An ultra-wideband parallel negative feedback low noise amplifier with extraordinary high gain

In this paper, an ultra-wideband parallel negative feedback low noise amplifier (LNA) is designed and implemented. Based on the parallel negative feedback topology, an extraordinary high gain and a low noise figure (NF) can be achieved in the LNA operating from 2GHz to 8 GHz after the input and output impedance matching. Simulation and experimental results show that the LNA has a good performance. Measured results show that the LNA can give over 34-dB gain, less than 3.47-dB NF and 4.39-dB in-band gain flatness from 2 GHz to 8 GHz. It also provides less than −11-dB S11/S22 and over 5-dBm P1dB performance in the work band.