Design of low noise amplifier (LNA) for WiMax applications

In this report, 2.3 – 2.6GHz mobile WiMAX LNA is presented. The WiMAX technology provides up to 3 Mb/s broadband speed without the need for cables. The technology is based on the IEEE 802.16 standard. The WiMAX LNA is configured in cascode structure using inductive degeneration method for input matching. It was implemented using commercially available CSM 0.18μm process and the Cadence SpectreRF was used for circuit design and simulation. The LNA was carefully designed by taking into account the layout effect and its variation. The silicided and unsilicided polysilicon resistors were used for LNA design because of its low parasitic capacitance and low voltage coefficient characteristics. The orthogonal spiral inductors implemented in metal 6 were chosen to reduce the substrate parasitic effect. For the low-noise performance, the amplifier was employed with high quality spiral inductors with quality factor higher than 7. The MOSFET M1 layout was optimized for low noise condition while M2 layout was configured for inter-stage matching between the two transistors (M1 and M2) to yield the better S22. The simulation results show that LNA noise figure is less than 1.7dB with a forward gain of ~14dB at the power dissipation of 6.52mW.Bachelor of Engineerin