H. Attia

Publications (7)3.52 Total impact

• Source

  Available from: jhu.edu

  Article: Analytical Model for Calculating the Radiation Field of Microstrip Antennas With Artificial Magnetic Superstrates: Theory and Experiment

  H. Attia, L. Yousefi, O.M. Ramahi
  [show abstract] [hide abstract]
  ABSTRACT: A fast analytical solution for the radiation field of a microstrip antenna loaded with a generalized superstrate is proposed using the cavity model of microstrip antennas in conjunction with the reciprocity theorem and the transmission line analogy. The proposed analytical formulation for the antenna's far-field is much faster when compared to full-wave numerical methods. It only needs 2% of the time acquired by full-wave analysis. Therefore the proposed method can be used for design and optimization purposes. The method is verified using both numerical and experimental results. This verification is done for both conventional dielectric superstrates, and also for artificial superstrates. The analytical formulation introduced here can be extended for the case of a patch antenna embedded in a multilayered artificial dielectric structure. Arguably, the proposed analytical technique is applied for the first time for the case of a practical microstrip patch antenna working in the Universal Mobile Telecommunications System (UMTS) band and covered with a superstrate made of an artificial periodic metamaterial with dispersive permeability and permittivity.
  IEEE Transactions on Antennas and Propagation 06/2011; · 2.15 Impact Factor
• Source

  Available from: edu.sa

  Conference Proceeding: Metamaterial for gain enhancement of printed antennas: Theory, measurements and optimization

  H. Attia, O. Siddiqui, L. Yousefi, O.M. Ramahi
  [show abstract] [hide abstract]
  ABSTRACT: Metamaterials have been shown to enhance specific performance parameters of low profile and high-profile antennas. Our focus in this paper on specifically increasing the gain of low-profile antennas and in particular the microstrip patch antenna. By placing a metamaterial slab above a microstrip patch antenna (as a superstrate), we show that the gain of the antenna can be enhanced appreciably. The key advantage of using the superstrate is to maintain the low-profile advantage of microstrip patch antennas. In previous works, different types of superstrates were proposed to enhance the gain of microstrip antennas, however, to the best of our knowledge, no theory was developed to understand the mechanism behind the enhancement in the gain. In this paper, we present a simple analytical formulation that provides a very accurate prediction of the gain when a superstrate is used. In fact, our analytical technique is capable of predicting the gain when a multilayer superstrate structures is used. To validate the theory of gain enhancement, antennas and superstrates using metamaterials were fabricated and tested in an echoic chamber. The metamaterials developed were based on split-ring resonators. Strong agreement was found between the measurements and full-wave simulation using commercial tools. Finally, we present optimization results to demonstrate the maximum gain enhancement potential that can be achieved when superstrates are used.
  Electronics, Communications and Photonics Conference (SIECPC), 2011 Saudi International; 05/2011
• Conference Proceeding: Theoretical and experimental investigation of patch antennas loaded with engineered magnetic superstrates

  H. Attia, L. Yousefi, O.M. Ramahi
  [show abstract] [hide abstract]
  ABSTRACT: In this paper, the cavity model of a microstrip patch antenna in conjunction with the reciprocity theorem is used to develop a fast analytical solution for the radiation field of a microstrip patch antenna loaded with an engineered magnetic superstrate and to investigate the effect of the artificial superstrate on improving the gain and radiation pattern of the printed patch antenna. The broadside coupled split ring resonator (SRR) inclusions are used in the design of the engineered magnetic superstrate. The proposed antenna configuration has been designed, fabricated, and measured. A good agreement is observed between the analytical solution, numerical simulations and measurement results.
  Wireless Technology Conference (EuWIT), 2010 European; 10/2010
• Conference Proceeding: High-gain low-profile antenna using artificial magnetic superstrates

  H. Attia, L. Yousefi, O.M. Ramahi
  [show abstract] [hide abstract]
  ABSTRACT: In this paper, a novel engineered magnetic superstrate is designed to enhance the gain of a microstrip patch antenna without any substantial increase in the profile of the whole structure (the antenna with the superstrate). The modified split ring resonator (MSRR) inclusions are used in the design of the engineered magnetic superstrate. Numerical fullwave simulations as well as analytical models are used to analyze the whole radiating system. The broadside gain of the antenna is improved by about 3 dB after using the engineered superstrate.
  Antennas and Propagation Society International Symposium (APSURSI), 2010 IEEE; 08/2010
• Source

  Available from: Muhammed Said Boybay

  Article: Enhanced-Gain Microstrip Antenna Using Engineered Magnetic Superstrates

  H. Attia, L. Yousefi, M.M. Bait-Suwailam, M.S. Boybay, O.M. Ramahi
  [show abstract] [hide abstract]
  ABSTRACT: This letter presents a novel engineered magnetic superstrate designed to enhance the gain and efficiency of a microstrip patch antenna without any substantial increase in the profile of the whole structure (the antenna with the superstrate). The modified split ring resonator (MSRR) inclusions are used in the design of the engineered magnetic superstrate. Numerical full-wave simulations as well as analytical models are used to analyze the entire radiating system. Considering as an example a microstrip antenna operating within the UMTS band, the broadside gain of the antenna was improved by 3.4 dB and the efficiency was improved by 17% when using the engineered superstrate. The total height of the proposed structure, antenna with superstrate, is lambda₀/7, where lambda₀ is the free-space wavelength at the resonance frequency of the antenna.
  IEEE Antennas and Wireless Propagation Letters 02/2009; · 1.37 Impact Factor
• Conference Proceeding: EBG superstrate for gain and bandwidth enhancement of microstrip array antennas

  H. Attia, O.M. Ramahi
  [show abstract] [hide abstract]
  ABSTRACT: Two different designs have been studied for the application of EBG as a superstrate for 2 X 2 microstrip array antenna. It was shown that the cross-stacked EBG superstrate improves the input impedance bandwidth and reduces the overall size of the antenna in comparison to previous designs.
  Antennas and Propagation Society International Symposium, 2008. AP-S 2008. IEEE; 08/2008
• Source

  Available from: jpier.org

  Article: Broadband experimental characterization of artificial magnetic materials based on a microstrip line method

  L Yousefi, H Attia, O M Ramahi
  [show abstract] [hide abstract]
  ABSTRACT: A broadband method is introduced to measure the effective constitutive parameters of artificial magnetic materials. The method is based on the microstrip line topology, thus making it easy to retrieve the constitutive parameters over a wide band of frequencies. To demonstrate the effectiveness of this method, artificial magnetic materials with Fractal Hilbert inclusions are fabricated and characterized. Good agreement between the experimental and numerical simulation results verifies the accuracy of the proposed method.