Design of a GaAs-Based Ka-Band Low Noise Amplifier MMIC with Gain Flatness Enhancement

This paper presents a GaAs-based Ka-band low noise amplifier (LNA) with gain flatness enhancement. Active device optimization and inductive degeneration techniques were employed to obtain a low noise figure (NF) and good input/output return loss. In order to achieve a flat gain response over a wide bandwidth, the stagger tuning technique was utilized. The proposed LNA was implemented by 0.15 mu m GaAs pHEMT process, and the chip area is only 1.5 x 0.9 mm(2). Measurement results show that the presented LNA exhibits a small signal gain of 21.5 +/- 0.3 dB, and the NF of the LNA is less than 2.2 dB from 32 to 40 GHz at room temperature.