Wideband low noise amplifier with optimised gain-band width

A three-stage low noise ultra-wide band amplifier for 0.5GHz–15GHz frequency band has been designed in Silicon-Germanium hetero junction bipolar technology using AMS 0.35µ BiCMOS process. Simulation results in CADENCE Spectra show input return loss of 14dB and a gain of 33dB along the band of interest. The gain curve of the first stage, which has been optimized for the input impedance matching along the full band of interest, is straightened by using the gain characteristic of the Cascode stage which has been added as second stage. The simulation results of the studied LNA have been compared with referenced low noise amplifiers and showed the achievement of better gain level along a wider band while providing the noise figure and impedance matching requirements.