Filtering gating device and testing system

Abstract

The utility model relates to a filtering gating device and a testing system, the filtering gating device comprises at least two filtering circuits, each filtering circuit comprises a first switch module, a filtering module and a second switch module, and the filtering frequency bands of the filtering modules in the filtering circuits are different; wherein the output end of the first switch module is connected with the input end of the filtering module, and the output end of the filtering module is connected with the input end of the second switch module. According to the invention, the problem that automatic switching of the test frequency points cannot be realized is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of filtering, in particular to a filtering gating device and a test system. BACKGROUND

[0002] In high-speed ADC (Analog to Digital Converter) performance testing, an ideal input signal can help ADC chip developers better and faster obtain the real performance of the ADC chip. Since the currently known signal sources cannot generate the ideal signal required for high-speed ADC testing, the industry usually cascades a band-pass filter after the signal source to suppress high-order harmonics and spurs, thereby obtaining an ideal input signal.

[0003] With the rapid development of ADC, the number of ADC channels is increasing, and the number of frequency points to be tested is also increasing. Manual testing is not only time-consuming and laborious, but also cannot meet the needs of large-scale screening. Therefore, how to design a filter control board that can automatically switch the test frequency points is particularly important. The current filter control device design suitable for high-speed ADC performance testing mainly has the following problems:

[0004] At present, there is no effective solution to the problem that the test frequency points cannot be automatically switched in the related art. CONTENT OF THE INVENTION

[0005] The embodiments of the present application provide a filtering gating device and a test system to at least solve the problem of automatic switching of test frequency points in the related art.

[0006] In a first aspect, the embodiments of the present application provide a filtering gating device, which comprises at least two filtering circuits, each of the filtering circuits comprises a first switch module, a filtering module and a second switch module, and the filtering modules in each of the filtering circuits have different filtering frequency bands; wherein

[0007] The output end of the first switch module is connected with the input end of the filtering module, and the output end of the filtering module is connected with the input end of the second switch module.

[0008] In some embodiments, the filtering gating device comprises a signal source, the output end of the signal source is connected with the input end of the first switch module in each of the filtering circuits; wherein

[0009] The signal source is configured to output the first signal corresponding to different frequency bands.

[0010] In some embodiments, the filtering gating device further comprises a gating module, the gating module comprises a first output end and a second output end; wherein

[0011] The first output end of the gating module is connected with the control end of the first switch module in each filter circuit; the first output end of the gating module is used for outputting a second signal, and the first switch module turns on or turns off the circuit connection between the input end of the first switch module and the output end of the first switch module in response to the second signal;

[0012] The second output end of the gating module is connected with the control end of the second switch module; the second output end of the gating module is used for outputting a third signal, and the second switch module turns on or turns off the circuit connection between the input end of the second switch module and the output end of the second switch module in response to the third signal.

[0013] In some embodiments, each filter gating device filter circuit further comprises a first amplification module, the input end of the first amplification module is connected with the first output end of the gating module, and the output end of the first amplification module is connected with the control end of the first switch module; and / or,

[0014] The filter gating device further comprises a second amplification module, the input end of the second amplification module is connected with the second output end of the gating module, and the output end of the second amplification module is connected with the control end of the second switch module.

[0015] In some embodiments, the first switch module comprises a relay, and / or the second switch module comprises a relay.

[0016] In some embodiments, each filter module comprises at least two cascaded filters.

[0017] In some embodiments, each filter circuit further comprises a first debugging module and a second debugging module; wherein,

[0018] The first debugging module is connected with the input end of the filter module or the output end of the first switch module and / or the input end of the filter module in the filter circuit, and the first debugging module is used for providing an externally connected first debugging port.

[0019] Each filter circuit comprises a second debugging module, the second debugging module is connected with the output end of the filter module and / or the input end of the second switch module in the filter circuit, and the first debugging module is used for providing an externally connected second debugging port.

[0020] In a second aspect, the embodiments of the present application provide a test system, comprising: a signal source, a board card and a filter board; wherein,

[0021] The filter board comprises at least two filter circuits; each filter circuit comprises a first switch module, a filter module and a second switch module, the output end of the first switch module is connected with the input end of the filter module, and the output end of the filter module is connected with the input end of the second switch module; wherein the filter modules in each filter circuit are different in filter frequency band.

[0022] The output end of the signal source is connected with the input end of the first switch module in the filter board, and the signal source is configured to output a first signal corresponding to different frequency bands.

[0023] The board card comprises a first output end and a second output end; the first output end of the board card is connected with the control end of the first switch module, and the first output end of the board card is configured to output a second signal; the second output end of the board card is connected with the control end of the second switch module, and the second output end of the board card is configured to output a third signal.

[0024] In some embodiments, the test system further comprises an analog-to-digital converter, and the input end of the analog-to-digital converter is connected with the output end of the second switch module in the filter board.

[0025] In some embodiments, each filter module comprises a band-pass filter and a low-pass filter connected with each other.

[0026] Compared with the related art, the filter gating device and the test system provided by the embodiments of the present application can realize the switching of test frequency points by setting at least two filter circuits, changing the conduction states of the first switch module and the second switch module in the filter circuit, and changing the module for filtering the first signal, thereby solving the problem that the test frequency points cannot be automatically switched.

[0027] Details of one or more embodiments of the present application are presented in the following drawings and description to make other features, objects and advantages of the present application more apparent. BRIEF DESCRIPTION OF DRAWINGS

[0028] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The schematic embodiments of the present application and the description thereof are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0029] Figure 1 FIG. 1 is a schematic diagram of a filter gating device in an embodiment;

[0030] Figure 2 FIG. 2 is a schematic diagram of a first amplification module and a second amplification module in an embodiment;

[0031] Figure 3 FIG. 3 is a schematic diagram of a test system in an embodiment;

[0032] Figure 4 Fig. 1 is a schematic diagram of a connection between a board card and a first amplification module in an embodiment;

[0033] Figure 5 Fig. 2 is a schematic diagram of a suppression effect of a filter module in an embodiment;

[0034] Figure 6 Fig. 3 is a schematic diagram of a filter module with an SMA joint reserved in an embodiment;

[0035] Figure 7 Fig. 4 is a schematic diagram of a test system in another embodiment.

[0036] Fig. 1 is a schematic diagram of a connection between a board card and a first amplification module in an embodiment; DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described and illustrated in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of the present application. In addition, it should be understood that although the efforts made in this development process can be complex and lengthy, some designs, manufacturing or production changes made on the basis of the technical content disclosed in the present application by those of ordinary skill in the art related to the content disclosed in the present application are only routine technical means and should not be understood as insufficient disclosure of the present application.

[0038] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment that is not mutually exclusive with other embodiments. Those of ordinary skill in the art explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments without conflict.

[0039] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application means two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The terms “first,” “second,” “third,” etc., used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0040] This embodiment provides a filtering and gating device 1. Figure 1 This is a schematic diagram of a filtering and gating device 1 in this embodiment, as shown below. Figure 1 As shown, it includes at least two filter circuits 100, each filter circuit 100 including a first switch module 101, a filter module 102 and a second switch module 103, and the filter frequency band of the filter module 102 in each filter circuit 100 is different; wherein, the output terminal of the first switch module 101 is connected to the input terminal of the filter module 102, and the output terminal of the filter module 102 is connected to the input terminal of the second switch module 103.

[0041] The first switch module 101 and the second switch module 103 are used to turn on or turn off the circuit connection. The devices in different first switch modules 101 and second switch modules 103 can be the same or different. The first switch module 101 and the second switch module 103 can change their conduction states according to the externally input signals; they can also change their conduction states in response to user interaction. Optionally, the first switch module 101 and the second switch module 103 can be electronic switches, such as relays, transistors, field effect tubes, etc.; the first switch module 101 and the second switch module 103 can also be mechanical switches, such as buttons, switching valves, etc. The filtering module 102 is used to filter the first signal. Optionally, the filtering module 102 includes one or more filters; the filtering bands corresponding to each filter circuit 100 are different, so the filter parameters in different filtering modules 102 are different.

[0042] When the filter gating device 1 performs the filter gating function, the first signal is received by the first switch module 101; the first signal is filtered by the filtering module 102; and the filtered first signal is output by the second switch module 103 when it is turned on. Specifically, when the first switch module 101 and the second switch module 103 in the same filter circuit 100 output the conduction state at the same time, the filter circuit 100 can filter the first signal and output the filtered first signal. Conversely, if any of the first switch module 101 and the second switch module 103 is in the off state, the filter circuit 100 cannot output the filtered first signal. Optionally, the first signal is input to multiple different filter circuits 100, and by adjusting the first switch module 101 and the second switch module 103, if the first switch module 101 and the second switch module 103 in the filter circuit 100 are in the conduction state at the same time, the first signal can be transmitted to the filtering module 102 in the filter circuit 100 through the first switch module 101 in the filter circuit 100. After the filtering module 102 filters the first signal, the filtered first signal is output through the second switch module 103.

[0043] In this embodiment, at least two filter circuits 100 suitable for different frequency bands are provided, and by changing the conduction states of the first switch module 101 and the second switch module 103 in the filter circuit 100, different filtering modules 102 are selected to filter the first signal, realizing the switching of the test frequency point without manually laying out a new test module to adapt to different frequency input signals, solving the problem of unable to automatically switch the test frequency point.

[0044] In some embodiments, the filter gating device 1 includes a signal source 10, the output end of the signal source 10 is connected with the input end of the first switch module 101 in each filter circuit 100; wherein the signal source 10 is used to output the first signal corresponding to different frequency bands.

[0045] The signal source 10 can be a signal output by a generator of any waveform, for example, a sine wave signal, a pulse signal, etc.; or the signal source 10 can provide a stable direct current voltage or current output signal. The signal source 10 can output first signals of different frequency bands at different times. Alternatively, the signal source 10 outputs a 5MHz signal in a first time period and outputs a 20MHz first signal in a second time period. The signal source 10 can also output first signals of other frequency bands, and the output frequency and corresponding time length of the first signal are not limited herein. Alternatively, the frequency band of the first signal output by the signal source 10 corresponds to the filtering frequency band of the plurality of filtering modules 102 in each filtering circuit 100. In this embodiment, the signal source 10 is arranged in the filtering gating device 1 to ensure that the filtering circuit 100 in the filtering gating device 1 can always filter the first signal.

[0046] In some embodiments, the filtering gating device 1 further comprises a gating module 106, the gating module 106 comprising a first output end and a second output end; wherein the first output end of the gating module 106 is connected to the control end of the first switch module 101 in each filtering circuit 100; the first output end of the gating module 106 is used to output a second signal, and the first switch module 101 is turned on or off in response to the second signal to open or close the circuit connection between the input end of the first switch module 101 and the output end of the first switch module 101;

[0047] The second output end of the gating module 106 is connected to the control end of the second switch module 103, and the second output end of the gating module 106 is used to output a third signal, and the second switch module 103 is turned on or off in response to the third signal to open or close the circuit connection between the input end of the second switch module 103 and the output end of the second switch module 103.

[0048] The gating module 106 can be a microprocessor, programmable logic controller, timer or any other device capable of outputting signals to control the on-off states of the first switch module 101 and the second switch module 103. The second signal and the third signal have amplitudes matching the rated values of the first switch module 101 and the second switch module 103. Alternatively, the gating module 106 includes a plurality of first output terminals, each of which is connected to the first switch module 101 in each filter circuit 100, and each first output terminal synchronously or asynchronously outputs one or more second signals. The gating module 106 includes a plurality of second output terminals, each of which is connected to the second switch module 103 in each filter circuit 100, and each second output terminal synchronously or asynchronously outputs one or more third signals. Alternatively, the gating module 106 simultaneously outputs the second signal and the third signal to the first switch module 101 and the second switch module 103 in the same filter circuit 100, so that the first switch module 101 and the second switch module 103 in the filter circuit 100 are simultaneously in the on state.

[0049] In this embodiment, the gating module 106 outputs different signals to adjust the on-off states of the first switch module 101 and the second switch module 103, thereby achieving flexible control of the first switch module 101 and the second switch module 103.

[0050] Further, in some embodiments, the filter gating device 1 further includes a first amplification module 104, the input terminal of the first amplification module 104 is connected to the first output terminal of the gating module 106, and the output terminal of the first amplification module 104 is connected to the control terminal of the first switch module 101; and / or, the filter gating device 1 further includes a second amplification module 105, the input terminal of the second amplification module 105 is connected to the second output terminal of the gating module 106, and the output terminal of the second amplification module 105 is connected to the control terminal of the second switch module 103.

[0051] The first amplification module 104 and the second amplification module 105 are current amplification circuits. The first amplification module 104 is used to improve the driving capability of the second signal; the second amplification module 105 is used to improve the driving capability of the third signal. The amplification multiples of the first amplification module 104 and the second amplification module 105 can be set according to the driving capability improvement requirements.

[0052] Figure 2 A schematic diagram of the first amplification module 104 and the second amplification module 105 is provided as follows: Figure 2As shown, the first output end of the gating module 106 is connected with the input end of the first amplification module 104, and the output end of the first amplification module 104 is connected with the control end of the first switch module 101 in each filter circuit 100.

[0053] Optionally, the second amplification module 105 and the first amplification module 104 are respectively multi-channel drivers, and the number of channels of the drivers is not less than the number of the filter circuits 100. The first output end of the gating module 106 outputs multiple second signals to the first amplification module 104, and the first amplification module 104 respectively amplifies the current values of the multiple second signals and then inputs the amplified second signals to the control ends of the first switch modules 101 in the filter circuits 100. The second output end of the gating module 106 outputs multiple third signals to the second amplification module 105, and the second amplification module 105 respectively amplifies the current values of the multiple third signals and then inputs the amplified third signals to the control ends of the second switch modules 103 in the filter circuits 100.

[0054] In the embodiment, the first amplification module 104 and / or the second amplification module 105 are added in the filter gating device 1 to improve the current, improve the driving capability of the gating module 106 to output digital signals, and improve the stability of the filter gating device 1.

[0055] In some embodiments, the first switch module 101 includes a relay, and / or the second switch module 103 includes a relay. The first switch module 101 and the second switch module 103 can be selected from a normally open relay, a normally closed relay, or a change-over relay, etc. The relay in the first switch module 101 and the relay in the second switch module 103 can be the same type of relay or different relays, and thus the conduction conditions of the first switch module 101 and the second switch module 103 can be the same or different. Optionally, a filter circuit 100 is added at the output end of the first switch module 101 and / or the second switch module 103 to filter the output signal, absorb the reverse signal, and improve the stability of the circuit.

[0056] In the embodiment, the relay is used as the gating switch of the filter module 102 of different frequency bands, which has the advantages of low noise, good stability, and low cost compared with the traditional mechanical switch.

[0057] In some embodiments, each filter module 102 includes a plurality of cascaded filters. The cascaded filters can be connected in series or in parallel. The cascaded filters can be a low-pass filter 1021 and a band-pass filter 1022, or a low-pass filter 1021 and a low-pass filter 1021, a band-pass filter 1022 and a band-pass filter 1022, and so on. The cascaded filters in each filter module 102 can be the same or different.

[0058] The present embodiments can achieve wider bandwidth coverage by providing cascaded filters in the filter module 102, which is suitable for multi-band or multi-channel applications, improves impedance matching in the filter circuit 100, and reduces signal reflection and loss.

[0059] In some embodiments, each filter circuit 100 further includes a first debugging module and a second debugging module. The first debugging module is connected to the output of the first switch module 101 and / or the input of the filter module 102, and the first debugging module is configured to provide an external first debugging port. The second debugging module is connected to the output of the filter module 102 and / or the input of the second switch module 103, and the first debugging module is configured to provide an external second debugging port.

[0060] When the first debugging module is connected to the output of the first switch module 101 and the second debugging module is connected to the input of the second switch module 103, the first debugging port and the second debugging port can be connected to an external filter, so that the external filter processes the first signal. When the first debugging module is connected to the input of the filter module 102 and the second debugging module is connected to the output of the filter module 102, the first debugging port and the second debugging port can be connected to an external device, so that the external device checks the filter module 102.

[0061] Optionally, the first debugging module comprises a first switching unit and a first debugging port, the first debugging port is connected with a first end of the first switching unit, a second end of the first switching unit is connected with the output end of the first switch module 101, and a third end of the first switching unit is connected with the input end of the filter module 102. The first switching unit can change its conduction state to make the circuit between the first end and the second end of the first switching unit conductive connection, or the circuit between the first end and the third end of the first switching unit conductive connection. When the circuit between the first end and the second end of the first switching unit is conductive connection, the first debugging port can be connected with the output end of the first switch module 101 through the first switching unit, so that the filter circuit 100 can be connected to the external filter through the first debugging port; when the circuit between the first end and the third end of the first switching unit is conductive connection, the first debugging port can also be connected with the input end of the filter module 102 through the first switching unit, so that the filter module 102 can be connected to the external device through the first debugging port and verify the performance of the filter module 102.

[0062] Optionally, the second debugging module comprises a second switching unit and a second debugging port, the second debugging port is connected with a first end of the second switching unit, a second end of the second switching unit is connected with the output end of the second switch module 103, and a third end of the second switching unit is connected with the input end of the filter module 102. The second switching unit can change its conduction state to make the circuit between the first end and the second end of the second switching unit conductive connection, or the circuit between the first end and the third end of the second switching unit conductive connection. When the circuit between the first end and the second end of the second switching unit is conductive connection, the second debugging port can be connected with the input end of the output end of the second switch module 103 through the second switching unit, so that the filter circuit 100 can be connected to the external filter through the first debugging port; when the circuit between the first end and the third end of the first switching unit is conductive connection, the second debugging port can also be connected with the input end of the filter module 102 through the second switching unit, so that the filter module 102 can be connected to the external device through the second debugging port and verify the performance of the filter module 102.

[0063] In the embodiment, through the first debugging module and the second debugging module, when the filter module 102 is damaged or the performance cannot meet the demand of the screening sheet, the external filter can be used for filtering and verifying the performance of the filter module 102, so that the design flexibility of the filter gating device 1 is increased.

[0064] In the related art, the filter gating device 1 suitable for the performance test of the high-speed ADC is required to switch the test frequency point, and the high-speed ADC is particularly sensitive to noise, and the circuit layout and device selection are extremely harsh.

[0065] The embodiments also provide a test system for implementing the above-described embodiments and preferred embodiments, which have been described and will not be repeated. As used below, the terms "module", "unit", "sub-unit" and the like can be a combination of software and / or hardware that implements a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and contemplated.

[0066] In one embodiment, Figure 3 is a schematic diagram of a test system in the embodiments, as Figure 3 shown, the test system includes a signal source 10, a board card 11 and a filter board 12, the filter board 12 includes at least two filter circuits 100, each filter circuit 100 includes a first switch module 101, a filter module 102 and a second switch module 103, the output end of the first switch module 101 is connected with the input end of the filter module 102, the output end of the filter module 102 is connected with the input end of the second switch module 103; wherein the filter modules 102 in each filter circuit 100 are different in filter frequency band. The output end of the signal source 10 is connected with the input end of the first switch module 101 in the filter board 12, the signal source 10 is used for outputting a first signal corresponding to different frequency bands. The board card 11 includes a first output end and a second output end; the first output end of the board card 11 is connected with the control end of the first switch module 101, the first output end of the board card 11 is used for outputting a second signal; the second output end of the board card 11 is connected with the control end of the second switch module 103, the second output end of the board card 11 is used for outputting a third signal.

[0067] In one embodiment, the test system further includes an analog-to-digital converter 2, the analog-to-digital converter 2 is connected with the second switch module 103 in the filter board 12. Wherein the analog-to-digital converter 2 finally receives the filtered first signal output by the filter board 12.

[0068] Optionally, the signal source 10 is configured to generate the required different frequency ADC input signals, i.e. the first signals. The filter board 12 is provided with a plurality of filter circuits 100, each of which includes a first switch module 101, a filter module 102 and a second switch module 103 connected in sequence. The first switch module 101 includes an input end, an output end and a control end, the input end of the first switch module 101 is connected with the signal source 10, the control end of the first switch module 101 is connected with the gating module 106, and the output end of the first switch module 101 is connected with the input end of the filter module 102. The second switch module 103 includes an input end, an output end and a control end, the input end of the second switch module 103 is connected with the output end of the filter module 102, the control end of the first switch module 101 is connected with the gating module 106, and the output end of the first switch module 101 is connected with the high-speed ADC. The first switch module 101 and the second switch module 103 are selected from a relay. Optionally, the first switch module 101 and the second switch module 103 can be selected from a relay as a gating switch.

[0069] The NI board card 11 is used as the gating module 106, and the NI board card 11 is configured to generate a digital control signal to control the gating of the filter module 102 of the corresponding frequency band according to the frequency of the input signal. Optionally, the NI board card 11 is connected with the upper computer, and according to the output instruction of the upper computer, the first signal is output to the first switch module 101, and the second signal is output to the second switch module 103.

[0070] Optionally, since the NI board card 11 has weak digital signal driving capability, the test system further includes a first amplification module 104 connected with the NI board card 11, Figure 4 is a connection diagram of the NI board card 11 and the first amplification module 104 in the embodiment, as Figure 4 shown, the NI board card 11 outputs the second signals CTRL_FA, CTRL_FB, CTRL_FC, CTRL_FD, CTRL_FE and CTRL_FF to the first amplification module 104, wherein a driver can be selected as the first amplification module 104. After the second signals are amplified by the driver, the amplified signals CTRL_FA_Driver, CTRL_FB_Driver, CTRL_FC_Driver, CTRL_FD_Driver, CTRL_FE_Driver and CTRL_FF_Driver are output to the first switch module 101 in each filter circuit 100. Based on the same principle, the test system can further be provided with a second amplification module 105, the third signal is output to the second amplification module 105 by the NI board card 11, a driver is selected as the second amplification module 105, and the amplified signal of the driver is output to the second switch module 103.

[0071] Optionally, the test system further comprises a connector connected with the NI board card 11, and the second signal and the third signal output by the NI board card 11 are connected with the driver through the connector. By setting the connector, multi-channel signal transmission can be realized, and the modular degree of the test system is improved.

[0072] To measure the real performance of the high-speed ADC, in an embodiment, each filter module 102 comprises a low-pass filter 1021 and a band-pass filter 1022 connected with each other. By the low-pass filter 1021 and the band-pass filter 1022, the harmonics and the spurs of the signal source 10 can be effectively suppressed to achieve the ideal input signal required by the high-speed ADC. Figure 5 is a schematic diagram of the suppression effect of the filter module 102 in the embodiment, as Figure 5 shown, taking a 5MHz filter as an example, m1 point with a frequency (freq) of 10.01MHz and m2 point with a frequency of 20.17MHz are selected, and in combination with the loss value (dB), it can be seen that the insertion loss of the low-pass filter 1021 and the band-pass filter 1022 connected with each other is only 3.3dB, but the second harmonic suppression can reach 155dB, and the harmonics and the spurs of the signal source 10 can be completely suppressed to the noise floor. Therefore, by the low-pass filter 1021 and the band-pass filter 1022 connected with each other, the loss can be reduced while the second harmonic suppression is improved, and good high-speed ADC test performance can be obtained.

[0073] When the low-pass filter 1021 and the band-pass filter 1022 connected with each other filter the input signal of the signal source 10, because the narrow-band band-pass filter 1022 is particularly sensitive, in order to avoid impedance mismatch between the low-pass filter 1021 and the band-pass filter 1022, optionally, an impedance matching network can be arranged to be connected with the low-pass filter 1021 and the band-pass filter 1022, to ensure efficient transmission of the signal between the filters.

[0074] Optionally, in order to reserve a manual debugging and verification scheme in the filter circuit, in the embodiment, SMA connectors are reserved at the input and output ends of the low-pass filter 1021 and the band-pass filter 1022. Figure 6 A filter module 102 with SMA connectors is provided, as Figure 6As shown, the low-pass filter 1021 is connected in series with the band-pass filter 1022. For the low-pass filter 1021, the input end is connected with the first end of the resistor R4, the second end of the resistor R4 is connected with the first end of the resistor R1 and the first end of the resistor R3 respectively, the second end of the resistor R1 is used to receive the first signal, and the second end of the resistor R3 is connected with the first SMA joint J1. Among them, the resistor R4, the resistor R1 and the resistor R3 and the first SMA joint J1 constitute the first debugging module in the above-mentioned embodiment, and the first SMA joint J1 is the first debugging joint. The output end of the low-pass filter 1021 is connected with the first end of the resistor R5 and the first end of the resistor R2, the second end of the resistor R1 is connected with the second SMA joint J2, and the second end of the resistor R5 is connected with the input end of the band-pass filter 1022.

[0075] For the band-pass filter 1022, the input end is connected with the first end of the resistor R7 and the first end of the resistor R8, the second end of R7 is connected to the third SMA joint J3, and the second end of the resistor R8 is connected to the input end of the low-pass filter 1021; the output end of the band-pass filter 1022 is connected with the first end of the resistor R9, the second end of the resistor R9 is connected with the first end of the resistor R6 and the first end of the resistor R10 respectively, the second end of the resistor R5 is connected with the fourth SMA joint J4, and the second end of the resistor R10 is connected with the filter module 102. Among them, the resistor R9, the resistor R6 and the resistor R10 constitute the second debugging module in the above-mentioned embodiment, and the fourth SMA joint J4 is the second debugging joint.

[0076] Optionally, the two 0ohm resistors R1 and R3 of the SMA end adopt a common pad design. In the case that the overall test performance of the test system is not good, R3 can not be welded, and R1 can be welded; R5 can not be welded, and R2 can be welded. So that the two SMA joints can connect the low-pass filter 1021 to the instrument, verify the filter performance through the instrument, and achieve the effect of conveniently verifying the filter performance in segments while reducing the influence of the branch circuit in the compatible circuit to the maximum extent. Similarly, R8 and R10 can not be welded, and the band-pass filter 1022 can be connected to the instrument. When the filter designed on the board is damaged or the performance cannot meet the demand of screening the chip, R9 and R4 can be disconnected, and connected to the external filter through the first SMA joint J1 and the fourth SMA joint J4, so as to minimize the influence of the filter circuit on the board on the external filter. Increase the design flexibility of the filter control device.

[0077] In one embodiment, Figure 7 A preferred test system is provided, such as Figure 7As shown, the signal source 10 is selected as SMB100B; the board card 11 is selected as model NI-USB6281. The relay with model IM-B03IGR is used as the first switch module 101 and the second switch module 103 of the filter path selection, and this relay has the advantages of small size, very small VSWR (Voltage Standing Wave Ratio, voltage standing wave ratio), very small insertion loss, large isolation, and small mechanical switch noise, and is particularly suitable for use as a switch of the filter board 12 in the embodiment. The board card 11 outputs signals to each first switch module 101 and second switch module 103. Alternatively, since the NI board card 11 has weak digital signal driving capability, a driver with model TBD62003AFG can be used to drive the relay to control the corresponding filter module 102. A plurality of filter modules 102 can process first signals in the range of 5MHz to 200MHz respectively. It can be understood that other models of signal source 10, board card 11, relay and driver can be used, and the number of filter modules 102 is selected according to requirements. In order to realize the control of different frequency band filters, the frequency band of the filter in the filter module 102 can be increased, deleted or adjusted, and the control signal output by the NI board card 11, i.e. the first signal and the second signal, can be increased, deleted or adjusted according to the number of filter modules.

[0078] The test system in the embodiment uses a relay as a frequency band filter selection switch, and compared with a traditional radio frequency switch, such a mechanical switch has the advantages of low noise, good stability, low cost, etc.; the low-pass and band-pass filters 1022 are cascaded to have excellent harmonic and spurious suppression effect and high circuit integration; and the SMA port is set to have high debugging flexibility.

[0079] The filter control device based on the relay for selecting each frequency band LC filter has the advantages of low noise, good reliability, low cost, excellent harmonic and spurious suppression effect by cascading the low-pass and band-pass filters 1022, high integration level, high flexibility, convenient debugging, etc.

[0080] It should be noted that each of the above modules can be a functional module or a program module, and can be implemented by software or hardware. For the modules implemented by hardware, each of the above modules can be located in the same processor; or each of the above modules can also be located in different processors in any combination.

[0081] Those skilled in the art should understand that each technical feature of the above embodiments can be combined arbitrarily, and for the sake of brevity, each technical feature in the above embodiments is not described in all possible combinations, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the description.

[0082] The above embodiments only express several implementation manners of the application, the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are all within the protection scope of the application. Therefore, the protection scope of the patent of the application should be subject to the appended claims.

Claims

1. A filter gating device (1), characterized in that The filter gating device (1) comprises at least two filter circuits (100), each of the filter circuits (100) comprises a first switch module (101), a filter module (102) and a second switch module (103), the filter modules (102) in each of the filter circuits (100) are different in filter frequency band; wherein, the output end of the first switch module (101) is connected with the input end of the filter module (102), and the output end of the filter module (102) is connected with the input end of the second switch module (103).

2. The filter gating device (1) according to claim 1, characterized in that The filter gating device (1) comprises a signal source (10), and the output end of the signal source (10) is connected with the input end of the first switch module (101) in each of the filter circuits (100); wherein, the signal source (10) is used for outputting a first signal corresponding to different frequency bands.

3. The filter gating device (1) according to claim 1, characterized in that The filter gating device (1) further comprises a gating module (106), and the gating module (106) comprises a first output end and a second output end; wherein, the first output end of the gating module (106) is connected with the control end of the first switch module (101) in each of the filter circuits (100); the first output end of the gating module (106) is used for outputting a second signal, and the first switch module (101) is turned on or turned off in response to the second signal to connect or disconnect the circuit connection between the input end of the first switch module (101) and the output end of the first switch module (101); the second output end of the gating module (106) is connected with the control end of the second switch module (103), and the second output end of the gating module (106) is used for outputting a third signal, and the second switch module (103) is turned on or turned off in response to the third signal to connect or disconnect the circuit connection between the input end of the second switch module (103) and the output end of the second switch module (103).

4. The filter gating device (1) according to claim 3, characterized in that The filter gating device (1) further comprises a first amplification module (104), the input end of the first amplification module (104) is connected with the first output end of the gating module (106), and the output end of the first amplification module (104) is connected with the control end of the first switch module (101); and / or, The filter gating device (1) further comprises a second amplification module (105), the input end of the second amplification module (105) is connected with the second output end of the gating module (106), and the output end of the second amplification module (105) is connected with the control end of the second switch module (103).

5. The filter gating device (1) according to claim 1, characterized in that The first switch module (101) comprises a relay, and / or the second switch module (103) comprises a relay.

6. The filter gating device (1) according to claim 1, characterized in that Each of the filter modules (102) comprises at least two cascaded filters.

7. The filter gating device (1) according to claim 1, characterized in that Each of the filter circuits (100) further comprises a first debugging module and a second debugging module; wherein, the first debugging module is connected with the output end of the first switch module (101) and / or the input end of the filter module (102) in the filter circuit (100), and the first debugging module is used for providing an externally connected first debugging port; The second debugging module is connected with the output end of the filtering module (102) and / or the input end of the second switch module (103) in the filtering circuit (100), and the first debugging module is used for providing an externally connected second debugging port.

8. A test system, characterized by Comprise: A signal source (10), a board card (11) and a filter board (12); wherein, The filter board (12) comprises at least two filtering circuits (100); each filtering circuit (100) comprises a first switch module (101), a filtering module (102) and a second switch module (103), the output end of the first switch module (101) is connected with the input end of the filtering module (102), and the output end of the filtering module (102) is connected with the input end of the second switch module (103); wherein the filtering frequency bands of the filtering modules (102) in each filtering circuit (100) are different; The output end of the signal source (10) is connected with the input end of the first switch module (101) in the filter board (12), and the signal source (10) is used for outputting first signals corresponding to different frequency bands; The board card (11) comprises a first output end and a second output end; the first output end of the board card (11) is connected with the control end of the first switch module (101), and the first output end of the board card (11) is used for outputting second signals; the second output end of the board card (11) is connected with the control end of the second switch module (103), and the second output end of the board card (11) is used for outputting third signals.

9. The test system of claim 8, wherein, The test system further comprises an analog-to-digital converter (2), and the input end of the analog-to-digital converter (2) is connected with the output end of the second switch module (103) in the filter board (12).

10. The test system of claim 9, wherein, Each filtering module (102) comprises a band-pass filter (1022) and a low-pass filter (1021) which are connected in series.

Images