A 24–30 GHz GaN Front-End MMIC with Coupled-Resonator based Transmit/Receive Switch for 5G Millimeter-Wave Applications

This paper presents a compact wideband front-end MMIC with an integrated transmit/receive (T/R) switch based on coupled-resonator technique. The output matching network (OMN) of PA is utilized to generate additional resonant pole in the RX mode and enables impedance transformation in the TX mode simultaneously. The RX branch utilizes coupled resonators to broaden gain bandwidth and achieve wideband noise matching in the RX mode. To validate the proposed architecture, a 24–30 GHz front-end MMIC for 5G millimeter-wave applications is implemented using a commercial 0.15-μm GaN high electron mobility transistor (HEMT) process. In TX mode, it achieves a small signal gain over 17 dB, a 14.3–17 % saturated PAE and 27.8–29.3 dBm saturated output power. The average output power, measured with 64QAM 100MSysm/s modulated signal at an EVM of -25 dB, is 21 dBm with an average PAE of 3.7 %. Applying a 200-MHz OFDM signal with 10.77 dB PAPR, an ACLR of -29.5 dBc is measured without digital predistortion. The RX branch demonstrates a small-signal gain of over 18.8 dB, a noise figure of less than 4.4 dB, and an OP1dB of 9.7–12.9 dBm. In addition, the chip area is 2.1×2.6 mm
²
.