A multi-band low-noise amplifier with MOS varactors for wireless application

This paper presents the design and simulation results of a multi-band CMOS low-noise amplifier (LNA) from 1.9GHz to 2.4GHz. Input and output impedance matching networks are achieved with extra variable capacitor controlled by the voltage. The variable capacitors used in the circuit design can make the LNA operate at some key frequency bands between 1.9GHz and 2.4GHz. The LNA is designed using IBM 90nm RF CMOS process and employs a supply voltage of 1.5V and dissipates a DC power of 15mW. The complete circuit of LNA achieves good input and output matching with S11 lower than −15dB and S22 lower than −10dB between 1.9–2.4GHz. The gain is above 10dB. And the noise figure is lower than 2dB.