Improved Harmonic Suppression of Class-C Power Amplifiers Using Modified Bias Lines

This paper presents a modified bias line for class C power amplifiers. The modification helps to obtain higher power aided efficiency (PAE) and improved harmonic suppression. A prototype fabricated at 2.4 GHz shows 12.9% improvement of PAE than a conventional one. Further, a comparison with recently published works on harmonic suppression of class C amplifiers shows 10-20 dB rejection improvement of second to sixth harmonic frequencies. Detail analysis and design steps are provided.