U-shaped Conductor Research Articles

Высокоселективный волноводный полосно-пропускающий фильтр с уровнем подавления помех более 120 dB

The design of a 10th-order waveguide bandpass filter with an additional inductive cross-coupling between non-adjacent resonators has been proposed and studied. An inductive coupling is formed by a U-shaped conductor structure with grounded ends that is formed in the filter cover. This method of cross-coupling organization ensures not only the temperature stability of the characteristics, but also the manufacturability of the structure. The high selectivity of the device is achieved by both the attenuation poles located near the passband, as well as the level of suppression in the stopbands, exceeding 120 dB. The passband loss of the fabricated filter is ~0.8 dB at its central frequency f0 = 18.2 GHz and relative bandwidth Δf / f0 = 1.5%. The small dimensions (135×30×10 mm3) and the weight of about 200 g of the device, with simultaneously high electrical characteristics show the promise of its use, for example, in on-board and ground-based space communication systems.

A high-selectivity waveguide bandpass filter with interference suppression by more than 120 dB in rejection band

The design of a 10th-order waveguide bandpass filter with an additional inductive cross-coupling between non-adjacent resonators has been proposed and studied. An inductive coupling is formed by a U-shaped conductor structure with grounded ends that is formed in the filter cover. This method of cross-coupling organization ensures not only the temperature stability of the characteristics, but also the manufacturability of the structure. The high selectivity of the device is achieved by both the attenuation poles located near the passband, as well as the level of suppression in the stopbands, exceeding 120 dB. The passband loss of the fabricated filter is ~ 0.8 dB at its central frequency f0=18.2 GHz and relative bandwidth Delta f/f0=1.5%. The small dimensions (135x 30x 10 mm) and the weight of about 200 g of the device, with simultaneously high electrical characteristics show the promise of its use, for example, in on-board and ground-based space communication systems Keywords: bandpass filter, waveguide, resonator, cross-coupling.

Design and Implementation of Low Profile Antenna for Dual-Band Applications Using Rotated E-Shaped Conductor-Backed Plane

A novel configuration of a printed monopole antenna with a very compact size for satisfying WLAN operations at the 5.2/5.8 GHz and also for X-band operations at the 10 GHz has been proposed. The antenna includes a simple square-shaped patch as the radiator, the rotated U-shaped conductor back plane element with embedded strip on it, and the partial rectangular ground surface. By using the rotated U-shaped conductor-backed plane with proper values, good impedance matching and improvement in bandwidth can be achieved, at the lower and upper bands. The impedance bandwidth for S 11 < −10 dB is about 1.15 GHz for 5 GHz band and 5.3 GHz for X-band. The measured peak gains are about 1.9 dBi at WLAN-band and 4.2 dBi at X-band. The experimental results represent that the realized antenna with good omnidirectional radiation characteristics, enough impedance bandwidth, and reasonable gains can be appropriate for various applications of the future developed technologies and handheld devices.

Design of branch line coupler loaded capacitively with interdigitated fingers by using microstrip fed coplanar structures (L-shaped conductor backed asymmetric CPS and U-shaped conductor backed CPW)

In this letter, L-shaped conductor backed asymmetric coplanar stripline (LSCBACPS) and U-shaped conductor backed coplanar waveguide (USCBCPW) branch line coupler fed by microstrip transmission line have been investigated for the miniaturization. The number of interdigital finger unit cells located at the branch and through lines of the conventional branch line coupler is used to provide a desired miniaturization. The proposed branch line couplers in which all ports are formed by microstrip line have been constructed in two different configurations depending on the placement of the capacitively loaded fingers. The effects of the change of the cell number located at the branch and through lines on the center frequency and the propagation velocity are investigated. These effects are expressed by a simple formula depends on the cell number to use in the theoretical model obtained from the even-odd mode analysis of LSCBACPS and USCBCPW configurations. Proposed couplers are designed, fabricated, and tested for the experimental verification to compare with the simulation and theoretical results. Measured, theoretical, and simulation results are in a very good agreement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:816–820, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27442

Design of an Accuracy Current Sensor Using Amorphous Fine Wire of FeCoSiB

In this paper, we are interested in electric current reconstruction from magnetic field measurements. The major difficulty of this principle is in the ability to reject magnetic field perturbations which affect the accuracy of the measurements. The first experimental validation of the approach of gradient measurement shows large errors in the current reconstruction using two independent fluxgate sensors. These errors were attributed to mechanical alignment and different residual magnetic states of the fluxgate sensors. We then suggested an effective solution able to overcome these problems. This solution consists of a fluxgate gradiometer placed above U-shaped conductor carrying the unknown current to be reconstructed. The experimental results of this system show a good rejection of uniform and non-uniform magnetic field perturbations and furthermore an improvement of the accuracy of the measurements.

The geometry of the Iapetus Suture Zone in central Ireland deduced from a magnetotelluric study

The crustal geometry of the Iapetus Suture Zone (ISZ) in central Ireland is inferred from an electrical resistivity model derived from broadband and long period magnetotelluric measurements along a 200-km-long NNW-SSE profile. The model highlights an undulating high conductivity layer of thickness 10–15 km and resistivity 2–5 Ω m, at middle to lower crustal depths interpreted as sulphide-bearing graphitic sediments deposited between the converging continents of Laurentia and Avalonia during the closure of the Iapetus Ocean. The sediments underwent sinistral, transpressional deformation during convergence, and movements along the faults transported the sediments to depths of 5–10 km forming the U-shaped conductor beneath the centre of the profile correlative with the inferred location of the Iapetus Suture Zone. Two high resistivity blocks identified above the U-shaped conductor are interpreted as Caledonian granite bodies, and likely relate to late Caledonian igneous activity.

A broadband slot antenna with harmonic suppression

In this article, a slot antenna is proposed to achieve both harmonic suppression and wide bandwidth. To obtain these results, a T-shaped microstrip-line-fed slot antenna and U-shaped conductor line connected with the ground plane are applied. At the fundamental and harmonic frequencies, return loss and radiation characteristics are measured and compared with those of the conventional slot antenna. For the proposed antenna, the 10-dB return loss bandwidth could reach 1220 MHz (1730–2950 MHz), which is about 52% with respect to the center frequency of 2340 MHz, and it is observed that the second and third harmonics of the proposed antenna is effectively suppressed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1984–1987, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21828

Thermal management and resistive rail heating of a large-scale naval electromagnetic launcher

This work presents a model that can be implemented to quickly estimate the resistive heating and the resulting transient temperature response. Quantifying the energy deposited in the rails and implementing an effective thermal management system will be key elements of an effective design for a large-scale electromagnetic launcher. The total current was divided between the inside, upper/lower, and outside surface based on the results of a current distribution calculation. The diffusion of the magnetic field into each surface was modeled in order to determine the current distribution and the resistive heating. Cooling between shots was taken into account by solving the one dimensional transient heat diffusion equation within each surface. Repeating these calculations for a number of discrete segments down the length of the rail enabled the prediction of the total resistive rail heating and the temperature profile along the length of the rail. Experimental tests were conducted that verify the presence of localized heating in the corners of a U-shaped conductor made of 7075 Aluminum. Taking into account the localized resistive heating near the surface of the conductor will become increasingly important with large-scale guns.

Magnetic guide of cold atoms using a U-shaped current-carrying conductor

We propose a new scheme to magnetically guide cold neutral atoms using a U-shaped current carrying conductor. The spatial magnetic field distribution from the U-shaped current-carrying conductor and the relationship between the magnetic field and parameters of the U-shaped conductor are analysed. Our study shows that U-shaped current-carrying conductor can be used to realize single- or double-channel magnetic guiding of cold atoms in weak-field-seeking states and to construct various atom-optical elements. By using Monte Carlo simulations, the dynamic process of the guided atomic-beam splitting in an atomic-beam splitter composed by the U-shaped current-carrying conductor is studied and some results are presented.

Compact microstrip-fed meander slot antenna for harmonic suppression

A novel compact microstrip-fed meander slot antenna is proposed to achieve suppression of harmonics and miniaturisation of the antenna. To obtain these characteristics, a meander-type slot radiator and U-shaped conductor line connected with the ground plane are applied. The real parts of the measured input impedance at the second- and third-harmonic frequencies are nearly zero. In the measured radiation patterns in E- and H-plane, the second- and third-harmonic suppressions are observed to be approximately less than −30 dB.

Thermocouples whose Elements are Longitudinally and Transversely Magnetized Ferromagnetic Substances

A ferromagnetic wire is bent at right angles to form a square U-shaped conductor. If the two bends are kept at different temperatures and the section between the two corners is magnetized transversely while the portions leading from the right angles are longitudinally magnetized, an e.m.f. is set up between the bends. In the following paper, the values of this e.m.f. for different magnetic fields are shown. Also, the relations between this effect, discovered by Sir William Thomson in 1856, and an effect discovered by von Ettingshausen and Nernst, nearly thirty years later, are indicated.