ព័ត៌មានឧស្សាហកម្ម

តើខ្សែកាបគឺជាអ្វី?

2021-03-03

A ខ្សែ coaxial("coax"ជាភាសាអង់គ្លេស) គឺជាខ្សែមួយដែលមានខ្សែស៊ីឡាំងស៊ីឡាំងពីរដែលមានអ៊ីសូឡង់រួមគ្នាដើម្បីបង្កើតជាឯកតាមូលដ្ឋាន (គូជាគូ) ហើយបន្ទាប់មកគូតែមួយរឺច្រើនគូត្រូវបានគេប្រើដើម្បីបញ្ជូនទិន្នន័យនិងសញ្ញាវីដេអូក្នុងរយៈពេលយូរ។ ។

It is one of the first media to support 10BASE2 និង10BASE5 Ethernet, which can achieve 10 Mb/s transmission up to 185 meters or 500 meters, respectively. The term "coaxial" means that the central conductor of the cable និងits shield have the same axis or center point. Some ខ្សែ coaxials may have multiple shielding layers, such as a four-shielded ខ្សែ coaxial, which contains two layers of shielding, និងeach layer of shielding is composed of aluminum foil wrapped with wire mesh. The shielding characteristics of ខ្សែ coaxial make it have strong anti-electromagnetic interference ability និងcan transmit high-frequency signals over long distances. There are many different types of main types of ខ្សែ coaxials that support a wide range of professional applications, such as satellite communications, industrial, military និងmarine applications. The three most common types of non-industrial ខ្សែ coaxials are RG៦, RG11និងRG៥៩, ក្នុង​ចំ​នោម​នោះRG៦ត្រូវបានប្រើជាទូទៅបំផុតនៅក្នុងស៊ីស៊ីធីវី និងស៊ីធីវីកម្មវិធីនៅក្នុងបរិស្ថានសាជីវកម្ម។ ចំហាយកណ្តាលនៃRG11គឺក្រាស់ជាងRG៦, which means that its insertion loss is lower និងthe signal transmission distance is longer.

ទោះយ៉ាងណាក៏ដោយក្រាស់ជាងខ្សែ RG11 are more costly និងvery difficult to bend, which makes them unsuitable for deployment in internal applications, but more suitable for long-distance outdoor installations or straight backbone links. RG៥៩ គឺអាចបត់បែនបានច្រើនជាងRG៦, but its loss is higher. It is rarely used in other applications except for low-bandwidth, low-frequency analog video applications (rear-view cameras in automobiles) with short distances និងlimited wiring space. ខ្សែ coaxial also have different impedances-usually 50, 75, និង93 Ω។ ៥០Ω ខ្សែ coaxials have high power handling capabilities និងare mainly used in radio transmitters such as amateur radio equipment, civil bនិងradio (CB) និងwalkie-talkies. 75 Ω cables can maintain signal strength well និងare mainly used to connect various types of receiving equipment, such as cable television (ស៊ីធីវី) receivers, high-definition televisions និងdigital video recorders. 93 Ω Cខ្សែ oaxial was used in IBM mainframe networks in the 1970s និងearly 1980s, with very few applications និងexpensive. Although the 75 Ω ខ្សែ coaxial impedance is most commonly encountered in most applications today, it is important to note that all components in the ខ្សែ coaxial system should have the same impedance to avoid possible signal loss និងsignal loss at the connection point. Internal reflections that reduce video quality. The digital signal 3 (DS3) signal used in the central office (also known as T3 line) transmission service also uses ខ្សែ coaxials, including 75 Ω 735 type និង734 type. The 735 type cable has a coverage distance of 69 meters, while the 734 type cable has a coverage distance of 137 meters. RG៦ cableក៏អាចត្រូវបានប្រើដើម្បីបញ្ជូនសញ្ញា DS3 ផងដែរប៉ុន្តែចម្ងាយគ្របដណ្តប់គឺខ្លីជាង។