A 64-QAM 94-GHz GaAs Transceiver with 18 dBm Output Power for High Data-Rate Communication

This paper presents a 90–96 GHz GaAs transceiver chip with printed on-board low-loss microstrip line to waveguide transition. By introducing power enhancing technique in the design of the double-balanced passive tripler of the LO multiplier chain, the impedance matching of the tripler is improved. Benefiting from the introduced high-pass matching network in the LO chain, the out-of-band unwanted harmonics suppression are improved to be over 70 dBc within the entire bandwidth, which makes the system have better spectral purity to support high-order modulation. The transmitter chip achieves a measured maximum output power of 18 dBm at 90 GHz and delivers a Psat of 17.4 to 18 dBm from 90 to 96 GHz. The receiver chip achieves a noise figure better than 5.1 dB. In the system wireless data transmission measurement, the transmitter and receiver chips are connected to horn antennas through the designed low-loss microstrip line to waveguide transition structure. The measured TX-to-RX EVM in 400 MHz 64QAM 5G NR signal is 4.86% at a 1 m distance. Compared to other state-of-arts that support high order modulation and to the best of the authors' knowledge, the transmitter's output power is the highest in the 94 GHz band.