What is an EMC Power Amplifier?

        EMC Power Amplifier

EMC immunity tests are conducted to verify whether the equipment can function properly when exposed to high levels of RF energy. Typically, the EMC immunity test requires a high field strength (3–200 V/m). EMC power amplifier is an electronic amplifier used to generate the power to create the field strengths (V/m) required for EMC testing. The purpose of this amplifier is to generate field strength at a given distance from the antenna. A signal generator creates the test signal which is then amplified by the power amplifier and sent to the E-Field Generator that created an E-Field.

EMC power amplifiers are available in Class A / Class B / Class AB / Class C operating modes. These amplifiers have features such as protection circuits to avoid damage in the case of input overload, improper output connections (shorted or improper loads), over-temperature, as well as over-current conditions, integrated VSWR alarm to prevent the amplifier’s output circuitry from the reflected power caused by impedance mismatches, low-noise, and manual/remote control options.

The EMC power amplifiers are ideal for applications, such as high-power IC testing, antenna testing, laboratory use, and electromagnetic compatibility/electromagnetic interference test.

How to select an EMC Power Amplifier?

The key parameters to evaluate when selecting an EMC Power Amplifier are listed below.

Frequency: Represents the frequency range of an EMC power amplifier.

Class of Operation: EMC power amplifiers are available in Class A/Class B/ Class AB/Class C operating mode.

Output Power (saturated): Represents the maximum RF power output from the amplifier in Watts.

P1dB: Represents RF power output from the amplifier at 1dB compression point. At 1dB compression point, the actual output power is 1 dB less than the expected (linear) output power (because of non-linearity at that point).

Gain: Represents the power gain of the power amplifier in dB.

Power gain Flatness: Represents the flatness response deviation (accuracy) in ± dB.

IP3: IP3 is the point where 3rd order products would overtake fundamentals in output power. It is represented in dBm.

Output impedance: Represents the output terminal impedance of the power amplifier. Usually, the output impedance is 50 ohms.

Input impedance: Represents the input terminal impedance of the power amplifier. Usually, the output impedance is 50 ohms.

Input VSWR (typical): Represents the measure of how efficiently radio-frequency power is transmitted from the signal generator into the input terminal of the power amplifier. A low input VSWR is the indication of a good power amplifier.

Output VSWR (typical): Represents the measure of how efficiently radio-frequency power is transmitted from the output terminal of the power amplifier into the load (antenna). A low input VSWR is the indication of a good power amplifier.

Noise figure: It is the measure of degradation of the signal-to-noise ratio (SNR) (caused by components in a signal chain). It is represented in dB.

RF input power: Represents the maximum RF power input that a power amplifier can handle. It is represented in dBm.

RF Input Signal Format: CW/AM/FM/PM/Pulse

Harmonics: Represents the harmonics present in the output signal at 1dB compression point. It is represented in dBc @ P1dB.

Spurious signals: Represents the spurious signals present in the output signal at 1dB compression point. It is represented in dBc @ P1dB.

Dimension: Represents the dimension of the power amplifier in L × W × H mm.

Weight: Represents the weight of the power amplifier in Kg.

Operating temperature: Represents the safe operating temperature limit of the power amplifier in °C.