dbi و dbm چیست؟

[gorzin85]

سلام
می خواستم بدونم که در دستگاه های نانو استیشن dbi و dbm داریم منظور از این کلمات چیست و چه تفاوتی دارند
ممنون

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موضوعات مشابه:

• www چیست؟
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• SDH چیست؟
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[nazi88]

سلام
شاید منظورش اینه که این کلمات مخفف چه کلماتی هستند؟

[basic]

dbi برای تبیین Gain (بهره) انتن و dbm(دسی بل میلی وات) برای تبیین قدرت سیگنال به کار میره.

[hamid khan]

What is dBm and dBi

What is dBm:
dBm is an abbreviation for the power ratio in decibel (dB) of the measured power referenced to one milliwatt (mW). The "m" stands for "milliwatt".

The term dB is mainly used for an attenuation or an amplification, but dBm for a measured power.

dBm is used in communication work as a measure of absolute power values. Zero dBm equals one milliwatt. A 3 dBm increase represents roughly doubling the power, which means that 3 dBm equals roughly 2 mW. For a 3 dBm decrease the power is reduced by about one half, making -3 dBm equal to about 0.5 milliwatt.

Formula for converting dBm to milliwatts:
dBm = log10 (mW)*10

Formula for converting milliwatts back to dBm:
mW =10^(dBm/10)

What is dBi:
A ratio, measured in decibels, of the effective gain of an antenna compared to an isotropic antenna. The greater the dBi value, the higher the gain and, as such, the more acute the angle of coverage.