5.4 GHz reconfigurable quadrature amplitude modulator using very high-speed OTAs

Summary form only given, as follows. A quadrature amplitude modulator that can be reconfigured between 4 QAM, 16 QAM and higher modulation formats is described. Vector sum in current domain is employed to perform the direct digital modulation. The measured data throughput at 5.4 GHz carrier frequency was 16 Mbit/s. In the 16 QAM modulation state, the error vector magnitude (EVM) was 6.20% and the dynamic range was −52 dBm to −8 dBm. The 1.2 V, 20 mA chip was fabricated in 130 nm CMOS technology and its core occupied an area of 0.09 mm².