A vector diagram of Maxwell's time-harmonic equations in homogeneous isotropic media is derived and proposed so as to include chiral media. The diagram may be used to obtain a number of common relationships between fields, potentials and source by equating appropriate components of the vectors in it. The construction of the diagram is based on the formal similarity between many theorems of vector calculus and those of vector algebra. Construction of the diagrams for two different gauge choices, Lorentz and Coulomb's gauges, is explained in detail and some of equations which can possibly be derived from one of the diagram are presented. In this work this approach is applied to a numerical calculation of a two-dimensional chiral slab. This work could be a tool for designing Wireless Communications Systems devices, in a spectral range from 1 GHz to about 60 GHz, for example, duplexers based on power splitters and a rear frequency selective filtering though the use of SRR/CSRR (splits ring resonator)/(coplanar SRR) cells. The circuit devices using SRR/CSRR have a very small size, due to its operations in a sub-lambda system. Also this work may be useful to discuss the design, among others, of a circularly polarized printed patch for S- Band and different types of filters and others devices using metamaterials and Coplanar Wave Guides.