An X-Band SiGe BiCMOS Triple-Cascode LNA With Boosted Gain and P1dB

In this brief, the design, implementation, and experimental results of an X-band low noise amplifier (LNA) implemented in 0.13 μm SiGe BiCMOS process technology is reported. The presented LNA based on an inductively degenerated triple-cascode topology employing SiGe hetero-junction bipolar transistors (HBT) featuring f
_T
/f
_max
of 250/330 GHz. To authors' best knowledge, this brief is the first LNA incorporating triple-cascode topology and HBTs. Design techniques explored to enhance the gain, noise figure (NF), and linearity performance, along with the investigation of advantages provided by utilizing triple-cascode configuration are addressed. The measurement of the proposed LNA results in a minimum NF of 1.35 dB at 8 GHz, which remains less than 1.7 dB across 6-12 GHz frequency band. In addition, the LNA delivers a peak gain of 20.5 dB at 9 GHz, where it exhibits a state-of-the-art output 1-dB compression point (OP
_1dB
) of 18.75 dBm and third-order intercept point OIP3 of 24.75 dBm, while drawing 21 mA dc current from a 4.8-V supply. According to the utilized figure-of-merit, the measured results are better compared to previously reported work in the open literature.