Gain

Pikeun kagunaan séjén, tempo Gain (disambiguasi).

Dina éléktronika, gain biasana dihartikeun perbandingan kaluaran sinyal hiji sistim dibandingkeun jeung asupan sinyal sistim éta. Gain lima nunjukkeun yén voltase atawa data naék saloba faktor lima (lima kali). Hal ieu miboga aplikasi nu lega dina panguat.

Unit logaritmis jeung désibel

Artikel ieu keur dikeureuyeuh, ditarjamahkeun tina basa Inggris. Bantuanna didagoan pikeun narjamahkeun.

In electronics, it is common to use logarithmic units to measure gain. Originally, the bel was used:

Gain = log₁₀(P₂/P₁) bel

where P1 and P2 are the input and output powers respectively.

Using the bel unit, however, results in small numbers, so the decibel (one tenth of a bel) became popular in its place. As there are ten decibels (dB) in a bel:

Gain = 10 * log₁₀(P₂/P₁) dB

(A similar unit using natural logarithms is called the neper.)

When gain is calculated using voltage instead of power, making the substitution (P=V²/R), the formula is:

• Gain = 10 * log ((V₂²/R) /(V₁²/R) ) dB

• Gain = 10 * log ((V₂/V₁)² ) dB

• Gain = 20 * log (V₂/V₁) dB

This formula only holds true if the load impedances are identical. In many modern electronic devices, output impedances are low enough and input impedances high enough that load can be ignored without significantly affecting the calculation.

Conto

If an amplifier produces an output of 1 volt into a 1 ohm load, then it is providing 1 watt of output power. If the amplifier is then altered to produce an output of 10 volts into the same load, it is now providing 100 watts of output power ($P=V^{2}/R$). Therefore:

voltage gain = 10 times
power gain = 100 times

— which by definition is said to be a gain of 20 dB.

A gain of factor 1 or (equivalent to 0 dB) where both input and output are at the same voltage level is also known as unity gain.

Tempo ogé

• Kaluaran daya transmiter
• Gain absolut
• Loop gain
• Insertion gain
• Gain diréktif
• Gain pamrosésan sinyal
• Net gain
• Automatic gain control (AGC)
• Karugian, Aperture-to-medium coupling loss, Effective radiated power

Artikel ieu ngandung bahan ti Federal Standard 1037C, numana, minangka pagawéannana Pamaréntah Amérika Sarikat, aya dina domain publik.