Amplifier Power Gain
Ap = Av · Ai
Quick answer
This calculator solves Ap = Av × Ai for Power Gain. With Voltage Gain 1.1, Current Gain 2.35, the result is 2.585. It solves in 3 directions, so you can enter the values you have and get the one you need.
Calculator
Formula
Description
An amplifier’s power gain is the product of its voltage gain and its current gain. A common-emitter stage amplifies both voltage and current, giving the highest power gain of the three basic configurations. A follower has near-unity voltage gain but high current gain, while a common-base stage has high voltage gain but current gain under one.
Variables
- Ap — Power gain
- Av — Voltage gain (magnitude)
- Ai — Current gain (magnitude)
Practical Notes
In decibels, power gain in dB = 10·log10(Ap). The three configurations trade voltage vs current gain but the common-emitter gives the largest overall power gain.
Symbols and units
| Symbol | Meaning | Default unit | Accepted units |
|---|---|---|---|
| Ap | Power Gain | — | — |
| Av | Voltage Gain | — | — |
| Ai | Current Gain | — | — |
Step by step
- 1. What you know: Voltage Gain 1.1, Current Gain 2.35
- 2. The relation: Ap = Av × Ai
- 3. Substitute: Av = 1.1, Ai = 2.35
- 4. Result: Power Gain = 2.585
Worked examples
Minimum range
Given: Voltage Gain 0.055, Current Gain 0.118
Result: Power Gain = 0.00649
Low range
Given: Voltage Gain 0.55, Current Gain 1.18
Result: Power Gain = 0.649
Typical
Given: Voltage Gain 1.1, Current Gain 2.35
Result: Power Gain = 2.585
High range
Given: Voltage Gain 1.76, Current Gain 3.76
Result: Power Gain = 6.618
Maximum range
Given: Voltage Gain 17.6, Current Gain 37.6
Result: Power Gain = 661.8
Solving for each variable
Solve for Power Gain
Voltage Gain 0.055, Current Gain 0.118 → 0.00649
Solve for Voltage Gain
Power Gain 0.025, Current Gain 0.118 → 0.2119
Solve for Current Gain
Power Gain 0.025, Voltage Gain 0.055 → 0.4545
How Power Gain changes with Voltage Gain
| Voltage Gain (input) | Power Gain (result) |
|---|---|
| 0.11 | 0.2585 |
| 0.275 | 0.6463 |
| 0.55 | 1.293 |
| 0.825 | 1.939 |
| 1.1 | 2.585 |
| 1.65 | 3.878 |
| 2.2 | 5.17 |
| 4.4 | 10.34 |
| 7.7 | 18.1 |
| 11 | 25.85 |
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<p><a href="https://vbatpower.com/formulas/amplifier-power-gain/">Amplifier Power Gain</a> Calculator by vbatpower.com</p>Frequently asked questions
How do you calculate Amplifier Power Gain?
Use Ap = Av × Ai. With Voltage Gain 1.1, Current Gain 2.35, Power Gain works out to 2.585.
What is the formula for Amplifier Power Gain?
The formula is Ap = Av × Ai. An amplifier’s power gain is the product of its voltage gain and its current gain.
How do you find Voltage Gain when you know the other values?
Rearrange for Voltage Gain: with Power Gain 0.025, Current Gain 0.118, Voltage Gain is 0.2119.
How do you find Current Gain when you know the other values?
Rearrange for Current Gain: with Power Gain 0.025, Voltage Gain 0.055, Current Gain is 0.4545.
Related Concepts
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