Radio frequency assembly, radar system, and method of operating a radio frequency system

Abstract

The present invention relates to monitoring and detecting a phase difference between several mutually coupled transceivers, and for this purpose it is proposed to decouple a radio frequency signal from the transmission path of each transceiver, divide the frequency of the decoupled radio frequency signal by a predetermined factor and compare the frequency-divided signals in order to detect the phase difference.

Description

[Technical Field]

[0001] The present invention relates to a radio frequency assembly and to a method of operating such a radio frequency assembly, and further to a radar system comprising such a radio frequency assembly. [Background technology]

[0002] Modern radar systems, such as those used in automobiles for environmental awareness, typically utilize multiple transmit and receive channels. Cascading multiple transceivers is particularly suitable for this purpose. Therefore, high-frequency signals as well as digital signals can be exchanged as reference signals. In this context, a stable phase relationship between the reference signals in all transceivers is important for reliable angle estimation by the radar system.

[0003] Document DE102018117688A1 describes, for example, a radar method in which a high-frequency signal from a transmission path of a first channel is transmitted to a second transmission unit. Summary of the Invention

[0004] The present invention provides a radio frequency assembly, a radar system and a method for operating a radio frequency assembly having the features of the independent patent claims. Further advantageous embodiments are the subject of the dependent claims.

[0005] Based on this: A radio frequency assembly is provided that includes multiple transceivers and a calibration mechanism. The multiple transceivers include a first transceiver and at least one second transceiver. The first transceiver is designed to decouple a first radio frequency signal from one transmission path of the first transceiver and to divide the frequency of the decoupled first radio frequency signal by a predetermined integer value. Based on this, the divided first radio frequency signal can be provided as a first intermediate frequency signal. Each of the second transceivers is designed to decouple a second radio frequency signal from one transmission path of a respective second transceiver and to divide the frequency of the decoupled second radio frequency signal by a predetermined integer value. Based on this, the divided second radio frequency signal can be provided as a second intermediate frequency signal. The calibration mechanism is designed to detect a phase difference between the first intermediate frequency signal and a respective one of the second intermediate frequency signals from one of the second transceivers.

[0006] moreover: A radar system is provided that includes a radio frequency assembly according to the present invention, in which a plurality of transceivers are each designed to generate a radar signal and transmit the generated radar signal on a respective transmission path.

[0007] lastly: A method for operating a radio frequency system with multiple transceivers is provided, where the multiple transceivers include a first transceiver and at least one second transceiver. The method includes the steps of decoupling a first radio frequency signal from one transmission path of the first transceiver, dividing the frequency of the first radio frequency signal by a predetermined integer value, and providing the divided first radio frequency signal as a first intermediate frequency signal. The method further includes the steps of decoupling a second radio frequency signal from one transmission path of each second transceiver and dividing each decoupled second radio frequency signal by a predetermined integer value. Based on this, one or more divided second radio frequency signals can be provided as second intermediate frequency signals. Finally, the method includes the step of detecting a phase difference between the first intermediate frequency signal from the first transceiver and a respective one of the second intermediate frequency signals from one of the second transceivers.

[0008] Advantages of the Invention The present invention is based on the finding that in a high-frequency system with multiple cascaded transmitting units, it is desirable for the signals transmitted by the transmitting units to be synchronized with one another. For this purpose, it is particularly desirable to provide a fixed and as accurately known phase relationship between the signals of the individual transmitting units. Especially if, for this purpose, a reference signal is provided to each transmitting unit, and each transmitting unit generates its transmission signal based on this reference signal, there is a risk that a phase drift may occur during operation due to internal or external influences, such as temperature fluctuations or the like, which may cause the phase relationship between the individual transmitting units to shift.

[0009] The idea of ​​the present invention is therefore to take this knowledge into account and provide a concept for a radio frequency system with multiple transmitting units or transceivers, in which changes in the phase relationships between the transmitted signals in the individual units can be simply recognized and possibly corrected.

[0010] By lowering the frequency of the high frequency signal in the transmission path by a predetermined factor, an intermediate frequency signal can be obtained, which allows for relatively simple routing and distribution of signals on a printed circuit board without the need to use special high frequency boards for this purpose.

[0011] In this case, the phase difference of the high frequency signal in the transmission path of the transceiver can be simply derived from the phase difference of the two intermediate frequency signals, which is then multiplied by a predetermined value used to reduce the decoupled transmission signal.

[0012] By continuously or periodically monitoring such phase differences, changes in the phase of the individual transmit signals of the transceivers can be identified and taken into account. For example, the identified phase differences can be taken into account during subsequent signal processing. Additionally or alternatively, appropriate measures can be taken to at least partially correct the identified phase differences. Alternatively, the operating behavior of the radio frequency assembly can be solely determined or classified based on the detected phase differences.

[0013] According to one embodiment, the predetermined integer value for dividing the frequency of the first radio frequency signal in the first transceiver and the second radio frequency signal in the one or more second transceivers is equal to or greater than 2. For example, a fixedly set value may be selected in the range between 2 and 32. However, in principle, other integer values ​​for dividing or reducing the frequency of the radio frequency signals are also possible.

[0014] According to one embodiment, a radio frequency system is designed to perform signal processing using one or more detected phase offsets. In particular, subsequent processing of signals associated with radio frequency signals from a first and one or more second transceivers can take the detected phase offsets into account. For example, signals associated with the transceiver's transmit signals can be further processed in the digital domain, and the respective detected phase offsets can be incorporated into the processing to correct the phase offsets. For example, in a radar system, such processing can include evaluation of radar echoes originating from the transmit signals transmitted as radar signals.

[0015] According to one embodiment, a first transceiver is designed to provide a reference signal having a set frequency. This reference signal can be used to generate a transmission signal in the first transceiver. The reference signal can also be provided to at least one second transceiver. Accordingly, the at least one second transceiver is designed to generate a transmission signal using the reference signal from the first transceiver. In this way, both the frequency and the phase response of the transmission signals in the individual transceivers can be synchronized with each other.

[0016] In one embodiment, the calibration mechanism is located within the first transceiver, where the generation of the reference signal on which the transmit signal is based and the monitoring of the phase shift within the individual transceivers are performed within the same transceiver.

[0017] According to an alternative embodiment, the calibration mechanism is located in one of the second transceivers. In this configuration, the generation of the reference signal and the monitoring of the phase shift can be performed in different transceivers. In particular, one calibration mechanism can be provided in each of several or all of the second transceivers. In this case, the transceivers equipped with the calibration mechanism can receive both the reference signal and the first intermediate frequency signal from the first transceiver, use the reference signal to generate a transmission signal in the corresponding second transceiver, derive a second intermediate frequency signal from this transmission signal, and determine the phase difference between the first and second intermediate frequency signals based on this.

[0018] According to one embodiment, a calibration mechanism is designed to adjust the phase shift in the transmission path of the first transceiver and / or the second transceiver using one or more detected phase offsets. For example, a phase shift element can be provided in the transmission path of each transceiver, and this phase shift element can be adjusted using the detected phase difference between the reference signal and the calibration signal. In this way, the identified phase difference can be corrected before the transmission of the transmission signal.

[0019] According to one embodiment, the transceivers, i.e., the first transceiver and at least one second transceiver, are fabricated as a monolithic microwave integrated circuit (MMIC) or as a system on a chip (SoC). In this way, particularly compact high-frequency circuits can be realized. Furthermore, the individual transceivers can be arranged on a common printed circuit board.

[0020] According to one embodiment of the radar system, multiple transceivers are each designed to receive radar echoes. The radar system may accordingly be designed to process the received radar echoes using one or more detected phase offsets. In particular, each transceiver can receive the radar echoes, process them, and convert them into the digital domain. The detected phase offsets can then be taken into account during further processing of the digital signal.

[0021] The above-described embodiments and variations may be combined with one another in any meaningful way. Further embodiments, variations, and implementations of the invention include not-explicitly-listed combinations of the features of the invention described above or below in connection with the exemplary embodiments. In particular, those skilled in the art will also add individual aspects as improvements or supplements to each basic embodiment of the invention.

[0022] Further features and advantages of the present invention are described below with reference to the accompanying drawings. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic block diagram of a radio frequency assembly according to one embodiment. [Figure 2] 1 is a schematic block diagram of a radio frequency assembly with one first and one second transceiver according to one embodiment; [Figure 3] 1 is a schematic block diagram of a radio frequency assembly according to an embodiment comprising multiple second transceivers. [Figure 4] FIG. 1 is a flow diagram underlying a method of operation of a radio frequency assembly in accordance with one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] 1 shows a schematic block diagram of a radio frequency assembly 1 according to one embodiment, which can be used, for example, for a radar system in which a radio frequency radar signal is generated and emitted, and then reflections of this radar signal are received and evaluated as radar echoes to detect objects in the field of view of the radar sensor.

[0025] The radio frequency assembly 1 according to Fig. 1 may include two or more transmitting units or transceivers. This radio frequency assembly 1 includes at least one first transmitting unit or first transceiver 10 and one or more further second transmitting units or transceivers 20. Even though the term transceiver is used preferentially in the present invention, this can also basically be a pure transmitting unit depending on the application. In this regard, each individual transceiver 10, 20 may have multiple transmitting and / or receiving paths.

[0026] Each transmit / receive path of one transceiver 10, 20 may be coupled to one corresponding antenna A1, A2 or corresponding antenna system. Thus, a high frequency signal generated in the transceiver 10, 20 may be transmitted via the corresponding antenna A1, A2. In some cases, the antenna A1, A2 or antenna system may also receive the high frequency signal and send the received signal to the corresponding transceiver 10, 20 for further processing.

[0027] The evaluation of the processed received radio frequency signals can be performed, for example, by the processing unit 40. In the case of a radar system, the processing unit 40 can, for example, evaluate the received radar echoes in relation to the transmitted radio frequency signals and, on this basis, determine information about possible objects in the field of view of the radar sensor.

[0028] To synchronize the signal generation or processing of the high-frequency signals in the transmit and receive paths of the first transceiver 10 and one or more second transceivers 20, the first transceiver 10 may provide one or more second transceivers 20 with a suitable reference signal R. This may be, for example, an intermediate-frequency reference signal, based on which both the first transceiver 10 and the second transceiver 20 synchronously generate their high-frequency signals. The desired high-frequency signal may be generated from the reference signal R by multiplying the frequency by a factor n. In this regard, phase drift may occur in the individual transmit paths of the transceivers 10, 20 due to various causes during operation, such as temperature fluctuations or the like. This drift may be due, on the one hand, to phase errors in the transmission path of the reference signal between the first transceiver 10 and the second transceiver 20, or, on the other hand, to individual characteristics of the individual transmit paths, e.g., phase shifters, amplifying elements, etc. Therefore, the following describes concepts as to how such drifts or changes in the phase response of the transmit paths within the individual transceivers 10, 20 can be identified and possibly even corrected.

[0029] In order to monitor the phase shift between the transmission paths in the individual transceivers 10, 20, the high-frequency signals can be decoupled from the transmission paths of each of the transceivers 10, 20 and compared with each other. For this purpose, for example, a calibration mechanism 30 can be provided. Such a calibration mechanism 30 is preferably provided in the first transceiver 10 or in one of the second transceivers 20. This allows the high-frequency signals decoupled from the transmission paths of the transceiver equipped with the calibration mechanism 30 to be directly available in the respective transceiver 10 or 20, while the remaining decoupled signals must be supplied to the calibration mechanism 30 via a corresponding connection.

[0030] In this case, the high-frequency signal decoupled from the transmission path can first be reduced in frequency by a predetermined division. For example, the frequency of the decoupled high-frequency signal can be divided by a predetermined value, for example an integer value between 2 and 32, to obtain a correspondingly lower-frequency intermediate-frequency signal. Such lower-frequency intermediate-frequency signals can then be exchanged relatively easily between the transceivers 10, 20. In particular, this reduces the demands on the high-frequency lines and / or printed circuit boards required for this purpose.

[0031] In the example shown in FIG. 1 , for example, an intermediate frequency signal K2 is output from the second transceiver 20 to the first transceiver 10. This intermediate frequency signal K2 from the second transceiver 20 can be compared with a correspondingly lowered intermediate frequency signal from the first transceiver 10. Based on this comparison, the calibration mechanism 30 can determine the phase difference between the phase of the high-frequency signal in one transmission path of the first transceiver 10 and the high-frequency signal in one transmission path of the second transceiver 20. This detected phase difference can be output as an output signal O. For example, a voltage signal corresponding to the phase difference can be output. Of course, any other signal for indicating the phase difference is also possible. The output signal O can be output as an analog or digital signal to any external device, for example for further processing. Alternatively, the detected phase difference can already be used within the calibration mechanism, or a corresponding adaptation can be made within the transceiver 10 based on the detected phase difference.

[0032] For example, the detected phase difference between the high-frequency signal in one transmission path of the first transceiver 10 and the high-frequency signal in one transmission path of the second transceiver 20 can be supplied to the processing unit 40. Based on this, the processing unit 40 can incorporate this phase difference information into its processing. For example, the evaluation of the received radar echoes can be adapted accordingly to the detected phase difference. Similarly, for example, the processing unit 40 can use the phase difference information to accordingly adapt the generation of the high-frequency signals in the transmission paths of the individual transceivers 10, 20. In this way, for example, the detected phase difference can already be incorporated when generating the high-frequency signals, so that the detected phase difference can possibly be at least partially corrected. Additionally or alternatively, it is also possible to influence the phase difference and, if necessary, correct it, for example, by means of a phase shifter or the like in the transmission paths.

[0033] Furthermore, the detected phase difference can also be monitored, for example to check whether the radar system 1 is still within a set specification. For example, a signal can be generated if the phase difference exceeds a predetermined threshold. This case can therefore be used to determine the accuracy and / or reliability of the detected object when utilizing or evaluating information from the radio frequency system 1, in particular information about the detected object of, for example, a radar system.

[0034] 2 shows a schematic block diagram of a radio frequency assembly 1 with one first transceiver 10 and one second transceiver 20. In this regard, in order to simplify the understanding of the concept according to the invention, only the components essential for one respective transmission path are depicted. Of course, the transceivers 10, 20 may also contain appropriate components for further transmission and / or reception paths.

[0035] The first transceiver 10 may include, for example, a frequency generator 11 that provides a reference signal R for generating a radio-frequency signal. This reference signal R may be multiplied by a corresponding factor n in a component 12. This generates a radio-frequency signal of the desired frequency, which may be amplified in an amplifier 13 and then output. For example, the radio-frequency signal may be emitted via an antenna or an antenna array. Furthermore, any further components for modulation or the like may also be provided in the transmission path. In particular, for example, a phase shifter 14 may be provided in each transmission path, which may accordingly modify the phase response of the transmission signal as required.

[0036] The reference signal R generated by the frequency generator 11 may also be supplied to one or possibly several second transceivers 20, which may then each generate a high-frequency transmission signal in their transmission path based on the reference signal R. Due to various causes, such as temperature-induced drift or the like, the phase relationship of the high-frequency signal in the transmission path of the first transceiver 10 to the high-frequency signal in the transmission path of the second transceiver 20 may change over time. To detect such changes in the phase relationship, for example, the concept described below may be applied.

[0037] To determine the phase relationship between a high-frequency signal in one transmission path of the first transceiver 10 and a high-frequency signal in one transmission path of a second transceiver 20, the first high-frequency signal can be decoupled from the corresponding transmission path of the first transceiver 10. For this purpose, a suitable decoupling element 15 can be provided. The frequency of this first high-frequency signal can be reduced by a suitable frequency divider 16. For this purpose, the frequency of the decoupled first high-frequency signal can be divided by a fixed factor k. At the output of this frequency divider 16, an intermediate-frequency signal is provided whose frequency is reduced by the factor k compared to the frequency of the high-frequency signal in the transmission path to be monitored of the first transceiver 10. This first intermediate-frequency signal can be provided to a calibration mechanism 30.

[0038] In the same way, a high-frequency signal can be decoupled from one of the transmission paths of one of the second transceivers 20. This decoupled high-frequency signal can also be reduced in frequency by a factor k and supplied to the calibration mechanism 30 as a second intermediate-frequency signal. To reduce the frequency of the high-frequency signal, the integer factor k can be selected preferably within the range of 2 to 32. The calibration mechanism 30 compares the two intermediate-frequency signals K1 and K2 and determines the phase difference between them. For example, an IQ mixer can be used for this purpose. However, in principle, any other concept for determining the phase difference is also possible, such as a phase detector or a time-to-digital converter (TDC). Based on this, the calibration mechanism 30 can output an output signal O corresponding to the detected phase difference between the first intermediate-frequency signal K1 and the second intermediate-frequency signal K2. This can be, for example, a signal with a voltage value corresponding to the phase difference. However, any other signal for specifying the phase difference is also possible. If the frequency of the decoupled transmit signal is divided by a value k for the intermediate frequency signal, the phase difference between the high frequency signal in the monitored transmit path of the first transceiver 10 and the high frequency signal in the monitored transmit path of the second transceiver 20 is revealed by k times the detected phase difference of both intermediate frequency signals K1 and K2.

[0039] FIG. 3 shows a schematic block diagram of a radar system 1 including one first transceiver 10 and multiple second transceivers 20-i. If more than one second transceiver 20 is used, for example, the intermediate frequency signals K2-i of all second transceivers 20-i may be provided to the first transceiver 10. For example, the intermediate frequency signals K2-i of the second transceivers 20-i may be provided to a combiner 31. This combiner 31 may be provided, for example, within the calibration facility 30. Alternatively, the combiner 31 may be provided outside the calibration facility 30. In particular, the combiner 31 may be provided outside the first transceiver 10. This allows the calibration facility 30 to be provided only with the output signal of the combiner 31, thereby reducing the number of inputs to the calibration facility 30. This combiner 31 may be realized, for example, by a passive structure or additional components to combine the input signals into a single signal. In this case, each second transceiver 20-i can output a corresponding intermediate frequency signal K2-i corresponding to the high-frequency signal of one transmission path, while the remaining transmission paths do not output any intermediate frequency signals during this period. That is, each second intermediate frequency signal K2-i is compared with the intermediate frequency signal of the first transceiver 10 via the combiner 31, thereby determining the respective phase differences. In this regard, if, for example, the intermediate frequency signals of all transmission paths of the second transceiver 20-i are fed to the combiner 31 in sequence according to a set scheme, the individual phase differences can also be determined in sequence accordingly.

[0040] If the radio frequency assembly 1 is, for example, a radar system or the like that transmits desired signals at set time intervals with intervals between the desired signals, the determination of the phase difference can be performed during the intervals between the transmission of the desired signals. In this regard, for example, the phase differences of all monitored transmission paths can be determined during one interval between the transmission of two desired signals. Alternatively, only one phase difference or a portion of the phase difference can be determined during one interval between the transmission of two desired signals.

[0041] In order to reduce the number of connections required between the individual transceivers, in particular between the first transceiver 10 and the second transceiver 20, all intermediate frequency signals K2-i can also be conducted via one common connection, with one intermediate frequency signal K2-i of each second transceiver 20-i being passed on in turn in a suitable multiplexing operation, although in principle any other concept for exchanging the intermediate frequency signals K2-i is also possible.

[0042] In each of the examples described above, the calibration mechanism 30 is provided in the first transceiver 10, which also provides the reference signal R. Furthermore, the calibration mechanism 30 may also be provided in one or more of the second transceivers 20-i, i.e., in a transceiver that receives the reference signal R from another transceiver, where the first transceiver 10 provides the reference signal R as well as the first intermediate frequency signal K1 of one of the transmission paths of each of the first transceivers 10.

[0043] In addition to the above-described configuration in which all phase differences are determined by a single calibration mechanism 30 in one of the transceivers 10, 20, any other configuration is also possible. For example, a ring-like arrangement is also possible, in which in each transceiver, a phase difference is determined between at least one transmission path of one transceiver 10, 20 and one transmission path of an adjacent transceiver 10, 20 in the ring. However, any further concepts and arrangements are of course possible.

[0044] 4 shows a flow diagram that may serve as the basis for a method of operating the radio frequency assembly 1 according to one embodiment. This method may be applied in principle to any radio frequency assembly, for example the radio frequency assembly 1 described above. Accordingly, the details already given above in relation to the described radio frequency assembly 1 also apply to the method described below. Similarly, any components that may be necessary for the implementation of the method described below may be provided within the radio frequency assembly 1 described above.

[0045] In step S10, the first high frequency signal is decoupled from the transmission path of the first transceiver 10. In step S11, the frequency of the first high frequency signal is divided by a predetermined value k, and in step S12, the divided first high frequency signal is provided as a first intermediate frequency signal K1.

[0046] Based on this, in step S20, the second high frequency signal is decoupled from the transmission path of the second transceiver 20, and in step S21, the frequency of the decoupled second high frequency signal is divided by a predetermined value k. Finally, in step S22, the divided second high frequency signal is provided as a second intermediate frequency signal K2.

[0047] Based on this, in step S30, the phase difference between the first intermediate frequency signal K1 and the second intermediate frequency signal K2 is detected. Based on this, in a further step S40, for example, information about the detected phase difference between the first intermediate frequency signal K1 and the second intermediate frequency signal K2 can be used to correct the detected phase difference. For example, the phase shifters in the respective transmission paths can be adapted accordingly. Alternatively, for example, if a set threshold value for the detected phase difference is exceeded, it is also possible to recognize a malfunction and output an appropriate signal transmission. In some cases, the detected phase difference can also be used to adapt further processing of the signal, in particular the received signal, for example, the radar echo. Furthermore, any further measures using the detected phase difference can of course also be performed.

[0048] In summary, the present invention relates to monitoring and detecting a phase difference between multiple mutually coupled transceivers. For this purpose, it is proposed to decouple a high frequency signal from each of the transceivers' transmission paths, divide the frequency of the decoupled high frequency signal by a predetermined factor, and compare the frequency-divided signals to detect the phase difference.

Claims

1. a plurality of transceivers (19, 20), the plurality of transceivers (10, 20) including one first transceiver (10) and at least one second transceiver (20); a calibration mechanism (30), the first transceiver (10) is designed to decouple a first high frequency signal from one transmission path of the first transceiver (10), by dividing the frequency of the decoupled first high frequency signal by a predetermined integer value (k) and supplying the result as a first intermediate frequency signal (K1); Each of the second transceivers (20) is designed to decouple a second high frequency signal from one transmission path of the respective second transceiver (20), by dividing the frequency of the decoupled second high frequency signal by the predetermined integer value (k) and providing it as a second intermediate frequency signal (K2); and A radio frequency assembly (1), wherein the calibration mechanism (30) is designed to detect a phase difference between the first intermediate frequency signal (K1) from the first transceiver (10) and a second intermediate frequency signal (K2) from each of the second transceivers (20).

2. 2. The radio frequency assembly (1) of claim 1, wherein the predetermined integer value (k) for dividing the frequencies of the first radio frequency signal and the second radio frequency signal is 2 or greater.

3. 3. The radio frequency assembly (1) according to claim 1 or 2, wherein the radio frequency assembly (1) is designed to perform signal processing using the one / more detected phase offsets.

4. the first transceiver (10) is designed to provide a reference signal (R) having a set frequency; and 4. The radio frequency assembly (1) according to claim 1, wherein the at least one second transceiver (20) is designed to generate a transmission signal using the reference signal (R) from the first transceiver (1).

5. 5. The radio frequency assembly (1) according to any one of claims 1 to 4, wherein the calibration mechanism (30) is arranged within the first transceiver (10).

6. 6. The radio frequency assembly (1) according to claim 1, wherein the calibration mechanism (30) is designed to adjust a phase shift in the transmission path of the first transceiver (10) and / or the second transceiver (20) using the one or more detected phase offsets.

7. 7. The radio frequency assembly (1) according to claim 1, wherein the first transceiver (10) and the at least one second transceiver (20) are fabricated as a monolithic microwave integrated circuit (MMIC) or a system on a chip (SoC).

8. 8. A radar system comprising a radio frequency assembly (1) according to any one of claims 1 to 7, wherein the first transceiver (10) and the at least one second transceiver (20) are each designed to generate and transmit a radar signal on a respective transmission path.

9. 9. The radar system of claim 8, wherein the first transceiver (10) and the at least one second transceiver (20) are each designed to receive radar echoes, and the radar system is designed to process the received radar echoes using the one / more detected phase offsets.

10. A method of operating a radio frequency assembly having a plurality of transceivers (10, 20), the plurality of transceivers (10, 20) including a first transceiver (10) and at least one second transceiver (20); a step (S10) of decoupling a first radio frequency signal from one transmission path of the first transceiver (10); A step (S11) of dividing the first high frequency signal by a predetermined integer value (k); (S12) providing the divided first high frequency signal as a first intermediate frequency signal (K1); A step (S20) of decoupling a second high frequency signal from one transmission path of one second transceiver (20); Dividing each of the decoupled second high-frequency signals by the predetermined coefficient (k) (S21); (S22) providing each of the divided second high frequency signals as a second intermediate frequency signal (K2); and detecting (S30) a phase difference between the first intermediate frequency signal (K1) from the first transceiver (10) and a second intermediate frequency signal (K2) of one of the second transceivers (20).

11. 11. The method of claim 10, further comprising a step (S40) of adapting the transmission path in the first transceiver (10) and / or the transmission path of the second transceiver (20) using the detected phase difference.

12. 12. The method according to claim 10 or 11, comprising the step of outputting a signalling for an error message if the detected phase difference exceeds a set threshold.

Images