This paper presents a low voltage and low-power CMOS low noise amplifier for 3-5 GHz ultra-wideband receivers. The proposed LNA cascades two common source amplifiers leading to perform high gain while using low supply voltage. In addition, the LNA input network includes a combination of high pass filtering structure with inductive degeneration technique to achieve a wideband input matching with low noise figure. Using a 0.18 μm CMOS technology, simulation results show a power gain S₂₁ better than 18 dB with noise figure below 2.7 dB in the frequency range of 3-5 GHz. The return losses S₁₁ and S₂₂ are better than -10 dB and -11 dB, respectively. All achieved results are obtained while consuming 2.1-mW from a 0.6-V supply voltage.