Calculate the approximate power added efficiency of following power amplifier:

DC Voltage : 8 volts

DC Current : 5 Amp.

AC Input signal : 0 dBm

O/P power : 30 dBm

Explanation:

Power Added Efficiency of Power Amplifier

Definition: Power added efficiency (PAE) is a key performance metric for power amplifiers, particularly in RF and microwave engineering. It measures the efficiency with which the amplifier converts the DC power it consumes into useful RF output power, considering the input signal power as part of the calculation.

Formula:

PAE is calculated using the following formula:

PAE = [(P_out - P_in) ÷ P_DC] × 100

Where:

• P_out: Output power (RF power delivered by the amplifier).
• P_in: Input signal power (RF power fed into the amplifier).
• P_DC: DC power supplied to the amplifier.

Calculation:

Given data:

• DC Voltage (V_DC): 8 volts
• DC Current (I_DC): 5 amps
• AC Input Signal Power (P_in): 0 dBm
• Output Power (P_out): 30 dBm

Step 1: Convert dBm values to watts.

• P_in (in watts) = 10^((0 - 30)/10) = 10^(-3) = 0.001 watts
• P_out (in watts) = 10^((30 - 30)/10) = 10^(0) = 1 watt

Step 2: Calculate DC power (P_DC).

P_DC = V_DC × I_DC

P_DC = 8 × 5 = 40 watts

Step 3: Calculate Power Added Efficiency (PAE).

PAE = [(P_out - P_in) ÷ P_DC] × 100

Substitute the values:

PAE = [(1 - 0.001) ÷ 40] × 100

PAE = [0.999 ÷ 40] × 100

PAE ≈ 0.025 × 100

PAE ≈ 2.5%

Conclusion: The approximate power added efficiency of the given power amplifier is 2.5%, which corresponds to Option 2