This paper reports on several solid-state power amplifier (PA) modules operating at frequencies around the 220-GHz propagation window. Included is a single module demonstrating saturated output power ≥60 mW from 205 to 225 GHz and peak output power of 75 mW at 210 GHz using eight-way on-chip power combining. The output power is further increased by using waveguide power combining with WR-4 waveguide. Results include a single two-way combined module achieving >; 100 mW of power from 210 to 225 GHz and four-way combining using two two-way combiners to reach 185 mW of output power at 210 GHz. The amplifier MMICs uses sub-50-nm InP HEMT transistors, coplanar waveguide (CPW) technology, and on-chip electromagnetic transitions to waveguide. Finally, preliminary burn-in and initial room-temperature lifetest data is shown.