A 6 GHz fully integrated SiGe LNA with simplified matching circuitries

A two stage bipolar low noise amplifier based on common-emitter configuration is presented in this work. From transistor size scaling to complete two stage integration, various design aspects and issues will be investigated. It will be shown that by following the proposed design methodology, the input as well as the interstage matching of the low noise amplifier (LNA) can be highly simplified without any serial inductors. This in turn minimizes the additional losses, chip area and improves the performance of the LNA without degrading the matching characteristics. At 5.8 GHz, the measured results of the LNA comprise 18.8 dB gain, 2 dB noise figure, input and output matching better than 10 dB, -14.5 dBm of input power at 1 dB gain compression and -6 dBm of input third order intercept point. The LNA consumes 18 mA of current from 1.8 V power supply. The calculated LNA ITRS figure of merit of 5.9 makes it as one of the best implementations among the bipolar LNAs reported in this frequency range of operation.