List of Articles حفره

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  1 - Parametric analysis of a broadband Archimedean spiral antenna with cavity
  Hamed  noroozy Shahrokh  jam
  In this article an Archimedean spiral antenna is designed and analyzed that has good operation in broadband application. By analyzing this design, the effects that different parameters have on antenna operation will be studied and ways of optimization will be found.  In More

  In this article an Archimedean spiral antenna is designed and analyzed that has good operation in broadband application. By analyzing this design, the effects that different parameters have on antenna operation will be studied and ways of optimization will be found.  Influences of cavity height and number of turns to obtain good matching and gain in a frequency interval of 4 to 18 GHz will be discussed. In addition, using cavity wall around the antenna, side lobes are decreased or deleted. By tapering the arms at feeding center, better matching will be attained. For making S11 bandwidth better, increasing the cavity height or reducing the number of turns can be used. Changing number of turns does not have a significant effect on the gain. To improve the antenna gain, the cavity height needs to be adjusted such that the reflected wave from cavity and radiated wave from spiral arms are constructing. Manuscript profile
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  2 - Design, Simulation and Implementation of Compact and Wideband Microwave Filter Using Semi-Hexagonal Cavity by Substrate Integrated Waveguide (SIW) Technology
  m.h. n. Rasoul Rahmani
  In this paper, a compact wideband microwave filter in X band using substrate integrated waveguide technology is designed, simulated and implemented. At first, the structure of hexagonal and semi-hexagonal microwave resonators is studied and their resonate modes, resonan More

  In this paper, a compact wideband microwave filter in X band using substrate integrated waveguide technology is designed, simulated and implemented. At first, the structure of hexagonal and semi-hexagonal microwave resonators is studied and their resonate modes, resonance frequencies and field distribution inside these resonators are investigated. Then, a second order Chebyshev filter is designed by coupling matrix of two semi-hexagonal cavities with center frequency of 10 GHz and fractional bandwidth of 20%. The first designed filter based on theoretical modeling is simulated by a full wave simulator and the geometrical parameters of the structure are adjusted for the required response. A prototype of the designed filter is implemented by TLY031 substrate and its characteristics are successfully measured. The results show that the measured results agree well with those obtained by simulation. The center frequency of the implemented filter is 8.7 GHz and it provides 27.3% bandwidth, with maximum insertion loss of 2.1 dB. Manuscript profile