In this manuscript, higher-order Orbital Angular Momentum (OAM) modes and parameters affecting vortex in the radiation pattern have been studied. A uniform circular array resonating at 10 GHz frequency is formed using eight identical rectangular patch antennas. Three uniform circular arrays are analyzed, simulated, and fabricated for OAM modes 0, +1, and -1 respectively. The higher-order OAM mo...

Background: Over the past several years, the rapidly increasing use of mobile phones has raised global concerns about the biological effects of exposure to radiofrequency (RF) radiation. Numerous studies have shown that exposure to electromagnetic fields (EMFs) can be associated with effects on the nervous, endocrine, immune, cardiovascular, hematopoietic and ocular systems. In spite of genetic...

The photoconductive terahertz measurement technique was used for measurement of the radiation pattern from thick metal slits. Picosecond pulses were generated and detected by an ultrafast optoelectronic technique using a femtosecond pulse laser and a subpicosecond photoconductor. Photoconductive sampling measurements of the polarization-dependent diffraction of the picosecond electromagnetic pu...

In this paper a novel method for computing the radiation pattern and also the input impedance of a planar rectangular micro-strip antenna array with consideration of mutual coupling and mutual impedance is presented. Each two triangles with a common edge make an Edge element or RWG. Any such edge element is considered as an infinitesimal dipole. The electrical currents over each dipole can be c...

Our aim is to develop a microwave antenna whose radiation pattern is electronically controlled. The radiation pattern of regular antennas is determined by the Fourier-transform of the complex illumination function on the antenna aperture. This radiation pattern is mechanically fixed so its alteration is impossible. Therefore we construct an antenna system of several antenna elements. All elemen...

antenna structures with low side lobe levels are normally the main goal during antenna design. in this paper, a new method for reduction of radiation pattern side lobe level in phased array antenna with uniform and non-uniform weighting is presented. in this method, by changing the array elements weight or adding several elements, such as slc technique, the pattern with low side lobe level can ...

Introduction: Little information is available concerning the radiation exposure of anesthesiologists, and no such data have previously been collected in Iran. This prospective study was performed to determine the amount of radiation exposure of anesthesiologists for the purpose of assessing whether or not dangerous levels of radiation exposures were being reached, and to identify factors that c...