How A Cell Phone Signal Booster Works

Cell phone signal boosters are relatively simple devices that bring stronger network signals to your phone. As you may have guessed, this is generally needed when the signal coming in from the nearest tower gets weakened for some reason. Any cell phone is basically a two-way radio with a modern user interface. It communicates with the nearest cell tower by means of radio frequency (RF) signals.

A signal booster generally functions by pulling in a weakened signal coming in from the nearest tower, amplifying it, and then rebroadcasting it throughout the smaller area where you want to improve your reception. The booster itself is a three-part system.

The Basic Mechanics

Signal boosters do the following:

  • Detect and collect very faint signals (even fainter than your phone can detect).
  • Help these signals get past obstructions.
  • Amplify these signals up to usable levels.
  • Broadcast the amplified signals inside an interior space so that phones and other cellular devices can use them

The Components

  • The Exterior Antenna: This is the component that is usually mounted on the roof of the house. It grabs weak signals coming in from the cellular tower. Depending on the type of antenna (omnidirectional or unidirectional) you can either boost signals from multiple directions or just one. The latter type of antenna is best suited for when the phone is getting no usable signal to speak of. It pulls signal from a 45-degree LOS, so you must know where your nearest cell tower is.
  • The Amplifier: This component is also known as a cellular repeater, and is the second major part of the signal booster. Its purpose is to boost the weak signal that the exterior antenna pulls in, and expand its coverage to a range between 500 and 7,000 feet. Amplifier output is measured in dB, and power in dBm. The amplifier boosts the dB reading of any signal it processes; a good home amplifier is capable of improving signal by at least +60dB.
  • The Internal Antenna: This is the component of the signal booster which rebroadcasts amplified signals into the area where they are needed. You have panel antennas which can be mounted on walls, and which are able to rebroadcast strongly within closer areas (helpful when there is a specific room without strong reception). There are also dome antennas, which can be mounted on the ceiling and are able to send out signals in equal strength omnidirectionally.