Extend the Class-B to Class-J Continuum Mode by Adding Arbitrary Harmonic Voltage Elements
An extended Class-B to Class-J continuum mode is presented and a power amplifier(PA) based on this theory is realized in this paper. The enhanced voltage waveform formulation, which gives multiple impedances solutions of the fundamental and harmonics for the target performance by adding the harmonic elements, has been described mathematically. Unlike conventional continuous Class-J mode, the optimal impedance solutions of the new mode can contain real and imaginary parts of arbitrary even harmonics. To verify this theory, a high-efficiency PA from 2.85-4.25 GHz is designed at the package plane. The measurement results illustrate that the fabricated PA outputs 11.7-15.8 W saturation power with drain efficiency(DE) of 58% to 78% and PAE of 54.5%-74% across the entire band. For a 5 MHz WCDMA signal with a peak-to-average ratio (PAR) of 8.6 dB, an adjacent channel leakage ratio (ACLR) of -31.5 to -38 dBc is measured at an average DE of 38%-48% when the output power (Pout) is 36 dBm from 2.85-4.25 GHz.