "pass" provided by the GUI.

[0088] In particular, the radiation detector may be used in the system and method according to the present disclosure.The features and advantages described with respect to the radiation detector and the test arrangement analogously apply to the method according to the present disclosure, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 Schematically shows a test arrangement with a radiation detector according to an embodiment of the present invention,

[0090] Figure 2 Schematically shows a test arrangement with a radiation detector according to another embodiment of the present invention,

[0091] Figure 3 schematically shows a radiation detector according to yet another embodiment of the present invention, and

[0092] Figure 4 is a flow chart illustrating a method according to the present invention. DETAILED DESCRIPTION

[0093] The detailed description set forth below in conjunction with the accompanying drawings (in which like reference numerals refer to like elements) is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided only as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise form disclosed.

[0094] For purposes of this disclosure, the phrase "at least one of A, B, and C" means, for example, (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C), including all other possible permutations when more than three elements are listed. In other words, the term "at least one of A and B" generally means "A and / or B", i.e., "A" alone, "B" alone, or "A and B".

[0095] Figure 1 A test arrangement 10 with a radiation detector 12 according to a first embodiment of the present disclosure is schematically shown. The test arrangement 10 comprises the radiation detector 12, a radome 14 and a radar device 16 configured to radiate radar signals.

[0096] The radiation detector 12 includes a receiving antenna 18 for receiving radar signals (ie, radar signals radiated by the radar device 16 ).

[0097] The radiation detector 12 is located at a distance 20 relative to the radome 14 and / or the radar device 16. In the embodiment shown, the radiation detector 12 is located at a distance 20 relative to the radome 14.

[0098] The radome 14 can be in an assembled state such that the radar detector 12 is also located at a distance 20 relative to the radar device 16. A radome 14 in an assembled state is to be understood in particular as a radome 14 which is mounted to cover the radar device 16. Thus, a fixed relationship between the radome 14 and the radar device 16 is provided. In other words, in the assembled state, a movement of the radome 14 relative to the radar device 16 is not possible.

[0099] The radar device 16 is configured to radiate at least one radar signal that passes through the radome 14. This means that at least one radar signal passes through the radome 14. In other words, the radome 14 is exposed to the at least one radar signal. The radiation detector 12 is configured to receive at least one radar signal radiated by the radar device 16.

[0100] It may take a certain amount of time, for example between 1 and 3 seconds, for the radar device 16 to radiate at its maximum power. This is particularly taken into account when the radar signal is measured by the radiation detector 12 .

[0101] Radiation detector 12 is also configured to determine a radiated power, such as a calculated radiated power, such as a maximum EIRP, based on the radar signal received at distance 20 .

[0102] The radiation detector 12 is also configured to compare the (calculated) radiated power (e.g. the (actually determined) maximum EIRP) with a reference value of the radiated power (e.g. the (theoretical or more precisely previously determined) maximum EIRP of the radar device 16) in order to determine information about the RF attenuation of the radome 14.

[0103] A reference value of the radiated power (e.g., the maximum EIRP of the radar device 16) may be obtained by performing a reference measurement without any radome 14 being located between the radiation detector 12 and the radiation detector 12 (e.g., after the radome 14 is removed). The respective reference measurement may involve normalization. The reference measurement may be performed for a radar device 16 (e.g., a radar device 16 implemented in a vehicle) or a similar radar device having the same characteristics (e.g., a spare part).

[0104] Alternatively, a reference value of the radiated power (eg, the maximum EIRP of radar device 16 ) may be obtained differently, such as from a manual or a data sheet.

[0105] Thus, the effect of the radome 14 , in particular its transmission attenuation, can be determined.

[0106] Furthermore, the radiation detector 12 may include a storage medium 15 including stored data / information related to a reference value of the radiation power, such as a maximum EIRP of the radar device 16 .

[0107] Furthermore, calibration data of the radiation detector 12 may be stored on the storage medium 15. The calibration data may be frequency resolved. The calibration data particularly comprises calibration data for each polarization, for example horizontal polarization and / or vertical polarization.

[0108] Typically, the reference value of the radiated power may relate to equivalent isotropic radiated power (EIRP), such as a maximum EIRP or an average EIRP. The respective type of reference value used may depend on the characteristics of radar device 16. For example, the maximum EIRP may be particularly advantageous for a frequency modulated continuous wave (FMCW) radar, while the average EIRP may be more advantageous for a pulse-based radar.

[0109] Figure 2 A test arrangement 10 with a radiation detector 12 according to a second embodiment of the present disclosure is schematically shown. Figure 1 The differences in the test arrangement shown in .

[0110] The test arrangement 10 further comprises a signal guide 22 which may have a length between 20 cm and 80 cm. The signal guide 22 is in particular a component of the test arrangement comprising the radiation detector 12 and the signal guide 22 .

[0111] The signal guide 22 may include an absorber structure 24. The absorber structure 24 may be positioned on an inner wall of the signal guide 22. The absorber structure 24 particularly includes a radiation absorbing material for absorbing incident RF radiation. The absorber structure 22 absorbs unwanted RF signals caused, for example, by reflection. Thus, unwanted RF signals from the environment may be prevented from reaching the radiation detector 12, thereby improving measurement accuracy.

[0112] In particular, the signal guide 22 may be an absorber tube, ie a tube comprising an absorber structure 24 .

[0113] Figure 3 A specific embodiment of a radiation detector 12 for testing the radio frequency (RF) attenuation of a radome 14 is schematically shown.

[0114] exist Figure 1 and Figure 2 In the test arrangement 10 shown, one can use Figure 3 A radiation detector 12 is shown.

[0115] The radiation detector 12 may include or may be a power meter, a receiver, a spectrum analyzer, a vector network analyzer, etc. In particular, the radiation detector 12 has a "max hold" measurement feature for determining the maximum power.

[0116] The radiation detector 12 includes an electronic circuit 26 and a graphical user interface (GUI) 28. The electronic circuit 26 may be a processing circuit. The receiving antenna 18 is connected to the electronic circuit 26 so that the radar signal received via the receiving antenna 18 is converted by the receiving antenna 18 into an electrical signal, which is forwarded to the electronic circuit 26 for evaluation. The electronic circuit 26 may be part of a power meter, a receiver, a spectrum analyzer, or a vector network analyzer.

[0117] Therefore, the radiation detector 12 is configured to receive Figure 1 and Figure 2 14 . As discussed above, the radar signal radiated by the radar device 16 passes through the radome 14 . In other words, it propagates through the radome 14 .

[0118] When evaluating radar signals, in particular electrical signals derived from received radar signals, radiation detector 12 is configured to determine (calculate) radiation power, eg maximum equivalent isotropic radiated power (EIRP), based on the radar signals received at distance 20 .

[0119] In particular, this determination is performed by the electronic circuit 26 of the radiation detector 12 .

[0120] As already discussed above, the radiation detector 12 is also configured to obtain a reference value of the radiation power, for example, the maximum EIRP of the radar device 16. The reference value of the radiation power may be obtained, for example, from the storage medium 15, a data sheet or an instruction manual of the radar device 16. Thus, the reference value of the radiation power (for example, the maximum EIRP of the radar device 16) may be obtained in a theoretical manner (i.e., by referring to the data sheet or the instruction manual). Furthermore, the corresponding value may be stored, for example, during the calibration of the radar device 16, which is performed after the manufacture of the radar device 16.

[0121] Alternatively, a reference value of the radiated power, such as a maximum EIRP of radar device 16 , may be obtained by performing a reference measurement, ie without inserting radome 14 between radar device 16 and radiation detector 12 .

[0122] The radiation detector 12 is configured to compare the (calculated) radiated power (e.g. the calculated maximum EIRP, i.e. the value obtained with the radome 14 inserted) with a reference value of the radiated power (e.g. the maximum EIRP of the radar device 16) in order to determine the RF attenuation of the radome 14. In practice, the deviation of the calculated radiated power (based on the received radar signal) relative to the reference value of the radiated power (e.g. the maximum EIRP of the radar device 16) is compared, thereby obtaining information about the radio frequency (RF) attenuation. In particular, the comparison is performed by the electronic circuit 26 of the radiation detector 12.

[0123] The GUI 28 is connected to the electronic circuit 26. The GUI 28 is thus able to receive evaluation data of the electronic circuit 26, which evaluation data are determined when evaluating the received radar signals.

[0124] The GUI 28 is also configured to visualize a result based on the evaluation data, wherein the result indicates whether the radome 14 passed or failed an attenuation test during which information about the radio frequency attenuation of the radome 14 was derived. This can be done in a visual manner, such as by displaying text or by displaying a specific color such as "red" or "green".

[0125] As an alternative to the GUI 28, an output interface may be provided, for example at an optical output interface like at least one light source, for example a red light emitting diode (LED) and a green LED. The at least one light source is controlled by the electronic circuit 26, in particular based on evaluation data.

[0126] Additionally or alternatively, the output interface may be configured to provide acoustic or tactile (eg vibration) feedback.

[0127] Figure 41 is a flow chart showing a method of testing the radio frequency (RF) attenuation of the radome 14. For example, the attenuation of a frequency varying signal may be tested. In particular, the method may be described above with reference to Figure 1 and Figure 2 The radiation detector 12 described herein performs the following.

[0128] The method comprises step 32 of providing a radiation detector 12 (eg Figure 3 ), a radar cover 14, and a radar device 16 configured to radiate radar signals. The radar device 16 is in particular a radar device of the vehicle or a radar sensor of the vehicle. The radar device 16 may be part of an advanced driver assistance system (ADAS).

[0129] The method further comprises step 34 of positioning the radar device 16 and / or the radome 14 at a distance relative to the radiation detector 12. Figure 1 As discussed, in the case where the radome 14 is provided in an assembled state, the radome 14 may be positioned at the distance 20 such that the radar device 16 has a defined distance relative to the radiation detector 12 .

[0130] Optionally, the method may include the step of providing a signal guide 22 (e.g., Figure 2 ). The signal guide 22 may in particular be a spacer, ie a structure which ensures that objects arranged at its end points have a distance 20 relative to each other.

[0131] The method further comprises a step 36 of obtaining a reference value of the radiated power, for example the maximum equivalent isotropic radiated power (EIRP) radiated by the radar device 16 .

[0132] The radiation detector 12 may be configured to obtain a reference value (e.g., the maximum EIRP radiated by the radar device 16) via an interface of the vehicle. The interface may be wired or wireless. The radiation detector 12 may be connected to the vehicle's automotive Ethernet to obtain the value. Alternatively, the reference value of the radiated power may be obtained from a data sheet or instruction manual of the radar device 16. In another alternative, the reference value (e.g., the maximum EIRP of the radar device 16) may be collected by performing a reference measurement.

[0133] The method further comprises a step 38 of receiving, by the radiation detector 12 , a radar signal radiated by the radar device 16 , wherein the radar signal passes through the radome 14 .

[0134] The method further comprises a step 40 of determining a calculated radiated power (e.g., a maximum EIRP) based on the radar signal received at the distance 20. The calculated radiated power (e.g., a maximum EIRP) can be calculated based on the received power measured by the radiation detector 12 and the free space path loss depending on the distance 20. The calculation in particular also takes into account the conversion gain of the receiver chip of the radiation detector 12:

[0135] EIRP calc =P meas -g conv +FSPL.

[0136] P calc represents the calculated radiation power (eg, the maximum EIRP of the radiation detector 12), such as a theoretical value obtained, P meas is the received power measured by the radiation detector 12, g conv is the conversion gain of the receiver chip of the radiation detector 12 and includes all losses on the receiver chain to the receiver chip. FSPL is the free space path loss which depends on the distance between the radiation detector 12 and the radar device 16 radiating the radar signal, wherein in particular the following relationship holds:

[0137] FSPL = 20log 10 (4πd / λ).

[0138] Therein, d is the distance between radar device 16 and radiation detector 12 , in particular the distance between antennas of radar device 16 and radiation detector 12 , and λ is the wavelength of the radar signal.

[0139] The method further comprises a step 42 of deriving information about the radio frequency attenuation of the radome 14 from the (calculated) radiated power by using a reference value of the radiated power.

[0140] Furthermore, the method may also comprise the step of determining at least one attenuation measure of the radome 14. Thus, a measure (indicator value) is collected which can be used for comparison purposes.

[0141] The method may further comprise a step 44 of comparing the determined attenuation measure of the radome 14 with a threshold attenuation value. The threshold attenuation value may be, for example, greater than 1 dB, 2 dB or 2.5 dB. The threshold attenuation value may be less than 6 dB, 7 dB or 8 dB. For example, the threshold attenuation value may be 5 dB or 3 dB.

[0142] The method may further include the step of outputting a result indicating whether the radome 14 has passed or failed an attenuation test during which information regarding the radio frequency attenuation of the radome 14 is determined.

[0143] The results may be output on a graphical user interface (GUI) configured to visualize the results, such as Figure 3 12. In particular, the visualization of the results can show the non-RF professional whether it is a pass or a fail, for example in words, via a traffic light symbol, etc. Of course, the RF professional will also get intuitive feedback.

[0144] When the execution is used to obtain the measured power P meas When measuring a maximum power, a maximum hold measurement can be performed to ensure that the maximum power is detected. Based on the detected maximum power, for example, the maximum EIRP can be calculated.

[0145] Typically, a corresponding attenuation test of the radome 14 can be performed on a vehicle equipped with the radome 14 and the radar device 16. In other words, the radome 14 can be a bumper of the vehicle or a radome of the vehicle. In fact, the radome 14 can be integrated into the bumper of the vehicle, which includes other parts in addition to the radome 14. Therefore, the radar device 16 is a vehicle-mounted radar device. Therefore, the radiation detector 12 is located at a distance 20 relative to the vehicle equipped with the radar device 16 and the radome 14.

[0146] Therefore, it is not necessary to dismantle the radome 14 in order to test the attenuation of the radome 14. In fact, the radar characteristics of the radar device 16 of the vehicle can be used, which have already been characterized. Therefore, the corresponding information / data about the radar device 16 of the vehicle are known, i.e. they can be read out from a data sheet, an instruction manual or more precisely a storage medium (e.g. of the radar device 16 or of the radiation detector 12). Alternatively, only a spare part of the radar device 16 of the vehicle can be tested in order to obtain a reference value of the radiated power of the vehicle, for example, a value of the maximum equivalent isotropic radiated power (EIRP) of the radar device 16.

[0147] Typically, the radome 14 may be a repaired radome, such as a (re)painted or fixed radome (after an accident). Therefore, the radome 14 is tested for radio frequency attenuation after the radome is repaired in order to assess whether the entire radar system (of the vehicle) (including the radome 14 and the radar device 16) still works in the desired manner. In other words, it can be assessed whether the repair of the radome 14 has any impact on the functionality.

[0148] After reworking the radome 14 , for example with a new coating, the radiation detector 12 may be used to determine the calculated radiated power (eg, EIRP) of the entire radar system (ie, for example, the radar device 16 and the radome 14 in the assembled state).

[0149] If the calculated radiated power (e.g. calculated EIRP) is lower than a reference value of the radiated power of the radar device 16 (e.g. reference EIRP) (in particular minus the expected RF attenuation of the radome 14 and a suitable confidence interval), then in a first step it is assumed that the radome 14 has a higher RF attenuation.

[0150] Thus, the radome 14 can be removed while the attenuation measurement is performed again only with the radar device 16. If the calculated radiated power (e.g. the calculated maximum EIRP) of the radar device 16 now complies with a reference value for radiated power (e.g. the reference EIRP) (e.g. the reference value from a data sheet or more precisely from the instruction manual), it can be verified that the deviation comes from the reworked radome 14. However, if the calculated radiated power (e.g. the maximum EIRP) of the radar device 16 is too low, it can be determined that the radar device 16 itself needs to be replaced.

[0151] Certain embodiments disclosed herein (particularly corresponding (multiple) modules and / or units) utilize circuit systems (e.g., one or more circuits) to implement the standards, protocols, methods or techniques disclosed herein, operably couple two or more components, generate information, process information, analyze information, generate signals, encode / decode signals, convert signals, send and / or receive signals, control other devices, etc. Any type of circuit system may be used.

[0152] In one embodiment, the circuit system specifically includes one or more computing devices, such as a processor (e.g., a microprocessor), a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a system on a chip (SoC), etc., or any combination thereof, and may include discrete digital or analog circuit elements or electronic devices or combinations thereof. In one embodiment, the circuit system includes a hardware circuit implementation (e.g., an implementation in an analog circuit system, an implementation in a digital circuit system, etc., and a combination thereof).

[0153] In one embodiment, the circuit system includes a combination of circuits and a computer program product having software or firmware instructions stored on one or more computer-readable memories that work together to cause the device to perform one or more protocols, methods, or techniques described herein. In one embodiment, the circuit system includes circuits that require software, firmware, etc. to operate, such as, for example, a microprocessor or portion of a microprocessor. In one embodiment, the circuit system includes one or more processors or portions thereof and accompanying software, firmware, hardware, etc.

[0154] The application may refer to amounts and quantities. Unless otherwise specified, these amounts and quantities should not be considered restrictive, but examples of possible amounts or quantities associated with the application. Also in this regard, the application may use the term "plurality" to refer to amounts or quantities. In this regard, the term "plurality" refers to any number greater than 1, for example, 2, 3, 4, 5, etc. The terms "approximately", "approximately", "close to", etc. mean ±5% of the value.

Claims

1. A method for testing the radio frequency attenuation of a radome, the method comprising the following steps: -Provide radiation detectors; - positioning the radiation detector at a distance relative to the radar device and / or the radome; - obtain a reference value of the radiated power; - receiving, by the radiation detector, a radar signal radiated by the radar device, wherein the radar signal passes through the radome; - determining the radiated power based on the received radar signal; as well as - deriving information about the radio frequency attenuation of the radome from the radiated power determined by using the reference value.

2. The method according to claim 1, further comprising the step of determining at least one attenuation metric of the radome.

3. The method of claim 2, further comprising the step of comparing the determined attenuation metric of the radome with a threshold attenuation value. The method according to claim 3 , wherein the threshold attenuation value is 5 dB.

5. The method according to any of the preceding claims, further comprising the step of outputting a result indicating whether the radome has passed or failed an attenuation test during which information about the radio frequency attenuation of the radome is derived.

6. The method of claim 5, wherein the results are output on a graphical user interface (GUI) configured to visualize the results.

7. A method according to any preceding claim, further comprising the step of providing a signal guide between the radar device and the radiation detector. The method of claim 7 , wherein the signal guide comprises an absorber structure.

9. The method according to any of the preceding claims, wherein the radome is a radome or a bumper.

10. The method according to any of the preceding claims, wherein the radiation detector is positioned at the distance relative to a vehicle equipped with the radar device and the radome.

11. The method according to any one of the preceding claims, wherein the reference value is obtained from a storage medium, a data sheet or an instruction manual of the radar device.

12. The method according to any of the preceding claims, wherein the radome is a repaired radome and wherein the radio frequency attenuation of the radome is tested after the radome has been repaired.

13. The method according to any of the preceding claims, wherein the radiated power is calculated based on a received power measured by the radiation detector, calibration data of the radiation detector, and a free space path loss that depends on the distance.

14. A radiation detector for testing radio frequency attenuation, the radiation detector comprising an electronic circuit, in, The radiation detector is positionable at a distance relative to the radome and / or the radar device; Wherein, the radiation detector is configured as: receiving at least one radar signal radiated by a radar device, wherein the radar signal passes through the radome, determining a radiated power based on the received radar signal, and Information about the radio frequency attenuation of the radome is derived from the radiated power by using a reference value of the radiated power.

15. The radiation detector of claim 14, wherein the radiation detector comprises a storage medium comprising calibration data of the radiation detector.

16. The radiation detector of claim 15, wherein the calibration data is frequency resolved.

17. The radiation detector of claim 15 or 16, wherein the calibration data comprises calibration data for each polarization.

18. The radiation detector according to any one of claims 14 to 17, comprising a graphical user interface, the graphical user interface being configured to visualize a result indicating whether the radome has passed or failed an attenuation test during which information about the radio frequency attenuation of the radome is derived.

19. A testing arrangement comprising a radiation detector according to any one of claims 14 to 18 and further comprising a signal guide.

20. The test arrangement of claim 19, wherein the signal guide has a length of between 20 cm and 80 cm.

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