A Digitally Modulated 60GHz Polar Transmitter in 40nm CMOS

A Digitally Modulated 60GHz Polar Transmitter in 40nm CMOS ■

Khaled Khalaf, Khaled Khalaf, Khaled Khalaf, Vojkan Vidojkovic, Vojkan Vidojkovic, Vojkan Vidojkovic, Kristof Vaesen, Kristof Vaesen, Kristof Vaesen, John R. Long, John R. Long, John R. Long, Wim Van Thillo, Wim Van Thillo, Wim Van Thillo, Piet Wambacq, Piet Wambacq, Piet Wambacq

Abstract ■

A 60GHz polar Tx prototype implemented in 40nm CMOS includes a two-stage PA with an RF-DAC, an I-Q upconversion mixer, a 60GHz LO hybrid and a digital synchronization interface. Saturated output power is approx. 10dBm, while RF output and baseband input bandwidths are 9GHz and 1.2GHz, respectively. The linear RF-DAC resolution is 5 bits. EVM degradation and spectral mask out-of-band distortion appear at input powers higher than 6dB above P-1dB. EVM is -19dB and -16dB at full rate, and -25.5dB and -22dB at reduced rates for QPSK and 16-QAM signals, respectively. The Tx consumes 75mW from 0.9V, and the core occupies 0.18mm2 of the 2.38mm2 testchip.