Design of a broadband Ka-band MMIC LNA using deep negative feedback loop

In this paper, we present a broadband Ka-band LNA using 0.15-mu m GaAs pseudomorphic high electron mobility transistor (pHEMT) process. By using bandwidth enhancement techniques and deep negative feedback technology, the LNA achieves relatively broadband performances. The LNA attains 20 dB small signal gain from 25 to 40 GHz and shows a measured noise figure of 2.8 dB from 25 to 40 GHz with 230-mW dc power consumption. The input and output return loss of the LNA is less than 8 dB, which is competitive compared with other published Ka-band LNAs. The size of the chip is 2.5 mm x 1.2 mm.