2.6 GHz 4 watt GaN-HEMT two-stage power amplifier MMIC for LTE small-cell applications

This paper presents a two-stage PA MMIC using 0.4-μm GaN-HEMT. Two-stage structure is adopted to take its high gain property and simple inter-stage matching network. The size and loss of the inter-stage matching network can be reduced by including bond wires as a part of the shunt inductors in the matching network. The two-stage PA MMIC was fabricated with a size of 2.0×1.9 mm2 and was mounted on the 4×4 QFN package for evaluation. Using a downlink LTE signal with a PAPR of 6.5 dB and a channel bandwidth of 10 MHz at the 2.6 GHz band, the PA MMIC exhibited a gain of 30 dB, a DE of 32%, and an ACLR of -31.4 dBc at an average output power of 36 dBm. Using two PA MMICs for carrier and peaking amplifiers, DPA was designed and evaluated. At a 6-dB back-off output power level of 39 dBm, a gain of 24.7 dB and a DE of 43.5% were achieved.