Analysis and Design of a 2-40.5 GHz Low Noise Amplifier With Multiple Bandwidth Expansion Techniques

This paper analyzes the main factors limiting bandwidth expansion of low-noise amplifiers (LNA) and designs a broadband LNA with 2-40.5 GHz. The is designed using multiple methods, including cascode, resistance feedback, cascode Darlington amplifier. amplitude-frequency characteristics principle three structures are studied theoretically based on small-signal equivalent circuit model. Thanks to these techniques, three-stage in 0.15-μm GaAs pseudomorphic high-electron-mobility (pHEMT) process. measured results show that achieves an average gain 21.6 dB GHz while maintaining noise figure (NF) below 3.6 dB. output 1-dB compression point (OP1 dB) from 4.5 12.8 dBm input/output return loss better than 5 chip area only 1.57 mm 2 , input test pads.