A low EVM SiGe BiCMOS 40–100 GHz Direct Conversion IQ Modulator for Multi-Gbps Communications Systems

This paper presents a 40-100 GHz wideband direct conversion IQ modulator with IQ correction capability and flip-chip packaging in GF8HP 0.12μm SiGe BiCMOS technology. The modulator chip covers Q-, V-, E-, and W-bands and is flipped on a low-cost RF board for connectorized measurements. The measured IQ modulator conversion gain is 5-8 dB at 40-100 GHz with an OP1dB of -2 to -5 dBm. A single-sideband (SSB) rejection higher than 42 dBc and an LO leakage rejection better than 35 dBc is measured. A 64-QAM modulated waveform with a data rate of 12 Gb/s (2Gbaud/s) and 2.4% error vector magnitude (EVM) is successfully demonstrated at 72 GHz. To our knowledge, this modulator achieves state-of-the-art performance in terms of bandwidth, wideband SSB rejection, and EVM at multi-Gbps data rate, and with applications in millimeter-wave high data-rate 5G systems.