Abstract
In recent years, there has been an increasing interest in mm-wave communication. W-band (75-110 GHz) wireless system is a potential candidate due to its wider bandwidth, less congested spectrum and smaller circuit. In this thesis, a W-band low noise amplifier (LNA) and two W-band receiver front-ends in the TSMC 90nm CMOS 1P9M process are presented. The first design is a W-band LNA with a shunt-series transformer feedback at the input and gm-boosting technique is used in the following cascode stage. The LNA has a measured gain of 6.5 dB at 89 GHz, a 3-dB bandwidth of 86.8-90.9 GHz, a minimum noise figure of 12 dB, an input compression point of -24 dBm, and the power consumption is 11.3 mW. The second design consists of an improved LNA of the first one and a tunable downconversion mixer to realize a tunable W-band receiver front-end. The first stage of LNA is a common source stage with inductive degeneration and second stage of the LNA is a cascode stage with gm-boosting technique. This topology has smaller noise measure than the previous work, which means it has better trade-off between gain and noise. From simulation, this work has a conversion gain of 13 dB at 100 GHz and 12 dB at 108 GHz, and a minimum noise figure of 15 dB. However, the conversion gain drop to -3.5 dB at 100 GHz and 1 dB at 107.5 GHz, and the minimum noise figure is 28 dB. It is because the gain of the LNA in the previous work drops by 14 dB and the LNA in this work is based on the previous work, the discrepancy between the simulated and measured results can be attributed to the lower gain of the LNA. Other specifications of the receiver front-end include an input compression point of -11.6 dBm, and a power consumption of 113.4 mW. The third work is another tunable W-band receiver front-end. This work further improves the LNA. This LNA has a single-ended input differential outputs. The common source stage with inductive degeneration is used and an on-chip balun converts the single-ended signal to differential ones. In the differential stage, a cross-coupling capacitance is added to increase the gain. The differential outputs of LNA are connected to transformers that have current gain and these transformers coupled the signal to a double-balanced mixer. The simulated conversion gain is 19.7 dB at 96 GHz and 20.8 at 103 GHz. The minimum noise figure is 13.3 dB, and input compression point of -11 dBm with a power consumption of 122.4 mW.