Empirical design formulae for series‐fed substrate integrated waveguides power divider

Abstract

In this article, empirical design formulae for a unit cell of series-fed substrate integrated waveguide power divider for a wide range of power division ratio from 1:1 to 1:40 are presented. These formulae are determined through extensive simulations carried out in Ansys HFSS. The physical dimensions of the power divider for any given power division ratio can be directly determined through the design formulae presented in the article. A simple design procedure is discussed and verified with the help of experimental and simulation results. For experimental verification, a power divider is designed to operate in X band, and its prototype is developed on RT Duroid 5880, the measured results for this power divider are in close agreement with simulated as well as predicted results. Also, for validating the design procedure over a wide range of frequencies, many power dividers are designed with different power division ratios, different operating frequencies and different cut-off frequencies of TE10 mode. The cut-off frequency (fc) of TE10 mode is varied from 15 to 25 GHz, and the operating frequency is adjusted in between 1.2fc and 1.8fc. That is, 18–40 GHz, which is suitable for many microwave and millimeter wave applications. The obtained results are very close to the desired power division ratios.