A 0.75 dB NF LNA in GaAs pHEMT utilizing gate–drain capacitance and gradual inductor**Project supported by the External Cooperation Program of BIC, Chinese Academy of Sciences (No. 172511KYSB20130108).

Abstract

A two-stage monolithic microwave integrated circuit (MMIC) low noise amplifier (LNA) fabricated in 0.5 μm GaAs pHEMT is presented. The Miller effect introduced by the parasitic gate–drain capacitance is utilized to decrease the value of the input inductor. Additionally, the input on-chip inductor is a novel high Q gradual structure. The noise figure is reduced with these two methods. With good input and output matching, the LNA achieves a noise figure of 0.75 dB and a small signal gain of 32.7 dB over 698–806 MHz. The input 1 dB compression point is −21.8 dBm and the input third order interception point is −10 dBm.