A novel and effective technique to reduce electromagnetic radiation absorption on biotic components at 2.45 GHz.

A strong evidence of the effects of radiation absorption on the living community together with a better solution to reduce the radiation intensity without compromising the usage of wireless communication systems is presented. This study analyses the radiation effects on living things and validates the proposed techniques for specific absorption rate (SAR) value reduction at 2.45 GHz. To reduce these radiation impacts on the living community, proper shielding from the radiation and effectively reorienting antenna radiation patterns are the solutions suggested. An analogous antenna configuration in wireless communication systems - a coplanar waveguide fed loop antenna is considered and an open loop resonator (OLR) optimized in ANSYS HFSS at 2.45 GHz is incorporated on the back side of the proposed antenna for achieving SAR value reduction. Theoretical and experimental validation is carried out by measuring the variation in absorption power on each vegetable sample using vector network analyzer E5080A. The existence of OLR on the back side of the antenna reduces the absorption power upto 2 dB. From experimental validation, the proposed technique provides 88% to 98% reduction in SAR value when tested in each sample. Along with this OLR exhibits the capability to enhance the shielding characteristics to the controlled environment of experimental setup for analyzing the stages of seed germination, which helps in reducing the reported radiation effects and growth retardation. The proposed method of EMR reduction with miniaturized planar resonator can be effectively used in the communication systems operating at 2.45 GHz for creating a reduced radiation environment.

Development of a Microwave Sensor for Solid and Liquid Substances Based on Closed Loop Resonator.

In this work, a compact dielectric sensor for the detection of adulteration in solid and liquid samples using planar resonators is presented. Six types of filter prototypes operating at 2.4 GHz are presented, optimized, numerically assessed, fabricated and experimentally validated. The obtained experimental results provided an error less than 6% with respect to the simulated results. Moreover, a size reduction of about 69% was achieved for the band stop filter and a 75% reduction for band pass filter compared to standard sensors realized using open/short circuited stub microstrip lines. From the designed filters, the miniaturised filter with Q of 95 at 2.4 GHz and size of 35 mm × 35 mm is formulated as a sensor and is validated theoretically and experimentally. The designed sensor shows better sensitivity, and it depends upon the dielectric property of the sample to be tested. Simulation and experimental validation of the designed sensor is carried out by loading different samples onto the sensor. The adulteration detection of various food samples using the designed sensor is experimentally validated and shows excellent sensing on adding adulterants to the original sample. The sensitivity of the sensor is analyzed by studying the variations in resonant frequency, scattering parameters, phase and Q factor with variation in the dielectric property of the sample loaded onto the sensor.