In this paper, two microstrip-fed printed slot antennas have been introduced to be used in modern communication systems, as alternatives for conventional Hilbert slot antenna. The slot structures of the proposed antennas are in the form of the 3rd iteration of two variants of the conventional Hilbert space-filling curves. These antennas are fed with 50 Ω microstrip line printed on the reverse s...

A multiband double square loop antenna with fractal concept is proposed. The design is based on an initial model of fractal geometry and a double square slot antenna structure. The initial model of fractal geometry influences to the second frequency band and it will be carefully investigated. The radiation patterns of the proposed antenna are still similarly to bidirectional radiation pattern. ...

Power patterns in the frequency domain are usually used to describe the antenna performance in narrowband communication systems; however, they are not sufficient for ultra wideband (UWB) antennas in wideband communication systems. In this paper, energy pattern and energy gain are introduced to describe the performance of UWB antennas. Numerical simulations and measurements are used to demonstra...

A new meta-surface structure (MSS) with a near-zero refractive index (NZRI) is proposed to enhance the performance of a square loop antenna array. The main challenge to improve the antenna performance is increment of the overall antenna volume that is mitigated by assimilating the planar NZRI MSS at the back of the antenna structure. The proposed NZRI MSS-loaded CPW-fed (Co-Planar Waveguide) fo...