CN106053980B - A kind of backboard electromagnetic compatibility detection device and method - Google Patents

Abstract

The invention discloses a backplane electromagnetic compatibility detection device and method. The device includes: a detection processor, a modem module and multiple frequency source modules. The modem module is plugged into the modem slot on the backplane, and each frequency source module is plugged into a frequency source on the backplane. In the slot; the first frequency source module is used to transmit input signals to the modem module; frequency source modules other than the first frequency source module are used to transmit local oscillator signals to the modem module; the modem module transmits, It is used to mix the received input signal and the local oscillator signal to generate a point frequency signal; the detection processor is used to judge and know that the frequency value of the point frequency signal is within a preset range according to the input signal and the local oscillator signal, then Verify that the backplane is electromagnetically compatible. The invention can effectively detect the electromagnetic compatibility of the backboard by comparing the local oscillator signal of the module, the input signal input to the backboard and the output signal after frequency mixing.

Description

Device and method for detecting backplane electromagnetic compatibility

technical field

The invention relates to the technical field of circuit boards, in particular to a backplane electromagnetic compatibility detection device and method.

Background technique

The rack-mounted backplane structure is the mainstream technical architecture of large-scale electronic systems. Most modern telecommunication systems, data communication systems, and complex computer systems use modular rack structures. Because the rack-mounted backplane system has a backplane and multiple plug-in boards, the system performance and capacity can be greatly improved by adding more plug-in boards on the backplane and increasing the port density of the plug-in boards. Therefore, the rack-mounted backplane system has become the first choice for the development of complex electronic systems because of its high-capacity switching capabilities and excellent stability in terms of performance and application. Fundamentals of digital system design and implementation.

The backplane is a board-level interconnection composed of passive components, and acts as a communication highway between boards and boards in electronic equipment. As a bridge connecting daughter cards, the backplane is more and more widely used, whether it is a baseband processing board or a radio frequency board. In the system developed by the project, the backplane is mainly used for the connection between boards such as radio frequency modules and transceiver modules. The backplane is the core unit to realize data communication between boards in a multi-board electronic system. Almost no electronic system can be separated from the backplane, and the application of the backplane is ubiquitous.

There are many differences between the backplane and the general circuit board. For example, the backplane has a stronger load capacity and a relatively larger size. At the same time, its signal topology is more complex and the density of connectors is higher. Therefore, when designing the backplane, it is necessary to face signal integrity issues such as signal crosstalk, transmission line effects, and noise, as well as technical issues such as power distribution design and EMC/EMI control. In particular, the backplane is required to have a high level of electromagnetic compatibility.

Based on the connection between multiple modules of the electronic system through the backplane, the number of modules is gradually increasing, and the connection density and connection length of the modules on the backplane are also increasing. Therefore, it is very important to design the backplane and test and verify its electromagnetic compatibility. Necessary, at the same time, build a module-backplane-module interconnection system to test and verify the electromagnetic compatibility of the modular communication lines.

Contents of the invention

Aiming at the defects in the prior art, the present invention provides a backplane electromagnetic compatibility detection device and method, which can effectively detect the backplane electromagnetic compatibility.

The invention proposes a backplane electromagnetic compatibility detection device, including: a detection processor, a modulation and demodulation module, and multiple frequency source modules;

The modem module and the frequency source module are arranged on the backplane;

The first frequency source module among the plurality of frequency source modules is configured to transmit input signals to the modem module through the communication line of the backplane;

The frequency source modules other than the first frequency source module among the plurality of frequency source modules are used to transmit local oscillator signals to the modem module through the communication line of the backplane;

The modulation and demodulation module is used to mix the received input signal and the local oscillator signal to generate a point frequency signal;

The detection processor is configured to determine that the frequency value of the point frequency signal is within a preset range according to the input signal and the local oscillator signal, and then confirm that the backplane has electromagnetic compatibility.

Preferably, the backplane has a modem slot and a plurality of frequency source slots;

The modem module is plugged into the modem slot, and each frequency source module is plugged into a frequency source slot.

Preferably, each frequency source slot is provided with an input port;

The modem slot is provided with a plurality of output ports, the first output port in the plurality of output ports is used as the total output port of the modem slot, and the first output port of the plurality of output ports is The output port other than the output port establishes a one-to-one correspondence with the input port;

Wherein, the corresponding input port and output port are connected through the communication line on the backplane.

Preferably, the detection processor is further configured to acquire the input signal, the local oscillator signal and the point frequency signal collected by the probe to detect the input port and the total output port, and according to the input signal and the local oscillator signal A preset range is set to determine whether the frequency value of the spot frequency signal is within the preset range.

Preferably, the detection processor is further configured to acquire the signal spectrum at the input port, the output port and the total output port detected by the probe when only one frequency source module is working;

The frequency spectrum of the signal is detected, and it is determined that the frequency value of the point frequency signal is within the preset range, and then it is confirmed that the backplane and the frequency source module have electromagnetic compatibility.

Preferably, it also includes: a plurality of connectors;

The connector is used to connect the modem module and the modem slot, and the frequency source module and the frequency source slot.

It can be seen from the above technical solution that the backplane electromagnetic compatibility detection method proposed by the present invention can effectively detect the backplane EMC by comparing the local oscillator signal of the module, the input signal input to the backplane, and the output signal after the frequency mixing process. electromagnetic compatibility.

The present invention also proposes a backplane electromagnetic compatibility detection method, including:

The first frequency source module transmits an input signal to the modem module through the communication line of the backplane;

At least one second frequency source module transmits a local oscillator signal to the modem module through the communication line of the backplane;

The modulation and demodulation module performs frequency mixing processing on the received input signal and the local oscillator signal to generate a point frequency signal;

The detection processor determines that the frequency value of the point frequency signal is within a preset range according to the input signal and the local oscillator signal, and then confirms that the backplane has electromagnetic compatibility.

Preferably, the step of judging and knowing that the frequency value of the point frequency signal is within a preset range according to the input signal and the local oscillator signal specifically includes:

Obtaining the input signal, local oscillator signal and point frequency signal collected by the probe to detect the input port and the total output port;

A preset range is set according to the input signal and the local oscillator signal to determine whether the frequency value of the spot frequency signal is within the preset range.

Preferably, when it is detected that only one frequency source module is working, the signal spectrum at the input port, the output port and the total output port detected by the probe is obtained;

The frequency spectrum of the signal is detected, and it is determined that the frequency value of the point frequency signal is within the preset range, and then it is confirmed that the backplane and the frequency source module have electromagnetic compatibility.

It can be seen from the above technical solution that the backplane electromagnetic compatibility detection device proposed by the present invention can effectively detect the backplane EMC by comparing the local oscillator signal of the module, the input signal input to the backplane, and the output signal after the frequency mixing process. electromagnetic compatibility.

Description of drawings

The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the accompanying drawings:

FIG. 1 shows a schematic structural diagram of a backplane electromagnetic compatibility detection device provided by an embodiment of the present invention;

Figure 2 shows a schematic structural view of the backplane in the backplane electromagnetic compatibility detection device provided by an embodiment of the present invention;

Fig. 3 shows a schematic flowchart of a backplane electromagnetic compatibility detection method provided by an embodiment of the present invention.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Fig. 1 is a schematic structural diagram of a backplane electromagnetic compatibility detection device provided by an embodiment of the present invention. With reference to Fig. 1, the backplane electromagnetic compatibility detection device includes: a detection processor (not shown in the figure), a modulation and demodulation Module 200 and a plurality of frequency source modules 300;

The modem module 200 and the frequency source module 300 are arranged on the backplane 100;

It should be noted that there are many ways to install the modem module 200 and the frequency source module 300 on the backplane 100 , such as welding, bonding, etc.; no limitation is given here.

The first frequency source module among the plurality of frequency source modules 300 is configured to transmit an input signal to the modem module 200 through the communication line of the backplane 100;

It should be noted that, the wiring on the backplane 100 may be determined as required.

The frequency source modules 300 of the plurality of frequency source modules 300 except the first frequency source module are used to transmit local oscillator signals to the modem module 200 through the communication line of the backplane 100;

The modulation and demodulation module transmission 200 is used to perform frequency mixing processing on the received input signal and the local oscillator signal to generate a point frequency signal;

The detection processor is configured to determine that the frequency value of the point frequency signal is within a preset range according to the input signal and the local oscillator signal, and then confirm that the backplane 100 has electromagnetic compatibility.

It should be noted that the backplane 100 is also provided with a port connected to a power supply device, so as to uniformly supply power to the modem module 200 and multiple frequency source modules 300;

The present invention can effectively detect the electromagnetic compatibility of the backplane 100 by comparing the local oscillator signal of the module, the input signal input to the backplane 100 and the output signal after frequency mixing.

Fig. 2 is a schematic structural diagram of a backplane in a backplane electromagnetic compatibility detection device provided by an embodiment of the present invention. With reference to Fig. 2, the backplane has a modulation and demodulation slot and a plurality of frequency source slots;

The modem module 200 is plugged into the modem slot, and each frequency source module 300 is plugged into a frequency source slot.

It is understandable that the modem slot and multiple frequency source slots are done when designing the backplane.

In this embodiment, each frequency source slot is provided with an input port;

The modem slot is provided with a plurality of output ports, the first output port in the plurality of output ports is used as the total output port of the modem slot, and the first output port of the plurality of output ports is The output port other than the output port establishes a one-to-one correspondence with the input port;

Wherein, the input port and the output port having a corresponding relationship are connected through the communication line of the backplane 100 .

In this embodiment, the detection processor is further configured to obtain the input signal, the local oscillator signal and the point frequency signal collected by the probe detection of the input port and the total output port, and according to the input signal and the local oscillator The signal is set in a preset range to determine whether the frequency value of the spot frequency signal is within the preset range.

The working principle of the above scheme is illustrated below, referring to Fig. 1 and Fig. 2, in this embodiment, there are three frequency source modules 300, three frequency source slots, the first frequency source slot, the second frequency source slot Groove and the 3rd frequency source slot, each frequency source slot inserts a frequency source module 300, and modem slot has one; Wherein, an input port Port1 is arranged in the first frequency source slot, the second frequency An input port Port3 is arranged in the source slot, an input port Port5 is arranged in the third frequency source slot, four output ports, Port2, Port4 and Port6, and a total output port are arranged in the modem slot;

The frequency source module in the first frequency source slot outputs a 2.4GHz point frequency signal to the modem module through the backplane as the local oscillator signal LO1; the frequency source module in the second frequency source slot also passes The backplane provides a 2.4GHz point frequency signal to the modem module as the local oscillator signal LO2; the frequency source module in the third frequency source slot provides a 2.35GHz input signal IN to the modem module through the backplane.

Correspondingly, the backplane includes three communication lines, namely Port1-Port2, Port3-Port4, and Port5-Port6, which respectively transmit 2.4GHz, 2.4GHz, and 2.35GHz radio frequency signals.

According to the communication thread and function, theoretically speaking, when the above four modules work at the same time, that is, when two 2.4GHz local oscillator signals and one 2.35GHz input signal are provided to the modulation and demodulation module, the modulation and demodulation module respectively undergoes down-conversion After up-conversion and up-conversion, the total output port will output a 2.45GHz point frequency signal.

In the actual test, when the backplane is supplied with a uniform 5V power supply and the above modules are working at the same time, if a 2.45GHz point frequency signal is generated at the total output port of the backplane, it proves that each module can work normally, and the entire backplane The interconnection device meets the requirements of electromagnetic compatibility, and the degree of interference between modules meets the requirements; if the frequency value of the measured point frequency signal is not 2.45GHz and is not within the allowable range, it proves that each module is in an abnormal working state, and the entire background The board interconnection device does not meet the electromagnetic compatibility requirements, and the degree of interference between modules does not meet the requirements.

In another feasible embodiment, the detection processor is further configured to acquire the signal spectrum at the input port, the output port and the total output port detected by the probe when only one frequency source module is working;

The frequency spectrum of the signal is detected, and it is determined that the frequency value of the point frequency signal is within the preset range, and then it is confirmed that the backplane and the frequency source module have electromagnetic compatibility.

See Figure 2, its working principle is as follows:

Make each frequency source module work independently, and the modem module does not work, that is, only one transmission line of the three transmission lines transmits radio frequency signals at a time.

Let's take one of the states to illustrate, that is, when the Port1-Port2 transmission line is working, and the Port3-Port4 and Port5-Port6 transmission lines are not working, at this time, Port1 can be considered as an input port, Port2 is an output port, and Port3, Port4, and Port5 and Port6 are associated ports, and this state can be described in Table 1:

Table 1 Port1-Port2 work

First, feed a 2.4GHz point frequency signal with a fixed power amplitude to the input port Port1 through the signal generator, and use the probe to test the signal spectrum at the four associated ports Port3, Port4, Port5, and Port6 respectively, and detect the signal coupled to the associated port Spectrum, according to the analysis of the interaction relationship between the six ports of theoretical simulation, test the signal amplitude to verify whether the module-backplane-module meets the requirements of electromagnetic compatibility.

The remaining two states are shown in Table 2 and Table 3:

Table 2 Port3-Port4 work

Table 3 Port5-Port6 work

The specific test and verification process is as described above. The electromagnetic compatibility of the modular communication circuit is detected and verified by feeding the signal and observing the signal spectrum at the associated port, which will not be repeated here.

In another feasible embodiment, the device further includes: a plurality of connectors 400;

The connector 400 is used for connecting the modem module 200 and the modem slot, and the frequency source module 300 and the frequency source slot.

Fig. 3 is a schematic flowchart of a backplane electromagnetic compatibility detection method provided by an embodiment of the present invention. Referring to Fig. 3, the backplane electromagnetic compatibility detection method includes:

S101. The first frequency source module transmits an input signal to the modem module through the communication line on the backplane;

S102. At least one second frequency source module transmits a local oscillator signal to the modem module through the communication line of the backplane;

S103. The modulation and demodulation module performs frequency mixing processing on the received input signal and the local oscillator signal to generate a point frequency signal;

S104. The detection processor determines and learns that the frequency value of the point frequency signal is within a preset range according to the input signal and the local oscillator signal, and then confirms that the backplane has electromagnetic compatibility.

The method for detecting electromagnetic compatibility of the backplane proposed by the invention can effectively detect the electromagnetic compatibility of the backplane by comparing the local oscillator signal of the module, the input signal input to the backplane and the output signal after frequency mixing processing.

As for the method implementation, since it is basically similar to the device implementation, the description is relatively simple, and for relevant parts, refer to the part of the description of the device implementation.

In this embodiment, step S104 specifically includes:

Obtaining the input signal, local oscillator signal and point frequency signal collected by the probe to detect the input port and the total output port;

A preset range is set according to the input signal and the local oscillator signal to determine whether the frequency value of the spot frequency signal is within the preset range.

As for the method implementation, since it is basically similar to the device implementation, the description is relatively simple, and for relevant parts, refer to the part of the description of the device implementation.

In this embodiment, when it is detected that only one frequency source module is working, the signal spectrum at the input port, the output port and the total output port detected by the probe is acquired;

The frequency spectrum of the signal is detected, and it is determined that the frequency value of the point frequency signal is within the preset range, and then it is confirmed that the backplane and the frequency source module have electromagnetic compatibility.

For the method implementation, for the sake of simple description, it is expressed as a series of action combinations, but those skilled in the art should know that the implementation of the present invention is not limited by the described action order, because according to the implementation of the present invention , certain steps may be performed in other order or simultaneously. Secondly, those skilled in the art should also know that the implementations described in the specification belong to preferred implementations, and the actions involved are not necessarily required by the implementations of the present invention.

Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention. within the bounds of the requirements.

Claims (9)

1. A kind of 1. backboard electromagnetic compatibility detection device, it is characterised in that including：Measurement processor, modulation /demodulation module and Multiple frequency source modules；

   The modulation /demodulation module and the frequency source module are arranged on the backboard；

   First frequency source module in the multiple frequency source module, for the communication line by the backboard to the modulation Demodulation module transmits input signal；

   Frequency source module in the multiple frequency source module in addition to first frequency source module, for passing through the logical of the backboard Believe circuit to the modulation /demodulation module transfer local oscillation signal；

   The modulation /demodulation module, Frequency mixing processing is carried out for the input signal to receiving and local oscillation signal, with generation point frequency Signal；

   The measurement processor, for knowing the point-frequency signal according to the input signal and the local oscillation signal, judgement Frequency values are in preset range, then confirm that the backboard possesses Electro Magnetic Compatibility.
2. 2. device according to claim 1, it is characterised in that the backboard has modulation /demodulation slot and multiple frequency sources Slot；

   The modulation /demodulation module is plugged in the modulation /demodulation slot, and each frequency source module is plugged on a frequency source and inserted In groove.
3. 3. device according to claim 2, it is characterised in that be provided with an input port in each frequency source slot；

   It is provided with multiple output ports in the modulation /demodulation slot, the first output port conduct in the multiple output port Total output port of the modulation /demodulation slot, output port in the multiple output port in addition to the first output port with Input port establishes one-to-one relationship；

   Wherein, the input port for possessing corresponding relation is connected with output port by the communication line of the backboard.
4. 4. device according to claim 3, it is characterised in that the measurement processor, be additionally operable to obtain probe in detecting institute Input signal, local oscillation signal and the point-frequency signal that input port and total output port collect are stated, and according to the input Whether signal and local oscillation signal set preset range, to judge the frequency values of the point-frequency signal in the preset range.
5. 5. device according to claim 3, it is characterised in that the measurement processor, be additionally operable in an only frequency When source module works, the signal frequency at the input port, output port and total output port that probe in detecting arrives is obtained Spectrum；

   The signal spectrum is detected, judgement knows that the frequency values of the point-frequency signal are in the preset range, then Confirm that the backboard possesses Electro Magnetic Compatibility with the frequency source intermodule.
6. 6. according to the device described in claim any one of 2-5, it is characterised in that also include：Multiple connectors；

   The connector, for connecting the modulation /demodulation module and the modulation /demodulation slot, and frequency source module and institute State frequency source slot.
7. A kind of 7. backboard electromagnetic compatibility detection method, it is characterised in that including：

   First frequency source module is by the communication line of the backboard to modulation /demodulation module transfer input signal；

   At least one second frequency source module is believed by the communication line of the backboard to the modulation /demodulation module transfer local oscillator Number；

   Modulation /demodulation module carries out Frequency mixing processing generation point-frequency signal to the input signal and local oscillation signal that receive；

   Measurement processor knows that the frequency values of the point-frequency signal are according to the input signal and the local oscillation signal, judgement In preset range, then confirm that the backboard possesses Electro Magnetic Compatibility.
8. 8. according to the method for claim 7, it is characterised in that

   The backboard has modulation /demodulation slot and multiple frequency source slots；

   An input port is provided with each frequency source slot；

   It is provided with multiple output ports in the modulation /demodulation slot, the first output port conduct in the multiple output port Total output port of the modulation /demodulation slot, output port in the multiple output port in addition to the first output port with Input port establishes one-to-one relationship；

   It is described according to the input signal and the local oscillation signal, judge to know that the frequency values of the point-frequency signal are in default model Step in enclosing specifically includes：

   Input signal, local oscillation signal and point frequency that input port described in probe in detecting and total output port collect is obtained to believe Number；

   Preset range is set according to the input signal and the local oscillation signal, whether to judge the frequency values of the point-frequency signal In the preset range.
9. 9. according to the method for claim 7, it is characterised in that

   The backboard has modulation /demodulation slot and multiple frequency source slots；

   An input port is provided with each frequency source slot；

   It is provided with multiple output ports in the modulation /demodulation slot, the first output port conduct in the multiple output port Total output port of the modulation /demodulation slot, output port in the multiple output port in addition to the first output port with Input port establishes one-to-one relationship；

   When detecting the work of only frequency source module, obtain the input port, output port that probe in detecting arrives and Signal spectrum at total output port；

   The signal spectrum is detected, judgement knows that the frequency values of the point-frequency signal are in the preset range, then Confirm that the backboard possesses Electro Magnetic Compatibility with the frequency source intermodule.