Ix. Microwave Electronics

During the past year, our principal activity in this area was concerned with the development of a small-signal theory for the behavior of stagger-tuned klystron amplifiers, and the construction of an experimental seven-cavity amplifier. In the coming year, we shall continue the work on the experimental tube, in order to get experimental verification of the theory. The limiting gain-bandwidth performance obtainable in stagger-tuned klystrons is now well understood. Further improvement will be possible if the bandwidth of the separate cavities can be raised. Double-tuned, double-gap cavities are now being studied with this in view. However, our interest is shifting to the problem of determining the factors that now limit the output efficiency of klystrons, and finding ways to increase this efficiency. (See the report on the "squeezer," Sec. IX-A2.)