An Ultra Wide Band LNA with Current Reused Topology in 0.18-\mu \mathrm{m}$ GaAs pHEMT Process

A current reused low noise amplifier with ultra wide bandwidth of 2–18 GHz and low power consumption is presented in this paper. Besides the current reuse technique to reduce the power consumption, a transistor-biased circuit is used to overcome the PVT problem. The proposed LNA is fabricated with $0.18-\mu \mathrm{m}$ GaAs pHEMT process. According to the post-layout simulation results, the LNA gives an average gain of 20.7 dB with a gain flatness of ±1.5 dB in the 2–18 GHz band. The noise figure is lower than 1.4 dB within the operating bandwidth. OP1dB of the LNA is over 3dBm. The power consumption is only 92 mW with single supply of 5V, which is extremely lower than the designs in literature. In addition, the proposed LNA has a compact size of $1.75\times 1\ \text{mm}^{2}$ .