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What is a branch distributor in a cable TV system
Views: 0 Author: Ada Publish Time: 2024-01-23 Origin: Site
A branch splitter is a passive device for power distribution of high frequency broadband signals. Its bandwidth has now reached 5-1000MHz, its simple structure, low price, work without power supply, widely used in the field of HFC cable TV. Devices are divided into indoor and field-type structure to adapt to the needs of different environments. In addition to waterproof function, field-type devices usually have over-current function to adapt to the need to supply power through cable networks.
The definition and function of branch allocator
Splitter: a power level distributor that takes a small portion of a signal from a main circuit and sends it to a branch port is called a splitter. The output/input ports of the main circuit are represented by OUT and IN respectively, and the branch ports of the branch circuits are represented by BR/TAP.
Function: the signal is separated from the transmission trunk line or the distribution line by a small insertion loss and sent to each user after attenuation.
Splitter: a power level splitter in which the input signal is equalized to the output is called a splitter. The output/input ports are represented by OUT and IN, respectively.
Role:
1. Distribution: the input signal power evenly divided into several channels.
2. Isolation: signal from one output has no effect on the other.
3. Matching: the output and input impedance are 75 ohms.
How a branch allocator works
How the allocator works
Two and three allocators are the most basic allocators, and the rest are made up of them.
One, two distributor working principle
Matching circuit: ensure impedance matching.
Distribution circuit: the input signal is equally distributed to two inputs, and let the two isolated two, three distributor principle and two distributor.
Specifications for branch allocators
Technical specifications for allocators
Allocation loss: the difference between the output level and the input level.
Isolation: adding a signal to one output and measuring the difference in the signal level at the other output is called mutual isolation.
3. Impedance: the input and output impedance is usually 75ω
4. VSWR: the power decibels of the reflected signal and the difference between the power decibels of the input signal
Technical specifications of the branch
1. Insertion loss: the level difference between the main output level and the input level.
Branch loss: the level difference between the branch output level and the input level.
3, reverse isolation: in this branch output plus a signal, in the main output measurement of this signal, the signal level difference, known as reverse isolation.
4, mutual isolation: output branches, in a branch output plus a signal, in another branch output measurement of this signal, the signal level difference, called mutual isolation.
The naming convention of branch allocators
Branch/allocator nomenclature is usually determined by the producer, but there are certain rules to follow. They are typically the main part of the name determined by the number of branch openings and the amount of decay.
Such as: a branch, branch attenuation of 8 db, called 108; branch attenuation of 14 db of the two branches, can be called 214... ... four splitters, output attenuation of 8 db, called 408.
