A spectrum analyzer

Abstract

A spectrum analyzer relates to the field of measurement technology. The spectrum analyzer includes a frequency conversion circuit, a switch module, a link self-test module, and a data processing module. The frequency conversion circuit is used to convert the signal to be detected by mixing it with a local oscillator signal, and output the converted signal to be detected. 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 signal to be detected and the self-test signal output by the previous frequency conversion circuit into the selected frequency conversion circuit. The link self-test module is respectively connected to the self-test signal input end of each switch module, and selectively inputs the self-test 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 self-test signal is input to the corresponding switch module, and perform fault detection on the frequency conversion circuit based on 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 technology, spectrum analyzers, as essential test and measurement instruments, are experiencing continuous technological advancements, leading to increasingly complex circuit designs and functions. This complexity has led to an ever-expanding range of applications for spectrum analyzers, encompassing a wide range of fields, including communications, electronic equipment manufacturing, scientific research, and national defense. In these fields, spectrum analyzers not only play a central role in spectrum analysis, but their reliability and measurement accuracy are also crucial. However, current spectrum analyzers still suffer from significant deficiencies in reliability and self-test functionality, which not only impacts user testing efficiency but also increases operational risks.

[0003] Existing spectrum analyzers often lack effective self-diagnosis features, making it impossible to promptly and accurately determine whether they are operating normally. This means that users may not immediately detect problems with the analyzer's internal circuitry or key components. Continued use of a spectrum analyzer in a faulty state often results in inaccurate test data and can even mislead users into making incorrect judgments and decisions, potentially leading to financial losses or technical errors.

[0004] Furthermore, the lack of effective self-diagnosis features in spectrum analyzers creates additional challenges for maintenance and repair. For maintenance personnel, the lack of automatic diagnostics in the analyzer often necessitates manual troubleshooting, significantly increasing the complexity of troubleshooting and repairing the problem. 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:

[0007] N frequency conversion circuits connected in sequence, used to perform frequency conversion processing on the signal to be detected by mixing it with the local oscillator signal, and output the frequency-converted signal to be detected, where N is greater than or equal to 2;

[0008] At least two switch modules,

[0009] 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 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 preceding frequency conversion circuit, and is used to selectively input the signal to be detected and the self-test signal output by the preceding frequency conversion circuit into the selected frequency conversion circuit.

[0010] or,

[0011] 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;

[0012] A link self-test module, which is connected to the self-test signal input terminals of each switch module and selectively inputs a self-test signal to the corresponding switch module;

[0013] 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.

[0014] In one embodiment, the spectrum analyzer includes N switch modules, a first switch module being connected between a first frequency conversion circuit and a signal input terminal of the spectrum analyzer, and being used to input a signal to be detected or a self-test signal into the first frequency conversion circuit; and the other switch modules being connected respectively between the output terminals of two adjacent preceding-stage frequency conversion circuits and the input terminals of subsequent-stage frequency conversion circuits, and being used to selectively input the signal to be detected and the self-test signal outputted by the preceding-stage frequency conversion circuit into the subsequent-stage frequency conversion circuit.

[0015] In one embodiment, the link self-test module includes a self-test signal source and a first switch switching device;

[0016] 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;

[0017] When fault detection is performed on the frequency conversion circuit to be tested, the first switch switching device switches 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.

[0018] In one embodiment, the link self-test module further includes a signal extraction device;

[0019] 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;

[0020] When performing fault detection on the self-test signal source, the first switch switching device switches to connect the self-test signal source to the signal extraction device; and performs fault detection on the self-test signal source according to the voltage value of the self-test signal source obtained by the data processing module.

[0021] In one embodiment, the signal extraction device includes a first detector;

[0022] 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.

[0023] 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.

[0024] In one embodiment, the local oscillator self-test 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;

[0025] 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;

[0026] When performing fault detection on the local oscillator signal source in each frequency conversion circuit, the second switch switching device switches 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.

[0027] In one embodiment, the signal detection device includes a coupler and a second detector;

[0028] 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.

[0029] 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.

[0030] In one embodiment, the spectrum analyzer further includes a control module, wherein 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 to the corresponding switch module in a set order to perform fault detection on the frequency conversion circuit to which the self-test signal is input.

[0031] In one embodiment, setting the sequence includes:

[0032] The control module controls the first switch 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;

[0033] After the fault detection of the third frequency conversion circuit passes, the control module controls the first switch 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;

[0034] After the fault detection of the second frequency conversion circuit passes, the control module controls the first switch 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.

[0035] 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.

[0036] 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.

[0037] According to the spectrum analyzer of the above embodiment, at least two switch modules are provided in the frequency conversion circuit of the spectrum analyzer, a link self-test module is connected to each switch module, and a data processing module 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 to the corresponding switch module. Based on this voltage value, fault detection is performed on the frequency conversion circuit to which the self-test signal was input. By providing a switch module between the input end of the frequency conversion circuit to be tested and the output end of the preceding circuit, and connecting the link self-test module to the corresponding switch module, fault self-test can be performed on the selected frequency conversion circuit to be tested. This allows for timely detection of problems with the spectrum analyzer itself, avoiding test anomalies caused by problems with the spectrum analyzer itself, thereby improving the reliability of the spectrum analyzer's detection. When a fault occurs, it can help maintenance personnel initially identify the location of the problem and quickly locate the problem, thereby increasing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the structure of a superheterodyne spectrometer in an embodiment;

[0039] Figure 2 A schematic structural diagram of a spectrum analyzer in an embodiment;

[0040] Figure 3 A schematic structural diagram of a frequency conversion circuit in one embodiment;

[0041] Figure 4 A schematic diagram of the structure of a link self-test module in an embodiment;

[0042] Figure 5 A schematic structural diagram of a local oscillator self-test module in an embodiment;

[0043] Figure 6 FIG. 4 is a circuit diagram of a spectrum analyzer with three frequency conversion circuits in an embodiment. DETAILED DESCRIPTION

[0044] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or 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 portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0045] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0046] Component numbers used herein, such as "first" and "second," are used solely to distinguish the components being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0047] Please refer to Figure 1One embodiment provides a superheterodyne spectrum analyzer structure, including a triple frequency converter. 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, a third mixer, a third intermediate frequency amplifier, a third intermediate frequency filter, and an analog converter. The local oscillator signal for the first mixer is provided by a first local oscillator, the local oscillator signal for the second mixer is provided by a second local oscillator, and the local oscillator signal for the third mixer is provided by a third local oscillator. The 1-S port path in the first switch serves as the normal test channel for the spectrum analyzer, while the 2-S port path in the first switch serves as a troubleshooting channel. To troubleshoot the spectrum analyzer itself, the first switch switches to the 2-S port path, and a self-test source provides the input signal. After passing through the mixers, corresponding amplifiers, and filters, the analog converter collects the power value of the input signal. Based on the input signal power value, it is determined whether the spectrum analyzer's link is abnormal.

[0048] In the above circuit, the self-test signal is input at the very beginning of the spectrum analyzer link and tested at the very end. This makes the self-test relatively crude, only able to determine whether the spectrum analyzer as a whole is abnormal, but unable to pinpoint the fault location. Furthermore, there is no effective mechanism for checking the self-test source, making it impossible to guarantee that the self-test signal is being generated properly, which can easily lead to misjudgments.

[0049] 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-test module 130 , a local oscillator self-test module 140 , a data processing module 150 , and a control module 160 .

[0050] In one embodiment, the frequency conversion circuit 110 may comprise N serially connected frequency conversion circuits, where N is greater than or equal to 2. The frequency conversion circuit is one of the core components of a spectrum analyzer, used to convert the input high-frequency RF signal into an easier-to-process intermediate frequency signal for subsequent filtering, amplification, detection, and analysis. The number of frequency conversions in the spectrum analyzer 100 is not fixed, and therefore this application does not limit the number of frequency conversion circuits. In actual applications, different frequency conversions may be used based on design requirements.

[0051] Please refer to Figure 3In 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. 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 to output 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 unwanted interference signals or image frequencies.

[0052] In one embodiment, the spectrum analyzer 100 includes at least two switch modules 120 , and the configuration of the two switch modules 120 includes two situations.

[0053] In one embodiment, the first scenario is as follows: 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 provided 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 preceding frequency conversion circuit 110, and is used to selectively input the signal to be detected and the self-test signal output by the preceding frequency conversion circuit 110 into the selected frequency conversion circuit 110.

[0054] 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 pre-stage frequency conversion circuit 110, and are used to selectively input the to-be-detected signal and the self-test signal output by the pre-stage frequency conversion circuit 110 into the selected frequency conversion circuit 110.

[0055] 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 .

[0056] It should be noted that, regardless of the number of frequency conversion circuits 110, at least two switch modules 120 are provided in each frequency conversion circuit 110. The link self-test module 130 inputs self-test signals to different switch modules 120, thereby performing a fault self-test on the selected frequency conversion circuit 110. In other words, among the frequency conversion circuits 110 of the spectrum analyzer 100, it is possible to determine whether at least the selected frequency conversion circuit 110 has a fault.

[0057] In one embodiment, to comprehensively determine the specific location of a fault in the spectrum analyzer 100, the spectrum analyzer 100 includes N switch modules 120. Specifically, the number of switch modules 120 corresponds to the number of frequency conversion circuits 110. A first switch module 120 is connected between the first frequency conversion circuit 110 and a signal input terminal of the spectrum analyzer 100 and is configured to input a signal to be detected or a self-test signal into the first frequency conversion circuit 110. The remaining switch modules 120 are connected between the output terminals of two adjacent preceding-stage frequency conversion circuits 110 and the input terminals of subsequent-stage frequency conversion circuits 110 and are configured to selectively input the signal to be detected or the self-test signal outputted by the preceding-stage frequency conversion circuit 110 into the subsequent-stage frequency conversion circuit 110.

[0058] It should be noted that a switch module 120 is provided in each frequency conversion circuit 110, and a link self-test module 130 connected to the switch module 120 is used to input a self-test signal to each frequency conversion circuit 110, thereby performing self-test on each frequency conversion circuit, so as to determine the specific location of the fault.

[0059] In one embodiment, the data processing module 150 is connected to the output end of the last frequency conversion circuit and is configured 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 to the corresponding switch module 120, and to perform fault detection on the frequency conversion circuit 110 that received the self-test signal based on the voltage value. The data processing module 150 may utilize a first analog-to-digital converter and a controller, with the controller determining whether a fault has occurred in the frequency conversion circuit 110 based on the voltage value obtained by the analog converter.

[0060] 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. 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.

[0061] Please refer to Figure 4In 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 4 In the embodiment, the output end of the first switching device 132 is connected to the first switching module 120a, the second switching module 120b, and the third switching module 120c, respectively. The input end of the signal extraction device 133 is connected to the output end of the first switching device 132, and the output end of the signal extraction device 133 is connected to the data processing module 150. When performing fault detection on the frequency conversion circuit 110 to be tested, the first switching device 132 switches, thereby connecting the switch module 120 in the frequency conversion circuit 110 to be tested with 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. 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 based on the voltage value, thereby completing the fault self-test of the frequency conversion circuit 110 to be tested.

[0062] 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.

[0063] 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 and 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.

[0064] In one embodiment, the signal extraction device 133 employs a first detector 133a, which is configured to perform amplitude detection on the self-test signal from the self-test signal source 131, thereby monitoring in real time the detection voltage output by the self-test signal source 131. The input of the first detector 133a is connected to the input of the signal extraction device 133, and the output of the first detector 133a is connected to the output of the signal extraction device 133.

[0065] In one embodiment, the spectrum analyzer 100 also includes N local oscillator self-test modules 140, i.e., 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 connected to a 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.

[0066] Please refer to Figure 5 In one embodiment, the figure shows the connection relationship of the local oscillator self-test module 140 with 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, namely 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-to-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 of each signal detection device 141 is respectively connected to the multiple inputs of the second switching device 142, and the output of the second switching device 142 is connected to the signal receiving device 143.

[0067] In one embodiment, when fault detection is performed on the local oscillator signal source 114 in each frequency conversion circuit 110, the second switch 142 is switched to connect the signal detection device 141 connected to the local oscillator signal source 114 to be tested to 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 the fault detection of the local oscillator signal source 114 to be tested is completed based on the voltage value obtained by the signal receiving device 143.

[0068] 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.

[0069] 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 of each coupler is connected to the input of the corresponding signal detection device 141. The output of each coupler is connected to the input of the second detector. The output of the second detector is connected to the output 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.

[0070] 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, based on the forward-to-backward direction of the signal flow of the signal to be detected, the spectrum analyzer 100 includes an RF input attenuator, a prefilter, a first frequency conversion circuit 110a, a second frequency conversion circuit 110b, and a third frequency conversion circuit 110c. 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. Additionally, a fourth switch module 120d is provided at the output end of the third frequency conversion circuit 110c. The RF input attenuator is used to reduce the amplitude of the signal to be detected, preventing excessively large signals from damaging the mixer or other front-end components of the spectrum analyzer. The prefilter is used to filter out unwanted interference signals, reduce spurious responses at the front end of the spectrum analyzer, and ensure that the mixer only receives signals within the target spectrum range.

[0071] Please refer to Figure 6In 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.

[0072] 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 prefilter, the output end of the prefilter 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.

[0073] 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.

[0074] In one embodiment, in three frequency conversion circuits connected in sequence, the couplers in the signal detection device 141 are respectively a first coupler 141a, a second coupler 141b, and a third coupler 141c, and the second detectors in the signal detection device 141 are respectively a second detector 141d, a second detector 141e, and a second detector 141f (the second detectors are identical 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 connected to the first local oscillator signal source 114a, the second local oscillator signal source 114b, and the third local oscillator signal source 114c, respectively. The output ends of the first coupler 141a, the second coupler 141b, and the third coupler 141c are connected to the input ends of the first mixer 111a, the second mixer 111b, and the third mixer 111c, respectively. The output ends of the first coupler 141a, the second coupler 141b, and the third coupler 141c are also connected to the input ends of the second detector 141d, the second detector 141e, and the second detector 141f, respectively. The output ends of the second detector 141d, the second detector 141e, and the second detector 141f are connected to port 1, port 2, and port 4 of the second switching device 142, respectively. The S port of the second switching device 142 is connected to the second analog-to-digital converter.

[0075] In one embodiment, the output of self-test signal source 131 is connected to port S of first switching device 132. Ports 3, 1, 2, and 4 of first switching device 132 are connected to the first switch module, the second switch module, the third switch module, and the fourth switch module, respectively. Port 5 of first switching device 132 is connected to the input of first detector 133a, and the output of first detector 133a is connected to port 3 of second switching device 142.

[0076] In one embodiment, the control module 160 in the spectrum analyzer 100 controls the first switching devices 132 in a predetermined sequence, thereby selectively inputting self-test signals to corresponding switch modules. Similarly, the control module 160 controls the second switching devices 142 in a predetermined sequence, thereby selectively performing self-tests on each local oscillator signal source.

[0077] It should be noted that the control module 160 may be a separate control module or a controller in the data processing module 150 .

[0078] In one embodiment, in the three sequentially connected frequency conversion circuits described above, the control module 160 controls the first switch device 132 to switch, thereby connecting the fourth switch module to the self-test signal source 131, to determine the third intermediate frequency filter 113c to which the fourth switch module is connected, thereby completing fault detection of the third intermediate frequency filter 113c. When the fourth switch module is disposed between the third intermediate frequency filter 113c and the data processing module 150, the fourth switch module can be ignored.

[0079] In one embodiment, after completing the fault detection of the third intermediate frequency filter 113c, the control module 160 controls the first switch 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.

[0080] In one embodiment, after completing the fault detection of the third frequency conversion circuit, the control module 160 controls the first switch 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.

[0081] In one embodiment, after completing the fault detection of the second frequency conversion circuit, the control module 160 controls the first switch 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.

[0082] It should be noted that the above fault detection is performed on 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.

[0083] In one embodiment, before performing fault detection on all frequency conversion circuits, the control module 160 first controls the first switch 132 to switch to perform fault detection on the self-test signal source 131. That is, after ensuring that the self-test signal source 131 is not faulty, the fault detection on each frequency conversion circuit is performed.

[0084] In one embodiment, after determining that self-test signal source 131 is not faulty, and before each frequency conversion circuit performs fault detection, control module 160 further controls second switch 142 to switch, thereby performing fault detection on the local oscillator signal source in the frequency conversion circuit. In other words, after determining that self-test signal source 131 is safe, before performing fault detection on a specific frequency conversion circuit, the safety of the local oscillator signal source in that circuit is first determined, thereby locating the fault to other hardware in that frequency conversion circuit.

[0085] In summary, according to Figure 5 The fault detection sequence of the spectrum analyzer's triple frequency conversion circuit is as follows:

[0086] 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 is faulty.

[0087] 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 there is a fault in the circuit between the fourth switch module and the first analog-to-digital converter.

[0088] The second switch device 142 switches 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 is faulty.

[0089] 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 and the fourth switch module has a fault.

[0090] 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.

[0091] 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 and the third switch module has a fault.

[0092] 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.

[0093] 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 there is a fault in the circuit between the first switch module and the second switch module.

[0094] This application can effectively detect the local oscillator signal source of the spectrum analyzer, quickly determine whether the local oscillator signal source link is faulty, and the self-test signal source is input to different positions of the spectrum analyzer's receiving channel, which can more accurately locate the fault location, improving production or maintenance efficiency. In addition, the spectrum analyzer also adds detection of the self-test signal source to ensure that the self-test signal emitted by the self-test signal source is normal, avoiding false fault judgments.

[0095] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above embodiments can be implemented by hardware or by computer program. When all or part of the functions in the above embodiments are implemented by computer program, 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 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 functions can be implemented. In addition, when all or part of the functions in the above embodiments are implemented by computer program, 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 saved in the memory of the local device by downloading or copying, or the system of the local device is updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be implemented.

[0096] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A spectrum analyzer, characterized in that: include: N frequency conversion circuits connected in sequence, used to perform frequency conversion processing on the signal to be detected by mixing it with the local oscillator signal, and output the frequency-converted signal to be detected, where 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 of the frequency conversion circuits is selected, and the second switch module is connected between the input end of the selected frequency conversion circuit and the output end of the previous-stage frequency conversion circuit, and is used to selectively input the to-be-detected signal and the self-test signal output by the previous-stage frequency conversion circuit into the selected frequency conversion circuit; Alternatively, 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-stage frequency conversion circuit, and is used to selectively input the to-be-detected signal and the self-test signal output by the previous-stage frequency conversion circuit into the selected frequency conversion circuit; A link self-test module, the link self-test module being connected to the self-test signal input terminal of each switch module and selectively inputting a self-test signal to the corresponding switch module; a data processing module connected to the output end of the last frequency conversion circuit; configured to determine a voltage value output by the last frequency conversion circuit when the link self-test module inputs a self-test signal to the corresponding switch module, and perform fault detection on the frequency conversion circuit that receives the self-test signal based on the voltage value; The link self-test module includes a self-test 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 respectively connected to each switch module; when performing fault detection 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, so as to input the self-test signal to the frequency conversion circuit to be tested; The link self-test 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 fault detection is performed 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; fault detection is performed on the self-test signal source based on the voltage value of the self-test signal source obtained by the data processing module.

2. The spectrum analyzer according to claim 1, wherein: 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 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, wherein: 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.

4. The spectrum analyzer according to claim 2, wherein: 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.

5. The spectrum analyzer according to claim 4, wherein: The local oscillator self-test 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 switches 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 obtained by the signal receiving device.

6. The spectrum analyzer according to claim 5, wherein: 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.

7. The spectrum analyzer according to claim 5, wherein: 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.

8. The spectrum analyzer according to claim 7, wherein: The spectrum analyzer also includes a control module. 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 to the corresponding switch module in a set order to perform fault detection on the frequency conversion circuit to which the self-test signal is input.

9. The spectrum analyzer according to claim 8, wherein: The setting sequence includes: The control module controls the first switch 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 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 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.

10. The spectrum analyzer according to claim 8, wherein: 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.

11. The spectrum analyzer according to claim 8, wherein: 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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