The Resistive-Wall Amplifier

Theory and experimental results are presented for a basically new type of electron-stream amplifier in which the stream flows near a resistive wall. The values of gain and bandwidth obtainable are found to be comparable to those of other microwave amplifiers, such as traveling-wave tubes. In contrast to such tubes, however, the gain is affected very little by appreciable changes in the circuit parameters or operating voltage; furthermore, self-oscillation is inherently absent because the input is effectively isolated from the output. Experiments are described that were performed mainly to verify the theory; the existence of the growing wave was demonstrated, and the measured gain was in good agreement with the theory.