# dBm

Decibels relative to 1mW (dBm) is a unit of measurement used to quantify the power of an electrical signal when transmitted through a cable. It is commonly used to compare the power of different cables, as well as to measure the strength of a signal at different points along a cable.

dBm is a logarithmic scale, meaning that a 3 dBm increase in power represents a doubling of the power. It is measured in decibels (dB), which is a ratio of two power levels. The “m” stands for milliwatts and the reference level is 1 milliwatt, meaning that a signal of 0 dBm is equal to 1 milliwatt of power.

dBm is commonly used to measure the power of a signal at various points from its source. This allows engineers to identify any signal loss that may have occurred along the cable, as well as any points where the signal is getting weaker. By measuring the signal strength of a cable, engineers can determine the best locations for amplifiers, repeaters, and other devices, as well as the best cable type for a given application.

Cables come in a variety of types, each with their own power rating. Low-power cables require a lower dBm rating than higher-powered cables, as the signal is weaker. Similarly, when connecting two cables with different signal strengths, a signal amplifier may be needed to boost the weaker signal.

Overall, dBm is an important tool for measuring the power of an electrical signal when transmitted through a cable. By measuring the signal strength of a cable, engineers can determine the best locations for amplifiers, repeaters, and other devices, as well as the best cable type for a given application.