An electromagnetic model is proposed to detect water pollution in underground pipelines. Contaminants present above a certain level in water can be a public health hazard. The contrast in the dielectric constant between contaminated and fresh water is one of the most important parameters to be considered for detecting the presence of pollutants in water. Simulations of frequency response and time domain pulse wave through a multi-layer medium are presented. The complex dielectric permittivity of polluted water has been measured as a function of frequency and analytically represented by Cole-Cole fit model. Water pollution can be detected by observing the variation of the reflection coefficient or reflected signals from unpolluted and polluted water. 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. Microwave technique discussed in this manuscript for water pollution study is a pioneer technique to detect various pollutants in water.

In this paper, a novel compact dual-band complementary split ring resonator (CSRR)-loaded microstrip patch antenna placed on ground plane loaded with L-shape slot is proposed for satisfying WLAN and WiMAX applications simultaneously. The proposed antenna consists of a complementary split ring resonator (CSRR) embedded on the patch structure and an L-shape slot on the ground plane. The resonant frequency and effective parameters of the CSRR are also determined. In addition, a design evolution and various parametric analysis of the antenna are carried out in order to study the effects of various parameters and to provide information for designing, modifying, and optimizing such an antenna. The CSRR is exploited to create resonance at 5.775 GHz while the L-shape slot resonates at 3.550GHz for dual-band operation. The -10dB return loss bandwidths of the antenna are 290 MHz (3.40-3.69) GHz and 210MHz (5.65-5.86) GHz, which cover both the WiMAX frequency band (3.4-3.69) GHz and the WLAN frequency band (5.725-5.825) GHz. The overall size of the antenna is 37mm×25mm×1.6mm. Gains of 0.5dB and 2 dB are obtained at 3.550 GHz and 5.775 GHz, respectively.

In this paper the effects of water loading (termed as superstrate) on the characteristics of an electromagnetically (EM) and coupled pentagonal patch antennas operating in the ISM band have been described. The proposed antenna structures are analyzed using HFSS and the influence of the superstrate on resonant frequency, bandwidth, VSWR and radiation characteristics have also been analyzed. The obtained results also reveal that a larger bandwidth can be found in case the dielectric substrate is separated by air gap spacing. In addition, though impedance matching is little deteriorated due to loading, however the operating frequency band (BW) shifted to lower side significantly.

Meeting the demands that are expected from future wireless generation networks poses intriguing challenges for today's wireless system designers. The demand for higher data rate and better quality of service (QoS) in wireless communications continue to grow rapidly in current world global community. Obtaining these requirements becomes challenging for wireless communication systems due to the problems of channel fading, higher power and bandwidth limitations. One of the most promising solutions to this problem is the Multiple Input Multiple Output (MIMO) system. This paper compared the performance of spatial multiplexing MIMO scheme with beamforming at a data rate of 100Mb/s. The proposed wireless system was developed with smart antenna arrays at both the transmitter and receiver. The results obtained show that spatial multiplexing technique produced better spectral efficiency than beamforming. The BER performance of beamforming technique outperforms that of spatial multiplexing technique even when enhanced by V-BLAST algorithm under the same simulation environment. The proposed system outperforms the conventional MIMO.