Measuring instrument and measuring method for measuring radio frequency signal
By introducing independent measurement and trigger paths in the RF signal measurement instrument, the problem of power triggering being unrelated to bandwidth is solved, and a simplified device and low-cost broadband SEM measurement are achieved.
Patent Information
- Application Number
- CN202411669269.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-03-14
- Filing Date
- 2024-11-21
- Publication Date
- 2025-09-16
AI Technical Summary
When existing RF signal measuring instruments perform broadband SEM measurements, power triggering is unrelated to the bandwidth of the measuring instrument, resulting in complex measurement devices and increased costs.
A measuring instrument is provided, comprising an independent measurement path and a trigger path, wherein the trigger path is used to detect signals outside the bandwidth of the measurement path to ensure that the measurement starts at an appropriate time.
The measurement setup is simplified, costs are reduced, and out-of-band emissions in adjacent frequency bands can be effectively detected, enabling efficient execution of broadband SEM measurements.
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Figure CN120658323A_ABST
Abstract
Description
Technical Field
[0001] Embodiments of the present disclosure generally relate to a measuring instrument for measuring radio frequency signals.Embodiments of the present disclosure also relate to a measuring method. Background Art
[0002] Measuring instruments, also known as test instruments, are known in the art for performing measurements on radio frequency (RF) signals. For example, spectrum emission mask (SEM) measurements are performed, which measure out-of-band emissions in frequency bands adjacent to a specific carrier. In other measurements known in the art, such as adjacent channel power (ACP) measurements, these emissions may remain undetected when measuring the integrated power in the frequency band of the corresponding carrier. SEM measurements utilize a configurable spectrum mask or limit to measure the margin of the emission level relative to the limit.
[0003] When testing modern communications equipment, it may be necessary to perform wideband SEM measurements on gated signals with a power trigger, such as those for WLAN 802.11ax or similar standards. However, the power trigger will not trigger at the start of the SEM measurement because the power trigger is not linked to the bandwidth of the power detector used by the measurement instrument to perform the measurement.
[0004] In order to overcome this problem, a complicated measuring device is required, which requires great effort in setting up the corresponding measuring device, and thus, the cost associated with the measurement increases.
[0005] Therefore, the aim is to provide a simple and cost-effective possibility to perform these measurements. Summary of the Invention
[0006] The following summary of the disclosure is intended to introduce various concepts in a simplified form that are further described in the detailed description provided below. This summary is neither intended to represent essential features of the disclosure nor should this summary be used as an aid in determining the scope of the claimed subject matter.
[0007] Embodiments of the present disclosure provide a measuring instrument for measuring radio frequency signals. The measuring instrument is configured to analyze received radio frequency signals. The measuring instrument includes a measurement path configured to analyze radio frequency signals at a measurement frequency within a measurement bandwidth. The measuring instrument also includes a trigger path configured to detect signals at a trigger frequency within the trigger bandwidth. The trigger path is configured to trigger on the measurement path within a trigger bandwidth outside the measurement bandwidth of the measurement path.
[0008] The embodiment of the present disclosure also provides a measurement method, which includes the following steps:
[0009] - providing a measuring instrument for measuring a radio frequency signal, wherein the measuring instrument comprises a measurement path configured to analyze the radio frequency signal at a measurement frequency in a measurement bandwidth, wherein the measuring instrument further comprises a trigger path configured to trigger signal detection at a trigger frequency in the bandwidth;
[0010] - being triggered by the trigger path on the measurement path in a trigger bandwidth outside the measurement bandwidth of the measurement path; and
[0011] - Performing radio frequency measurements at a measurement frequency in a measurement bandwidth via the measurement path.
[0012] The key idea is to provide two separate and independent paths for enabling triggering outside the evaluation range (i.e., outside the measurement bandwidth of the measurement path). Thus, one path is used for measurement, the measurement path, and one path is used for triggering, the trigger path. Signal detection via the trigger path triggers measurement via the measurement path. Therefore, triggering can occur at the start of the corresponding measurement, as the trigger is independent of the measurement path, particularly with regard to bandwidth. In other words, a measurement in a specific frequency band can be triggered by a signal in a completely different frequency band, ensuring that the measurement starts at the appropriate time. This allows the frequency range of triggering to be extended.
[0013] One aspect provides that the measurement frequency and the trigger frequency can be independently set to different values. Alternatively or additionally, the measurement bandwidth and the trigger bandwidth can be independently set to different values. In a specific operating mode, the measurement frequency and the trigger frequency are independently set to different values. Alternatively or additionally, in a specific operating mode, the measurement bandwidth and the trigger bandwidth are independently set to different values. Thus, the user can manually set the corresponding frequency / bandwidth. Alternatively, the frequency / bandwidth can be automatically set with the help of an executed test routine. Depending on the specific application scenario, it may be necessary to trigger the measurement by a signal in a frequency band directly adjacent to the frequency band to be evaluated. However, in other application scenarios, the triggering should be performed in a frequency band located away from the frequency band to be evaluated.
[0014] Another aspect provides that the trigger path is configured to provide a power trigger. Thus, the power of the signal processed by the trigger path is detected, so that triggering occurs on the measurement path if the detected power reaches or exceeds a trigger level associated with the trigger path.
[0015] According to a specific embodiment, the trigger frequency is outside the bandwidth of a power detector located in the measurement path. The power detector is associated with the measurement path. The bandwidth of the power detector can be quite small relative to the trigger frequency used by the trigger path. In fact, the difference between the trigger frequency (f1) and the measurement frequency (f2) can be smaller than the bandwidth (BW) of the power detector. In other words, the frequency difference between the trigger signal (i.e., the trigger frequency) and the evaluation range (the measurement bandwidth) can be wider than the analysis bandwidth of the measuring instrument (i.e., the bandwidth of the power detector). Because the trigger path and, therefore, the trigger frequency, are independent of the measurement path and the measurement frequency, it is still possible to capture the RF signal with the aid of the measurement path.
[0016] Furthermore, the measuring instrument can be configured so that the trigger bandwidth of the trigger path can be set to a value smaller than the measurement bandwidth of the measurement path. In certain operating modes, the trigger bandwidth of the trigger path is set to a value smaller than the measurement bandwidth of the measurement path. Therefore, narrowband triggering can be applied. In other words, the trigger path bandwidth can be very small to achieve narrowband observation triggering. This correspondingly improves the dynamic range of power detection.
[0017] The measurement path and trigger path can be located within a single housing of the measuring instrument. This provides a single device containing two independent paths (i.e., the measurement path and the trigger path). In other words, neither the measurement path nor the trigger path is external, as both paths are internal to the same measuring instrument. This effectively provides a simplified measurement device.
[0018] On the other hand, separate RF downconverters are provided for the measurement path and the trigger path, respectively. This allows for different (center) frequencies to be set for the measurement path and the trigger path, respectively. The RF downconverters specifically include mixers connected to corresponding local oscillators, which receive local oscillator signals from the local oscillators to downconvert the RF signals.
[0019] Furthermore, the measuring instrument can include separate bandwidth filters for the measurement path and trigger path. This allows different bandwidths to be implemented for the measurement path and trigger path, respectively. The corresponding bandwidth filters can be adjustable, allowing the bandwidth to be adjusted.
[0020] Furthermore, the measuring instrument can include separate analog-to-digital converters for the measurement path and trigger path, respectively. Thus, the digitization of the signals processed by the measurement path and the trigger path can be performed separately from each other. In practice, different analog-to-digital converters suitable for the respective applications can be used, depending on the different requirements for the measurement and trigger paths.
[0021] In particular, the radio frequency downconverter, the resolution bandwidth filter and / or the analog-to-digital converter are also located in the same housing of the measuring instrument, for example in a single device.
[0022] According to one embodiment, the measuring instrument has a splitter that connects the measurement path and the trigger path to a common radio frequency input of the measuring instrument. The common radio frequency input can be provided at the front end of the measuring instrument so that a single radio frequency signal is input, which is split and forwarded independently of each other to the measurement path and the trigger path for further processing.
[0023] According to another embodiment, a measuring instrument has at least two separate RF inputs, one for a measurement path and one for a trigger path. A first of the at least two separate RF inputs is connected to the trigger path, while a second of the at least two separate RF inputs is connected to the measurement path. Thus, the first RF input can be referred to as a trigger input, while the second RF input can be referred to as a measurement input. Both RF inputs can be located on the front end of the measuring instrument.
[0024] The measuring instrument may be a signal analyzer or a spectrum analyzer. Accordingly, corresponding triggering operations by means of the independent paths may be provided in the signal analyzer or the spectrum analyzer.
[0025] Typically, the measurement frequency can be a sweeping frequency within a specified frequency range within the measurement bandwidth. Thus, performing RF measurements can include sweeping the measurement frequency within the specified frequency range within the measurement bandwidth. The specified frequency range can be defined as a range from a start frequency to a stop frequency, or as a span around a center frequency. Thus, measurements can be performed within the specified frequency range even if the measurement is triggered by a trigger frequency outside the specified frequency range.
[0026] Measuring instruments and methods often allow for real-time measurements. Therefore, the respective real-time bandwidths of the paths, or more precisely, the channels, must be taken into account: the real-time bandwidth of the measurement path / channel and the real-time bandwidth of the trigger path / channel. The real-time bandwidth can be narrower, so that the trigger bandwidth lies outside the measurement bandwidth, e.g., the trigger frequency lies outside the measurement frequency.
[0027] The RF measurement can be a spectrum emission mask (SEM) measurement. The method and measurement instrument described above enable wideband SEM measurements of gated signals with a power trigger. The extended frequency range of the power trigger ensures that the power trigger is triggered at the start of the SEM measurement.
[0028] In particular, the measurement frequency can be swept across the frequency range of the spectrum emission mask, with the trigger frequency being fixed. The measurement frequency can be swept across a specific frequency range, allowing detection of out-of-band emissions in adjacent frequency bands. Separate and independent trigger paths ensure timely start of SEM measurements.
[0029] RF measurements can be spurious emission measurements. Similarly, spurious emissions can be detected, ensuring that the measurement starts at the appropriate time thanks to the extended frequency range used for power triggering. Indeed, thanks to the extended frequency range used for triggering, emissions caused by unwanted transmitter effects can be reliably detected. Signals radiated outside of a transmitter's assigned channel are an example of spurious emissions.
[0030] RF measurements can also include harmonic distortion measurements. Harmonic distortion can also be detected, whereby the extended frequency range for power triggering ensures that the measurement starts at the appropriate time.
[0031] Regarding the advantages and other characteristics of electronic equipment, please refer to the explanations given above regarding test instruments and methods, which also apply to electronic equipment and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The foregoing aspects of the claimed subject matter and many of the attendant advantages will become more readily understood and better appreciated by reference to the following detailed description when taken in conjunction with the accompanying drawings, in which:
[0033] - Figure 1 schematically shows a measuring instrument according to a first embodiment of the present disclosure, and
[0034] - Figure 2 A measuring instrument according to a second embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION
[0035] The detailed description set forth below in conjunction with the accompanying drawings, in which like numerals refer to like elements, is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed.
[0036] For purposes of this disclosure, the phrase "at least one of A, B, and C" means, for example, (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C), including all further possible permutations when more than three elements are listed. In other words, the term "at least one of A and B" generally means "A and / or B," i.e., "A" alone, "B" alone, or "A and B."
[0037] Figure 1 A measuring instrument 10 for measuring radio frequency signals is schematically shown.
[0038] The measuring instrument 10 has a housing 12 with a front end 14 at which a single radio frequency input 16 is provided for receiving a radio frequency signal to be measured.
[0039] A single RF input 16 is connected to a splitter 18 enclosed by the housing 12 .
[0040] The splitter 18 is connected to a measurement path 20 and a trigger path 22. The measurement path 20 is configured for analyzing radio frequency signals received at a measurement frequency within a measurement bandwidth, while the trigger path 22 is configured for signal detection at a trigger frequency within a trigger bandwidth.
[0041] In practice, both the measurement path 20 and the trigger path 22 comprise radio frequency downconverters 24, 26 having mixers 28, 30. Each mixer 28, 30 receives a local oscillator signal from a corresponding local oscillator 32, 34, so that the radio frequency signal received via the input 16 is downconverted accordingly.
[0042] Optionally, filters 36 and 38 are respectively provided in the measurement path 20 and the trigger path 22, as shown in FIG. Figure 1 Indicated by the dotted line in .
[0043] Furthermore, both the measurement path 20 and the trigger path 22 include analog-to-digital converters (ADCs) 40 , 42 , which digitize the (down-converted) signals processed by the measurement path 20 and the trigger path 22 , respectively.
[0044] The various components, namely the RF downconverters 24, 26, the mixers 28, 30, the local oscillators 32, 34, the filters 36, 38 and the analog-to-digital converters 40, 42, are located within the housing 12 of the measuring instrument. Figure 1 Furthermore, these components are independent of each other.
[0045] This ensures different bandwidths and / or different center frequencies for the signals processed in the measurement path 20 and the trigger path 22 , respectively.
[0046] In practice, the above-mentioned components may be set by a user, for example via a user interface 44 of the measuring instrument 10 .
[0047] The two paths, namely the measurement path 20 and the trigger path 22, are further distinguished from each other by their purpose, as described above. In fact, the trigger path 22 comprises a trigger circuit 46 for triggering the measurement path 20, namely the measurement performed by the measurement circuit 48.
[0048] The trigger circuit 46 itself may also be power-triggered, such that a trigger event is detected if the power level of the signal processed in the trigger path 22 reaches or exceeds a certain level (ie, a trigger level).
[0049] Because different bandwidths and / or different center frequencies can be set for the measurement path 20 and the trigger path 22, the measuring instrument 10 generally ensures that the trigger path 22 is configured to trigger on the measurement path 20 within a trigger bandwidth that is outside the measurement bandwidth of the measurement path 20. In other words, the trigger path 22 can be associated with a specific frequency band, while the measurement path 20 is associated with a different frequency band, which can be ensured by different bandwidths and / or different center frequencies.
[0050] Therefore, a trigger event in a specific frequency band analyzed by trigger path 22 triggers measurement in measurement path 20 on a different frequency band. Therefore, since trigger path 22 and measurement path 20 are independent of each other, the frequency range of the trigger can be extended accordingly.
[0051] As described above, the various components associated with the measurement path 20 and the trigger path 22 are independent of each other. Therefore, the measurement frequency and the trigger frequency and / or the measurement bandwidth and the trigger bandwidth can be independently set to different values.
[0052] In practice, the power measurement can be triggered by the trigger path 22, in particular the trigger circuit 46. The power measurement can be accomplished with the aid of a power detector 50 associated with the measurement path 20. The power detector 50 also has a bandwidth that can limit the performance of the measuring instrument 10. Since the trigger path 22 is independent of the measurement path 20, and therefore independent of the power detector 50 located in the measurement path 20, the trigger frequency can be outside the bandwidth of the power detector 50.
[0053] Typically, the trigger bandwidth of trigger path 22 can be set to a value that is smaller than the measurement bandwidth of measurement path 20, for example by means of filters 36, 38. In other words, a narrowband bandpass filter can be used in trigger path 22, so that trigger path 22, or more precisely the trigger channel, is relatively narrow compared to measurement path 20, or more precisely the measurement channel.
[0054] The measuring instrument 10 further comprises a detection circuit 52 which is connected to the measuring circuit 48 , so that the measurement signal is detected by means of the detection circuit 52 , in particular for further processing.
[0055] exist Figure 2 In, another embodiment is shown, with Figure 1 The embodiment shown differs in that two RF inputs 16 are provided at the front end 14, which are directly connected to the measurement path 20 and the trigger path 22, respectively. Therefore, the splitter 18 is no longer provided, since the first RF input 16 is directly connected to the measurement path 20, while the second RF input 16 is directly connected to the trigger path 22. Thus, the first RF input 16 may be associated with the measurement input, while the second RF input 16 may be associated with the trigger input.
[0056] Due to the different RF input 16, the trigger path 22 may receive a different RF signal than the RF signal forwarded to the measurement path 20. Thus, this embodiment of the measuring instrument may apply different trigger conditions.
[0057] Typically, the measuring instrument 10 may be a signal analyzer or a spectrum analyzer. Accordingly, the corresponding measurements performed by the measuring instrument 10 may be spectrum emission mask measurements, spurious emission measurements, and / or harmonic distortion measurements.
[0058] In particular, the measurement frequency can be swept within the frequency range of the spectrum emission mask. In other words, when performing RF measurements, the measurement frequency is swept within a specified frequency range within the measurement bandwidth. However, the trigger frequency can be fixed during the corresponding measurement. In practice, the trigger frequency can be in a different frequency band than the measurement frequency, i.e., the frequency range within which the measurement frequency is swept.
[0059] In any case, measuring instrument 10 is capable of performing RF signal measurements. In effect, trigger path 22 triggers on measurement path 20 within a trigger bandwidth that is outside the measurement bandwidth of measurement path 20. This enables measurement path 20 to perform RF measurements at a measurement frequency within the measurement bandwidth. As described above, this ensures that measurements can be performed over a frequency range different from the frequency range used for triggering.
[0060] Certain embodiments disclosed herein, particularly corresponding module(s) and / or unit(s), utilize circuitry (e.g., one or more circuits) to implement the standards, protocols, methods, or techniques disclosed herein, operatively couple two or more components, generate information, process information, analyze information, generate signals, encode / decode signals, convert signals, transmit and / or receive signals, control other devices, etc. Any type of circuitry may be used.
[0061] In an embodiment, the circuit system includes, among other things, one or more computing devices such as a processor (e.g., a microprocessor), a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a system on a chip (SoC), or the like, or any combination thereof; and may include discrete digital or analog circuit elements or electronic devices, or a combination thereof. In an embodiment, the circuit system includes a hardware circuit implementation (e.g., an implementation in an analog circuit system, an implementation in a digital circuit system, and the like, and a combination thereof).
[0062] In an embodiment, the circuit system includes a combination of circuits and a computer program product having software or firmware instructions stored on one or more computer-readable memories, the instructions working together to cause the device to perform one or more protocols, methods, or techniques described herein. In an embodiment, the circuit system includes circuits that require software, firmware, and the like to operate, such as, for example, a microprocessor or portion of a microprocessor. In an embodiment, the circuit system includes one or more processors or portions thereof, and accompanying software, firmware, hardware, and the like.
[0063] This application may refer to quantities and numbers. Unless otherwise specified, such quantities and numbers should not be considered as limiting, but rather examples of possible quantities or numbers associated with this application. In addition, in this regard, this application may use the term "plurality" to refer to a quantity or number. In this regard, the term "plurality" means any number greater than one, for example, two, three, four, five, etc. The terms "approximately," "approximately," "close to," etc., mean plus or minus 5% of a specified value.
Claims
1. A measuring instrument for measuring radio frequency signals, wherein: The measuring instrument is configured to analyze a received radio frequency signal, wherein the measuring instrument includes a measurement path configured to analyze the radio frequency signal at a measurement frequency in a measurement bandwidth, wherein the measuring instrument further includes a trigger path configured for signal detection at a trigger frequency in a trigger bandwidth, and wherein the trigger path is configured to trigger on the measurement path in the trigger bandwidth outside the measurement bandwidth of the measurement path.
2. The measuring instrument according to claim 1, wherein The measurement frequency and the trigger frequency and / or the measurement bandwidth and the trigger bandwidth can be independently set to different values.
3. The measuring instrument according to claim 1, wherein The trigger path is configured to provide a power trigger.
4. The measuring instrument according to claim 1, wherein The trigger frequency is outside the bandwidth of a power detector located in the measurement path.
5. The measuring instrument according to claim 1, wherein The measuring instrument is configured such that a trigger bandwidth of the trigger path can be set to a value smaller than a measurement bandwidth of the measurement path.
6. The measuring instrument according to claim 1, wherein The measurement path and the trigger path are located within a single housing of the measuring instrument.
7. The measuring instrument of claim 1, comprising independent radio frequency downconverters for the measurement path and the trigger path, respectively.
8. The measuring instrument of claim 1, comprising independent bandwidth filters for the measurement path and the trigger path, respectively.
9. The measuring instrument of claim 1, comprising separate analog-to-digital converters for the measurement path and the trigger path, respectively.
10. The measuring instrument of claim 1, comprising a splitter connecting the measurement path and the trigger path to a common radio frequency input of the measuring instrument.
11. The measuring instrument of claim 1, comprising at least two separate radio frequency inputs for the measurement path and the trigger path, respectively.
12. The measuring instrument according to claim 1, wherein The measuring instrument is a signal analyzer or a spectrum analyzer.
13. A measurement method comprising: - providing a measuring instrument for measuring a radio frequency signal, wherein the measuring instrument comprises a measurement path configured to analyze the radio frequency signal at a measurement frequency within a measurement bandwidth, wherein the measuring instrument further comprises a trigger path configured to trigger signal detection at a trigger frequency within the bandwidth; - triggering on the measuring path via the trigger path in the trigger bandwidth outside the measuring bandwidth of the measuring path; and - performing radio frequency measurements at a measurement frequency in the measurement bandwidth via the measurement path.
14. The method according to claim 13, wherein Performing the radio frequency measurement includes scanning the measurement frequency within a specified frequency range in the measurement bandwidth.
15. The method according to claim 14, wherein The measurement frequency and the trigger frequency and / or the measurement bandwidth and the trigger bandwidth can be independently set to different values.
16. The method according to claim 13, wherein: The radio frequency measurements are spectrum emission mask measurements.
17. The method according to claim 16, wherein The measurement frequency is swept within a frequency range of a spectrum emission mask, and wherein the trigger frequency is fixed.
18. The method according to claim 13, wherein The radio frequency measurement is a spurious emission measurement.
19. The method according to claim 13, wherein The radio frequency measurement is a harmonic distortion measurement.