An efficient harmonic amplifier

Summary form only given, as follows. We present the design considerations, computer simulations and initial experimental results of a new high-efficiency microwave harmonic amplifier (HARA). The HARA is a very compact, lightweight amplifier that can deliver multi-kilowatt radiation with very high efficiency and gain. The HARA system employs a rotating helical beam to excite circularly polarized radiation in an output Tm/sub max/ cavity that operates at a frequency that is an m multiple harmonic number of the rotating frequency of the beam. We present a 35 GHz HARA design including three-dimensional particle-in-cell simulations performed in SOS. The design is aimed at the generation of 150 kW of 35 GHz radiation using the 6th harmonic with an efficiency of 65%. We also present initial experimental results of the prototype under development. An important feature of this novel device is that it does not require a beam focusing system which makes the HARA very appealing for a large number of applications where size, weight and efficiency are critical.