• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.37-43
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• 2009

This paper describes a monolithic Darlington-cascade amplifier (DCA) operating at X-band, realized with a 0.35-micron SiGe bipolar process, which provides 45 GHz $f_T$. A conventional cascade amplifier was also designed on the same process and tested to establish a reference. Compared to the reference cascade amplifier, the proposed monolithic amplifier circuit exhibits an improved gain of 2.5 dB and improved output power 1-dB compression point of 5.2 dB with 72% wider bandwidth. Measurement results show 19.5 dB gain, 11.2 dBm 1-dB compression power, and 3.1 GHz bandwidth. These results demonstrate that the Darlington-cascade cell is an advantageous substitute to the conventional cascade amplifier.