Design and characterization of a 12–40 GHz power amplifier in SiGe technology

This paper presents a power amplifier (PA) fabricated in a 0.13 μm-SiGe-BiCMOS technology, which can fully cover the Ku-, K- and Ka-band and delivers a saturated output power of about 20dBm. The extremely-wide bandwidth results from a distributed structure. The gain cells, which consist of a cascode structure with one stacked transistor, are also optimized for high output power. AC-block transmission lines are used in this design for the DC supply, thus no external bias-tee is needed for circuit operation. Measurements of the fabricated distributed power amplifier (DPA) show a 3 dB-bandwidth of the output power from 12 GHz to 40 GHz. The maximum output power is 19.8dBm at 1 dB-compression-point (P1dB) and 21.5 dBm in saturation, which to the best knowledge of the authors are the highest reported values for PAs in SiGe-technologies operating in these bands. Together with the peak gain of 13.9 dBm very high power added efficiencies (PAEs) of 13.4 % at P1dB and 20.1 % in saturation are achieved.