Power Amplifier

A Power Amplifier is an electronic device that boosts the power level of a signal so it can drive a load, such as an antenna, loudspeaker, or transmission line. It converts a low-power input into a high-power output while maintaining the signal’s shape and frequency.

Power amplifiers are classified by operation class, which affects efficiency and linearity:

• Class A: Highly linear but low efficiency (~25–30%).

• Class B: Higher efficiency but introduces distortion.

• Class AB: Balance between Class A and B.

• Class C: Very efficient but used for narrowband signals.

• Class D/E/F: Switch-mode amplifiers with high efficiency for digital or RF systems.

In RF and communication systems, a PA boosts the modulated RF signal to a level sufficient to be transmitted through an antenna, ensuring adequate coverage or link range.

Important PA specifications include:

• Output Power (Pout): Maximum power delivered to the load.

• Gain (dB): Amplification factor.

• Efficiency: Ratio of RF output power to DC input power.

• Linearity: Ability to amplify without distortion.

• Bandwidth: Frequency range of operation.

• Power Added Efficiency (PAE): A common efficiency metric for RF PAs.

Linearity determines how accurately the amplifier reproduces the input signal at higher power levels. Poor linearity causes signal distortion, leading to spectral regrowth and interference in adjacent channels—critical concerns in modern communication systems like LTE, 5G, and Wi-Fi.

Linear power amplifiers maintain signal integrity with minimal distortion, ideal for complex modulations. Nonlinear amplifiers are typically more efficient and used in applications where signal distortion is less critical.

Common semiconductor materials include:

• Silicon (Si): Cost-effective and mature.

• Gallium Arsenide (GaAs): High frequency, good efficiency.

• Gallium Nitride (GaN): High power density and ruggedness.

• LDMOS (Laterally Diffused MOS): Common in base stations for high efficiency and robustness.

Efficiency is limited by heat dissipation, biasing conditions, and signal waveform characteristics. For linear amplifiers (e.g., Class A, AB), maintaining fidelity reduces efficiency. Switch-mode designs (Class D, E, F) improve efficiency but may reduce linearity.

Proper impedance matching between the amplifier and the load (often 50 Ω in RF systems) ensures maximum power transfer and prevents reflections that can cause signal loss or device damage.

Power amplifiers are used in:

• Wireless transmitters (cellular, Wi-Fi, satellite)

• Radar and defense systems

• Broadcasting (radio and TV transmitters)

• Audio systems

• Test and measurement equipment

Consider the following:

• Operating frequency and bandwidth

• Required output power level

• Efficiency vs. linearity trade-off

• Power supply and cooling requirements

• Technology (GaN, GaAs, LDMOS, etc.)

• Cost, size, and reliability constraints

Yes, MCV power amplifiers are built in rugged, connectorized enclosures designed to operate reliably in challenging conditions such as outdoor, industrial, and military environments.

To place an order for power amplifier please contact us and we will help you!