Power combining amplifiers for mobile millimetre wave block up converters

Abstract

The use of power combining techniques allows the realization of millimetre wave solid state amplifiers with output power levels that are not achievable from a single solid state source. The need for efficient and low cost amplifiers for mm-wave systems has propitiated an intense area of research during the last years in power combining techniques. This thesis presents the development of compact and efficient power amplifiers based on new power combining structures using solid state devices. In addition, the implementation of a mm-wave block up-converter (BUC) is included, with the aim to evaluate the performance of the amplifier in a real system. The developed power combiner is based on a travelling wave architecture, which is demonstrated to be a very convenient solution at mm-wave frequencies because of its high efficiency and compactness. The new structure proposed, consists of a double side waveguide geometry which provides a 50% size reduction compared to existing solutions. This structure is validated by manufacturing a 12-way power combiner and amplifier prototype. In order to achieve the goal of testing the amplifier in a real system, an L-to-Ka band block up-converter is then designed and implemented. The performance of the block up-converter is demonstrated for a single and a double conversion architectures. Finally, the performance of the BUC is demonstrated under digital modulated signals.