Mathematical Formulation and Experimental Evaluation of Efficient 8-Way Microwave Radial Power Combiner for High Power Applications

Abstract

An 8 port narrowband Radial Power Combiner (RPC) with excellent combining efficiency is presented. A novel useful criteria for optimal design of the RPC is developed and the design is studied based on it. Also to provide a reliable, tolerant and cost effective mechanical design, the mechanical structure of the combiner is simplified for fabrication and assembly. The designed RPC has standard waveguide ports at inputs, so it can be used in standard high power applications without any adaptors. The physical structure simplicity guarantees the product reliability for industrial high power applications. The optimized RPC design is fabricated and the measurement results are presented. The back-to-back measurement setup using customized through lines and two identical combiners have helped to take into account other efficiency degrading phenomena like port junctions’ discontinuity. It is shown that simulated power combining efficiency of 99% and measured power combining efficiency of 97.7 % is achieved.

Keywords

• combining efficiency
• radial power combiner
• high power amplifier
• graceful degradation
• rectangular waveguide.