Radiosonde system is one of the modern systems that measure meteorological variables. This system consists of two parts, the ground station and Radiosonde transmitter system. Radiosonde carried by airborne balloon and is equipped with various sensors to measure temperature, humidity, air pressure, direction and wind speed. After measuring the parameters, the measured data Send by radio transmitter to the ground station. Radiosonde transmitted measured data at 403MHz and 1680MHz radio frequencies. At high altitudes, airborne balloon’s orientation is affected by the winds of the atmosphere above the ground and it is impossible to determine precisely the direction of its movement. That's why we need an omnidirectional receiver antenna at radiosonde working frequency in order to receive information from transmitter. From various design options, the 6-segment patch antenna is an appropriate choice. According to the features described, the antenna in the picture is designed as 7 separate patch antennas at 403MHz frequency. Easy to carry, Lower weight than similar models, no need for Radome coatings, affordable prices and easy installation are the Features of this design. also The design of this antenna is such that only with changing the upper part of the antennas makes it possible to change the working frequency from 403MHz to 1680MHz
In this thesis, we briefly review the effects of RF waves’ exposure on human health and compare the common standards in this area. Afterwards, using the above results, the current level of waves in the Faculty of Electrical Engineering in K. N. Toosi University of Technology, in the range of 860 to 950 MHz and 2.4 to 2.5 GHz, are measured. The resulted RF map, comparing the level of the signals with the existing standards, has been produced.