Design and Simulation of Low Power Low Noise Amplifier For Cognitive Radio Applications

Cognitive radio is well known as an ultra-wideband communication system that intelligently optimizes the available frequency spectrum by implementing the dynamic spectrum monitoring method. The receiver of such a system requires an ultra-wideband low noise amplifier (from 50 MHz to 10 GHz). In this work, a low power ultra-wideband low noise amplifier is proposed by quasi-differential structure and active inductors. Using active circuits as inductors, in addition to expanding the amplifier bandwidth and reducing the chip area, have an inherent gain and due to their high quality factor, have the ability to adjust the inductance and frequency. In addition, the quasi-differential structure increases the transconductance of transistors and reduces both power consumption and noise figure of this circuit. The simulation results in a 0.18 µm CMOS process show that the proposed LNA achieved NF changes 3-7 dB and input matching less than -10 dB in the 0.05-10 GHz band. The voltage gain changes from 16.5-19 dB and third-order intercept point is -6.7 dBm. The power consumption of the main circuit is 1.98 mW with 1.8 V power supply.