A compact high efficiency GaN-Si PA implemented in a low cost DFN package with 71% fractional bandwidth

Abstract

Abstract - This work presents a high performance GaN on Silicon ( GaN-Si ) PA that exploits high efficiency Class-J modes over greater than one octave bandwidth. With appropriate choice of device layout, device size, package and operating drain voltage, a design methodology has been applied to obtain a highly efficient, broadband PA realization. A 2mm GaN-Si die housed in a low cost plastic package was selected for the design of a compact, hybrid Class-J PA from 1-2.1 GHz. The PA delivered 13-18 W of output power with drain efficiencies from 60-69% measured across the band. Modulated signal performance is also demonstrated across the band, where average drain efficiencies of greater than 33% have been found with an ACPR in excess of -33 dBc using a 9.1 dB PAPR W-CDMA excitation signal. Index Terms - Broadband, Class J, Gallium Nitride, GaN, high efficiency, power amplifiers. I. INTRODUCTION Modern cellular network operators demand greater power amplifier (PA) performance by improving the amplifier's operating efficiency and bandwidth capability to reduce overall operating expenditure (OPEX) and system complexity. For the realization of high performance PAs with high output power, Gallium Nitride (GaN) has become the leading device technology due to its high current density, high breakdown voltage and low device parasitic capacitances. The processing difficulty and cost of GaN source material has led to the proliferation of Silicon Carbide (SiC) substrates for GaN device fabrication, due to its high thermal conductivity