Wire optic AOC transmission scheme is effective

The data transmission capacity carried by the high-speed transmission interface continues to challenge the physical limit of the copper cable, but the copper cable is used for long-distance deployment applications even through better coating isolation or signal pre-processing. Under the transmission speed and signal identification will be affected by the length of the distance, and the transmission wire is changed to the fiber material, not only the signal quality can be improved, but also the transmission distance can be greatly changed.

Keywords: fiber optic AOC transmission

The amount of data carried by the high-speed transmission interface continues to challenge the physical limits of the copper wire, but the copper wire is treated with a better coating isolation or signal pre-processing, facing the wire in long-distance deployment applications. Transmission speed and signal recognition will be affected by the lengthening of the distance, and the transmission wire will be changed to the fiber material, not only the signal quality can be improved, but also the transmission distance can be greatly improved!

With the 4K2K audio and video applications and digital cameras and cameras challenging the ultra-high resolution recording function, the data transmission performance requirements of the existing transmission interface are also getting higher and higher, such as USB 3.0, Thunderbolt and other high-speed transmission interfaces, although the transmission efficiency The leap-forward type has been greatly improved, but the wire distance is elongated. Because the entity is transmitted through the copper cable, the material properties of the copper cable are not conducive to long-distance high-speed transmission!

The same situation has also occurred in the recent HDTV trend of HDTV to UHDTV. When entering the UHDTV process, the biggest challenge of TV products is how the 4K2K high-definition video is transmitted through the wire. The existing HDMI 1.x transmission interface is bound to need to be greatly upgraded and improved to carry the high-quality audio and video of UHDTV on the wire.

The development of the optical transmission interface of the electronic product enables the connection performance to be further expanded in terms of transmission efficiency and connection distance.

Video transmission interface extends transmission distance requirements

Especially for audio-visual transmission interfaces such as HDMI/DisplayPort, the pressure on developing high-efficiency transmission interfaces will be much greater than that of digital electronic products! Because audio-visual equipments are not synchronized or delayed due to the transmission process, because of the human eye. For the viewing experience of the playback process, it is easy to detect the image setback problem. Therefore, the audio-visual products have a strong demand for the high-speed transmission interface brought by the 4K2K UHDTV, and the demand for the transmission cable fiber will be strong, but the data transmission efficiency application. Because the impact level is less obvious, the demand for copper fiber optics is less urgent.

In the development of fiber optic applications, the electrical specifications and connectors of the transmission interface itself, if originally designed for electronic signal requirements, will cause signal conversion problems when converting copper to fiber cables; instead, it is now more popular. The method is to maintain the electrical specifications and requirements of the original high-speed transmission interface on both the transmitting end and the receiving end. After the electro-optical signal is converted, the original electronic signal is pre-converted into an optical signal at the connector end, and the original Copper cable can be replaced by fiber optic cable. It does not consume too much design energy for the original design and connector design. Through the simplified product design process, the fiber optic cable can be used to transmit signal bits over long distances. There is less advantage in quasi-transmission distance limitation. When developing Netcom integration required by individuals or small enterprises, the use efficiency of fiber-optic network can be achieved with minimum cost.

Active fiber optic cable solutions improve the connection distance of most copper cables and EMI/ISI problems.

AOC fiber transmission scheme is effective

Among the many transmission fiber optic applications, AOC (Active Optical Cable) is currently used to easily convert the original copper cable into a fiber optic cable application environment for commercial interfaces such as USB 3.0, Thunderbolt, and HDMI. The transmission interface can also enjoy the benefits of fiber optic cables, such as longer transmission distances and higher signal quality.

In the existing AOC scheme, in order to maintain the electrical specifications of the original transmission wire connector, only the signal bidirectional transmission part uses the photoelectric conversion module to convert the electrical signal into an optical signal transmission, although the technical complexity is not high, but the complexity of the signal conversion. With accuracy, in order to meet the level of electrical signal requirements, the performance requirements for real-time processing are relatively high.

Especially in the long-distance application, with the existing commercial interfaces such as USB 3.0, Thunderbolt, HDMI, etc., in the transmission connection demand of more than 100 meters, the existing copper cable is inevitably unable to be used directly, and the signal is improved with the repeater. Quality will also increase the transmission cost, and also affect the transmission quality and stability of the interface! If the active optical cable technology is used to integrate the transmission interface, and the optical cable is used for transmission, the transmission signal characteristics of the optical fiber should be used to pull the transmission distance. More than 100 meters in length can easily meet the needs, but also can easily construct low-cost medium-distance transmission applications up to 150 meters.

AOC mode can extend the transmission distance by more than 150 meters

At present, in the development of AOC active optical cable, the application market of HDMI is the most significant in terms of application requirements. At present, related solutions have been launched, and the AOC application schemes of Thunderbolt and USB 3.0 have also been launched. It is based on the medium-distance transmission application of 25 to 150 meters. Even if it is more than 150 meters away, it can be extended with the existing long-distance optical fiber transmission scheme.

In addition to the external type of transmission interface, such as USB 3.0, Thunderbolt, HDMI actively into the AOC application program, in fact, now the PC industry, the active development of the high-speed transmission interface of the internal device is moving outward, and will make the AOC application program a new one. The technology solution solution, for example, in the advanced internal connection type high-speed transmission interface applications such as SAS (Serial Attached SCSI) and PCIe (PCI Express), it is also actively expanding the demand for extended external applications of related interfaces, facing the development of this market. Trends, using copper applications for data transmission, will inevitably lead to development projects facing EMI, copper power consumption and other product development and verification issues, but if you replace the copper transmission medium with fiber optic cable solutions, you can limit EMI problems to the transmission endpoints. Or improvement in the chassis, for the external connection requirements of the internal interface, the optical fiber wire can avoid external electromagnetic interference and additional design problems, which can make the design goal of the interface externalization easier to implement.

Copper EMI/EMC/ISI problems can be improved with fiber optic solutions

High-speed transmission using copper media usually produces EMI/EMC (Electro-Magnetic Interference / Compatibility) problems, and also causes ISI (Inter Symbol Interference) interference problems. When designing physical cables, it is necessary to increase the copper cable diameter. Introducing the Equalizer circuit, signal compensation and other design solutions, which will make the related design of the interface more complicated, not only increase the design cost, but also increase the line complexity of the relevant interface, and if the transmission wire needs to extend the transmission distance, the copper of the wire itself The amount of wire must be increased, the wire becomes thicker and heavier. The overall application scheme is not only costly in interface connectors, related circuits and cables, but also disadvantageous in marketing and sales of terminal design goods.

Especially in cable applications that exceed the critical point of 10Gbit/sec transmission performance requirements, the difference between copper cable and fiber cable selection will increase, even when the transmission distance increases to 15-20 meters or more. The use efficiency of copper cables is diminishing, which has forced the market to replace copper cables with optical cables to improve the efficiency of use. The AOC solution, which does not require additional changes to the design of the original peripheral and end product transmission interfaces, can be used in terms of cost and transmission distance benefits. Further expanding the advantages of using fiber optic cables, the equipment itself does not need to change the electrical specifications of the connection interface to meet the application requirements of the transmission medium cable, and maintain the original design with the AOC solution, so that the application system has the advantage of the optical cable application.

Audio and video products market is keen to introduce AOC wire solutions

Among the AOC transmission cable products, the most popular HDMI application is currently developed. Taking the HDMI AOC wire products in the existing market as an example, in the HDMI 1.4 interface part, the transmission distance can be extended to 150 in the AOC solution. ~200 meters or more, although the application value in the HDMI 1.4 interface can only achieve the medium/long-distance transmission advantage in the transmission distance, if it is used to respond to the UHDTV transmission 4K2K video quality application HDMI 2.0 interface technology solution, use a higher speed transmission margin The AOC cable application solution can further highlight the application advantages of UHDTV video cable.

Under the UHDTV demand, both the transmission distance and the transmission performance requirements, only the AOC wire solution can meet the application requirements.

     For the AOC cable solution, with the existing product observation, under the active micro-integration of the integrated circuit, the single-chip solution and packaging technology can be used to actively convert the photoelectric signal, and the connector of the AOC application integrates the photoelectric conversion module. It is not much different from copper cables and connectors. Compared with existing Thunderbolt copper cable transmission products, the wire of the AOC solution is the same as that of the general copper cable. It can also be used in comparison with the original copper Thunderbolt wire for the bending application. The Thunderbolt AOC solution is a relatively practical option for the existing Thunderbolt application solution with a connection capacity of more than 2 meters.

In the USB/Thunderbolt high-speed transmission interface-derived PC/NB multimedia application Dock product boom, for high-speed transmission Dock extended video conversion, expansion connection interface conversion application, USB 3.0, Thunderbolt AOC solution can effectively Dock multimedia The connection distance of the pedestal is extended to more than 2 to 100 meters. This is the only way to expand the remote application base or use the terminal use with USB 3.0, Thunderbolt, and only adopt the AOC active optical cable transmission solution to meet this kind of commercial use. The copper cable application design is limited by the copper cable transmission distance and the flexibility of the system application.