Fractal antenna, as name concerns, uses fractal i.e. structure does not change and repeat it when large focus has created upon it. This repetition feature of this antenna provides a great flexibility that it can be designed and can used in different frequencies. Fractal geometry has shown its potential in many fields of engineering and technology. In antenna engineering fractal geometry is very...

The design and development of a proximity fed dualband microstrip patch antenna based on David fractal geometry are presented. David fractal microstrip antenna offers good performance in the 1.754 1.816 GHz and 3.37 3.415 GHz bands and is suitable for GSM 1800, WiMAX applications. The use of David fractal geometry offers miniaturization of the antenna structure. The proposed first iteration fra...

Ge-on-Si plasmonics holds the promise for compact and low-cost solutions in manipulation of THz radiation. We discuss here plasmonic properties doped Ge bow-tie antennas made with a low-point cost CMOS mainstream technology. These display resonances between 500 700 GHz, probed by time domain spectroscopy. show surface functionalization thin layer α-lipoic acid that red-shifts antenna about 20 G...

We describe measurements of the angular radiation patterns from lens-coupled terahertz antennas fabricated on photoconductive substrates. These measurements have been performed using a novel terahertz time-domain spectrometer in which the femtosecond optical pulses used to gate the emitter and receiver antennas are delivered via optical fiber. We have used this system to perform a comparison be...

Terahertz radiation was generated with several designs of photoconductive antennas (three dipoles, a bow tie, and a coplanar strip line) fabricated on low-temperature-grown (LT) GaAs and semi-insulating (SI) GaAs, and the emission properties of the photoconductive antennas were compared with each other. The radiation spectrum of each antenna was characterized with the photoconductive sampling t...

Plasmonic nanoantennas are efficient devices to concentrate light in spatial regions much smaller than the wavelength. Only recently, their ability to manipulate photons also on a femtosecond time scale has been harnessed. Nevertheless, designing the dynamical properties of optical antennas has been difficult since the relevant microscopic processes governing their ultrafast response have remai...

This paper presents rectangular, fractal and proximity coupled patch antennas on a two layer substrate with the air-gap. The antennas have been designed on εr = 2.2, h = 1.5748 mm with initial dimension 49 x 41.01 mm of simple rectangular patch. The simulated resonant frequency of rectangular patch is 2.42 GHz. The fractal antenna and the Fractal antenna with Layered Stack shows the multi band ...

Mastering dynamic free-space spectral control and modulation in the near-infrared (NIR) and optical regimes remains a challenging task that is hindered by the available functional materials at high frequencies. In this work, we have realized an efficient metadevice capable of spectral control by minimizing the thermal mass of a vanadium dioxide phase-change material (PCM) and placing the PCM at...

Terahertz wave diagnostics have been developed for current and future high-temperature and high-density fusion plasma measurements. Since the combined system of a reflectometer and a delayometer requires a wideband frequency source for the density profile measurements, a terahertz pulse is a possible candidate. A test system using terahertz time-domain spectroscopy has been constructed to devel...