A low cost compact LTCC-based GaN power amplifier module

In this paper, we explore different implementation levels of RF power amplifiers, including a hybrid PCB approach and a system-in-package (SiP) approach based on low temperature co-fired ceramic (LTCC) technology. The selected device of the amplifier is a low cost Si based AlGaN/GaN high electron mobility transistor (HEMT). Measured results show that the LTCC-PA module can exhibit an output power of 1 W and a drain efficiency of 41% at 3.8 GHz, while the PCB-PA module can deliver 1.5 W output power together with 47% drain efficiency at 3.8 GHz. The major advantage of using a SiP approach with LTCC technology is the dramatic cost reduction compared to a monolithic microwave integrated circuit (MMIC) and the size reduction compared to a hybrid PCB approach.