Dual-Band Design of Integrated Class-J Power Amplifiers in GaAs pHEMT Technology

This paper presents two integrated concurrent dual-band class-J power amplifiers (PAs) in AlGaAs–InGaAs pHEMT technology. Design flexibility of class-J space is employed to explore the availability of a dual-band PA where the center frequency of the second band is twice the center frequency of the first band (<inline-formula> <tex-math notation="LaTeX">$f_{2}=2f_{1}$ </tex-math></inline-formula>). The theoretical formulations are developed for <inline-formula> <tex-math notation="LaTeX">$f_{2}=2f_{1}$ </tex-math></inline-formula> case, for which it is not feasible to obtain high efficiencies using class-F⁻¹, class-F, and other high-efficiency modes. A proof of concept 5/10-GHz class-J PA is manufactured in a 0.1-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> GaAs pHEMT technology. The proposed PA delivers 26.9- and 26-dBm output power with peak power added efficiencies (PAEs) of 49% and 46% at 5 and 10 GHz, respectively. Another 6/16-GHz (<inline-formula> <tex-math notation="LaTeX">$f_{2}\neq 2f_{1}$ </tex-math></inline-formula>) dual-band concurrent class-J PA with a PAE of more than 50% in both bands is also fabricated in a 0.25-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> GaAs pHEMT technology. The designed dual-band class-J PA delivers 26- and 25.5-dBm output power at 6 and 16 GHz, respectively.