A Narrow-band 8.7 GHz SiGe HBT LNA with a Passive Frequency Selective Feedback

Abstract

AbstractThis paper presents a low noise amplifier (LNA) with differential output using a passive frequency selective feedback. The introduced feedback stabilizes the amplifier at lower frequencies and improves the gain in the desired frequency band. The LNA consists of two stages. Additionally, a buffer at the output is added for measurements. The amplifier was implemented in a 0.35 μm SiGe technology. For measurements the LNA was bonded to a substrate. A peak gain of 28.1 dB and a minimum noise figure of 2.2 dB at a supply voltage of 3 V were achieved.