It is possible to generate high‐power microwave pulses with fast rise time by using resonant cavities to obtain power gain from pulse compression. In the usual case, especially when normal‐conducting cavities are used, the principal output pulse from a pulse‐compression device is preceded by a precursor signal that may be only 40 dB below the main pulse. For some applications this large a prepulse is unacceptable. We have developed a prototype normal‐conducting,x‐band, pulse‐compression cavity in which the prepulse is suppressed by more than 70 dB. When this cavity is driven by a 20‐kW source, output pulses with 200‐kW peak power, 5‐ns pulse width, and sub‐nanosecond rise time can be obtained. We have also built ans‐band cavity that has produced pulses of 5‐ns width, 200‐MW peak power, and under 3‐ns rise time. Thes‐band cavity is typically driven at 5–10 MW and has a prepulse that can be more than 80 dB below the peak of the main pulse.