This paper presents measured results for two-stage and three-stage high-voltage/high-power (HiVP) amplifiers implemented in a commercial 0.12 μm silicon germanium (SiGe) heterojunction bipolar transistor (HBT) bipolar Complementary Metal Oxide Semiconductor (BiCMOS) process at millimeter wave. The HiVP configuration provides a new tool for millimeter-wave silicon designers to achieve large output voltage swings, high output power density, customizable bias, and a way to minimize, if not eliminate, matching circuitry at millimeter-wave frequencies. The two-stage amplifier has achieved a PSAT = 5.41 dBm with a power added efficiency (PAE) of 8.06% at center frequency 30 GHz. The three-stage amplifier has achieved a PSAT = 8.85 dBm with a PAE of 11.35% with a total chip area of 0.068 mm2 at center frequency 30 GHz. Simulation, layout, fabrication, and measurement results are presented in this paper.