A 2.8-4 GHz Common Source Cascode LNA Design Using 90-nm CMOS Technology

This paper presents a novel design of a Low Noise Amplifier (LNA) optimized for wideband (2.8–4 GHz) wireless communication applications using 90-nm CMOS technology. The proposed LNA architecture is a two-stage design, where the first stage employs a common-gate (CG) transistor configuration to ensure effective wideband input impedance matching, while the second stage utilizes a common-source (CS) cascode topology to minimize the noise figure and maximize gain. The design, simulated using the Cadence Virtuoso environment, demonstrates superior performance with key metrics including an input reflection coefficient (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf>) of -11.78 dB, an impressive reverse isolation (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</inf>) of -37.83 dB, and a high forward gain (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</inf>) of 18.19 dB. The output reflection coefficient (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">22</inf>) was measured at -14.44 dB, indicating excellent output matching. Additionally, the LNA achieves a low noise figure of 4.75 dB, making it highly suitable for modern wideband applications where low noise and high linearity are critical. The circuit’s simplicity, low component count, and use of 90-nm CMOS technology make it cost-effective and suitable for integration into large-scale systems. This design offers a promising solution for next-generation wideband wireless communication receivers, balancing noise, gain, and stability trade-offs.