Design of an X-Band Suspended Stripline Unequal Split Power Distribution Network

This paper discusses the design of an 8-way X band power distribution network for antenna applications. A suspended stripline is chosen as transmission line and it is optimized to provide low loss while avoiding the presence of higher order modes. The low loss structure makes the 50 Ω line very wide compared to the wavelength and therefore lower impedance lines are not recommended. The design method for implementing unequal split Wilkinson dividers without using low impedance lines is presented. This technique also reduces discontinuities within the dividers. The losses in the network are lower than 0.4 dB in X band over 10% bandwidth and it achieves a very low amplitude error with respect to the theoretical value over the entire band. The structure is shown to be more robust to output mismatches than a similar power distribution using T junctions. Finally, the higher frequency behaviour of the power splitter is studied and the higher frequency limitations of the suspended stripline structure are explained.