Hybrid antenna-amplifier: A concept of high-power microwave source and first results of its exploration

The concept of a hybrid antenna-amplifier device, a combination of a surface wave antenna with a relativistic Cherenkov amplifier, is described. The key feature of the device providing its potential as a compact controllable high-power microwave source is that a rod antenna feed waveguide serves, at the same time, as a hollow cathode holder of a diode producing a relativistic electron beam. This is possible if a beam is generated using a compact linear induction accelerator (LIA) module. The results obtained in the scope of exploration of this concept are reported. This includes the linear theory, 1-D nonlinear multimode theory, design of the LIA module, initial results of the 3-D simulations using the MAGIC code, and first results of model experiments on annular beam transport with a rod antenna inside.