High Gain Fully-Integrated Broadband Differential LNAs in 0.15-µm GaAs pHEMT Process Using R-L-C Feedback Gain Compensation for Radio Astronomical Receiver

This paper presents two fully-integrated broadband, high-gain MMIC low noise amplifiers (LNAs) with differential input and single-ended output for Square Kilometre Array (SKA) astronomical receiver. This amplifier was implemented using 0.15-µm GaAs pseudomorphic high electron mobility transistor (pHEMT) process. The R-L-C feedback is applied for broadband design, and the fully on chip LC balun is introduced behind the first-stage in LNA1 and the third-stage in LNA2, respectively. The 3-dB bandwidth of the LNA1 covers from 2.7 to 5.7 GHz and LNA2 covers from 4.3 to 16.3 GHz. The measurement results demonstrate small signal peak gain 31.7/35.4 dB, average in-band noise figure of 0.92/1.05 dB with DC power consumption of 48/90 mW. The chip area of both the amplifiers is 2.5 × 2 mm².