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.

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

  • heat pump

    - A heat pump is a device that takes heat from one source and moves it to another location through electric or mechanical means. Heat pumps may be used either to heat or cool. Heat pump technologies ... (WhatIs.com)

  • integrated solar

    - Integrated solar is the inclusion of solar power technology as a part of original construction rather than as a separate module that is added later. Solar energy may be gathered thermally or throug... (WhatIs.com)

  • segmented memory

    - Segmented memory is a system of addressing computer memory, which may be physical or virtual and may be operating in real or protected mode. The segmented memory system was used to expand the 64KB... (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 About decibels relative to one milliwatt (dBm)Powered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

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