220-to-320-GHz Fundamental Mixer in 60-nm InP HEMT Technology Achieving 240-Gbps Dual-Band Data Transmission

We designed and fabricated a 300-GHz-band fundamental mixer in indium phosphide (InP) high electron mobility transistor (HEMT) technology for 6G wireless communications. We devised a widely split frequency matching network to widen the bandwidth of a resistive mixer. The mixer IC achieved a conversion gain of$-$15 and$-$6-dB RF bandwidth of 100 GHz (220–320 GHz), the widest ever reported. We implemented the mixer IC as a WR3.4 waveguide mixer module and performed a back-to-back data transmission experiment in three different frequency bands. Data rates of 120, 152, and 168 Gbps were achieved in each band. We also developed a dual-band data transmission system with a local oscillator (LO) leakage canceling method. It was capable of transmitting data at 240 Gbps, the highest rate reported to date, and suppressing LO leakage by 60 dB.