Kocakarin, I. | Yegin, K.
Article | 2012 | International Journal of Antennas and Propagation2012
Surface plasmon-enhanced gold nanoantenna structures on glass substrate are studied for increased localized electric field and fluorescence at the feed gap locations of the antennas. Dipole, Archimedean balanced spiral, and bowtie and double bowtie geometries are studied for surface plasmon effect. Different flare angles for bowtie geometries are compared to each other. Double bowtie geometry with dual polarization capability exhibited superior performance with almost 56 dB field enhancement factor. We also studied the effect of substrate thickness on electric field enhancement and we found that glass thickness plays a critical role . . . for coherent addition of surface plasmons at the feed gap location. The surface plasmon effect is proven by considering perfect electric conductor model of gold instead of its modified Drude model. © 2012 Isa Kocakarin and Korkut Yegin Daha fazlası Daha az
Article | 2013 | International Journal of Antennas and Propagation2013
Several nanoantennas for infrared energy harvesting applications at 30 THz are studied. Contrary to usual antenna designs, we implemented glass superstrate as opposed to glass substrate for better antenna performance. We defined a figure of merit (FOM) which includes antenna fractional bandwidth, peak gain, and half-power beamwidth of the antenna under consideration. Three different antenna structures with glass superstrate and one of them with glass substrate are studied in detail. According to our FOM definition, the Archimedean balanced spiral antenna exhibited superior performance among other structures with less sensitivity to . . .the incoming polarization of the electromagnetic wave. © 2013 Isa Kocakarin and Korkut Yegin Daha fazlası Daha az
Isik, G. | Topaloglu, S.
An ultrawideband antenna is designed, simulated, and realized. To overcome the narrow bandwidth characteristics of basic patch antennas, the structure of the radiation pattern is optimized by the aid of elliptical and rectangular patches. Also triangular patches are applied to the antenna edge in order to enhance the VSWR and gain properties. A typical VSWR of 1.5 (less than 2 in the whole frequency range) and a typical gain of 2 dBi (mainly above 1 dBi in the whole frequency range) are observed. The simulations present that the designed antenna has a bandwidth ratio of 5: 1 within the frequency range of 4-19.1 GHz with compact dime . . .nsions of 25 × 26 mm2. It is fabricated on a 0.5 mm thick, RO3035 substrate. The input impedance, gain, and radiation characteristics of the antenna are also presented. With these properties, it is verified that, with its novel shape, the proposed antenna can be used for various UWB applications. © 2013 Gokmen Isik and Serkan Topaloglu Daha fazlası Daha az
Şişman, I. | Yegin, K.
Article | 2017 | International Journal of Antennas and Propagation2017
We propose a simple solution for jamming mitigation of L1 band GPS by electronically switching antenna beam for wide and narrow beamwidths. Assuming the jamming signal is directed from low elevation angles, antenna reception can be made significantly lower at these angles by electronically reconfiguring the antenna beamwidth. Four-element antenna array and one of the elements of the array are designated as antijam (array) mode and normal mode of the antenna. The antenna is placed on a degenerate-ground with symmetric slots in the ground. Front-end configuration for this antenna is also discussed. Simulations and measurements are per . . .formed to validate the proposed design. The antenna achieves more than 15 dB rejection in measurements and more than 20 dB cross-polarization improvement compared to standalone (normal mode) antenna. The system can easily be replaced with existing active antenna to improve antijam capability of the receiver. © 2017 İsmail Şişman and Korkut Yegin Daha fazlası Daha az
