STUDY OF PARASITIC CAPACITANCE EFFECT ON NOISE FIGURE OF IDCLNA IN DEEP SUBMICRON CMOS TECHNOLOGIES

Low noise amplifier (LNA) is an important component in RF receiver front end. An inductively degenerated cascode low noise amplifier (IDCLNA) is mostly preferred for producing good trade-offs such as high gain, low noise figure (NF), high reverse isolation and low power consumption for narrowband applications. This IDCLNA structure is also used to reduce the gate induced noise on the noise performance by inserting the capacitance in parallel with the gate-to-source capacitance of main transistor. Usually, the parasitic overlap capacitances can impose serious constraints on achievable performance and is taken into account in IDCLNA. In this paper, IDCLNA is designed at a frequency of 2.4 GHz with analyzing the impact of parasitic overlap capacitances on IDCLNA in terms of unity current gain frequency (f T ) which will affect the NF of IDCLNA and simulated using 130 nm, 90 nm and 65 nm CMOS technologies. The NF of IDCLNA with and without parasitic overlap capacitances are analyzed and compared for different short channel CMOS processes. Simulation results show that the parasitic overlap capacitances have advantageous to reduce the gate induced noise in IDCLNA for 130-nm CMOS process for 2.4 GHz applications.