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Naturally, existing lignocelluloses fibers showed outstanding potential in paper industry and other conventional applications. On the other hand, lignocellulose fibers are suitable candidate for high-tech applications under the scope of abundance, flexibility, light-weight and environment friendliness. In this study, paper sheets were prepared from lignocelluloses fibers extracted from self-growing plant, typha angustifolia. Lignocelluloses paper sheets were characterized for scanning electron microscopy (SEM), universal testing machine (UTM) and vector network analyzer (VNA). Flexible paper sheets displayed a tensile strength of 9.1 MPa and further used as a substrate in patch antenna to observe dielectric characteristics. The patch antenna is designed at 5.1 GHz which showed return loss less than −10 dB and dielectric constant 3.71. The use of lignocelluloses paper sheet as a substrate in patch antenna will provide the opportunity of miniaturization of size and weight in comparison of a jean substrate based antenna. [ABSTRACT FROM AUTHOR]

Sparse antenna arrays with irregularly spaced elements are increasingly being used in large array applications such as radio astronomy and radar. These antenna arrays may consist of hundreds of elements and therefore optimisation of these arrays becomes computationally expensive. This study proposes a novel solution to the problem of null synthesis in such arrays, where nulls are formed in prescribed locations for two-dimensional irregular sparse antenna arrays. The technique is based on a subarray and hybrid synthesis solution, where each subarray spans the entire antenna aperture. Single and multiple null formations with array gain maximisation are considered. The technique's effectiveness is demonstrated using evolutionary optimisation algorithms; however, the basic technique can be used with other optimisation methods. The simulation results presented compare the null synthesis performance with and without subarraying and it has shown that the use of subarray results in improved convergence compared with a direct full array synthesis. Furthermore the technique is appropriate for ready application to parallel computer architectures. [ABSTRACT FROM AUTHOR]

ABSTRACT Reduced size dual band patch antenna is designed on pulp fibers-based substrate, obtained from a self-growing plant, Typha angustifolia. The proposed design is low cost and has <10 dB return loss at 2.4 and 5.7 GHz, with 6.9 dBi antenna gain and also has potential for conformal designs. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2146-2148, 2016 [ABSTRACT FROM AUTHOR]