| dc.description.abstract | In this thesis, we design three broadband low noise amplifiers (LNAs) for ultra-wideband (UWB) communication systems, which are implemented in TSMC 0.18 um CMOS technology. The design of the amplifiers concentrates on low power-consumption and low costs as well.
In the first section, two amplifiers are designed on the basis of LC high-pass filters which are used for wideband impedance match. The two amplifires are designed with and without Darlington pair, respectively. In the second circuit, a Darlington pair is used at the second stage to achieve high gain performance. The measurement of the first LNA without Darlington pair shows that the maximum gain is 11 dB, 3-dB bandwidth is from 3.9 GHz to 10.3 GHz, the minimum noise figure is 4.5 dB, S11 is less than -13.4 dB, IIP3 is better than -9 dBm, and the total power consumption is 15.4 mW. The chip size is 0.86 mm2. For the second LNA with Darlington pair, the measurement shows that the maximum gain is 13 dB, 3-dB bandwidth is from 3.0 GHz to 10.7 GHz, the minimum noise figure is 3.57 dB, S11 is less than -8 dB, IIP3 is better than -14 dBm, and the total power consumption is 20.3 mW. The chip size is 0.78 mm2.
In the second section, a low-power consumption and high-gain broadband LNA utilizing a common-gate stage connected with a common-source stage by using a current-reused structure is proposed. The measured maximum gain is 14.2 dB, 3-dB bandwidth is from 2.7 GHz to 8.4 GHz, the minimum noise figure is 3.93 dB, S11 is less than -8 dB, IIP3 is better than -12.5 dBm, and the total power consumption is 7.2 mW. The chip size is 0.78 mm2. | en_US |