A Broadband 4.5–15.5-GHz SiGe Power Amplifier With 25.5-dBm Peak Saturated Output Power and 28.7% Maximum PAE

This paper presents the design of a broadband power amplifier (PA) in 130-nm SiGe BiCMOS technology. First, a single-stage broadband single-cell PA covering the 4.5-18-GHz frequency band is introduced. In this frequency range, this single cell achieves a measured gain, saturated output power ( Psat), output 1-dB compression point ( P1dB), and power-added efficiency (PAE) in the range from 12.8 to 15.7 dB, 18.8 to 23.7 dBm, 16.7 to 19.5 dBm, and 11.4 to 31.9%, respectively. Its peak saturated output power and maximum PAE are both obtained at 8.5 GHz. Second, to increase the output power, a PA consisting of two parallel broadband cells with a power combination is presented. This PA operates in the 4.5-15.5-GHz frequency range with measured gain, P
_sat
, P
_1dB
, and PAE in the range from 11 to 16.6 dB, 21.3 to 25.5 dBm, 18.7 to 21.7 dBm, and 11.9 to 28.7%, respectively. It achieves its peak saturated output power of 25.5 dBm at 8.5 GHz and its maximum PAE of 28.7% with an associated output power of 23.6 dBm at 6.5 GHz. Each of those two PAs achieves better performances than the state-of-the-art in broadband SiGe technology when comparing the output power level and efficiency.