A 300-400MHz band high efficiency power amplifier with intrinsic harmonics termination for SDR

A 300-400MHz band 2-stage amplifier with power add efficiency of 59% and output power of 23dBm has been developed. To obtain a high efficiency in the band width, we have terminated second harmonic and third harmonic source impedance optimally as well as load impedance. We have designed the source harmonics termination has a parallel resonant circuit comprised of lumped element, and load harmonics termination without quarter-wavelength or eighth-wavelength impedance transformer.