Method of determining phase information and RF device

Abstract

The present disclosure relates to methods and RF devices of determining phase information. Examples related to determining phase information indicative of a phase error of a phase shifter are described and disclosed herein.

Description

Technical Field

[0001] This disclosure relates to phase information for determining the phase error of an indicator phase shifter. Background Technology

[0002] Radio frequency (RF) circuits in the MHz to THz range are now used in many applications. For example, RF circuits are used to transmit data according to modern communication protocols or to generate and transmit radar signals for object detection. In radar applications, angle-resolved object detection may require the transmission of MIMO (Multiple In Multiple Out) signals with different phases via several antennas. The phase setting for each transmission path can be changed using a phase shifter capable of moving the phase of the transmitted signal. In each of the above applications, it is desirable to set the phase with high precision when transmitting RF signals to avoid undesirable and harmful effects. For example, in radar applications, inaccurate phase setting of the transmission channel can lead to additional spectral components, which can significantly reduce the accuracy of angle detection. Summary of the Invention

[0003] According to one aspect, a method for determining phase information indicating the phase error of a phase shifter in a transmit path of an RF device includes: controlling a phase shifter of the transmit path to apply a phase shift according to a target phase value in a set of target phase values ​​to generate an RF transmit signal associated with the target phase value; transmitting the RF transmit signal via the transmit path; and receiving a plurality of RF receive signals in a plurality of receive paths, each of the plurality of RF receive signals being associated with a corresponding receive path and including crosstalk from the corresponding RF transmit signal to the corresponding receive path. The method further includes: down-flattening the plurality of RF receive signals to generate a plurality of down-converted receive signals; and in each of the plurality of receive paths, processing the corresponding down-converted receive signal associated with the corresponding receive path to generate a measurement associated with the target phase value applied by the phase shifter for each receive path.

[0004] The method further includes: generating multiple measurement sets, each of the multiple measurement sets being associated with a corresponding receiving path in a plurality of receiving paths, wherein the multiple measurement sets are generated by repeating phase shifter control, RF transmit signal transmission, downconversion, and processing in each receiving path, so as to generate a corresponding measurement value in the corresponding measurement set for each target phase value in the target phase value set in each corresponding receiving path. Phase information is determined based on the processing of the multiple measurement sets.

[0005] According to another aspect, an RF device includes: a transmit path configured to transmit an RF transmit signal via the transmit path; a phase shifter disposed in the transmit path and configured to apply a phase shift to the RF transmit signal according to a target phase value in a set of target phase values; and a plurality of receive paths configured to receive a plurality of RF receive signals, the plurality of RF receive signals including crosstalk from the respective RF transmit signal to the respective receive path. A plurality of mixers are disposed in the plurality of receive paths to down-convert the plurality of RF receive signals into a plurality of down-converted receive signals. A controller is configured to control the phase shifter to apply each target phase value in the set of target phase values. The RF device also includes measurement circuitry for generating a plurality of sets of measurements based on the plurality of down-converted receive signals, wherein each set of measurements is associated with a respective receive path in the plurality of receive paths, and each measurement within a set of measurements is associated with a respective target phase value applied by the phase shifter. The RF device also includes a processor configured to process the plurality of sets of measurements and determine phase information indicating a phase error of the phase shifter based on the plurality of sets of measurements.

[0006] Those skilled in the art will recognize the additional features and advantages after reading the following detailed description and reviewing the accompanying drawings. Attached Figure Description

[0007] The invention is illustrated in the accompanying drawings by way of example and not limitation, in which the same reference numerals denote similar or identical elements. The elements in the drawings are not necessarily to scale relative to each other. Various features of the illustrated examples can be combined unless excluded from each other.

[0008] Figure 1A The illustration shows an RF device and a first example of crosstalk from the RF device's transmit path to multiple receive paths.

[0009] Figure 1B The illustration shows an RF device and a second example of crosstalk from the RF device's transmit path to multiple receive paths.

[0010] Figure 1C The illustration shows an RF device and a third example of crosstalk from the RF device's transmit path to multiple receive paths.

[0011] Figure 2A , 2B Figures 2 and 2C show examples of measurements and fitted curves for different receiving paths.

[0012] Figure 3A , 3B The 3C example shows a set of measured phase values ​​and fitted curves for different receiving paths.

[0013] Figure 4A ,4B Figure 4C shows examples of the set of measured phase step values ​​and the expected target phase step values ​​for different receiving paths.

[0014] Figures 5A to 5D Other examples of sets of measurement phase step values ​​for different receiving paths are shown.

[0015] Figures 6A to 6D The set of measured phase step values ​​after applying sliding window processing is shown, as well as the results for... Figures 5A to 5D The example shown is a set of first-order derivative values ​​of the fitted curve for measuring the phase step value.

[0016] Figure 7 shows the target Figure 5A Examples of the distribution of measured phase step values, and examples of the distribution of measured phase step values ​​after outlier removal.

[0017] Figure 8 An example of a combined and averaged set of measured phase step values ​​is shown after combining and averaging multiple sets of measured phase step values. Detailed Implementation

[0018] The examples described herein provide a novel concept for determining phase information indicating the phase error of a phase shifter. This concept is based on using crosstalk information from the transmit path to multiple receive paths to determine the phase error of the phase shifter's phase setting in the transmit path. The receive paths used to determine the phase error are also intended for precise measurements during field use of RF equipment, such as receiving radar signals reflected from a radar target to determine the target's distance and velocity.

[0019] Because this concept utilizes existing receive paths, it can be implemented in existing RF devices without any hardware changes, and may require only additional processing or software capabilities and / or minor reconfigurations that can be performed on-the-fly across multiple receive paths. This concept can be used to obtain phase shifter calibration during one or more calibration intervals. Calibration intervals can be scheduled before the expected operation of the RF device, such as after powering on the RF device, or between operational phases of the RF device, such as after transmitting a radar chirp frame.

[0020] In addition to calibration, this concept can be used additionally or optionally for monitoring phase shifters.

[0021] In one example, the phase error can be determined for each of the predetermined set of target phase steps. A target phase step is the difference between a pair of target phases that have been applied by a phase shifter (e.g., a pair of most recent target phases).

[0022] This concept can be used in any configuration or situation, such as in the case where there is no connected antenna, in the case where an antenna is connected, or in the case where a nearby object reflects crosstalk back to the receiving path.

[0023] This concept achieves very high phase measurement accuracy, which is 4 to 5 times better than existing concepts using dedicated built-in measurement circuitry. This is achieved by using multiple receiver paths that are also configured to receive RF signals during normal operation and to receive crosstalk with different phase delays.

[0024] Now for reference Figure 1A This section will describe a first example of an RF device 10A according to this concept. The RF device 10A includes a transmit path 12 and multiple receive paths 14-1, 14-2, and 14-3. The transmit path 12 includes a transmit channel 13 implemented in a semiconductor chip. The transmit channel 13 may include a phase shifter 16. The phase shifter 16 is coupled to a local oscillator (LO) 11 for receiving an LO signal (also referred to herein as a first representation of the LO signal). The phase shifter 16 is configured to apply a phase shift to the LO signal received from the local oscillator according to a target phase value input from a controller 33 to the phase shifter 16, in order to generate a phase-shifted signal. The phase shifter 16 may include any type of phase shifter, such as an analog phase shifter or a digital phase shifter. For example, in one example, the phase shifter 16 may include an IQ modulator capable of shifting the phase by setting the amplitudes of the I and Q paths. In one example, the phase shifter 16 may include one or more elements selected from resistive, capacitive, or inductive elements. In one example, the phase shifter 16 may include a delay line and a switching element. Phase shifter 16 is coupled to power amplifier 18 to amplify the phase-shifted signal to generate a transmit signal. Transmit path 12 may also include port 15 for transmitting the transmit signal to an external location on the semiconductor chip.

[0025] Each of the multiple receive paths 14-1, 14-2, and 14-3 includes a corresponding receive channel 20 implemented in a semiconductor chip. Each corresponding receive channel 20 includes a mixer 22, upstream coupled to a corresponding port 23, for down-converting the received signal received from the corresponding port 23. In some examples, a low-noise amplifier may be arranged between the mixer 22 and the corresponding port 23. In one example, the receive channel 20 may be implemented as an IQ receiver, and the mixer 22 may be implemented as an IQ mixer. Each corresponding mixer 22 is coupled to a local oscillator 11 for receiving the LO signal (also referred to herein as the corresponding representation of the LO signal) for down-converting the corresponding received signal. Each mixer 22 is also downstream coupled to an optional analog baseband circuitry 24 for processing the down-converted signal. The analog baseband circuitry 24 may include, for example, an amplifier and / or an analog filter. The analog baseband circuitry 24 is downstream coupled to an analog-to-digital converter (ADC) 26, which generates digital measurements based on the received down-converted received signal. The ADC 26 is downstream coupled to an optional digital baseband circuit 28 for providing digital processing operations for each corresponding receive channel 20. The digital baseband circuit 28 may include, for example, digital filters, upsampling or downsampling circuitry, etc. The ADC 26 and the optional digital baseband circuit 28 can form a measurement circuit 29 that generates measurement values ​​based on the down-converted signal.

[0026] Each corresponding measurement circuit 29 is coupled to a processor 30 for processing the measurement values ​​received from each corresponding receiving path, which will be described later.

[0027] According to some examples, transmit channel 13 and each corresponding receive channel 20 can be implemented in a single semiconductor chip. In some examples, transmit channel 13 and receive channel 20 can be implemented in different semiconductor chips, such as in the semiconductor chip of a cascaded radar system. In some examples, RF device 10A may include more than one transmit path 12.

[0028] According to some examples, RF device 10A is a radar device configured to transmit and receive radar signals during radar operation mode to detect the distance, velocity, or angular position of an object. Radar operation can use, for example, frequency modulated continuous wave (FMCW) radar signals. Therefore, local oscillator 11 is configured to generate FMCW signals during radar operation mode.

[0029] As described above, RF device 10A is configured to determine phase error information related to the phase error introduced by phase shifter 16 during the second operating mode. The phase error information can be determined using only RF device 10A without any additional hardware components or circuitry. Determining the phase error information may include reconfiguration, such as dynamic modification or switching of some components compared to the expected field operation of RF device 10A. According to one example, filters in the corresponding analog baseband circuitry 24 and / or digital baseband circuitry 28 may be dynamically modified to bypass or eliminate high-pass filtering of the down-converted signal during the second operating mode. At the end of the second operating mode (after calibration and / or monitoring are completed), the high-pass filter may be reactivated or switched back to the receive path.

[0030] The determination of phase error information is based on crosstalk from the transmit path to multiple receive paths 14-1, 14-2, and 14-3. Although crosstalk is generally an unwanted signal component during radar operation (e.g., in radar operating mode), the proposed concept utilizes crosstalk signals to determine phase error information during a second operating mode.

[0031] Crosstalk can occur in different parts of transmit path 12 and receive paths 14-1, 14-2 and 14-3. Figure 1A An RF device 10A without transmit and receive antennas is shown. In this case, crosstalk 34 is mainly caused by crosstalk coupling between port 15 and port 23 of each corresponding receive path.

[0032] Figure 1B It shows a connection to an antenna. Figure 1A RF device 10B is shown as RF device 10A. Therefore, transmit path 12 also includes transmit antenna 17 and antenna path 19 coupled between transmit antenna 17 and port 15. Furthermore, each of the plurality of receive paths 14-1, 14-2, and 14-3 includes receive antenna 31 and antenna path 32 coupled between the respective receive antenna 31 and the respective pad 23 for transmitting the respective received signal from the receive antenna to the respective port 23. In this example, in addition to crosstalk 34, crosstalk 36 generated by the coupling from transmit antenna 17 to each respective receive antenna 31 is included in the crosstalk signal.

[0033] In some examples, the transmitting antenna 17 may be a waveguide antenna, a patch antenna, or other type of RF antenna. The antenna path 19 may include, for example, one or more wireless sections and / or one or more wired sections. In some examples, the antenna path 19 may include at least one of waveguides, striplines, substrate-integrated waveguides, etc. In some examples, the antenna path 19 may include elements for coupling from one section to another, such as couplers, transmitters, etc. Typically, crosstalk signals can be generated outside the semiconductor chip because good RF isolation between the transmit and receive channels is typically provided within the semiconductor chip. However, this concept is not limited to this.

[0034] It should be noted that this concept does not depend on specific crosstalk between specific parts. In fact, crosstalk from multiple crosstalk paths can accumulate and increase the strength of the crosstalk signal, which can be beneficial. Therefore, in some examples, each crosstalk signal may include crosstalk originating from multiple crosstalk paths. Therefore, the following considers all cases of crosstalk introduced into the corresponding receiving paths 14-1, 14-2, 14-3.

[0035] This concept can also be further used to reflect signals from fixed close-range locations to receiving paths 14-1, 14-2, and 14-3. Figure 1C An example is shown where, in addition to crosstalk 34 and 36, indirect signals 38 generated by reflections of transmitted signals from nearby object 40 are reflected back to receiving paths 14-1, 14-2, and 14-3. For the above concept to be used in this case, the distances from nearby object 40 to receiving paths 14-1, 14-2, and 14-3 need to be fixed. Nearby object 40 could, for example, be metal walls arranged at fixed intervals. Figure 1C It shows something similar to Figure 1B The RF device 10C of the RF device 10B shown is placed at a fixed distance in front of the object 40 to reflect the transmitted signal back to the corresponding receiving path. The above can be applied in a similar manner to this situation.

[0036] According to one example, in a second operating mode, the local oscillator 11 is controlled to generate a continuous wave signal with a fixed RF frequency. For example, the RF frequency can be selected between 20 and 100 GHz.

[0037] In the case where the RF system includes more than one transmit channel 13, the corresponding other transmit channels are controlled to not transmit during the aforementioned measurement, so that crosstalk caused by only one transmit channel is introduced into the receive paths 14-1, 14-2, and 14-3. After the phase information of transmit channel 13 is determined, each of the other transmit channels can then be activated sequentially to determine the phase information of the corresponding other transmit channels.

[0038] To determine phase error information, controller 33 is configured to control phase shifter 16 to sequentially apply target phase values ​​from a set of target phase values. It should be noted that in some examples, controller 33 may be implemented, in whole or in part, in processor 30, using software, for example, executed by processor 30 to generate the set of target phase values.

[0039] Transmit channel 20 generates a corresponding RF transmit signal associated with the applied target phase value. The transmit signal is transmitted via transmit path 12. In each receive path 14-1, 14-2, and 14-3, the corresponding RF receive signal, including the corresponding crosstalk from RF transmit path 12 to the corresponding RF receive path, is received by the corresponding mixer 22 and down-converted. The down-converted signal is processed by analog baseband circuitry 24 and converted into a digital measurement value using analog-to-digital converter 26.

[0040] In one example, the measured value represents the DC value of the down-converted signal. In radar operation, high-pass filters in analog and / or digital baseband circuitry are typically used to filter out the DC portion of the down-converted signal. However, in the second mode, the appropriate receiver path is reconfigured so that the high-pass filter is bypassed or low-frequency filtering is not applied, allowing the measurement of the DC value of the down-converted signal.

[0041] For each target phase value applied by phase shifter 16, a corresponding measurement value is generated in each of the plurality of receiving paths 14-1, 14-2, 14-3. Therefore, a plurality of measurement value sets are generated, each set associated with one of the receiver paths 14-1, 14-2, 14-3. Each measurement value in one of the measurement value sets is associated with a target phase setting in one of the target phase setting sets. According to one example, the target phase value set includes values ​​that can be obtained through... The target phase values ​​are determined at regular intervals between 0 and 360°, where N It is an integer, and n It is an integer from 0 to N-1.

[0042] The processor 30 then processes multiple sets of measurements to determine phase information.

[0043] According to one example, processor 30 can arrange the set of measurements in sequence such that the target phase corresponding to the measurements increases continuously before the target phase values ​​are applied in an increasing order.

[0044] Figures 2A to 2C Illustrative examples of multiple sets of measurements for 12 target phase values ​​are shown for receiving paths 14-1, 14-2, and 14-3. Figure 2ACorresponding to receiving path 14-1, Figure 2B Corresponding to receiving path 14-2, and Figure 2C Corresponding to receiving path 14-3. The measured value (DC value) is in the corresponding... Figures 2A to 2C It is indicated by a dot.

[0045] For continuous wave signals, the DC value of each measured down-converted signal can be described as: Where A is the amplitude of the corresponding sine curve matching the DC value, and B is the DC offset of the corresponding sine curve matching the DC value. err(n) When the target phase value is applied 360°n / N and The phase error introduced by the phase shifter, and This is the phase introduced by the crosstalk signal relative to the LO signal received at mixer 22. Note that the phase introduced by crosstalk varies depending on the length of the crosstalk path. This is different for each receiving path. However, for a given receiving path, the phase can be assumed. For all measurements, the conditions and lengths of the crosstalk paths are generally constant and do not change within the measurement period (which can range from hundreds of microseconds to milliseconds). For applications including automotive applications, this measurement period can be assumed to be sufficient. Note that, in the absence of phase error introduced by phase shifter 16, the measurements are expected to lie precisely on the sine curve (assuming no measurement error).

[0046] For each set of measurements M(n), processor 30 can be used to determine the fitted sine curve in order to determine the parameters. A , B and The fitted values. Parameters A and / or B and / or The value or representation of parameter A and / or B and / or The information about the value can also be referred to as the indicator parameter in this article. A and / or B and / or Information. For example, this can be obtained by minimizing parameters. A , B and error function To determine the fitted sine curve.

[0047] In some examples, the processor 30 can be used to determine the parameters by performing a Fourier transform on the set of measurements M(n). A , B and The value of , where the 0th-order frequency component (DC component) indicates the offset B, the amplitude of the 3rd-order frequency component provides A, and the phase of the 3rd-order frequency component provides . .

[0048] Figures 2A to 2C Illustrative examples of fitted sine curves 202A, 202B, and 202C are shown, which are matched with the corresponding sets of measurements.

[0049] After determining the fitted sine curve and / or parameters A and B After obtaining the value, the processor 30 can calculate multiple sets of measurement phase values ​​from the multiple sets of measurement values ​​M(n) using the arcsine function to obtain... And apply it to each corresponding measurement value M(n).

[0050] Figures 3A to 3C An illustrative example is shown, illustrating multiple sets of measured phase values ​​(shown as points) and the corresponding curves fitted to each set of measured phase values. It can be noted that, taking into account the different cross-coupling paths of each receiving path, the fitted curves have the same slope but different offsets.

[0051] From multiple sets of measured phase values, multiple sets of measured phase step values ​​can be calculated by determining corresponding pairs of measured phase values ​​in the corresponding sets of measured phase values ​​and calculating the difference between the corresponding measured phase values ​​in each pair. According to one example, processor 30 determines adjacent pairs of measured phase values. and The corresponding measured phase step value is determined using the following equation. : (Equation 1).

[0052] As understood here, the adjacent measured phase values ​​of a corresponding measured phase value are the measured phase values ​​of the measured values ​​corresponding to the target phase value, which are derived from all target phase values ​​that are closest to the corresponding measured phase value. Therefore, the phase step value associated with the target phase value (e.g., index n) represents the phase difference between the measured phase value associated with the target phase value (e.g., index n) and the phase value associated with the adjacent target phase value (e.g., index n+1).

[0053] Figures 4A to 4C An illustrative example is shown of a set of multiple measured phase step values ​​determined using Equation 1. Furthermore, Figures 4A to 4CThe expected target phase step value is shown, which is the difference between a pair of target phase values, for example, in this case, the difference between two consecutive target phase values ​​of 360° / 12 = 30°. Assuming that the phase shifter 16 does not introduce phase error and there are no measurement errors or other processing errors, each phase step value in each set of phase step values ​​determined using Equation 1 will be calculated as exactly the target phase step value.

[0054] When phase error is introduced by phase shifter 16, if there is no measurement error, each set of measured phase step values ​​will follow the phase step error curve of phase shifter 16. In the presence of measurement error or other processing error, the measured phase step values ​​will jitter around the phase error curve of phase shifter 16.

[0055] In some examples, jitter (the deviation between the measured phase step value and the desired phase step error curve) can depend on the target phase value associated with the measured phase step value. In particular, it has been observed that in regions where the fitted sine curve has a maximum value, small deviations in the measured values ​​due to measurement errors lead to deviations in the determined phase values, reducing measurement accuracy. This can also be seen in Equation 1, since the first arcsine value needs to be subtracted from the second arcsine value. Any measurement error of a value close to the extremes of the sine curve near the extremes of the fitted set of measurements will significantly affect the results of Equation 1 when the absolute value of the derivative of the arcsine function approaches infinity at 90° and 270° (the extremes of the sine curve). Furthermore, the effect of measurement error or processing error on the results is even stronger when both measurements in Equation 1 are close to the extremes of the corresponding fitted sine curves.

[0056] Figures 5A to 5D Multiple sets of measured phase step values ​​are shown, obtained from actual measurements in four receiver paths RX1, RX2, RX3, and RX4, with a target phase step value of 360 / 256 = 1,40625°. Furthermore, it should be noted that measurements were performed using calibrated phase shifters to avoid introducing errors, and that the measured phase step values ​​are expected to be the target phase step values. It should be noted that in... Figures 5A to 5D In the measurement, the target phase applied by phase shifter 16 rotates twice continuously from 0° to 360° in steps of 1,40625° (target phase step size). Therefore, Figures 5A to 5D Each figure in the diagram shows a set of 512 measured phase step values, and the number of measurements i and 256+i correspond to the same target phase applied by the phase shifter 16.

[0057] Figure 5A The set of measured phase step values ​​corresponding to the receiving path RX1 is shown. (As can be seen from...) Figure 5AThe observed phase step values ​​showed increased fluctuations in the regions between measurement numbers of 10 to 40, 135 to 165, 265 to 295, and 395 to 425. Figures 5B to 5D Similar behavior can be observed, however in different regions.

[0058] Figures 6A to 6D The respective figures above show a set of multiple measured phase step values ​​after a 5-point moving average process. Figures 6A to 6D The corresponding figure below shows the absolute value of the derivative of the fitted sine curve that fits the corresponding set of measurements. It can be observed that the increased fluctuation in the measured phase step values ​​corresponds to the zero of the derivative of the corresponding fitted curve. In other words, the increased fluctuation occurs in the region near the extreme values ​​of the corresponding fitted curve for the measured values.

[0059] However, since the extreme values ​​of the fitted sine curve lie at different target phase values ​​across multiple receiving paths, a combination of the sets of measured phase step values ​​can provide an accurate measurement of the measured phase step value for all target phase values, which will be outlined in more detail below.

[0060] According to one example, multiple sets of measurement phase step values ​​are processed by combining one or more sets of measurement phase step values ​​using weighting factors. According to one example, a weighting factor can be determined for each n indicating the target phase value (from 1 to N) and each j indicating the corresponding reception path. w j (n) As an example, a weighting factor can be used. w j (n) according to To calculate the weighted sum, where J is the number of receive paths used in the calculation, and j is the index of the corresponding receive path, and It is the corresponding measured phase step value.

[0061] Based on some examples, a sine curve can be used at the corresponding target phase value. The slope information (first derivative) at (n) is based on the fitted sine curve. M fitting Determine the weighting factor w j (n) The value of the derivative of the fitted curve can be considered here as an example of the derivative value of the fit. According to one example, the weighting factor... w j (n) It can be determined as the corresponding target phase value The absolute value of the first derivative at point , the square of the first derivative Or a polynomial of degree 1, 2 or higher with its first derivative as a variable.

[0062] In some examples, slope information may include values ​​assigned to slope regions. For instance, a weighting factor may be assigned to the first region around the extrema of the fitted sine curve. w j (n) For the same value, but for the region outside the extreme value, a weighting factor can be assigned. w j (n) One or more other values.

[0063] Based on some examples, weighting factors can be determined based on statistical information from the set of each measured phase step values. w j (n) According to some examples, statistical information can be dispersion information that indicates the dispersion of the measured phase step values ​​within the corresponding set of measured phase step values.

[0064] Based on some examples, the weighting factor can be determined based on the distance between each measured phase step value and the median or mean. w j (n) In some examples, where the corresponding measured phase step value is outside a specific boundary, such as outside the 20th and 80th percentiles of the set of measured phase step values, the weighting factor can be adjusted. w j (n) Set to zero.

[0065] Based on some examples, weighting factors w j (n) Based on the amplitude of the down-converted signal, this amplitude can be determined, for example, by the amplitude A of the fitted curve for each receiving path. In some examples, the weighting factor... w j (n) The DC offset of the down-converted signal can be used as a basis, which can be determined, for example, by the offset B of the fitted curve for each receiving path.

[0066] According to some examples, the weighting factor can be based on a combination of statistical information and / or amplitude and / or measured DC offset. As one example, it can be based on... ,or ,or To determine the weighting factors, where σ j It is the standard deviation of the set of corresponding measurement phase step values ​​corresponding to the receiving path j. A jIt is the amplitude of the fitted curve corresponding to the receiving path j, and B j It is the measured DC offset of the fitted curve corresponding to the receiving path j, as described above.

[0067] According to some examples, the combination of the set of measured phase step values ​​includes removing outliers before averaging the measured phase step values.

[0068] Figure 7A The distribution of the set of measured phase step values ​​corresponding to the receiving path RX1 is shown. It can be observed that the average calculated phase step value is 1.4995°, and the standard deviation of the set of measured phase step values ​​is determined to be 0.57611. Figure 7B The distribution of the same preselected set of calculated phase step values ​​is shown, with outliers outside the 20th and 80th percentiles removed before processing. The average calculated phase step value was reduced to 1.4293°, which is closer to the expected value of 1.4062°. Furthermore, the standard deviation decreased to 0.10404, indicating an improvement achieved through outlier removal.

[0069] Figure 8 The diagram shows a set of measured phase step values, including the first measured phase step value generated using a weighting factor and averaged over 30 measurements. The weighting factor is obtained by using... It's confirmed.

[0070] By comparing the corresponding measured phase step value with the target phase value (e.g., by subtracting the corresponding measured phase step value from the target phase value), the phase step error of the phase shifter 16 can be determined for each target phase value. In this way, phase step error curves for the phase shifter 16 can be established for various target phase values.

[0071] Note that the phase error is approximately zero during the measurement because the phase shifter 16 used in the measurement was pre-calibrated. From Figure 8 It can be observed that the phase step value is determined to be very close to the desired target phase step value (dashed line), with an accuracy of + / - 0.3°. This demonstrates the high accuracy in determining the concept of the actual phase step error imposed by the phase shifter, or the corresponding error of the actual phase step introduced by the phase shifter, when the target phase value changes from the first value to the second value.

[0072] In addition to the embodiments described above, the following embodiments are disclosed herein.

[0073] According to one example, a method for determining phase information indicating the phase error of a phase shifter in the transmit path of an RF device involves a series of actions to measure and calculate the phase information. The method begins by controlling the phase shifter of the transmit path to apply a phase shift according to a target phase value from a set of target phase values, which may refer to a predetermined range of phase values, in order to generate an RF transmit signal associated with the target phase value. This RF transmit signal is then transmitted via the transmit path.

[0074] The RF transmitted signal is received as crosstalk in multiple receiving paths, each receiving path receiving an RF received signal that includes the crosstalk from the corresponding RF transmitted signal to that receiving path. Crosstalk can refer to the direct transfer of energy from the transmitting path to the corresponding receiving path, or the transfer of energy from the transmitting path to the corresponding receiving path via a nearby reflective object. The multiple RF received signals are then down-converted to generate multiple down-converted received signals. Down-conversion can refer to the process of converting a high-frequency signal to a low-frequency signal.

[0075] In each receiving path, the corresponding down-converted received signal is processed to generate a measurement associated with the target phase value applied by the phase shifter. This processing may include various signal processing techniques, such as filtering or amplification.

[0076] Multiple sets of measurements are generated by repeatedly controlling the phase shifter, transmitting the RF signal, downconverting, and processing the signal for each receive path. Each set of measurements is associated with a corresponding receive path and is generated for each target phase value in the target phase value set.

[0077] Phase information is then determined by processing multiple sets of measurements. This processing can include various algorithms and techniques, such as curve fitting, Fourier transform, or interpolation, to extract phase information from the measurements.

[0078] In one implementation, the RF transmitted signal is a continuous wave RF signal with a fixed frequency, and / or the target phase value set includes each phase value. N is a number equal to or greater than 4, and n is a number from 1 to N. This allows for target phase values ​​with regular intervals, which allows for the efficient use of processing techniques such as Fourier transform, curve fitting, etc.

[0079] In another implementation, determining phase information involves processing multiple sets of measurements to calculate multiple sets of measured phase values.

[0080] In another implementation, determining the phase information includes: processing each set of measurements to determine first information indicating the amplitude A and offset B of a corresponding sine curve matching the corresponding set of measurements; and processing the corresponding set of measurements to generate multiple sets of measured phase values. Processing the corresponding set of measurements may include, for example, applying the function arcsin((M(m)-B) / A) to each corresponding measurement M.

[0081] In another implementation, processing each set of measurements to determine the first information includes at least one of the following actions: performing a Fourier transform on the set of measurements to determine the first information, or fitting a sine curve to determine the first information.

[0082] In another implementation, determining the phase information includes processing multiple sets of measured phase values ​​to generate multiple sets of measured phase step values. Each corresponding set of phase step values ​​is calculated by determining corresponding pairs of measured phase values ​​within the corresponding set of measured phase values ​​and calculating the difference between the corresponding measured phase values ​​of each pair, and combining two or more sets of measured phase step values ​​to generate a first set of phase step values.

[0083] In another implementation, combining two or more sets of measurement phase step values ​​includes: determining a corresponding weighting factor for each measurement phase step value in the plurality of measurement phase step value sets, and using the corresponding weighting factor for each measurement phase step value to combine the plurality of measurement phase step value sets to determine a first phase step value set.

[0084] In another implementation, determining the corresponding weighting factor includes at least one of the following: determining amplitude information, determining slope information for each measured phase value, or determining dispersion information. Amplitude information indicates the amplitude of each corresponding RF received signal. Slope information indicates information about the difference between the corresponding measured phase value and its adjacent measured phase values, or indicates the derivative of a curve fitting the corresponding set of measured phase values. Dispersion information may indicate a dispersion measurement associated with the corresponding set of measured phase step values. The corresponding weighting factor is determined based on at least one of amplitude information, slope information, or dispersion information.

[0085] In another implementation, combining two or more sets of measured phase step values ​​to generate a first set of phase step values ​​includes: processing multiple sets of measured phase step values ​​to determine whether a measured phase step value is an outlier, and, if one or more outliers are identified, removing one or more measured phase step values ​​corresponding to one or more identified outliers from the respective sets of measured phase step values.

[0086] In another implementation, processing multiple sets of measured phase step values ​​to determine whether a measured phase step value is an outlier includes: processing the multiple sets of measured phase step values ​​by applying a statistical function to each set of measured phase step values ​​to generate statistical information, and using the statistical information to determine whether the corresponding measured phase step value is an outlier for each measured phase step value. The statistical information may include, for example, percentile information, such as 20-80 percentile information.

[0087] Another implementation includes comparing a first phase step value with a target phase step value to determine phase information, wherein the target phase step value is the difference between a pair of target phase values.

[0088] Another implementation includes at least one of the following actions: determining calibration information based on phase information and using the calibration information during operation of the RF device.

[0089] According to another example, an RF device includes: a transmit path configured to transmit an RF transmit signal via the transmit path; a phase shifter disposed in the transmit path and configured to apply a phase shift to the RF transmit signal according to a target phase value in a set of target phase values; and a plurality of receive paths configured to receive a plurality of RF receive signals, the plurality of RF receive signals including crosstalk from the respective RF transmit signal to the respective receive path. A plurality of mixers are disposed in the plurality of receive paths to down-convert the plurality of RF receive signals into a plurality of down-converted receive signals. A controller is configured to control the phase shifter to apply each target phase value in the set of target phase values, and measurement circuitry is configured to generate a plurality of sets of measurement values ​​based on the plurality of down-converted receive signals, wherein each set of the plurality of measurement value sets is associated with a respective receive path in the plurality of receive paths, and each measurement value within a set of measurement values ​​is associated with a respective target phase value applied by the phase shifter. The RF device also includes a processor configured to process the plurality of measurement value sets and determine phase information indicating a phase error of the phase shifter based on the plurality of measurement value sets.

[0090] In one implementation of an RF device, the transmit path is configured to generate an RF transmit signal as a continuous wave RF signal with a fixed frequency, and / or the controller is configured to control a phase shifter to apply each target phase value. , where N is a number equal to or greater than 4, and n is a number from 1 to N.

[0091] In another implementation, the measurement circuit is configured to determine the corresponding DC value of the down-converted received signal as the corresponding measurement value for each of the multiple receiving paths.

[0092] In another implementation, the processor is configured to process multiple sets of measurements to compute multiple sets of measurement phase values.

[0093] In another implementation, the processor is configured to process each set of measurements to determine first information indicating the amplitude A and offset B of a corresponding sine curve that matches the respective set of measurements, and the processor is also configured to process the set of measurements to generate multiple sets of measured phase values. In one example, processing the set of measurements may include applying the function arcsin((M(m) - B) / A) to each corresponding measurement M(m).

[0094] In another implementation, the processor is configured to process each set of measurements to determine first information by at least one of the following actions: performing a Fourier transform on the set of measurements to determine the first information, or fitting a sine curve to determine the first information.

[0095] In another implementation, the processor is configured to process multiple sets of measured phase values ​​to generate a corresponding set of measured phase step values ​​from multiple sets of measured phase step values ​​for each receive path. The processor is configured to generate a corresponding set of phase step values ​​based on determining corresponding pairs of measured phase values ​​and calculating the difference between the corresponding measured phase values ​​of each pair, and to combine two or more sets of measured phase step values ​​to generate a first set of phase step values.

[0096] In another implementation, the processor is configured to determine a first phase step value by determining a corresponding weighting factor for each of a plurality of measured phase step value sets and using the corresponding weighting factor for each measured phase step value to combine two or more sets of a plurality of measured phase step value sets.

[0097] In another implementation of the RF according to the second aspect, the processor is configured to determine at least one of the following: amplitude information, slope information, or dispersion information. The amplitude information may indicate the amplitude of each corresponding RF received signal; the slope information indicates the difference between a corresponding measured phase value and an adjacent measured phase value for each measured phase value, or may indicate the derivative of a curve fitting the corresponding set of measured phase values; and the dispersion information may indicate a dispersion measurement associated with the corresponding set of measured phase step values. The processor is also configured to determine a weighting factor based on at least one of the amplitude information, slope information, or dispersion information.

[0098] In another implementation, the processor is configured to process multiple sets of measured phase step values ​​to determine whether a measured phase step value is an outlier, and, if one or more outliers are identified, remove one or more measured phase step values ​​corresponding to one or more identified outliers from the corresponding set of measured phase step values.

[0099] In another implementation, the processor is configured to process multiple sets of measured phase step values ​​by applying a statistical function to each set of measured phase step values ​​in order to generate statistical information, and to apply the statistical information to determine whether the corresponding measured phase step value is an outlier for each measured phase step value.

[0100] In another implementation, the RF device is also configured to determine calibration information based on phase information and use the calibration information during operation of the RF device, and / or monitor the phase information during operation of the RF device.

[0101] Although specific examples have been shown and described herein, those skilled in the art will understand that various substitutions and / or equivalent implementations can be made to the specific examples shown and described without departing from the scope of the invention. This application is intended to cover any modifications or variations of the specific examples discussed herein. Therefore, the invention is defined only by the claims and their equivalents.

[0102] In another implementation of the method according to the second aspect, the processor is configured to process each set of measurements to determine first information by at least one of the following processing actions: performing a Fourier transform on the set of measurements to determine the first information, or fitting a sine curve to determine the first information.

[0103] It should be noted that the methods and apparatuses, including those with preferred embodiments outlined in this document, can be used alone or in combination with other methods and apparatuses disclosed in this document. Furthermore, features outlined in the context of the apparatus also apply to the corresponding methods, and vice versa. Moreover, all aspects of the methods and apparatuses outlined in this document can be combined arbitrarily. In particular, the features of the claims can be combined with each other in any manner.

[0104] It should be noted that the specification and drawings merely illustrate the principles of the proposed methods and systems. Those skilled in the art will be able to implement various arrangements that, while not explicitly described or shown herein, embody the principles, invention, and are included within their spirit and scope. Furthermore, all examples and embodiments outlined in this document are primarily intended for illustrative purposes only to aid the reader in understanding the principles of the proposed methods and systems. Moreover, all statements regarding the principles, aspects, and embodiments of the invention provided herein, as well as specific examples thereof, are intended to cover their equivalents.

Claims

1. A method for determining phase information indicating the phase error of a phase shifter in the transmit path of an RF device, the method comprising: A phase shifter controlling the transmission path applies a phase shift based on a target phase value from a set of target phase values, in order to generate an RF transmission signal associated with the target phase value. The RF signal is transmitted via the transmission path. Multiple RF received signals are received in multiple receiving paths, each of which is associated with a corresponding receiving path and includes crosstalk from the corresponding RF transmitted signal to the corresponding receiving path. The multiple RF received signals are down-converted to generate multiple down-converted received signals. In each of the plurality of receiving paths, the corresponding down-converted received signal associated with the respective receiving path is processed to generate a measurement value associated with the target phase value applied by the phase shifter for each receiving path. Multiple sets of measurement values ​​are generated, each set of which is associated with a corresponding receiver path among the multiple receiver paths. These multiple sets of measurement values ​​are generated by repeating the control of the phase shifter, the transmission of the RF transmitted signal, the down-conversion, and the processing in each receiver path, so as to generate a corresponding measurement value in the corresponding set of measurement values ​​for each target phase value in the target phase value set in each corresponding receiver path. The phase information is determined by processing the multiple sets of measurements.

2. The method according to claim 1, wherein the RF transmitted signal is a continuous wave RF signal with a fixed frequency, and / or the target phase value set includes each phase value. , where N is a number equal to or greater than 4, and n is a number from 1 to N.

3. The method according to any one of claims 1-2, wherein, The processing in each of the plurality of receiving paths includes: For each of the plurality of receiving paths, the corresponding DC value of the down-converted received signal is determined as a corresponding measurement value associated with the corresponding target phase value applied by the phase shifter.

4. The method according to any one of claims 1-3, wherein, Determining the phase information includes: The plurality of measurement value sets are processed to calculate a plurality of measurement phase value sets, wherein each measurement phase value set is associated with one of the plurality of receiving paths, and wherein each measurement phase value within the corresponding measurement phase value set is associated with a corresponding measurement value and indicates a measurement phase value of crosstalk in the corresponding receiving path.

5. The method according to claim 4, wherein, Determining the phase information includes: Each set of measurements is processed to determine first information, which indicates the amplitude A and offset B of a corresponding sine curve that matches the corresponding set of measurements. The corresponding set of measurements is processed to generate the plurality of sets of measurement phase values.

6. The method of claim 5, wherein processing each set of measurements to determine the first information includes at least one of the following actions: Perform a Fourier transform on the set of measurements to determine the first information, or A sine curve is fitted to determine the first information.

7. The method according to any one of claims 4-6, wherein, Determining the phase information includes: The plurality of measured phase value sets are processed to generate a plurality of measured phase step value sets, wherein each corresponding phase step value set is calculated by determining corresponding measured phase value pairs within the corresponding measured phase value set and calculating the difference between the corresponding measured phase values ​​in each pair. Two or more sets from the measured phase step value set are combined to generate a first phase step value set.

8. The method of claim 7, wherein combining two or more sets from the set of measured phase step values ​​comprises: For each measured phase step value in the plurality of measured phase step value sets, a corresponding weighting factor is determined. The plurality of measured phase step value sets are combined using the corresponding weighting factor for each measured phase step value to determine the first phase step value set.

9. The method according to claim 8, wherein, Determining the appropriate weighting factor includes at least one of the following: Determine the amplitude information indicating the amplitude of each corresponding RF received signal. Determine slope information, wherein the slope information indicates information about the difference between a corresponding measured phase value and its adjacent measured phase values, or indicates the derivative of a curve fitting the corresponding set of measured phase values, and determine the corresponding weighting factor based on the slope information. Determine dispersion information indicating the dispersion measure associated with the corresponding set of measured phase step values, and determine the weighting factor based on the dispersion information. The corresponding weighting factor is determined based on at least one of the amplitude information, the slope information, or the dispersion information.

10. The method of claim 7, wherein, Combining two or more sets from the measured phase step value set to generate a first phase step value set includes: The multiple sets of measured phase step values ​​are processed to determine whether the measured phase step value is an outlier, and If one or more outliers are identified, remove one or more measurement phase step values ​​corresponding to the identified one or more outliers from the corresponding set of measurement phase step values.

11. The method of claim 10, wherein, Processing the multiple sets of measured phase step values ​​to determine whether the measured phase step value is an outlier includes: The plurality of measured phase step value sets are processed by applying a statistical function to each set of measured phase step values ​​to generate statistical information, and The statistical information is used to determine whether each measured phase step value is an outlier.

12. The method according to any one of claims 5-11, further comprising: The first phase step value is compared with the target phase step value to determine the phase information, wherein the target phase step value is the difference between a pair of target phase values.

13. The method according to any one of claims 1-12, further comprising at least one of the following actions: Determine calibration information based on the phase information, and use the calibration information during operation of the RF device, or The phase information is monitored during the operation of the RF device.

14. An RF device, comprising: The transmission path is configured to transmit RF signals via the transmission path; A phase shifter is arranged in the transmission path and configured to apply a phase shift to the RF transmitted signal according to a target phase value in a set of target phase values. Multiple receiving paths are configured to receive multiple RF received signals, the multiple RF received signals including crosstalk in the respective RF transmitted signals to the respective receiving paths. Multiple mixers are arranged in the multiple receive paths to down-convert the multiple RF received signals into multiple down-converted receive signals. The controller is configured to control the phase shifter to apply each target phase value from the set of target phase values. A measurement circuit is configured to generate multiple sets of measurement values ​​based on the plurality of down-converted received signals, wherein each set of the plurality of measurement value sets is associated with a corresponding receiving path among the plurality of receiving paths, and each measurement value within a measurement value set is associated with a corresponding target phase value applied by the phase shifter. The processor is configured to process the plurality of measurement sets and determine phase information indicating the phase error of the phase shifter based on the plurality of measurement sets.

15. The RF device according to claim 14, wherein, The transmission path is configured to generate the RF transmission signal as a continuous wave RF signal with a fixed frequency, and / or the controller is configured to control the phase shifter to apply each target phase value. , where N is a number equal to or greater than 4, and n is a number from 1 to N.

16. The RF device according to claim 14 or 15, wherein, The measurement circuit is configured to determine the corresponding DC value of the down-converted received signal as a corresponding measurement value for each of the plurality of receiving paths.

17. The RF device according to any one of claims 14-16, wherein the processor is configured to process the plurality of measurement sets to calculate a plurality of measurement phase value sets, wherein each measurement phase value set is associated with one of the plurality of receive paths, and wherein each measurement phase value indicates a measurement transmit phase value corresponding to the respective measurement value.

18. The RF device of claim 17, wherein the processor is configured to process each set of measurements to determine first information, the first information indicating the amplitude A and offset B of a corresponding sine curve matching the corresponding set of measurements, and wherein the processor is further configured to process the set of measurements to generate the plurality of sets of measured phase values.

19. The RF device according to claim 18, wherein, The processor is configured to process each set of measurements by at least one of the following processing actions to determine the first information: Perform a Fourier transform on the set of measurements to determine the first information, or A sine curve is fitted to determine the first information.

20. The RF device according to any one of claims 17-19, wherein, The processor is configured to process the plurality of measurement phase value sets to generate a corresponding measurement phase step value set from the plurality of measurement phase step value sets for each receiving path, wherein the processor is configured to generate the corresponding phase step value set based on determining corresponding measurement phase value pairs and calculating the difference between the corresponding measurement phase values ​​in each pair, and The processor is configured to combine two or more sets of the measured phase step values ​​to generate a first set of phase step values.

21. The RF device of claim 20, wherein the processor is configured to determine a corresponding weighting factor for each of the plurality of measured phase step value sets, and to combine the plurality of measured phase step value sets using the corresponding weighting factor for each measured phase step value to determine the first phase step value.

22. The RF device of claim 21, wherein the processor is configured to determine at least one of the following: Amplitude information indicating the amplitude of each corresponding RF received signal. For each measured phase value, the slope information indicates the difference between the corresponding measured phase value and its adjacent measured phase value, or indicates the derivative of the curve fitting the corresponding set of measured phase values. Dispersion information indicating the dispersion measure associated with the corresponding set of measured phase step values. Furthermore, the processor is configured to determine the weighting factor based on at least one of the amplitude information, the slope information, or the dispersion information.

23. The RF device of claim 20, wherein the processor is configured to: The multiple sets of measured phase step values ​​are processed to determine whether the measured phase step value is an outlier, and If one or more outliers are identified, remove one or more measurement phase step values ​​corresponding to the identified one or more outliers from the corresponding set of measurement phase step values.

24. The RF device of claim 23, wherein the processor is configured to: The multiple sets of measured phase step values ​​are processed by applying a statistical function to each set of measured phase step values ​​in order to generate statistical information, and The statistical information is used to determine whether each measured phase step value is an outlier.

25. The RF device according to any one of claims 14-24, further configured to determine calibration information based on the phase information, and to use the calibration information during operation of the RF device, and / or to monitor the phase information during operation of the RF device.

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