Key Power-Amplifier Specifications

Adjacent-channel power ratio (ACPR): The ratio of the integrated signal interference power in an adjacent channel to the integrated power in the desired channel Error vector magnitude (EVM): A measure of the distortion in the I-Q constellation diagram of a signal due to phase or amplitude differences; it’s the length of the error vector drawn from the ends of the vector to the desired constellation plot to the vector drawn to the actual constellation plot expressed as a percentage of the peak signal levelHarmonics: The level of the harmonics compared to the main signal carrier expressed in dBcThird-order intercept (IP3): This measure of intermodulation distortion (IMD) involves a virtual point where extended plots from power input versus power output of the fundamental signal and the third-order product power intersect; it’s a theoretical point where the third-order intermodulation level is equal to the fundamental signal level; IP3 is expressed in dBOne-dB compression point (P1dB): A general measure of the maximum output power available from a linear amplifier; it’s the point where the amplifier gain drops at high signal levels to a point 1 dB below the theoretical linear power levelPower-added efficiency (PAE): A measure of the efficiency of a power amplifier that considers the RF drive power as well as normal dc power input and power output expressed as a percentage.Peak to average power ratio (PAPR): Also known as crest factor, it’s the ratio of the peak power of a waveform to its average value expressed as a percentagePower output: Given in watts but also given in dBm