This paper presents a new technique for improving the quality factor of conventional active inductors by using the drain-source capacitance of a MOSFET in the cut-off region. This inductor is utilized to design a tunable notch filter for interference rejection in UWB LNA. Using a 0.13µm CMOS technology, simulation shows that the notch frequency can be tuned for about 1GHz frequency range, and the quality factor is improved more than one order of magnitude compared to conventional active inductor. The power dissipation of the new active inductor is 2.4mW from 1.2V supply.