A new 2.4GHz CMOS low-noise amplifier with automatic gain control that provides an enhanced dynamic range of up to 40 dB over conventional low-noise amplifiers is proposed. The proposed low-noise amplifier automatically adjusts its voltage gain by monitoring the amplitude of its output voltage so as to achieve a large dynamic range. The proposed low-noise amplifier allows a receiver system to become adaptive to antenna array, waveguides, and transmission lines, as well as standard antenna signal powers. The amplifier provides a gain of over 35dB, a noise figure below 0.5dB, and reflection coefficient below -35dB at 2.4GHz. The transient time of the amplifier is approximately 2.5μs with the variation of the input RF power of 30dBm.