Design of a Broadband LNA Based on Various Distributed-Element Microwave Filters With Semi-Distributed Notch Filtering for Interference Rejection

In this paper, we have modeled a low-noise amplifier that we have adapted using a multisection filter at the input, a distributed-element bandpass coupled-resonator filter at the output, and a third notch filter for interference rejection. Results show that the amplifier is unconditionally stable over the entire [1.8-3] GHz band. In addition, the gain is satisfactory, and the reflection coefficients S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf> and S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">22</inf> at the input and output are low. This modeled amplifier can be integrated into systems dedicated to Wi-Fi, while also offering possibilities for use in other applications such as wireless communications, wireless sensor technologies, telemetry systems, and remote monitoring devices.