SiGe BiCMOS wideband Low Noise Amplifiers for application in Digital Beam-Forming Receivers

In this paper, the authors present two wideband Low Noise Amplifiers using a 0.25 μm SiGe BiCMOS Technology. The first IC is based on a cascode topology using resistive shunt feedback in combination with a diode DC level shifter. This highly compact IC (only 270 μm×370 μm) achieves a gain exceeding 20 dB between 1 GHz and 11 GHz, an input and output matching below - 10 dB over the whole operation bandwidth and an input referred 1 dB compression point of - 23 dBm at 5 GHz. The measured noise figure is between 2.5 dB at 3 GHz and 2.9 dB at 11 GHz. The second amplifier is using three stages with a combination of local series and shunt feedback. The circuit has a die area of only 340 μm×460 μm and achieves a gain over 29 dB between 1 GHz and 11 GHz, a worst case input reflexion coefficient below - 4 dB (simulation predicts a significant matching improvement with a mounted chip due to bondwire inductance) and an output reflexion coefficient below - 9 dB. The input 1 dB compression point is - 29 dBm. The on-chip noise figure is between 2.9 dB and 3.5 dB. The cascode and 3-stage LNAs consume 70 mW and 78 mW at 5 V supply voltage, respectively. These two ICs are intended for future implementation in highly integrated Digital Beam-Forming Receivers operating at S-, C- or X-band.