Abstract-The ground conductivity is the most important factor in the transmitter's coverage area in ground wave propagation. Regarding the day-to-day increase in digital broadcasting, a lower sensitivity of this kind of broadcasting and ability to create single frequency networks, it seems necessary to increase the accuracy of ground conductivity to minimize fading zones. The higher the abovementioned conductivity, the lower the ground wave attenuation. Also in this case, the transmitted wave will tilt less towards the ground to satisfy the boundary conditions in electric conductivity and so-called will enter the earth. In most of the presented papers to determine the field strength, conductivity is considered as known, but it's dependent upon the soil genus, the annual/monsoon precipitation and the heat average. Here it is intended to provide a new method based on Mie algorithm to determine the conductivity based on the difference of Horizontal Electric Dipole near the ground. The previous conductivity measurements included determining it in a point by point manner in a low frequency and determining the conductivity based on the coverage area intensity. The new method holds the two methods advantages together. 44Makki, Ershadi, and Abrishamian

Abstract-Based on theoretical calculations, the field intensity resulting from a transmitter of medium wave (waves propagation) enjoys a significant increase in the paths where ground conductivity increase and in special environmental conditions even if far away from the transmitter. This phenomenon distinguishes coverage areas of a transmitter from common procedures of determining coverage. This article examines and observes the above-mention issue and its results.

This paper present, the design and simulation of the Ka to v band RF-MEMS capacitive switch. The mechanic design and analysis of the RF-MEMS switches are based on both the finite element method and the full-wave electromagnetic simulation. A double-beam switch with a high impedance short transmission line is proposed to improve RF characteristics. The electronic characteristics, of the switches including insertion and return losses in up-state position, were more than -0.11 dB and less than -23 dB , respectively and isolation on down-state position was more than -30 dB on 50 GHZ frequency. In order to make lower actuated voltage, a serpentine spring folded suspension beam and low actuated area were used so that some important issues such as life and reliability of switch were considered in design.