Design and Analysis of a Broadband Low Noise Amplifier using 0.25 μm GaAs pHEMT Process

A detailed study of the first subsystem of a receiver, i.e., Low Noise Amplifier (LNA) for Satellite and Cellular System Application, is presented using 0.25 μm GaAs pHEMT process from United Monolithic Semiconductors (UMS). The proposed three-stage cascaded LNA covers a 20-30 GHz frequency range corresponding to a fractional bandwidth of 60 %. This design exhibits gain better than 22 dB with less than 2.6 dB minimum noise Figure (NFm) in the complete frequency range. The input and output return losses are better than 10 dB. The results presented in this paper are only simulated using ADS and are planned to be fabricated in the future. As per the literature available, this design has achieved a maximally flat gain response for a wide range of frequencies, and also the other performance specifications are among the best reported up-till now with minimal components using the similar 0.25 μm GaAs process in this frequency range.