Highly linear broadband GaN-based low-noise amplifier

A highly linear broadband low-noise amplifier is presented in this paper. The circuit is based on a GaN power transistor, directly bonded into a hybrid microstrip circuit. In order to achieve the highest linearity possible, a large device is used and biased in class A. Broadband low-noise operation in the range of 1.7 - 2.3 GHz is achieved, with a gain of about 15 dB and a noise figure below 2 dB, although matching of the large transistor cell is tedious. A record output IP3 of 49 dBm is measured for this device. This proves that the GaN technology is capable of combining extremely high linearity with low noise performance.