Definition

decibels relative to one milliwatt (dBm)

Part of the Electronics glossary:

The expression dBm is used to define signal strength in wires and cables at RF and AF frequencies. The symbol is an abbreviation for "decibels relative to one milliwatt," where one milliwatt (1 mW) equals 1/1000 of a watt (0.001 W or 10 -3 W). This unit is commonly used in test laboratories.

Next Steps

The dBm increment is based on the decibel , a logarithm ic measure of relative power . Suppose a signal has a power level of P mW. Then the signal strength in dBm, symbolized S dBm , is:

S dBm = 10 log 10 P

A 1-mW signal has a level of 0 dBm. Signals weaker than 1 mW have negative dBm values; signals stronger than 1 mW have positive dBm values.

This was last updated in March 2011
Contributor(s): Johan Sjoquist
Posted by: Margaret Rouse

Related Terms

Definitions

  • NAND flash memory

    - NAND flash memory is a type of non-volatile storage technology that does not require power to retain data. (WhatIs.com)

  • Mini-ITX 2.0

    - Mini-ITX 2.0 is a motherboard designed for use in small form factor personal computers (PCs). The physical boards measure 6.7 inches (17 centimeters) square. (WhatIs.com)

  • electroluminescence

    - Electroluminescence is a characteristic of a material, typically a semiconductor, that enables it to emit light in response to an electrical current or a strong electrical field. (WhatIs.com)

Glossaries

  • Electronics

    - Terms related to electronics, including definitions about electrical components and words and phrases about computers, laptops parts, digital cameras, televisions and home appliances.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question. Find an Answer.Powered by ITKnowledgeExchange.com

Ask An IT Question

Get answers from your peers on your most technical challenges

Ask Question

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.