A Signal Booster is a bidirectional amplifier created to boost weak cell phone signals in remote or hard-to-reach areas. Their purpose in boosting signals is to promote clearer reception for cellular phones users in difficult locations. There are many different causes of weak reception, from the use of certain building materials to the location of an area in relation to the closest cell phone tower. Thankfully, powerful, modern signal boosters can detect a signal too weak for the typical phone to catch and greatly amplify it, to provide service to one or more cellular phones without issue.