Developed for 5G base stations, Qorvo is sampling a single channel, 28 GHz front-end module (FEM) with a single transmit/receive (T/R) MMIC fabricated in GaN. The QPF4001 FEM covers 26 to 30 GHz and is sized to fit the required λ/2 element spacing for a phased array antenna, contained in a 5 mm x 4 mm air-cavity, laminate, surface-mount package.
Fabricated with Qorvo’s 0.15 μm gate length GaN on SiC process, the T/R MMIC comprises a three-stage power amplifier (PA), three stage low noise amplifier (LNA) and low loss T/R switch. The transmit chain provides 30 dBm saturated output power, 23 dBm at 3 percent or lower EVM, and 27 dB small-signal gain. The receive chain has 3.5 dB noise figure and 17 dB small-signal gain.
Qorvo advocates GaN for millimeter wave FEMs, as the higher power density enables higher linear output power from the PA, yielding arrays with fewer elements for a given radiated power.
The 28 GHz FEM, which Qorvo says is the first GaN-based FEM at 28 GHz, follows Qorvo’s release of a GaN-based FEM for the 39 GHz 5G band, the QPF4005, announced in June 2017.
“Our GaN technology is used in dozens of 5G field trials, and this new module will enable further reductions in size and power consumption, which are essential for the very small arrays critical to millimeter wave frequencies.” — James Klein, president of Qorvo’s infrastructure and defense products business