A novel design of printed monopole antenna loaded with wire medium is developed for radar applications. The advocated design aims to simultaneously enhance the gain and bandwidth of the proposed geometry. The proposed antenna is composed of a circular patch etched with double C‐shaped slots and the ground is defected to achieve wide bandwidth. Wire medium superstrate and a metal reflector are implemented to provide high gain. The promising tunable wire medium superstrate consists of a periodic array of parallel metallic wires arranged in a rectangular pattern that mimic the behavior of epsilon‐near‐to‐zero (ENZ) metamaterial. This medium is suspended at a distance of a quarter‐wavelength in air above the antenna to provide the optimum gain and reduce the side lobes level. Prototype of the optimized antenna is fabricated using Rogers's substrate to offer −10 dB bandwidth over the entire frequency range (900 MHz to 2.85 GHz). Details of the design process are investigated through full wave electromagnetic simulations performed by CST software. Experimental results of the fabricated prototype are presented and also compared with simulation results where an appreciable agreement between them is demonstrated.

The safety of drinking water is directly dependent on the chlorine content and therefore the study gains its importance. Chlorinated water is safe to drink as long as the levels of chlorine comply with the water quality factors. The purpose of this research is to study the effect of chlorine concentration on the complex dielectric permittivity of water. The measurement of the complex permittivity of chlorinated drinking water is reported in the frequency range 500 MHz - 4 GHz using open-ended coaxial probe technique. Measurements are carried out using a dielectric assessment system associated with an automatic network analyzer and a dielectric probe connected to a computer. The experimental set up is described and the procedure followed to obtain an effective permittivity data is outlined. These measurements are, to the best of the author's knowledge, the first of its kind to be published. The dielectric constant and loss factor for all measured samples are analyzed and the effect of the chlorine concentration is studied. The results indicate that chlorine content has a significant effect on both dielectric constant and the loss factor. Results of this work show that microwave sensing is an effective methodology for monitoring water quality and possible contamination.