List of Articles leakage rate

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  1 - Simulation of Leaky Wave Antenna with Cosecant Squared Pattern Using Genetic Algorithm
  Farnoosh Heidari Zahra Adelpoure Naser Parhizgar
  Realizing a cosecant-squared pattern is a challenging research area due to its widespread use in air-surveillance radar systems wherein the radiation characteristics of the tracking antenna play a significant role in accurate tracking of the targets. However, little res More

  Realizing a cosecant-squared pattern is a challenging research area due to its widespread use in air-surveillance radar systems wherein the radiation characteristics of the tracking antenna play a significant role in accurate tracking of the targets. However, little research has been performed on realizing a cosecant-squared pattern in leaky-wave antennas (LWAs). In this paper, the authors present a synthesis procedure for realizing a cosecant-squared pattern in LWAs using optimization. To achieve the cosecant-squared pattern, the antenna is divided into sections each with an appropriate length, periodicity, and leakage rate. The length of the sections is determined such that all the sections have the same directivity. Moreover, following the appropriate layout for the beam pointing angle of the sections, the periodicity of the sections is obtained. The objective then is to determine the values of the leakage rate. This objective is achieved using optimization, which in this study is a genetic algorithm. To this end, through defining a proper cost function, the objectives are determined following the proposed optimization procedure. The procedure is described within a substrate integrated waveguide (SIW) LWA. A prototype of the antenna is fabricated and measured. Apart from the good agreement between the simulation and the measurement results, the proposed synthesis procedure can provide a target pattern with low ripples in the shaped region (≤ 2 dB) and a low level of side lobes (≤ -18 dB), making the antenna suitable for air-surveillance radar systems. Manuscript profile
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  2 - Pattern Synthesis of Substrate Integrated Waveguide Leaky-Wave Antennas Using Optimization Algorithm
  Farnoosh Heidari Zahra Adelpour Naser Parhizgar
  In the modern era, the antennas with cosecant squared pattern play a significant role in radar applic­ations. These applications are used to cover an airspace to search for targets and estimate their height. In this article, a method is proposed for the synthesis of More

  In the modern era, the antennas with cosecant squared pattern play a significant role in radar applic­ations. These applications are used to cover an airspace to search for targets and estimate their height. In this article, a method is proposed for the synthesis of cosecant squared pattern using leaky wave antenna. The principal mechanism in the leaky wave antennae is wave attenuation due to power leakage while the wave propagates through the structure. Thus, by controlling the leakage and phase constants along the length of the structure, one can synthesize the desired radiation patterns. We have used the genetic algorithm to optimize the leakage constant and obtain the desired cosecant squared pattern In the range of 10 to 30 degrees. Conformity in simulation results and measured results indicates accuracy in the design process. The proposed method obtains the desired pattern with a ripple of less than 2 dB in the designated area and side lobe level less than -18 dB, which makes the antenna suitable for radar applications. Manuscript profile