CN213092896U

CN213092896U - High-frequency signal transmission system

Info

Publication number: CN213092896U
Application number: CN202021799178.4U
Authority: CN
Inventors: 杨文寿; 任家顺; 柴永超; 李静; 巴中磊
Original assignee: Newcapec Electronics Co Ltd
Current assignee: Newcapec Electronics Co Ltd
Priority date: 2020-08-24
Filing date: 2020-08-24
Publication date: 2021-04-30
Anticipated expiration: 2030-08-24

Abstract

The utility model relates to a high frequency signal transmission system belongs to signal transmission technical field. The utility model adds a shielding layer on the distribution line, and connects L, N lines of the distribution line together through the safety capacitor as a polarity end of signal transmission; the shielding layer is used as the other polarity end of signal transmission, when high-frequency signals are transmitted, the L, N end and the shielding layer S form common-mode coaxial communication, and the shielding layer reduces the influence of high-frequency interference signals on a power grid on communication and reduces the leakage of the high-frequency interference signals on the LN power grid; meanwhile, L, N has equal potential when transmitting signals, and forms differential signal transmission with the shielding layer, thereby effectively avoiding same-frequency harmonic interference between L/N; in addition, the shielding layer can expand the cable conductor section surface area, reduce high-frequency signal skin transmission loss, effectively promote signal receiving and dispatching gain, and effective communication distance is farther.

Description

High-frequency signal transmission system

Technical Field

The utility model relates to a high frequency signal transmission system belongs to signal transmission technical field.

Background

At present, there are two main ways for signal transmission, the first way is to separate signal transmission from energy transmission, i.e. different transmission cables are used for signal transmission and energy transmission, as shown in fig. 2 and 3, the signal line (A, B) is separated from the distribution line (L, N); although the mode can reduce the interference of the energy transmission line, the energy and the signal line are transmitted separately, and the wire cost and the wiring construction cost are increased.

The second way is to multiplex the power distribution line for signal transmission, as shown in fig. 1, a signal to be transmitted is loaded on a power line, and dual transmission of energy and the signal is realized through the power line, although the method can save the wire rod cost and the construction wiring cost, when the signal is transmitted by the multiplexed power distribution line, the energy and the signal are transmitted on the line, which causes great interference factors, especially when large-scale energy consumption equipment is accessed, the time variation is large, and the transmission rate and the distance are limited; particularly, the wire is not provided with a shielding layer, so that the wire is not only susceptible to external signals, but also is easy to be influenced by other communication lines on which harmonic interference signals of electric appliances are transmitted through radiation, conduction and the like. For example, when 2-28 MHz spread spectrum modulation signal communication is transmitted between LNs, the signal wavelength is close to 10M-150M, the quarter wavelength of the electromagnetic signal is less than 2M-30M, the transmission cable antenna emission effect appears, the effect consumes the power of the signal, the attenuation of the signal dielectric transmission impedance is increased, the received signal strength is reduced, and the signal transmission distance is severely limited. The higher the frequency of the signal is, the stronger the skin effect is, the smaller the cross-sectional area of the transmission line which is more concentrated on the metal surface is, the larger the impedance is, the higher the frequency is, the smaller the skin depth is, the larger the transmission resistance is, the obvious signal transmission loss of the common energy transmission line/non-shielding signal line is, and the limited signal transmission is.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a high frequency signal transmission system to solve the problem that the interference that exists when adopting multiplexing distribution lines to carry out high frequency signal transmission at present is big, transmission distance is short.

The utility model provides a solve above-mentioned technical problem and provide a high frequency signal transmission system, including transmission cable and signal transceiver, the transmission cable is the twin-core cable of taking the shielding layer, including L line, N line and parcel at L line and the outside shielding layer of N line, signal transceiver includes signal transceiver unit and isolation coupling transformer, and one side of isolation coupling transformer is connected with signal transceiver unit's signal end, and the one end of isolation coupling transformer's opposite side is connected with transmission cable's shielding layer through first ann rule electric capacity, and the other end of this side links to each other with the tie point of L line and N line, the tie point is formed through third ann rule electric capacity connection through second ann rule electric capacity and N line by the L line.

The utility model adds a shielding layer on the distribution line, and connects L, N lines of the distribution line together through the safety capacitor as a polarity end of signal transmission; the shielding layer is used as the other polarity end of signal transmission, when high-frequency signals are transmitted, the L, N end and the shielding layer S form common-mode coaxial communication, and the shielding layer reduces the influence of high-frequency interference signals on a power grid on communication and reduces the leakage of the high-frequency interference signals on the LN power grid; meanwhile, L, N has equal potential when transmitting signals, and forms differential signal transmission with the shielding layer, thereby effectively avoiding same-frequency harmonic interference between L/N; in addition, the shielding layer can also expand the cable conductor section surface area, reduce high frequency signal skin transmission loss, effectively promote signal receiving and dispatching gain, and effective communication distance is farther.

Furthermore, in order to facilitate the power supply of the signal transceiver unit, the transmission system further comprises a power module, and a power end of the signal transceiver unit is connected with the L line and the N line in the two-core cable through the power module.

Further, the power module is an AC/DC module.

Drawings

FIG. 1 is a schematic diagram of a transmission signal of a conventional multiplexed power distribution line;

FIG. 2 is a schematic diagram of a transmission signal with a conventional signal line separated from a distribution line;

FIG. 3 is a schematic diagram of a transmission signal with a conventional signal line separated from a distribution line;

fig. 4 is a schematic diagram of transmission signals of the multiplexing distribution line of the present invention;

fig. 5 is a schematic structural diagram of the high-frequency signal transmission system of the present invention;

fig. 6 is a schematic view of the working principle of the shielding layer in the high frequency signal transmission system of the present invention;

fig. 7 is a schematic diagram of the working process of the shielding layer in the high-frequency signal transmission system of the present invention.

Detailed Description

In order to solve the problem that the present distribution lines that adopts carry out signal transmission and exist, the utility model provides a high frequency signal transmission system, including transmission cable and signal transceiver, the utility model discloses transmission cable increases the shielding layer on the transmission cable of current distribution lines, under the condition that does not increase or increase the wiring cost less, prevents signal interference, separately transmits energy and signal line. The transmission cable of the utility model adopts 2 core wires with shielding layers, and the 2 core wires are respectively an L wire (live wire) and an N wire (zero wire) for power supply transmission; l and N are common mode terminals of the signal, and perform signal transmission with the shielding layer S, as shown in fig. 4, the transmission cable receives the signal through the signal transceiver. L, N, the isolation capacitor is used as a common mode terminal, and is used as a polarity terminal '+' of signal transmission, and the shielding layer S is used as a polarity terminal '-' of signal transmission; l, N after low-frequency filtering isolation, the potential is equal when the spread spectrum differential signal is transmitted, and the differential signal transmission is formed with the shielding layer S, so that the same-frequency harmonic interference between L/N is effectively avoided, and the potential is close to zero when no signal is transmitted between L/N and S; when high-frequency signals are transmitted, the L, N end and the shielding layer S form a common-mode coaxial communication mode, and the influence of high-frequency interference signals on the power grid on communication and the leakage of the high-frequency interference signals on the LN power grid are reduced through the shielding layer.

As shown in fig. 5, the specific signal transceiver includes a signal transceiver unit, and a high-frequency isolation coupling transformer, when connected to the transmission cable, one side of the high-frequency isolation coupling transformer is connected to the signal end of the signal transceiver unit, and one end of the other side of the high-frequency isolation coupling transformer is connected to the shielding layer of the transmission cable through a safety capacitor C1; the other end of the side is connected with the connection point of the L line and the N line, and the connection point is formed by connecting the L line and the N line together through respective safety capacitors C2 and C3. The high-frequency isolation coupling transformer is used for receiving high-frequency signals and converting amplitude values, and the signal transceiving unit is used for realizing AD/DC signal modulation and demodulation processing. The shielding layer is an annular shielding layer and is generally woven by a plurality of thin copper wires, when the shielding layer is connected with the signal receiving and transmitting unit, all the copper wires in the annular shielding layer are twisted into one wire, and the wire is connected to one side of the high-frequency isolation coupling transformer through a safety capacitor C1.

Meanwhile, the signal transceiver unit can be independently powered and can also be powered by a transmission cable, as shown in fig. 5, a power supply port of the signal transceiver unit is connected with the L line and the N line through a power supply module, and the power supply module adopts an AC/DC module and is used for converting alternating current on the transmission cable into direct current to supply power to the signal transceiver unit.

The utility model discloses an above-mentioned structure, common mode (as signal transmission 'S polarity end' + ') between L, N forms signal coaxial communication effect with shielding layer (signal transmission' S polarity end '-'), utilizes coaxial communication effect, and the equipotential when L, N transmission signal forms differential signal transmission with shielding layer S, and harmonic interference between the LN can not radiate away. The shielding layer serves two functions simultaneously: firstly, the influence of the high-frequency interference signals on the power grid on the communication is reduced, and secondly, the leakage of the high-frequency interference signals on the LN power grid is reduced, as shown in fig. 6 and 7.

The utility model discloses an ann rule electric capacity and high frequency isolation coupling transformer are with 2M ~ 28M 'S carrier signal coupling to L/N line and shielding layer S on, so the online transmission of L/N is 50 Hz' S alternating current power frequency voltage and the stack of one of them utmost point of differential carrier signal, what transmit on the shielding layer S is that differential carrier signal is another utmost point, at the receiving terminal, according to Z1/2 pi fC can know, ann rule electric capacity is less to carrier signal 'S impedance and great to 50 Hz' S power frequency voltage impedance. Therefore, the signal on the shielding layer S is hardly attenuated by the safety capacitor C1, one pole of the carrier signal sent by the output module can be directly restored, the carrier signal on the L/N line and the 50Hz alternating current power frequency voltage signal are separated by the LC high-pass filter formed by the C2/C3 and the high-frequency isolation coupling transformer, the other pole of the carrier signal sent by the output module is restored, and finally the L/N line and the carrier signal sent by the output module on the shielding layer S are restored by the Pi-type filter formed by the C2/C3, C1 and the high-frequency isolation coupling transformer and are coupled to the input end of the receiving module by the high-frequency isolation coupling transformer.

The size of the safety capacitor is determined according to the carrier signal frequency and the inductance of the high-frequency isolation coupling transformer, and once the inductance of the high-frequency isolation coupling transformer is determined, the frequency is cut off according to a high-pass filter

Where f is the frequency of the carrier signal, the capacitance can be calculated.

The utility model discloses transmission system adopts a two-core cable of taking the shielding layer to carry out the dual transmission of electric energy and signal, utilizes coaxial effect, and L, N equipotential when transmitting the signal forms differential signal transmission with shielding layer S, and the harmonic interference between L, N can not radiate away, has reduced the interference influence of electric wire netting signal; l, N, common-mode coaxial communication is formed between the shielding layer and the shielding layer, the shielding layer is used as a signal shielding net, and the electromagnetic field is limited between the inner conductor and the outer conductor, so that power grid noise and interference of external signals are well inhibited; the shielding layer can expand the cable conductor section surface area, reduce the high-frequency signal skin transmission loss, effectively improve the signal receiving and transmitting gain and improve the effective communication close range; meanwhile, the problem that characteristic impedance of the coaxial transmission line is unevenly distributed is effectively solved, signal reflection of a sending source end is inhibited during signal transmission, the signal transmission quality and stability are improved, and the signal transmission gain is improved.

Claims

1. The utility model provides a high frequency signal transmission system, includes transmission cable and signal transceiver, its characterized in that, the transmission cable is the twin-core cable of taking the shielding layer, including L line, N line and parcel at the outside shielding layer of L line and N line, signal transceiver includes signal transceiver unit and isolation coupling transformer, one side of isolation coupling transformer is connected with signal transceiver unit's signal end, the one end of the opposite side of isolation coupling transformer is connected with the shielding layer of transmission cable through first ann rule electric capacity, the other end of this side links to each other with the tie point of L line and N line, the tie point is for being connected through third ann rule electric capacity by L line through second ann rule electric capacity and N line and forming.

2. The high-frequency signal transmission system according to claim 1, further comprising a power supply module, wherein the power supply terminals of the signal transceiving unit are connected to the L-line and the N-line of the two-wire cable through the power supply module.

3. The high-frequency signal transmission system according to claim 2, wherein the power supply module is an AC/DC module.