SILICON (Si) bipolar complementary metal-oxide semiconductor (BiCMOS) still
has room for improvement, as demonstrated by a pair of low-noise amplifier
s (LNAs) designed and develop by Philips Semiconductors (Sunnyvale, CA). Fa
bricated with the firm's QUBiC4 0.25-mum Si BiCMOS process, these amplifier
s do not require the additional germanium (Ge) doping las in SiGe) to achie
ve noise figures of 1.1 dB or less at 2 GHz. With performance that rivals t
hat of gallium arsenide (GaAs) and SiGe LNAs, one of the designs exhibits a
noise figure of 0.99 dB and third-order intercept of +5 dBm at 2 GHz while
using only 4-mA current, while the other amplifier features a noise figure
of 1.1 dB and third-order intercept of +9 dBm with 6-mA current.