Research of Low Noise Amplifier, I/Q Demodulator, and Power Amplifier for Millimeter-wave Applications

This thesis is divided into three parts by three critical MMW front-end circuits for different applications. The first part presents a Q-band LNA using 0.15-μm GaAs pHEMT process for the radio astronomy applications. By adopting π-type and compensated matching networks, the LNA achieves broadband performance. The LNA attains 23 dB small signal gain from 28.5 to 50.5 GHz and a measured noise figure of 3.8 dB from 35 to 50 GHz with 62.6-mW dc power consumption. The second part exhibits an I/Q demodulator in 90-nm CMOS process for E-band point-to-point communication. The demodulator attains -3-dB conversion gain with only 26.6-mW power consumption and 4-dBm LO power by adopting push-push based sub-harmonic mixers. With the tunable capability of the 45° power divider, the demodulator achieves outstanding IRR higher than 40 dBc from 76 to 88 GHz, and demonstrates gigabit data rate transmission of 8.2% EVM 16-QAM modulation. The last part illustrates a PA using 40-nm CMOS process for a 38-GHz phased-array system. By using quasi-Doherty core, the proposed PA leaves only half of the combined paths in quiescent state. Besides, neutralization techniques and transformer matching are applied to the PA for gain and efficiency enhancement respectively. The PA attains 14-dBm PSAT, 11.5-dBm OP1dB, 19.3 % PAEpeak, 14 % PAE@OP1dB, and 8 % PAE@back-off 6dB in 67-mW dc power consumption.