Electrical Engineering Stack Exchange
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Questions tagged [power-amplifier]

An electronic amplifier that amplifies a low-power signal in order to make it more suitable for an application that requires higher power (e.g. driving a speaker). Power amplifiers have special challenges compared to lower power amplifiers (e.g. a voltage amplifier, which amplifies a signal's voltage but does not provide much output current capability); such challenges include more board space, cooling components that are dissipating high power, etc.

An electronic amplifier that amplifies a low-power signal in order to make it more suitable for an application that requires higher power (e.g. driving a speaker). Power amplifiers have special challenges compared to lower power amplifiers (e.g. a voltage amplifier, which amplifies a signal's voltage but does not provide much output current capability); such challenges include more board space, cooling components that are dissipating high power, etc.

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How can I choose the capacitor for a class B power amplifier?

In this class B power amplifier, the capacitor is fully charged when Qmax = C. Vcc and discharges in a negative period. Why is the capacitor full with Vcc instead of another voltage value?
South goodman
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Calculate resistor to adjust base current in Class AB amp

I was tinkering with this "pseudo" class AB amp. The transistors have a minimum gain of 160. For now I wish to have an output of about 160 mA, which mean that I need 1 mA at the base of the transistors. How can I adjust the resistor R3 to make sure…
Hans
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Circuit Definition

This is a circuit that I've found in my old amplifier board. Experts please help me identify this circuit and please describe how it works. I am sorry for my crude drawing, but this is what I found when drawing it from the circuit board. It was…
Nakib Hassan
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Amplify Arduino Due DAC output

I need to drive an inductive load from an Arduino Due analog output. The analog output delivers 0.55V-2.75V (yes, it doesn't deliver 0 volts). I need to get something like 0-14V with up to 3A maximum and so that the output voltage is linearly…
kradant
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Power amplifier large signal performanceand small signal performance

I'am designing a PA 50W and the large signal performance is good (Gain, delivered power, P1dB, PAE, etc) but the small signal performance is bad espacially the output return loss < -8dB). Is this situation acceptable for a general PA design?
Pascal R.
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Class AB power amplifier output signal

The way the input source is applied to the Class AB amp, it seems that there should be no output that appear. Because when the input is positive half cycle, the diode D1 is reversed biased, there would not be an input to Q1 and Q2 is cutoff. Why is…
Paumdrdo
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Class F amplifier analysis

I can't figure out why drain voltage is rectangular in the following circuit: I tried this: $$ V_{ds}=V_{DD}-I_{fund}R_lsin(\omega_0t)-I^{(2)}Z_{in}^{(2)}sin(2\omega_0t)-I^{(3)}Z_{in}^{(3)}sin(3\omega_0t)... $$ $$ I^{(k)}= \int…
Farzad
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Conventional current in a power amplifier?

I recently learned that electricity doesn't actually flow from + to - but the other way around.. So my question would be: if I was using a 2 channel power amp and connected a speaker to it with the positive wire on the left channel (+) and the…
Timinycricket
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Gain block vs power amplifier

I was searching for some IC to amplify a signal (like a RF frontend before an antenna) to have a stronger RF signal. I come across 2 terms and I don't really understand the difference between them. What is the difference between a gain block and a…
roi_saumon
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Power amplifier simulation

I have simulated the circuit with the following values. VDD = 1.8V, Vin is a sine wave with fin = 450MHz, pin = -5dBm, L1 = 12.5nH, C1 = 10pF, RL=50 ohm. I also gave a biasing dc voltage at the gate of MOSFET as 1V. I got the following graph after…
Swap
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Power amplifier circuit

In the power amplifier circuit shown if the input is an RF sine wave, with VDD=1.8V and Vgs = 1V, what will be the waveform at the drain of the MOSFET - sine or square wave? Is it possible to get a sine wave at the drain?
Swap
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mosfet common source amplifier

In this common source stage, the inductor acts as a current source and capacitor act as a voltage source. What happens if the inductor and capacitor are replaced by current and voltage sources respectively? How will it affect the circuit…
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Class E Power amplifier

I am designing a Class E power amplifier for 450MHz frequency. But how to fix the Q factor for the series LC in the output stage of the Power amplifier?
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