controlling and suppressing sidelobe level of a symmetric parabolic antenna is presented. This sidelobe suppression is done by adding three disc-shaped elements on the surface of the parabolic antenna. By adjusting the position and height of these elements, the surface of the side lobe is changed. With this method, the antenna is designed in the X-Band so that the output of the radiation pattern is such that the level of the first side lobe is relatively lower than the other side lobe. Also, the VSWR for the antenna is designed across the frequency range below 1.82. The simulations show that the level of the first side lobe on the right side of the antenna radiation pattern is reduced by 18dB compared with the simple reflex antenna with similar dimensions and specifications, and the VSWR in the frequency range (11.5GHz-12.5GHz) between 1.1 <VSWR <1.82 . Manuscript profile

A Printed Monopole, One Sixth Wavelength Blade Antenna using printing micro strip on substrate that reduces the cost & increases the ease & precision in manufacturing. In this paper, the process of combining conventional blade antenna that cut a desired piece of metal, & alternative the printed version is represented. Due to increase mechanical strength of parasitic element, it has substrate in common with main antenna. A sample of the proposed antenna has been designed & manufactured that measurement and simulation results are in good agreement with each other. Manuscript profile

Plasma antennas are radio frequency antennas that use ionized gas instead of metal conducting element of conventional antenna to transmit and receive signals. In this paper, the effect of changing material of the inside coupler on bandwidth, return loss and radiation pattern at Ultra High Frequency (UHF) band is investigated. It is demonstrated that the resonant frequency can be adjusted by choosing proper material for internal coupler without changing the antenna size and structure. The antenna and its coupler is simulated by practical software Computer Simulation Technology (CST) Microwave Studio. Manuscript profile

In this paper a method to design tapered slot antenna (TSA), a member of ultra-wideband (UWB) antenna, is presented. The proposed method is related to impedance matching of input and free space intrinsic impedance by Butterworth method. By this method, curve fitting converts step impedance to optimized curve and this optimized curve and its symmetry create Vivaldi antenna. The fractional bandwidth (FBW) of the antenna by the proposed method is 155% which is more than the methods of Chebyshev and attenuation. A prototype of this antenna is fabricated and simulation and measurement results are in good agreement. Manuscript profile

Substrate integrated waveguide (SIW) filers are good candidates to substitute for bulky and expensive metallic waveguide filters. Many methods are used to developed specific filter responses. One of them is using defected ground structures (DGS) in SIW filters to generate desired transmission zeros, which cannot be used in waveguide filters. In this paper, an elliptical third order bandpass SIW filter is designed in WLAN frequency band using the DGS technique. It is also shown that this technique reduces the filter size while providing good filtering response. The central frequency and fractional bandwidth of the filter is 2.4 GHz and 16.2%, respectively. Manuscript profile