Design of a Broadband Low-Noise Amplifier (LNA) Based on Coupled-Line Filters with a Notch Filter to Reject Unwanted Frequencies

In this article, we have designed a low-noise amplifier by optimizing its performance through the integration of line filters coupled at the input and output of the circuit, as well as a third notch filter for the suppression of undesirable frequencies. The obtained results conclusively confirm the unconditional stability of this amplifier over the entire frequency range from 2 to 3 GHz. Additionally, the gain achieved exceeds expectations, while the reflection coefficients at the input and output remain at minimum levels, essential to ensuring optimal amplifier performance. This amplifier design represents a versatile solution, ideal for integration into dedicated Wi-Fi systems, and offers promising prospects in areas such as wireless communications, wireless sensor technologies, telemetry systems, and remote monitoring devices. Using distributed elements, such as our filter, simplifies and makes the manufacturing process more cost-effective, requiring only two localized components, namely the resistor and the stability capacitor of our notch filter.