Compact ultra‐wideband fractal monopole antenna with high gain using single layer superstrate

Abstract

A novel technique is applied on fractal monopole antenna to enhance gain for ultra wideband (UWB) applications. The fringing field effect of the antenna is increased by using dielectric superstrate, and it is designed by fabricating rectangular conductor on single side of the superstrate with dimension 10 3 21.5 mm 2 . The fractal structure is designed by the identical triangle structure in the radiating patch. The dielectric superstrate is placed on the fractal monopole antenna. At the time of feeding, the conductor of the superstrate is connected through ground plane of the antenna. The overall dimension of the fractal monopole antenna with superstrate is 24.5 3 21.6 3 3.15 mm 3 . The measurement result of the reflection coefficient is below 210 dB indicating impedance bandwidth of 3.1 to 11 GHz. The measured radiation patterns are also improved and peak gain of the conventional antenna increases approximately 1.6 dB by using superstrate with reference to conventional design. Figure 11 Fringing fields (Electric fields) of the superstrate loaded fractal antenna (a) 5 GHz, (b) 7 GHz, (c) 9 GHz. [Color figure can be viewed at wileyonlinelibrary.com]ABSTRACT: This paper describes properties of a new 20-bit chipless RFID tag of the size 52 3 50 mm 2 , which exhibits an improved magnitude and robustness of the radar cross section. The tag is based on a novel slots-in-plate array approach, which is complementary to a typical tag consisting of an array of single resonators. In order to eliminate the detuning effect of the missing or shortening slots representing '0' bit information on the resonances of neighbouring slots signifying '1' bit information, the modification of the inter-element arrangement was proposed. Both ways of '0' bit information coding were studied and compared.

High Directivity Broadband Hexagonal Fractal Ring Antenna with Modified Ground

“…This paper proposes a compact hexagonal fractal geometry which generates a highly directive radiation pattern over a broadband. Bandwidth enhancement of fractals with high gain has been achieved by techniques consisting of a superstrate [20] or higher iteration fractal shapes [21][22][23][24]. Only a limited number of planar antennas achieved both the aforementioned objectives [22][23][24].…”