Amplifier Selection Tips
- In general EMC amplifiers are based on various technologies and functionality, such as: Solid State, TWTA, CW, Pulse, and their class of operation - Class A and AB.
- Class A solid state amplifiers are generally the best choice for EMC RI and CI testing. They are the most reliable, durable and rugged compared to other amplifier classes, or types.
- Amplifiers offering 100% rated power with-out foldback are a good choice. Typical EMC testing exposes amps to significant VSWR and reflected power.
- Also look for an amp that operates without damage or oscillation with any magnitude and phase of source and load impedance.
- Amps with good linearity and low harmonic distortion, result in clean, reproducible and measurable signals. Again, Class A amplifiers outperform other types.
- Modulation (AM, FM, PM) is required by most RI and CI test standards. Ask the amp manufacturer how well modulation is reproduced and under what conditions.
- If planning to use a multiple tones/signals or complex waveforms to speed up testing and better represent real-world threats, a broadband amplifier is most appropriate, versus a multiband amplifier so that all tones are amplified simultaneously.
- Determine the amp’s required power based on losses; cable, gain (antenna), and number of tones, if used with a multi-tone generator.
- Rated Output Power is a manufacturer defined specification. Beware of typical, average and maximum power level descriptions. These can be misleading.
- Power Output @P1dB: An important rating for applications with strict linearity requirements (IEC/R&D).
Originally published at INCompliancemag.com.