The spatial power combining technique based on novel antipodal finline

This paper presents the spatial power combining technique based on new waveguide-to-microstrip antipodal finline array. The technique adopts the structure of broadband multi-way oversized coaxial waveguide which is mainly composed of a twenty-way gradually changed antipodal finline array. The new finline is designed of a complex function of a linear function, a triangular function and an exponential function. All the finlines have the high uniformity of amplitude and phase. Through the application to 6-18 GHz coaxial spatial power combiner, the new finline provides a broadband performance without any additional resonance frequency. Measured results show that the spatial power combiner has a high combining efficiency of 80% and high output power of more than 20 watts in frequency range of 6-18 GHz.