Abstract
The design target of this thesis is to carry out a radio frequency (RF) frond-end circuit without inductor at 3.5 GHz for the WiMAX applications. For the matching issue, a common-gate low-noise amplifier (LNA) circuit was proposed with some skills for gain, noise and power issues. To enhance the gain of LNA, a high frequency active inductor load was analyzed. The quality factor of active inductor can be improved by the proposed topology with low power consumption. By simulation, the gain of LNA with active inductor load can be improved by 9 dB with extra 600 µA current consumption. As for the mixer, a double-balanced Gilbert cell is adopted. The designed LNA circuits were implemented in TSMC CMOS 0.18-µm technology. The measured LNA gain was 7 dB at 2.3 GHz, with NF 5.2 dB, P1dB -9.8 dBm and IIP3 -3.6 dBm. The total current consumption was 9 mA under 1.8 V supply voltage. The whole chip area was 700 µm ×700 µm including pads.