CN2547069Y - Electromagnetic wave suppressor of signal transmission loop - Google Patents
Electromagnetic wave suppressor of signal transmission loop Download PDFInfo
- Publication number
- CN2547069Y CN2547069Y CN 02231286 CN02231286U CN2547069Y CN 2547069 Y CN2547069 Y CN 2547069Y CN 02231286 CN02231286 CN 02231286 CN 02231286 U CN02231286 U CN 02231286U CN 2547069 Y CN2547069 Y CN 2547069Y
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- China
- Prior art keywords
- loop
- signal
- electromagnetic wave
- suppression device
- wave suppression
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Abstract
The utility model relates to an electromagnetic wave suppressor of signal transmission loop, wherein, the suppressor is connected with a signal transmission interface which comprises a signal transmitting loop and a signal receiving loop; the electromagnetic wave suppressor comprises a signal transmitting loop matched impedance which is connected inside the signal transmitting loop and is formed by two resistors connected in series; one pin of a first capacitor is connected with the joint between the two resistors, while the other pin is connected with a reference potential; a signal receiving loop matched impedance which is connected inside the signal receiving loop is formed by two resistors connected in series; in addition, one pin of a second capacitor is connected with the joint between the two resistors, while the other pin is connected with a reference potential. The utility model can be used to eliminate the electromagnetic noise of the signal transmitting loop and the signal receiving loop.
Description
(1) technical field
The utility model relates to a kind of design of electromagnetic wave suppression device, particularly relevant for the electromagnetic wave suppression device in a kind of signal transmission loop, during with signal transmission in the transmission of network or communication line and receiving loop, eliminates its electromagnetic wave noise.
(2) background technology
On many electronic products (especially computer or its peripheral unit), in transmitting signals, on its transmission line, on the circuit or product itself all can produce to a certain degree Electromagnetic Interference (RadiatedEmission and Conducted Emission, be called for short EMI), if this electronic product sends excessive EMI noise and can disturb other electronic product to operate normally, even causes the system of other electronic product or assembly to work as machine.
Therefore, reach each country in the world and detect for the EMI of electronic product its suitable standard is all arranged, and formulate different standards according to various different product machine classifications.With Europe is example, electronic product or equipment desire to enter the European market, the CE standard that must be stipulated jointly by the European Economic Community (European Community) of this product then, and checked by its accredited laboratory, if unlicensed or the electronic product that surpasses the EMI standard promptly can not be imported this area, and allly on the electronic product that CE authenticated, all ce mark to be arranged.
Because, the progress of electronic manufacturing technology, add that present electronic product tends to miniaturization gradually, so its circuit board wiring density is very high, and each electronic building brick is closely by being crowded together, and the Electromagnetic Interference problem that so can make each assembly produce worsens more, adds many electronic products and all need rely on the cable transmission signal, this allows the electromagnetic wave noise of electronic product emit as adding a transmitting antenna for electromagnetic wave.
The manufacturer of each tame electronics product spends many manpowers and material resources invariably, with the generation of the Electromagnetic Interference of improving electronic product.And attempt at present to reduce or all be method by Isolated Shield with the method that Electromagnetic Interference reduces, this has comprised that cable transmission line is coated one deck separation net places a metallic conduction thing or this type of conductive object arround conducting ground connection or the electronic building brick with the interference that can generate electromagnetic waves in the casing of electronic product, so that electromagnetic wave is guided ground connection.And the anti-system technology of these Electromagnetic Interference all can increase the manufacturing cost of electronic installation, and makes electronic product more complicated.The existing patented technology that number No. 347195 is disclosed at the TaiWan, China patent announcement for example, the structural design that promptly belongs to this type of, it is that an EMI conducting strip is established in the appropriate location of setting up various disc player room on computer housing, in order to the EMI noise that disc player produced is guided on the conducting strip of computer housing, again with its ground connection so that the unlikely design that emits of this EMI noise.
And in the system architecture of general LAN (LAN) or wideband network (as ADSL), the signal transmission of computer and other intercomputer mostly is to use RJ-45 network interface joint and 8 core transmission lines, and the network card in the computer also is to use the coffret of this RJ-45 network interface as network signal.The transmission length of this RJ-45 network interface can reach 100 meters far away, and transmitting bandwidth can reach the transfer rate of 10M or 100M/bps.
As shown in Figure 1, shown in the preferred circuit figure of RJ-45 network interface, for making this RJ-45 network interface 10 effectively keep its signal quality in the transmission range, in its specifications (DATA BOOK), advise in the TCT of this RJ-45 network interface 10 pin 101 and RCT pin 102 each electric serial connection one 0.01 μ F capacitor 1011,1021 to earthing potential.
In this RJ-45 network interface 10, include a signal and send loop (TD+, TD-) 103 and one signal receiving loop (RD+, RD-) 104, can be connected with another RJ-45 network interface 10a by one 8 core transmission lines 20, with transmission signal to each other, should be electric and connect one 100 Ω resistors 1031 and also advise in these specifications that this signal sends 103 in loop (TD+, TD-), and 104 of this signal receiving loops (RD+, RD-) are answered electric and are connect one 120 Ω resistors 1041, are in order to do impedance matching with 8 core transmission lines 20.Yet when the application of reality, the transmission quality that is found to this RJ-45 network interface is improved still for limited.
(3) utility model content
Artificial above-mentioned existing shortcoming and the actual demand of solving of the design of this case utility model, develop the electromagnetic wave that a kind of signal transmission loop and eliminate circuit, solving the EMI noise that electronic product is produced when seeing through the signal line transmission signal, and the utility model is applicable in the transmission of signal between all electronic products.
Main purpose of the present utility model is the electromagnetic wave suppression device that is to provide a kind of signal transmission loop, this electromagnetic wave suppression device is to be connected in a signal coffret, this signal coffret includes a signal at least and sends the loop, this electromagnetic wave suppression device comprises: the signal that signal transmission loop matched impedance is connected in described signal coffret sends between the loop, is formed by two resistors serial connection; And a capacitor, the one pin is connected in the junction between this two resistor, and another pin is connected to a reference potential, forms an electromagnetic wave suppression device, in order to eliminate the EMI noise that this signal sends the loop.
Another purpose of the present utility model provides the electromagnetic wave suppression device in a kind of signal transmission loop, this electromagnetic wave suppression device is to be connected in a signal coffret, this signal coffret includes at least: a signal receiving loop, this electromagnetic wave suppression device comprises that a signal receiving loop matched impedance is connected between this signal receiving loop, is formed by two resistors serial connection; And a capacitor, the one pin is connected in the junction between this two resistor, and another pin is connected to a reference potential, forms an electromagnetic wave suppression device, in order to eliminate the EMI noise of this signal receiving loop.
The electromagnetic wave suppression device of the utility model signal transmission line really can utilize above-mentioned technology contents, provides one simply and not to influence transmission quality, can eliminate the electromagnetic wave suppression device of EMI noise again really.Therefore the utility model may be able to improve whole use value.
For further specifying above-mentioned purpose of the present utility model, design feature and effect, the utility model is described in detail below with reference to accompanying drawing.
(4) description of drawings
Fig. 1 is the preferred circuit figure of existing RJ-45 network interface;
Fig. 2 is the embodiment circuit diagram of the utility model electromagnetic wave suppression device; And
Fig. 3 is the utility model EMI signal waveform figure measured through the laboratory.
(5) embodiment
Please at first consult shown in Figure 2ly, be the embodiment circuit diagram of the utility model electromagnetic wave suppression device.In this embodiment, be the embodiment explanation to be widely used in the RJ-45 network interface in computer local network (LAN) or the wideband network (as ADSL) and the framework of 8 core transmission lines at present equally.Include a signal equally and send a loop 103 and a signal receiving loop 104 in this RJ-45 network interface 10, this signal sends loop 103 and includes signal transmission pin TD+, TD-, and signal receiving loop 104 includes signal reception pin RD+, RD-.
The utility model electromagnetic wave suppression device 30 is to be connected in RJ-45 network interface 10, and this electromagnetic wave suppression device 30 promptly utilizes this signal to send 103 in loop (TD+, TD-) and 104 of this signal receiving loops (TD+, TD-) constitute a match circuit to constitute EMI inhibition filter circuit.
As shown in the figure, the electromagnetic wave suppression device 30 of present embodiment is that to send 103 in loop (TD+, TD-) at this signal electric and connect a signal and send loop matched impedance 31, and this signal to send loop matched impedance 31 be to be formed by one first resistor 311 and one second resistor, 312 electric serial connections.The total impedance that adds of this first resistor 311 and this second resistor 312 is about 100 Ω.
This signal sends in the loop matched impedance 31 and includes one first capacitor 32 in addition, it has the place that is electrically connected that one first pin 321 is connected in 312 of this first resistor 311 and this second resistors, and second pin 322 of this first capacitor 32 is to be electrically connected in a reference potential, and this reference potential is an earthing potential in the present embodiment.Utilize this first resistor 311, second resistor 312, and first capacitor 32 constituted an EMI jointly and suppressed filter circuit, in order to eliminate the EMI noise that this signal sends loop (TD+, TD-) 103.
Similarly, electric and connect a signal receiving loop matched impedance 33 104 of signal receiving loops (TD+, TD-), and this signal receiving loop matched impedance 33 is to be formed by one the 3rd resistor 331 and one the 4th resistor, 332 electric serial connections.The total impedance that adds of the 3rd resistor 331 and the 4th resistor 332 is about 120 Ω.
Include one second capacitor 34 in addition in this signal receiving loop matched impedance 33, it has the place that is electrically connected that one first pin 341 is connected in 332 of the 3rd resistor 331 and the 4th resistors, and second pin 342 of this second capacitor 34 is to be electrically connected in a reference potential, and this reference potential is an earthing potential in the present embodiment.Utilize the 3rd resistor 331, the 4th resistor 332, and second capacitor 34 constituted an EMI jointly and suppressed filter circuit, in order to eliminate the EMI noise of this signal receiving loop (TD+, TD-) 104.
The utility model electromagnetic wave suppression device 30 is found in the experiment test of reality, in the TCT pin 101 of this RJ-45 network interface 10 electricly be connected in series that can omit to 0.01 μ F capacitor of earthing potential need not, still do not influence its transmission quality, can eliminate its EMI noise again is lower than more than the 13dB at least, as shown in Figure 3, be the utility model EMI signal waveform figure measured through the laboratory, wherein EMI signal 51 is the limiting value (Limit) 52 of subaverage (Average), also far below the limiting value (Limit) 53 of quasi-peak value (Quasi-peak).And its test result is shown in subordinate list one, wherein:
(1) Q.P. is meant quasi-peak value (quasi-peak);
(2) AV. is meant mean value (average);
(3) "-" represents the sub-average limiting value of read value (Limit) 64dB of this quasi-peak value, so the detecting of mean value is unwanted;
(4) the frequency loss factor (Corr.Factor) is meant frequency loss (loss) factor of instrument and circuit; And
(5) difference (Margin) is meant the numerical value after EMI measuring value (Emission Level) deducts limiting value (Limit).
Subordinate list one
| Number sequence | Frequency | The frequency loss factor | Read value | The EMI measuring value | Limiting value | Difference (Margin) | ||||
| [dB(uV)] | [dB(uV)] | [dB(uV)] | (dB) | |||||||
| [MHz] | (dB) | ?QP | AV. | Q.P. | AV. | Q.P. | AV. | ?Q.P. | AV. | |
| 1 | 7.184 | 1036 | ?45.11 | - | 55.47 | - | 74.00 | - | -18.53 | - |
| 2 | 7.972 | 10.34 | ?46.89 | - | 57.23 | - | 74.00 | - | -16.77 | - |
| 3 | 9.230 | 10.44 | ?46.70 | - | 57.14 | - | 74.00 | - | -16.86 | - |
| 4 | 10.058 | 10.50 | ?49.87 | - | 60.37 | - | 74.00 | - | -13.63 | - |
| 5 | 10.563 | 10.50 | ?44.56 | - | 55.06 | - | 74.00 | - | 18.94 | - |
| 6 | 29.984 | 10.40 | ?42.63 | - | 53.03 | - | 74.00 | - | -20.97 | - |
Certainly, those of ordinary skill in the art will be appreciated that, above embodiment is used for illustrating the utility model, and be not to be used as qualification of the present utility model, as long as in connotation scope of the present utility model, all will drop in the scope of the utility model claims variation, the modification of the above embodiment.
Claims (10)
1. the electromagnetic wave suppression device in a signal transmission loop is connected in a signal coffret, and this signal coffret includes a signal at least and sends the loop, it is characterized in that described electromagnetic wave suppression device comprises:
One signal sends the loop matched impedance, is that the electric signal that is connected to described signal coffret sends between the loop;
One capacitor is electrically connected on this signal and sends the loop matched impedance, to send the common formation of loop matched impedance one electromagnetic wave suppression device with this signal, in order to eliminate the electromagnetic wave noise that this signal sends the loop.
2. as the electromagnetic wave suppression device in claim 1 a described signal transmission loop, it is characterized in that described signal coffret is a RJ-45 Network Transmission interface.
3. as the electromagnetic wave suppression device in claim 1 a described signal transmission loop, it is characterized in that the total resistance that adds of described signal transmission loop matched impedance is about 100 Ω.
4. transmit the electromagnetic wave suppression device in loop as claim 1 a described signal, it is characterized in that it is to be formed by two electric serial connections of resistor that described signal sends the loop matched impedance, one end of described capacitor is the junction that is connected in these two resistors, and the other end of capacitor then is connected to a reference potential.
5. as the electromagnetic wave suppression device in claim 4 a described signal transmission loop, it is characterized in that described reference potential is an earthing potential.
6. the electromagnetic wave suppression device in a signal transmission loop is connected in a signal coffret, and this signal coffret includes a signal receiving loop at least, it is characterized in that this electromagnetic wave suppression device comprises:
One signal receiving loop matched impedance is between the electric signal receiving loop that is connected to this signal coffret;
One capacitor is electrically connected on this signal receiving loop matched impedance, to constitute an electromagnetic wave suppression device jointly with this signal receiving loop matched impedance, in order to eliminate the electromagnetic wave noise of this signal receiving loop.
7. as the electromagnetic wave suppression device in claim 6 a described signal transmission loop, it is characterized in that described signal coffret is a RJ-45 Network Transmission interface.
8. as the electromagnetic wave suppression device in claim 6 a described signal transmission loop, it is characterized in that the total resistance that adds of described signal receiving loop matched impedance is about 120 Ω.
9. transmit the electromagnetic wave suppression device in loop as claim 6 a described signal, it is characterized in that described signal receiving loop matched impedance is to be formed by two electric serial connections of resistor, one end of described capacitor is connected in the junction of these two resistors, and the other end of capacitor then is connected to a reference potential.
10. as the electromagnetic wave suppression device in claim 9 a described signal transmission loop, it is characterized in that described reference potential is an earthing potential.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02231286 CN2547069Y (en) | 2002-05-08 | 2002-05-08 | Electromagnetic wave suppressor of signal transmission loop |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02231286 CN2547069Y (en) | 2002-05-08 | 2002-05-08 | Electromagnetic wave suppressor of signal transmission loop |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2547069Y true CN2547069Y (en) | 2003-04-23 |
Family
ID=33707053
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02231286 Expired - Lifetime CN2547069Y (en) | 2002-05-08 | 2002-05-08 | Electromagnetic wave suppressor of signal transmission loop |
Country Status (1)
| Country | Link |
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| CN (1) | CN2547069Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102035571A (en) * | 2009-10-03 | 2011-04-27 | 瑞昱半导体股份有限公司 | Signal transceiving circuit and noise reduction circuit |
-
2002
- 2002-05-08 CN CN 02231286 patent/CN2547069Y/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102035571A (en) * | 2009-10-03 | 2011-04-27 | 瑞昱半导体股份有限公司 | Signal transceiving circuit and noise reduction circuit |
| CN102035571B (en) * | 2009-10-03 | 2014-01-08 | 瑞昱半导体股份有限公司 | Signal transceiving circuit and noise reduction circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CX01 | Expiry of patent term |
Expiration termination date: 20120508 Granted publication date: 20030423 |