Spectrum analyzer

Abstract

A spectrometer relates to the technical field of measurement. The spectrum analyzer comprises a frequency conversion circuit, a switch module, a link self-checking module and a data processing module. And the frequency conversion circuit is used for mixing the to-be-detected signal with the local oscillator signal to realize frequency conversion processing, and outputting the to-be-detected signal after frequency conversion. Any two frequency conversion circuits are selected from the frequency conversion circuits, and each switch module is connected between the input end of the selected frequency conversion circuit and the output end of the preceding-stage frequency conversion circuit and is used for selectively inputting the to-be-detected signal and the self-detection signal output by the preceding-stage frequency conversion circuit into the selected frequency conversion circuit. The link self-checking module is connected with the self-checking signal input end of each switch module, and selectively inputs a self-checking signal on the corresponding switch module. The data processing module is connected to the output end of the last frequency conversion circuit; and the fault detection module is used for judging the voltage value output by the last frequency conversion circuit when the self-checking signal is input to the corresponding switch module, and performing fault detection on the frequency conversion circuit according to the voltage value.

Description

Technical Field

[0001] The present invention relates to the field of measurement technology, and in particular to a spectrum analyzer. Background Art

[0002] With the rapid development of modern science and technology, spectrum analyzers, as an important test and measurement instrument, have been continuously improving in technology, and their circuit design and functions have become increasingly complex. This complexity has made the application scope of spectrum analyzers more extensive, covering multiple fields such as communications, electronic equipment manufacturing, scientific research, and national defense. In these fields, spectrum analyzers not only play a core role in spectrum analysis, but their reliability and measurement accuracy have also become crucial. However, the current spectrum analyzers still have major defects in reliability and self-test functions, which not only affects the user's test efficiency, but also increases the risk of use to a certain extent.

[0003] Existing spectrum analyzers usually lack effective self-checking methods and cannot promptly and accurately determine whether their working status is normal. This means that when there is a problem with the internal circuit or key components of the spectrum analyzer, the user may not be able to detect it immediately. If the spectrum analyzer continues to be used in a faulty state, it will often lead to inaccurate test data and even mislead users to make wrong judgments and decisions, resulting in potential economic losses or technical errors.

[0004] In addition, the lack of effective self-diagnosis methods in spectrum analyzers also brings additional challenges to maintenance and repair work. For maintenance personnel, when a spectrum analyzer fails, since the equipment does not provide automatic diagnosis function, fault location often needs to rely on manual detection, which greatly increases the complexity of troubleshooting and repairing problems. Summary of the invention

[0005] The main technical problem solved by the present invention is to provide a spectrum analyzer with a self-checking function.

[0006] According to the first aspect, an embodiment provides a spectrum analyzer, including: N frequency conversion circuits connected in sequence, used to convert the signal to be detected by mixing it with the local oscillator signal, and output the signal to be detected after the frequency conversion, wherein N is greater than or equal to 2; At least two switch modules, The first switch module is connected between the first frequency conversion circuit and the signal input terminal of the spectrum analyzer, and is used to input the signal to be detected or the self-test signal into the first frequency conversion circuit; any one frequency conversion circuit is selected from the frequency conversion circuits, and the second switch module is connected between the input terminal of the selected frequency conversion circuit and the output terminal of the previous frequency conversion circuit, and is used to selectively input the signal to be detected and the self-test signal output by the previous frequency conversion circuit into the selected frequency conversion circuit; or, Any two frequency conversion circuits are selected from each frequency conversion circuit, and each switch module is respectively connected between the input end of the selected frequency conversion circuit and the output end of the previous frequency conversion circuit, and is used to selectively input the to-be-detected signal and the self-test signal output by the previous frequency conversion circuit into the selected frequency conversion circuit; A link self-check module, which is connected to the self-check signal input terminals of each switch module respectively, and selectively inputs a self-check signal to the corresponding switch module; The data processing module is connected to the output end of the last frequency conversion circuit; it is used to determine the voltage value output by the last frequency conversion circuit when the link self-test module inputs a self-test signal on the corresponding switch module, and perform fault detection on the frequency conversion circuit that inputs the self-test signal based on the voltage value.

[0007] In one embodiment, the spectrum analyzer includes N switch modules, the first switch module is connected between the first frequency conversion circuit and the signal input terminal of the spectrum analyzer, and is used to input the signal to be detected or the self-test signal into the first frequency conversion circuit; the other switch modules are respectively connected between the output terminals of two adjacent front-stage frequency conversion circuits and the input terminals of the rear-stage frequency conversion circuits, and are used to selectively input the signal to be detected and the self-test signal output by the front-stage frequency conversion circuit into the rear-stage frequency conversion circuit.

[0008] In one embodiment, the link self-check module includes a self-check signal source and a first switch switching device; The self-test signal source is connected to the input end of the first switch switching device, and the output end of the first switch switching device is connected to each switch module respectively; When fault detection is performed on the frequency conversion circuit to be tested, the first switch switching device is switched so that the switch module in the frequency conversion circuit to be tested is connected to the self-test signal source to input a self-test signal to the frequency conversion circuit to be tested.

[0009] In one embodiment, the link self-check module further includes a signal extraction device; The input end of the signal extraction device is connected to the output end of the first switch switching device, and the output end of the signal extraction device is connected to the data processing module; When performing fault detection on the self-test signal source, the first switch switching device is switched so that the self-test signal source is connected to the signal extraction device; and fault detection is performed on the self-test signal source according to the voltage value of the self-test signal source obtained by the data processing module.

[0010] In one embodiment, the signal extraction device includes a first detector; The input end of the first detector is connected to the input end of the signal extraction device, and the output end of the first detector is connected to the output end of the signal extraction device.

[0011] In one embodiment, the spectrum analyzer further includes N local oscillator self-test modules, each of which is connected to a local oscillator signal source in each frequency conversion circuit, and is used to perform fault detection on the local oscillator signal source in each frequency conversion circuit.

[0012] In one embodiment, the local oscillator self-check module includes a signal detection device, a second switch switching device and a signal receiving device, and the signal detection device corresponds to the local oscillator signal source one by one; The input end of each signal detection device is respectively connected to the corresponding local oscillator signal source to obtain the voltage value of the local oscillator signal source, the output end of each signal detection device is respectively connected to multiple input ends of the second switch switching device, and the output end of the second switch switching device is connected to the signal receiving device; When fault detection is performed on the local oscillator signal source in each frequency conversion circuit, the second switch switching device is switched so that the signal detection device connected to the local oscillator signal source to be tested is connected to the signal receiving device; fault detection is performed on the local oscillator signal source to be tested based on the voltage value obtained by the signal receiving device.

[0013] In one embodiment, the signal detection device includes a coupler and a second detector; The input end of each coupler is connected to the input end of the corresponding signal detection device, the output end of each coupler is connected to the input end of the second detector, and the output end of the second detector is connected to the output end of the corresponding signal detection device.

[0014] In one embodiment, the spectrum analyzer includes a first frequency conversion circuit, a second frequency conversion circuit, and a third frequency conversion circuit connected in sequence in the signal flow direction of the signal to be detected, a first switch module is connected to the input end of the first frequency conversion circuit, a second switch module is connected between the first frequency conversion circuit and the second frequency conversion circuit, and a third switch module is connected between the second frequency conversion circuit and the third frequency conversion circuit.

[0015] In one embodiment, the spectrum analyzer further includes a control module, and in the first frequency conversion circuit, the second frequency conversion circuit and the third frequency conversion circuit connected in sequence, the control module selectively inputs a self-test signal on the corresponding switch module according to a set order to perform fault detection on the frequency conversion circuit that inputs the self-test signal.

[0016] In one embodiment, setting the sequence includes: The control module controls the first switch switching device to switch so that the third switch module is connected to the self-test signal source to perform fault detection on the third frequency conversion circuit; After the fault detection of the third frequency conversion circuit passes, the control module controls the first switch switching device to switch so that the second switch module is connected to the self-test signal source to perform fault detection on the second frequency conversion circuit; After the fault detection of the second frequency conversion circuit passes, the control module controls the first switch switching device to switch so that the first switch module is connected to the self-test signal source to perform fault detection on the first frequency conversion circuit.

[0017] In one embodiment, before performing fault detection on all frequency conversion circuits, the control module controls the first switch device to switch to perform fault detection on the self-test signal source.

[0018] In one embodiment, before performing fault detection on each frequency conversion circuit, the control module controls the second switch device to switch to perform fault detection on the local oscillator signal source in the frequency conversion circuit.

[0019] According to the spectrum analyzer of the above embodiment, at least two switch modules are set in the frequency conversion circuit in the spectrum analyzer, the link self-test module is connected to each switch module, and the data processing module is used to determine the voltage value output by the last frequency conversion circuit when the link self-test module inputs the self-test signal on the corresponding switch module, and the frequency conversion circuit that inputs the self-test signal is fault-checked according to the voltage value. A switch module is set between the input end of the frequency conversion circuit to be tested and the output end of the previous circuit, and the link self-test module is connected to the corresponding switch module, so that the selected frequency conversion circuit to be tested can be self-checked, so that the problems of the spectrum analyzer itself can be discovered in time, and the test abnormality caused by the problems of the spectrum analyzer itself can be avoided, thereby improving the reliability of the spectrum analyzer detection, and when a fault occurs, it can help maintenance personnel preliminarily confirm the location of the problem and quickly locate the problem to increase efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of a superheterodyne spectrometer in an embodiment; Figure 2 A schematic diagram of the structure of a spectrum analyzer in an embodiment; Figure 3 A schematic diagram of the structure of a frequency conversion circuit in an embodiment; Figure 4 A schematic diagram of the structure of a link self-check module in an embodiment; Figure 5 A schematic diagram of the structure of a local oscillator self-test module in an embodiment; Figure 6 The circuit diagram of a spectrum analyzer with three-way frequency conversion circuits in one embodiment is shown in FIG. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0022] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0023] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0024] Please refer to Figure 1 In one embodiment, a superheterodyne spectrum analyzer structure is provided, including three frequency conversions. The spectrum analyzer includes a switch, an RF input attenuator, a prefilter, a mixer, an intermediate frequency amplifier, an intermediate frequency filter, two mixers, two intermediate frequency amplifiers, two intermediate frequency filters, three mixers, three intermediate frequency amplifiers, three intermediate frequency filters and an analog converter in the direction of input signal flow. The local oscillator signal of the first mixer is provided by the first local oscillator, the local oscillator signal of the second mixer is provided by the second local oscillator, and the local oscillator signal of the third mixer is provided by the third local oscillator. The 1-S port path in the first switch is the normal test channel of the spectrum analyzer, and the 2-S port path in the first switch is the troubleshooting path. When it is necessary to check whether the spectrum analyzer itself has a problem, the first switch is switched to the 2-S port path, and the input signal is provided by the self-test source. After passing through the mixer, the corresponding amplifier and the filter, the power value of the input signal is collected by the analog converter, and the power value of the input signal is determined according to the power value of the input signal. Whether the link of the spectrum analyzer itself is abnormal.

[0025] In the above circuit, the self-test signal is input at the front end of the spectrum analyzer link and tested at the end. The self-test is relatively rough and can only determine whether there is an abnormality in the spectrum analyzer as a whole, but cannot obtain a more accurate fault location. In addition, there is no effective inspection mechanism for the self-test source, and it is impossible to ensure whether the self-test signal is generated normally, which is easy to cause misjudgment.

[0026] Please refer to Figure 2 In one embodiment, a spectrum analyzer 100 is provided. The spectrum analyzer 100 includes a frequency conversion circuit 110 , a switch module 120 , a link self-check module 130 , a local oscillator self-check module 140 , a data processing module 150 and a control module 160 .

[0027] In one embodiment, the frequency conversion circuit 110 may use N frequency conversion circuits connected in sequence, where N is greater than or equal to 2. The frequency conversion circuit is one of the core components of the spectrum analyzer, and is used to convert the input high-frequency RF signal into an intermediate frequency signal that is easier to process for subsequent filtering, amplification, detection, and analysis. The number of frequency conversions in the spectrum analyzer 100 is not fixed, so the present application does not limit the number of frequency conversion circuits. In actual applications, different frequency conversions can be used according to design requirements.

[0028] Please refer to Figure 3 In one embodiment, the frequency conversion circuit 110 includes a mixer 111, an intermediate frequency amplifier 112, an intermediate frequency filter 113 and a local oscillator signal source 114. The input end of the mixer 111 is used to obtain a detection signal, and the input end of the mixer 111 is also connected to the local oscillator signal source 114. The output end of the mixer 111 is connected to the input end of the intermediate frequency amplifier 112, and the output end of the intermediate frequency amplifier 112 is connected to the intermediate frequency filter 113. The mixer 111 mixes the detection signal with the local oscillator signal sent by the local oscillator signal source 114, thereby outputting a lower frequency intermediate frequency signal. The intermediate frequency signal is usually weak, and the intermediate frequency amplifier 112 is used to amplify the intermediate frequency signal to increase the amplitude of the intermediate frequency signal. The mixed signal contains multiple frequency components, and the intermediate frequency filter 113 is used to select and pass the required intermediate frequency signal, and suppress unnecessary interference signals or image frequencies.

[0029] In one embodiment, the switch modules 120 in the spectrum analyzer 100 include at least two, and the configuration of the two switch modules 120 includes two situations.

[0030] In one embodiment, the first situation is: the first switch module 120 is connected between the first frequency conversion circuit 110 and the signal input terminal of the spectrum analyzer 100, and is used to input the signal to be detected or the self-test signal into the first frequency conversion circuit 110. The second switch module 120 can be set in any frequency conversion circuit 110, specifically connected between the input terminal of the selected frequency conversion circuit 110 and the output terminal of the previous frequency conversion circuit 110, and is used to selectively input the signal to be detected and the self-test signal output by the previous frequency conversion circuit 110 into the selected frequency conversion circuit 110.

[0031] In one embodiment, the second situation is: any two frequency conversion circuits 110 are selected from each frequency conversion circuit 110, and the two switch modules 120 are respectively connected between the input end of the selected frequency conversion circuit 110 and the output end of the previous-stage frequency conversion circuit 110, and are used to selectively input the signal to be detected and the self-test signal output by the previous-stage frequency conversion circuit 110 into the selected frequency conversion circuit 110.

[0032] In one embodiment, the link self-test module 130 is connected to the self-test signal input terminals of the two switch modules 120 respectively, and selectively inputs the self-test signal to the corresponding switch module 120 .

[0033] It should be noted that no matter how many frequency conversion circuits 110 there are, at least two switch modules 120 are provided in each frequency conversion circuit 110, and the link self-check module 130 is used to input self-check signals to different switch modules 120, so as to perform fault self-check on the selected frequency conversion circuit 110. That is, among the frequency conversion circuits 110 of the spectrum analyzer 100, it can be determined whether at least the selected frequency conversion circuit 110 has a fault.

[0034] In one embodiment, in order to fully determine the specific location of the fault in the spectrum analyzer 100, the spectrum analyzer 100 includes N switch modules 120, that is, the number of switch modules 120 is the same as the number of frequency conversion circuits 110. The first switch module 120 is connected between the first frequency conversion circuit 110 and the signal input terminal of the spectrum analyzer 100, and is used to input the signal to be detected or the self-test signal to the first frequency conversion circuit 110. The other switch modules 120 are respectively connected between the output terminals of two adjacent front-stage frequency conversion circuits 110 and the input terminals of the rear-stage frequency conversion circuit 110, and are used to selectively input the signal to be detected and the self-test signal output by the front-stage frequency conversion circuit 110 to the rear-stage frequency conversion circuit 110.

[0035] It should be noted that a switch module 120 is provided in each frequency conversion circuit 110, and a link self-check module 130 connected to the switch module 120 is used to input a self-check signal to each frequency conversion circuit 110, thereby performing a self-check on each frequency conversion circuit, so as to determine the specific location of the fault.

[0036] In one embodiment, the data processing module 150 is connected to the output end of the last frequency conversion circuit, and is used to determine the voltage value output by the last frequency conversion circuit 110 when the link self-test module 130 inputs a self-test signal on the corresponding switch module 120, and perform fault detection on the frequency conversion circuit 110 that inputs the self-test signal according to the voltage value. The data processing module 150 may use a first analog-to-digital converter and a controller, and the controller determines whether the frequency conversion circuit 110 has a fault according to the voltage value obtained by the module converter.

[0037] It should be noted that, since the frequency conversion circuits 110 are connected in sequence, the voltage value output by the last frequency conversion circuit 110 is also the voltage value output by the entire frequency conversion circuit 110. The difference is that after the switch module 120 connected to the input end of a certain frequency conversion circuit 110 is input with a self-test signal, the front-stage circuit of the selected frequency conversion circuit 110 is disconnected from the selected frequency conversion circuit 110, and then the entire frequency conversion circuit 110 is the circuit between the switch module 120 connected to the input end of the selected frequency conversion circuit 110 and the data processing module 150.

[0038] Please refer to Figure 4 In one embodiment, the figure uses three frequency conversion circuits 110, corresponding three switch modules 120 and a data processing module 150 to describe the connection relationship of the link self-test module 130. Among them, the three frequency conversion circuits 110 are respectively the first frequency conversion circuit 110a, the second frequency conversion circuit 110b and the third frequency conversion circuit 110c, and the corresponding three switch modules 120 are respectively the first switch module 120a, the second switch module 120b and the third switch module 120c. The link self-test module 130 includes a self-test signal source 131, a first switch switching device 132 and a signal extraction device 133. The self-test signal source 131 is connected to the input end of the first switch switching device 132, and the output end of the first switch switching device 132 is respectively connected to each switch module 120. In Figure 4In the embodiment, the output end of the first switch switching device 132 is connected to the first switch module 120a, the second switch module 120b and the third switch module 120c respectively. The input end of the signal extraction device 133 is connected to the output end of the first switch switching device 132, and the output end of the signal extraction device 133 is connected to the data processing module 150. When the frequency conversion circuit 110 to be tested is subjected to fault detection, the first switch switching device 132 is switched, so that the switch module 120 in the frequency conversion circuit 110 to be tested is connected to the self-test signal source 131. At this time, the self-test signal source 131 inputs a self-test signal to the selected switch module 120, and the self-test signal is input to the frequency conversion circuit 110 connected to the selected switch module 120. The data processing module 150 obtains the voltage value output by the last frequency conversion circuit 110, and determines the fault condition of the frequency conversion circuit 110 to be tested according to the voltage value, thereby completing the fault self-test of the frequency conversion circuit 110 to be tested.

[0039] In one embodiment, when fault detection is performed on the self-test signal source 131, the first switch switching device 132 is switched to connect the self-test signal source 131 with the signal extraction device 133, and the data processing module 150 obtains the voltage value of the self-test signal source 131 sent by the signal extraction device 133, and performs fault detection on the self-test signal source 131 according to the voltage value of the self-test signal source 131.

[0040] It should be noted that the output end of the signal extraction device 133 can be connected to the first analog-to-digital converter in the data processing module 150, or an additional analog-to-digital converter can be provided to be connected to the output end of the signal extraction device 133. Similarly, the controller in the data processing module 150 is used to read the voltage value in the analog-to-digital converter, thereby completing the fault detection of the self-test signal source 131.

[0041] In one embodiment, the signal extraction device 133 uses a first detector 133a, and the first detector 133a is used to perform amplitude detection on the self-detection signal of the self-detection signal source 131 to monitor in real time the detection voltage output by the self-detection signal source 131. The input end of the first detector 133a is connected to the input end of the signal extraction device 133, and the output end of the first detector 133a is connected to the output end of the signal extraction device 133.

[0042] In one embodiment, the local oscillator self-test modules 140 in the spectrum analyzer 100 are also N local oscillator self-test modules 140, that is, there are as many local oscillator self-test modules 140 as there are frequency conversion circuits 110. Each local oscillator self-test module 140 is respectively connected to the local oscillator signal source 114 in each frequency conversion circuit 110, and is used to perform fault detection on the local oscillator signal source 114 in each frequency conversion circuit 110.

[0043] Please refer to Figure 5In one embodiment, the connection relationship of the local oscillator self-test module 140 is described by two frequency conversion circuits 110, two corresponding switch modules 120 and a data processing module 150. Figure 4 The two frequency conversion circuits 110 are the same, and are respectively the first frequency conversion circuit 110a and the second frequency conversion circuit 110b. The first frequency conversion circuit 110a includes a first mixer 111a, a first intermediate frequency amplifier 112a, a first intermediate frequency filter 113a and a first local oscillator signal source 114a; the second frequency conversion circuit 110b includes a second mixer 111b, a second intermediate frequency amplifier 112b, a second intermediate frequency filter 113b and a second local oscillator signal source 114b. The corresponding two switch modules 120 are respectively the first switch module 120a and the second switch module 120b. The local oscillator self-test module 140 includes a signal detection device 141, a second switch switching device 142 and a signal receiving device 143, wherein the signal detection device 141 corresponds to the local oscillator signal source 114 one by one. The input end of each signal detection device 141 is respectively connected to the corresponding local oscillator signal source 114 to obtain the voltage value of the local oscillator signal. Figure 5 In the embodiment, the first signal detection device 1411 is connected to the first local oscillator signal source 114a, and the second signal detection device 1412 is connected to the second local oscillator signal source 114b. The output end of each signal detection device 141 is respectively connected to multiple input ends of the second switch switching device 142, and the output end of the second switch switching device 142 is connected to the signal receiving device 143.

[0044] In one embodiment, when the local oscillator signal source 114 in each frequency conversion circuit 110 is subjected to fault detection, the second switch switching device 142 is switched to connect the signal detection device 141 connected to the local oscillator signal source 114 to be tested with the signal receiving device 143. At this time, the signal detection device 141 inputs the detected voltage value of the local oscillator signal source 114 to the signal receiving device 143, and completes the fault detection of the local oscillator signal source 114 to be tested according to the voltage value obtained by the signal receiving device 143.

[0045] It should be noted that the signal receiving device 143 uses a second analog-to-digital converter, which can be replaced by the first analog-to-digital converter in the data processing module 150, or by an analog-to-digital converter additionally connected to the output end of the signal extraction device 133, or an additional analog-to-digital converter can be set.

[0046] In one embodiment, the signal detection device 141 includes a coupler and a second detector. The coupler is used to control the transmission direction and strength of the local oscillator signal. The input end of the coupler is connected to the input end of the corresponding signal detection device 141, the output end of each coupler is connected to the input end of the second detector, and the output end of the second detector is connected to the output end of the corresponding signal detection device 141. The second detector performs amplitude detection on the local oscillator signal distributed from the coupler 141a and monitors the detection voltage of the local oscillator signal in real time.

[0047] The present application provides a spectrum analyzer including multiple frequency conversions, for example, Figure 6 As shown, in one embodiment, a spectrum analyzer 100 including a third frequency conversion is provided. Figure 4 and Figure 5 Similarly, according to the signal flow of the signal to be detected from front to back, the spectrum analyzer 100 includes an RF input attenuator, a pre-filter, a first frequency conversion circuit 110a, a second frequency conversion circuit 110b and a third frequency conversion circuit 110c, and the first frequency conversion circuit 110a, the second frequency conversion circuit 110b and the third frequency conversion circuit 110c are respectively provided with a first switch module 120a, a second switch module 120b and a third switch module 120c. In addition, a fourth switch module 120d is additionally provided at the output end of the third frequency conversion circuit 110c. Among them, the RF input attenuator is used to reduce the amplitude of the signal to be detected to prevent excessive signals from damaging the mixer or other front-end components of the spectrum analyzer. The pre-filter is used to filter out unnecessary interference signals, reduce the spurious response of the front end of the spectrum analyzer, and ensure that the mixer only receives signals within the target spectrum range.

[0048] Please refer to Figure 6 In one embodiment, the first frequency conversion circuit 110a includes a first mixer 111a, a first intermediate frequency amplifier 112a, a first intermediate frequency filter 113a, and a first local oscillator signal source 114a. The second frequency conversion circuit 110b includes a second mixer 111b, a second intermediate frequency amplifier 112b, a second intermediate frequency filter 113b, and a second local oscillator signal source 114b. The third frequency conversion circuit 110c includes a third mixer 111c, a third intermediate frequency amplifier 112c, a third intermediate frequency filter 113c, and a third local oscillator signal source 114c.

[0049] In one embodiment, the input end of the first switch module 120a is used to obtain the signal to be detected, the output end of the first switch module 120a is connected to the input end of the RF input attenuator, the output end of the RF input attenuator is connected to the input end of the pre-filter, the output end of the pre-filter is connected to the input end of the first mixer 111a, the output end of the first mixer 111a is connected to the input end of the first intermediate frequency amplifier 112a, the output end of the first intermediate frequency amplifier 112a is connected to the input end of the second switch module 120b, the output end of the second switch module 120b is connected to the input end of the first intermediate frequency filter 113a, the output end of the first intermediate frequency filter 113a is connected to the input end of the second mixer 111b, and the second mixer 111a is connected to the input end of the first intermediate frequency amplifier 112a. The output end of the second intermediate frequency amplifier 112b is connected to the input end of the second intermediate frequency amplifier 112b, the output end of the second intermediate frequency amplifier 112b is connected to the input end of the third switch module 120c, the output end of the third switch module 120c is connected to the input end of the second intermediate frequency filter 113b, the output end of the second intermediate frequency filter 113b is connected to the input end of the third mixer 111c, the output end of the third mixer 111c is connected to the input end of the third intermediate frequency amplifier 112c, the output end of the third intermediate frequency amplifier 112c is connected to the input end of the fourth switch module 120d, the output end of the fourth switch module 120d is connected to the input end of the third intermediate frequency filter 113c, and the output end of the third intermediate frequency filter 113c is connected to the data processing module 150.

[0050] It should be noted that the first switch module 120a, the second switch module 120b and the third switch module 120c can be respectively arranged between the intermediate frequency amplifier and the intermediate frequency filter in each frequency conversion circuit, and the first switch module 120a, the second switch module 120b and the third switch module 120c can also be respectively arranged between the intermediate frequency filter in each frequency conversion circuit and the mixer of the next frequency conversion circuit.

[0051] In one embodiment, in three frequency conversion circuits connected in sequence, the couplers in the signal detection device 141 are respectively the first coupler 141a, the second coupler 141b and the third coupler 141c, and the second detectors in the signal detection device 141 are respectively the second detector 141d, the second detector 141e and the second detector 141f (the second detectors are the same detectors, and different numbers are used to indicate that the detectors belong to different frequency conversion circuits). The input ends of the first coupler 141a, the second coupler 141b and the third coupler 141c are respectively connected to the first local oscillator signal source 114a, the second local oscillator signal source 114b and the third local oscillator signal source 114c; the output ends of the first coupler 141a, the second coupler 141b and the third coupler 141c are respectively connected to the input ends of the first mixer 111a, the second mixer 111b and the third mixer 111c; the output ends of the first coupler 141a, the second coupler 141b and the third coupler 141c are also respectively connected to the input ends of the second detector 141d, the second detector 141e and the second detector 141f; the output ends of the second detector 141d, the second detector 141e and the second detector 141f are respectively connected to port 1, port 2 and port 4 of the second switch switching device 142; the S port of the second switch switching device 142 is connected to the second analog-to-digital converter.

[0052] In one embodiment, the output end of the self-test signal source 131 is connected to the S port of the first switch switching device 132, and the 3 port, 1 port, 2 port and 4 port of the first switch switching device 132 are respectively connected to the first switch module, the second switch module, the third switch module and the fourth switch module. The 5 port of the first switch switching device 132 is connected to the input end of the first detector 133a, and the output end of the first detector 133a is connected to the 3 port of the second switch switching device 142.

[0053] In one embodiment, the control module 160 is used in the spectrum analyzer 100 to control the first switch switching device 132 in a set order, so as to selectively input a self-test signal to the corresponding switch module. Similarly, the control module 160 is used to control the second switch switching device 142 in a set order, so as to selectively perform self-test on each local oscillator signal source.

[0054] It should be noted that the control module 160 may be a separate control module or a controller in the data processing module 150 .

[0055] In one embodiment, in the three frequency conversion circuits connected in sequence, the control module 160 controls the first switch switching device 132 to switch, so that the fourth switch module is connected to the self-test signal source 131 to determine the third intermediate frequency filter 113c connected to the fourth switch module, thereby completing the fault detection of the third intermediate frequency filter 113c. When the fourth switch module is set between the third intermediate frequency filter 113c and the data processing module 150, the fourth switch module can be ignored.

[0056] In one embodiment, after completing the fault detection of the third intermediate frequency filter 113c, the control module 160 controls the first switch switching device 132 to switch, so that the third switch module is connected to the self-test signal source 131 to perform fault detection on the third frequency conversion circuit.

[0057] In one embodiment, after completing the fault detection of the third frequency conversion circuit, the control module 160 controls the first switch switching device 132 to switch, so that the second switch module is connected to the self-test signal source 131 to perform fault detection on the second frequency conversion circuit.

[0058] In one embodiment, after completing the fault detection of the second frequency conversion circuit, the control module 160 controls the first switch switching device 132 to switch, so that the first switch module is connected to the self-test signal source 131 to perform fault detection on the first frequency conversion circuit.

[0059] It should be noted that the above fault detection is performed in the case of three frequency conversion circuits connected in sequence. When the number of frequency conversion circuits in the spectrum analyzer is not limited, then for the fault detection of the frequency conversion circuit, fault detection is performed on each frequency conversion circuit in sequence from back to front according to the signal flow direction of the signal to be detected.

[0060] In one embodiment, before performing fault detection on all frequency conversion circuits, the control module 160 first controls the first switch switching device 132 to switch, so as to perform fault detection on the self-test signal source 131. That is, after ensuring that the self-test signal source 131 has no fault, each frequency conversion circuit is then fault detected.

[0061] In one embodiment, after determining that the self-test signal source 131 has no fault, and before each frequency conversion circuit performs fault detection, the control module 160 further controls the second switch switching device 142 to switch, thereby performing fault detection on the local oscillator signal source in the frequency conversion circuit. That is, after determining that the self-test signal source 131 is safe, before performing fault detection on a frequency conversion circuit, it is first determined that the local oscillator signal source of that circuit is safe, so that the fault problem can be located in other hardware of the frequency conversion circuit.

[0062] In summary, according to Figure 5 The fault detection sequence of the third frequency conversion circuit of the spectrum analyzer is as follows: The first switch switching device 132 switches to the 5-S port to be turned on, the second switch switching device 142 switches to the 3-S port to be turned on, and the second analog-to-digital converter collects the voltage of the first detector 133a to determine whether the self-test signal source 131 fails.

[0063] After the fault detection of the self-test signal source 131 passes, the first switch switching device 132 switches to 4-S conduction, the fourth switch module switches to 2-S conduction, and the self-test signal is input to the third intermediate frequency filter 113c to determine whether the circuit between the fourth switch module and the first analog-to-digital converter has a fault.

[0064] The second switch switching device 142 is switched to the 4-S port to be turned on, and the second analog-to-digital converter collects the voltage value of the second detector 141f to determine whether the third local oscillator signal source 114c fails.

[0065] After the fault detection of the third local oscillator signal source 114c passes, the first switch switching device 132 switches to 2-S conduction, the third switch module switches to 2-S conduction, and the self-test signal is input to the second intermediate frequency filter 113b to determine whether the circuit between the third switch module to the fourth switch module has a fault.

[0066] After the fault detection from the third switch module to the first analog-to-digital converter is passed, the second switch switching device 142 switches to the 2-S port to be turned on, and the second analog-to-digital converter collects the voltage value of the second detector 141e to determine whether the second local oscillator signal source 114b is faulty.

[0067] After the fault detection of the second local oscillator signal source 114b is passed, the first switch switching device 132 switches to 1-S conduction, the second switch module switches to 2-S conduction, and the self-test signal is input to the first intermediate frequency filter 113a to determine whether the circuit between the second switch module to the third switch module has a fault.

[0068] After the fault detection from the second switch module to the first analog-to-digital converter is passed, the second switch switching device 142 switches to the 1-S port to be turned on, and the second analog-to-digital converter collects the voltage value of the second detector 141d to determine whether the first local oscillator signal source 114a is faulty.

[0069] After the fault detection of the first local oscillator signal source 114a passes, the first switch switching device 132 switches to 3-S conduction, the first switch module switches to 2-S conduction, and the self-test signal is input to the RF input attenuator to determine whether the circuit between the first switch module and the second switch module has a fault.

[0070] This application can effectively detect the local oscillator signal source of the spectrum analyzer, quickly determine whether the link of the local oscillator signal source is faulty, and the self-test signal source is input to different positions of the spectrum analyzer receiving channel, which can accurately locate the fault location and improve production or maintenance efficiency. In addition, the spectrum analyzer also adds the detection of the self-test signal source to ensure that the self-test signal emitted by the self-test signal source is normal, avoiding misjudgment of faults.

[0071] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0072] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A spectrum analyzer, characterized in that: include: N frequency conversion circuits connected in sequence, used to convert the signal to be detected by mixing it with the local oscillator signal, and output the signal to be detected after the frequency conversion, wherein N is greater than or equal to 2; At least two switch modules, The first switch module is connected between the first frequency conversion circuit and the signal input terminal of the spectrum analyzer, and is used to input the signal to be detected or the self-test signal into the first frequency conversion circuit; any one frequency conversion circuit is selected from the frequency conversion circuits, and the second switch module is connected between the input terminal of the selected frequency conversion circuit and the output terminal of the previous frequency conversion circuit, and is used to selectively input the signal to be detected and the self-test signal output by the previous frequency conversion circuit into the selected frequency conversion circuit; or, Any two frequency conversion circuits are selected from each frequency conversion circuit, and each switch module is respectively connected between the input end of the selected frequency conversion circuit and the output end of the previous frequency conversion circuit, and is used to selectively input the to-be-detected signal and the self-test signal output by the previous frequency conversion circuit into the selected frequency conversion circuit; A link self-check module, wherein the link self-check module is connected to the self-check signal input terminal of each switch module respectively, and selectively inputs a self-check signal to the corresponding switch module; A data processing module, the data processing module is connected to the output end of the last frequency conversion circuit; it is used to determine the voltage value output by the last frequency conversion circuit when the link self-test module inputs a self-test signal on the corresponding switch module, and perform fault detection on the frequency conversion circuit that inputs the self-test signal based on the voltage value.

2. The spectrum analyzer according to claim 1, characterized in that: The spectrum analyzer includes N switch modules, the first switch module is connected between the first frequency conversion circuit and the signal input end of the spectrum analyzer, and is used to input the signal to be detected or the self-test signal into the first frequency conversion circuit; the other switch modules are respectively connected between the output end of two adjacent front-stage frequency conversion circuits and the input end of the rear-stage frequency conversion circuit, and are used to selectively input the signal to be detected and the self-test signal output by the front-stage frequency conversion circuit into the rear-stage frequency conversion circuit.

3. The spectrum analyzer according to claim 2, characterized in that: The link self-check module includes a self-check signal source and a first switch switching device; The self-test signal source is connected to the input end of the first switch switching device, and the output end of the first switch switching device is connected to each switch module respectively; When fault detection is performed on the frequency conversion circuit to be tested, the first switch switching device is switched so that the switch module in the frequency conversion circuit to be tested is connected to the self-test signal source to input a self-test signal to the frequency conversion circuit to be tested.

4. The spectrum analyzer according to claim 3, characterized in that: The link self-check module also includes a signal extraction device; The input end of the signal extraction device is connected to the output end of the first switch switching device, and the output end of the signal extraction device is connected to the data processing module; When the self-test signal source is subjected to fault detection, the first switch switching device is switched so that the self-test signal source is connected to the signal extraction device; Fault detection is performed on the self-test signal source according to the voltage value of the self-test signal source acquired by the data processing module.

5. The spectrum analyzer according to claim 4, characterized in that: The signal extraction device comprises a first detector; The input end of the first detector is connected to the input end of the signal extraction device, and the output end of the first detector is connected to the output end of the signal extraction device.

6. The spectrum analyzer according to claim 4, characterized in that: The spectrum analyzer further comprises N local oscillator self-checking modules, each of which is connected to a local oscillator signal source in each frequency conversion circuit, and is used to perform fault detection on the local oscillator signal source in each frequency conversion circuit.

7. The spectrum analyzer according to claim 6, characterized in that: The local oscillator self-check module includes a signal detection device, a second switch switching device and a signal receiving device, and the signal detection device corresponds to the local oscillator signal source one by one; The input end of each signal detection device is respectively connected to the corresponding local oscillator signal source to obtain the voltage value of the local oscillator signal source, the output end of each signal detection device is respectively connected to multiple input ends of the second switch switching device, and the output end of the second switch switching device is connected to the signal receiving device; When fault detection is performed on the local oscillator signal source in each frequency conversion circuit, the second switch switching device is switched so that the signal detection device connected to the local oscillator signal source to be tested is connected to the signal receiving device; A fault detection is performed on the local oscillator signal source to be tested according to the voltage value acquired by the signal receiving device.

8. The spectrum analyzer according to claim 7, characterized in that: The signal detection device comprises a coupler and a second detector; The input end of each coupler is connected to the input end of the corresponding signal detection device, the output end of each coupler is connected to the input end of the second detector, and the output end of the second detector is connected to the output end of the corresponding signal detection device.

9. The spectrum analyzer according to claim 7, characterized in that: The spectrum analyzer includes a first frequency conversion circuit, a second frequency conversion circuit and a third frequency conversion circuit connected in sequence in the signal flow direction of the signal to be detected, a first switch module is connected to the input end of the first frequency conversion circuit, a second switch module is connected between the first frequency conversion circuit and the second frequency conversion circuit, and a third switch module is connected between the second frequency conversion circuit and the third frequency conversion circuit.

10. The spectrum analyzer according to claim 9, characterized in that: The spectrum analyzer also includes a control module, which selectively inputs a self-test signal to the corresponding switch module in a set order in the first frequency conversion circuit, the second frequency conversion circuit and the third frequency conversion circuit connected in sequence, so as to perform fault detection on the frequency conversion circuit to which the self-test signal is input.

11. The spectrum analyzer according to claim 10, characterized in that: The setting sequence includes: The control module controls the first switch switching device to switch so that the third switch module is connected to the self-test signal source to perform fault detection on the third frequency conversion circuit; After the fault detection of the third frequency conversion circuit passes, the control module controls the first switch switching device to switch so that the second switch module is connected to the self-test signal source to perform fault detection on the second frequency conversion circuit; After the fault detection of the second frequency conversion circuit passes, the control module controls the first switch switching device to switch so that the first switch module is connected to the self-test signal source to perform fault detection on the first frequency conversion circuit.

12. The spectrum analyzer according to claim 10, characterized in that: Before performing fault detection on all frequency conversion circuits, the control module controls the first switch device to switch, so as to perform fault detection on the self-test signal source.

13. The spectrum analyzer according to claim 10, characterized in that: Before performing fault detection on each frequency conversion circuit, the control module controls the second switch device to switch, so as to perform fault detection on the local oscillator signal source in the frequency conversion circuit.

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