A 30-to-41 GHz SiGe Power Amplifier With Optimized Cascode Transistors Achieving 22.8 dBm Output Power and 27% PAE

Abstract

In this brief, A two-stage power amplifier (PA) with a four-way series-parallel power combiner is presented for Ka-band applications. A compact power stage with optimized cascode transistors is proposed to minimize the parasitic effects and boost the amplifier output power at the mm-wave frequencies. The output network employs two spiral transformers and a transmission-line combiner to realize low-loss power matching and broadband series-parallel combining. The PA is fabricated in a 130-nm SiGe BiCMOS technology and it occupies a core area of 0.48 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The PA achieves a peak gain of 25.3 dB with the 3-dB bandwidth of 30-to-41 GHz. At the frequency of 35 GHz, the measured saturated output power (P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SAT</sub> ), 1-dB compressed power (OP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> ), and power-added efficiency (PAE) are 22.8 dBm, 22.6 dBm, and 27%, respectively.