This paper relates for the first time, multiple resonant frequencies of fractal element antennas using Koch curves to their dimension. Dipole and monopole based studied so far have generally been limited certain standard configurations geometry. It is possible generalize geometry by changing its indentation angle, vary similarity variation results in self-similar which can be generated a recursive algorithm. Such found direct influence on input characteristics dipole antennas. The primary...

Abstract The usefulness of fractal Hilbert curves in antenna geometry is explored here for the first time. Apart from being simple and self‐similar, these have additional property approximately filling a plane. These properties are exploited realizing “small” resonant antenna. This approach has resulted an size smaller than λ/10 still resonant, with performance comparable to dipole whose length close λ/2. Numerical predictions input impedance been compared experiments. effect iterations on...

Abstract Conducting polymer ultrathin films with high absolute electromagnetic interference (EMI) shielding effectiveness (SE) is highly desirable for their facile processability. The conducting polymer, poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), possesses excellent conductivity. However, a thin film of PEDOT:PSS water soluble, making it disadvantageous EMI shielding. Here, cross‐linked, water‐insoluble, evaluated. A 9 ± 1 µm thick cross‐linked exhibits an average...

In this paper we propose a circularly polarized (CP) microstrip antenna on suspended substrate with coplanar capacitive feed and slot within the rectangular patch.The has an axial ratio bandwidth (< 3 dB) of 7.1%.The proposed exhibits much higher impedance about 49% (S 11 < -10 also yields return loss better than -15 dB in useful range circular polarization.Measured characteristics are good agreement simulated results.The radiation patterns indicate cross polarization rejection low back lobe...

The design and analysis of a coplanar capacitive fed microstrip antenna suspended above the ground plane is presented. It demonstrated that proposed approach can be used for designing antennas with impedance bandwidth about 50% good gain to operate in various microwave bands. model incorporates feed strip which by coaxial probe using equivalent circuit approach, matches simulation experimental results. here basically rectangular capacitor formed from truncated transmission line all its open...

This paper presents a generalized approach to design an electromagnetically coupled microstrip ring antenna for dual-band operation. By widening two opposite sides of square antenna, its fractional bandwidth at the primary resonance mode can be increased significantly so that it may used practical applications. attaching stub inner edge side feed arm, some losses in electrical length caused by regained. More importantly, this addition also alters current distribution on and directs...

This paper reports an improvement in Pt/n-GaN metal-semiconductor (MS) Schottky diode characteristics by the introduction of a layer HfO2 (5 nm) between metal and semiconductor interface. The resulting Pt/HfO2/n-GaN metal-insulator-semiconductor (MIS) showed increase rectification ratio from 35.9 to 98.9(@ 2V), barrier height (0.52 eV 0.63eV) reduction ideality factor (2.1 1.3) as compared MS Schottky. Epitaxial n-type GaN films thickness 300nm were grown using plasma assisted molecular beam...

In this paper, we report fabrication and dynamic characterization of low-actuation-voltage capacitive radio frequency microelectromechanical systems (RF MEMS) switches with improved electromechanical performance. Electromechanical electromagnetic modeling is used to modify the previously known geometries number size holes in them improve their overall characteristics. The are fabricated on a Pyrex glass substrate using low-complexity four-mask surface micromachining process. These designs...

Lack of reliability radio-frequency microelectromechanical systems (RF MEMS) switches has inhibited their commercial success. Dielectric stiction/breakdown and mechanical shock due to high actuation voltage are common impediments in capacitive MEMS switches. In this work, we report low-actuation RF switch its test. Experimental characterization fabricated devices demonstrate that proposed topology needs very low (4.8 V) for actuation. The resonant frequency, f0, quality factor, Q, switching...

Nanocrystalline zinc ferrite (ZFO) has been synthesized from metal acetylacetonates by microwave irradiation for 5 min in the presence of a surfactant. The as-prepared material is ZFO and subjected air to conventional furnace annealing rapid at different temperatures. Both protocols lead well-crystallized ZFO, with crystallite sizes range ∼8–20 nm, which ferrimagnetic, even room temperature, magnetization attaining saturation. While MS conventionally annealed varies size expected manner,...

The polymer nanocomposite thin film is of interest due to many advantages for electromagnetic interference (EMI) shielding. In this work, low temperature (−30 ± 2 °C) in situ synthesized polyaniline (PANI)–MnO2 nanorod composite (PMN) were solution processed, followed by acid vapor treatment preparing free standing films and EMI shielding effectiveness (SE) investigated the frequency range i.e. X-band (8.2–12.4 GHz) Ku-band (12.4–18 GHz). As prepared PMN (169 µm) shows most effective SE ~ 35...

Variations in material properties, boundary conditions, or the geometry can be expected most electromagnetic problems. When these uncertainties different regions of model space are considered simultaneously, stochastic dimensionality and computational cost increase. Hence, uncertainty quantification such problems is seldom attempted even though its leads to a robust model. In this letter, nonintrusive least square polynomial chaos expansion method employed quantify due variation properties....

A triband band-stop spatial filter shield using frequency selective surface is designed and analyzed to block GSM 900, 1800, Wi-Fi 2400 MHz bands. Three constituent resonant elements exhibiting stop-bands are two Jerusalem cross (JC) with tortuous main arms, a 45° rotated JC. The proposed unitcell compact size 0.078λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> x , where λ the wavelength of lowest in free space. An equivalent circuit...

An approximate formulation for the resonant frequency of a dipole Hilbert curve fractal antenna (HCFA) is derived here. These can be used as small antennas, useful in VHF/UHF communication. The formulas presented here appropriately inverted to obtain design equations antenna, given frequency.