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Silica composites with low dielectric constants have broad application prospects in the fields of low dielectric and thermal insulation materials. However, silica composites still face challenges such as strong water absorption and strict storage conditions in practical applications. Modification of SiO2@quartz fiber composites was conducted with hydrophobic modifiers (hexamethyldisilazane HMDS, stearic acid, sodium dodecyl sulfate) to study the effects of type and mass fraction of hydrophobic modifiers on the hydrophobic and dielectric properties of the composites. The hydrophobic-modified composites were made into coaxial cables to study the effect of heat treatment on the performance of the cables. The results show that the 3% HMDS-modified composite have the best hydrophobic modification with contact angle of 151.6°, the lowest contact angle is 132.6° after 240 days of storage, and the dielectric constant is as low as 1.87 after 200 °C calcination. The hydrophobic-modified composites were made into coaxial communication cables, and the cables had a voltage standing wave ratio of 1.48, an attenuation value of 1.56 dB, and a characteristic impedance of 48 Ω. The hydrophobic-modified composite materials exhibit excellent cable performance, demonstrating potential application value in communication cables and other fields. [ABSTRACT FROM AUTHOR]

A novel compact wideband dual-polarized printed dipole antenna for base station application is presented. The proposed antenna is composed of four assembled substrates. Two pairs of identical arrow-shaped conductive lines on the tophat substrate form two orthogonal polarized dipoles. Two baluns connected with 50O coaxial cables are integrated on another two vertical substrates to excite the dipoles. The other horizontal board at bottom provides grounding. A rectangular boxshaped reflector is also used to enhance its stability in radiation patterns over the operating frequencies. It achieves 22% size reduction from the conventional printed half-wavelength cross-dipole, and 43.2% impedance bandwidth (VSWR < 2), while maintaining a stable radiation pattern with measured Cross-Polarization Degradation (XPD) better than -22 dB at boresight and an average peak gain of 8.4 dBi for a 65° Azimuth Beamwidth base station application at 700/800/900 MHz bands. With the scalable miniature structure, it may also find itself suitable for side-by-side multiband Multi-Input Multi-Output (MIMO) or Large-Scale Antenna (LSA) 5G base station applications. A 4 × 4 array prototype of the LSA is also designed and fabricated, and it achieves 27.8% impedance bandwidth (VSWR < 1.5) with well decorrelated element performance and array XPD better than -20 dB across as large as 30° tilting range. [ABSTRACT FROM AUTHOR]

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The paper presents the comprehensive experimental study of radiation characteristics of a single slot in a coaxial cable shield. The slot was realized in four different embodiments, which varied by slot orientation and length. Three orthogonal polarizations of radiated electric field were analyzed along the axis perpendicular to cable, broadside to the slot, in a broadband frequency range (80-1000 MHz). The analysis was based on thorough measurements of the coupling loss, which is the common parameter for the leaky cable characterization. The obtained results showed that the electric field component longitudinal to the cable axis considerably dominates over other two orthogonal components, for all four slot types. Doubling the length of the slot caused a ca. 20 dB increase of the radiated field. Different slot orientations, having the same length in the crosssection projection, yielded approximately equal field strengths. The results of this experimental study clearly and visibly demonstrate the radiating slot field dependence on polarization and slot geometry in a wide frequency range. Thus they are useful for planning of wireless communication systems based on radiating cables, as well as for understanding polarization related issues in such systems. [ABSTRACT FROM AUTHOR]

A parallelized in-situ plasma measurement setup, consisting of two multipole resonance probes (MRP), a passive signal divider, and two coaxial cables with different lengths is presented in this contribution. The combined reflection coefficient of the applied probes is measured, separated in the time domain, and evaluated. Here, each MRP is able to measure the spatially resolved plasma electron density via its resonance behavior precisely and quasi-simultaneously. Furthermore, the return loss (RL) changes with the collision frequency, which can be detected for each probe. The parallelization and the applied signal processing are confirmed by simulations and combined measurements in CST Schematic as well as by in-situ measurements in an argon plasma. The resulting error is below 1% for the resonance frequency and below 8% for the corresponding RL. Hence, the input power and gas pressure of a plasma process can be controlled effectively. [ABSTRACT FROM PUBLISHER]

This paper presents new measurement methodologies for ultra-miniature antennas. A first one is dedicated to the impedance measurement and the second one to the radiation measurement. Both methods are detailed focusing on an ultra-compact antenna design at 2.4 GHz, whose electrical dimensions, including the ground plane, are \lambda0/25\times\lambda0/25\times\lambda0/62.5. Given the very small antenna size compared to the wavelength, measurements by means of conventional coaxial cable can affect the characterization results. The issues related to the use of a feeding coaxial cable in both simulation and prototype measurements are first discussed. Then, specific methods to deduce the isolated antenna properties are proposed. Both methodologies rely on the use of electromagnetic simulation to compensate perturbations introduced by the measuring device. [ABSTRACT FROM PUBLISHER]

In this paper, the design, calibration, and performance improvement of four self-integrating Rogowski coils are presented. These coils are wound in single and double layers by a coaxial cable without its polyvinyl chloride (PVC) jacket and with air and ferrite cores. Nonuniformities due to the variation of turn density and/or core deformation are compensated by using a one-turn return loop placed inside the helical winding in the opposite direction to the pitch advancement. Oscillatory and overdamped unidirectional current waveforms up to a 7-kA peak value are generated by using different linear and nonlinear loads and impulse-current generator configurations. These large-magnitude short-duration current pulses are measured by different methods, namely, a commercial impulse-current transformer, a commercial Rogowski coil, and the four newly designed self-integrating Rogowski coils. The distortion of the measured current pulses is studied by using the lumped-element model of Rogowski coil and its termination resistance and the signal cable and its matching resistance. The optimal coil termination resistance is obtained under these impulses, and the linearity of all newly designed self-integrating Rogowski coils' output voltages is also investigated. Results reveal that the magnitudes of measurement errors for the current peak and front and tail times are very low when using ferrite cores with a low termination resistance. The trend of the results is also explained in terms of coil termination resistance, transit time, and sensitivity bandwidth. [ABSTRACT FROM PUBLISHER]

Tray-type quasi-optical (QO) power combiners are able to combine the high- and medium-output power of QO systems with the well-known advantages of pulsed ultra-wideband (UWB) systems. In this work, an alternative low-profile tray-type passive structure for 3GHz-10GHz power combining is proposed. The purpose of the proposed solution is to reduce the physical size with respect to other existing architectures by using hybrid coaxial lines. In spite of the reduced size, the structure maintains ultra-wideband operation and high combining efficiency, as proved through measurements. Therefore, the proposed structure is suitable for integration with monolithic microwave integrated circuit (MMIC) amplifiers for medium- and high-power generation, depending on the type of MMICs which are integrated into the passive combiner. Numerical analyses of the designed power combiner integrated with some MMIC amplifiers reveal its benefits in terms of increased output power and wider dynamic range compared to isolated MMICs. [ABSTRACT FROM AUTHOR]

We investigate a new mean of decreasing leakage and material loss from coaxial cables using different metallic shield and central conducting part geometries. The suggested model is composed of a central conductor surrounded by 40 metallic wires circularly disposed. The proposed cable is also a hybrid one allowing simultaneous transmission of optical as well as radio frequency (RF) signals. The fabrication techniques for the proposed cable are similar to the one applied in the realization of optical fibers. Besides the fact that the attenuation along the proposed cable is reduced, the most important result of this study is that the interference generated by this source on external cables is also lowered. [ABSTRACT FROM AUTHOR]

The influences of coaxial measuring cables on waveform parameters have been neglected in lightning impulse measurements. This is partly because the tolerable uncertainty for determining the front time T1 in the reference measuring system is 3% and the induced influence due to using a long measuring cable is expected to be much smaller than the margin. The authors have suspected the validity of the expectation as a result of experience. This paper proposes an analytical treatment of the impulse response at the end of a lossy measuring cable. Using the proposed technique, the measured parameter errors are compared to numerically evaluated ones and it is confirmed that the two are in good agreement. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(6): 1–7, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10288 [ABSTRACT FROM AUTHOR]

The accurate measurement of fast rise time EMP is critical. The loss and dispersion characteristics of signal measurement cables cause distortion in these measurements. To compensate for a distorted pulse, an appropriate compensation method is essential. Ordinary methods are not accurate, and the FFT calculation method requires a great deal of computer resources. An analytic derivate equation using Cauchy's theorem shows good results which have been proved by comparing the equation's results with real world pulse measurements. [ABSTRACT FROM AUTHOR]

Many applications in geotechnical engineering require knowledge of total pressure distributions. So far, only measurements at single points at individual locations of interest can be carried out with conventional geotechnical measurement devices. Time-domain reflectometry (TDR) has already been used to assess the amount of shearing at multiple distinct locations along coaxial cables grouted in a rock or soil mass. However, pressure profile determination has not been investigated up to now. A novel approach has been investigated to determine pressure profiles from the time-domain reflection data of transmission lines. Mechanical forces change the distance between rubber-insulated conductors of transmission lines and, therefore, affect the spatial distribution of capacitance and inductance. These variations lead to partial reflections of an incident step pulse from which physical parameter distributions along the inhomogeneous transmission line are reconstructed. A reconstruction algorithm that was originally developed for soil moisture profile determination (Spatial-TDR), was adopted and applied in laboratory experiments. A further experiment illustrates TDR signals that can be expected in actual applications under different load conditions. [ABSTRACT FROM AUTHOR]

A fully differential 40-Gb/s cable driver with adjustable pre-emphasis is presented. The circuit is fabricated in a production 0.18 µm SiGe BiCMOS technology. A distributed limiting architecture is used for the driver employing high-speed HBTs in the lower voltage predriver, and a high-breakdown MOS-HV-HBT cascode, consisting of a 0.18 µm n-channel MOSFET and a high-voltage HBT (HV-HBT), for the high voltage output stages. The circuit delivers up to 3.6 V peak-to-peak per side into a 75 Ω load with variable pre-emphasis ranging from 0 to 400%. S-parameter measurements show 42 dB differential small-signal gain, a 3-dB bandwidth of 22 GHz, gain peaking control up to 25 dB at 20 GHz and input and output reflection coefficients better than -10 dB up to 40 GHz. Additional features of the driver include output amplitude control (from 1 VPP to 3.6 VPP per side), pulse-width control (35% to 65%) and an adjustable input dc level (1.1 V to 1.8 V) allowing the circuit to interface with a SiGe BiCMOS or MOS-CML SERDES. The transmitter is able to generate an eye opening at 38 Gb/s after 10 m of Belden 1694A coaxial cable which introduces 22 dB of loss at 19 GHz. Measurement results also demonstrate that the transmitter IC operates as a standalone equalizer for 10-Gb/s data transmission over 40 m of Belden cable without the need for receiver equalization. [ABSTRACT FROM AUTHOR]

We propose a procedure to determine the validity range of any empirical model of the open-ended coaxial probe transition that is used to measure the permittivity of materials. The procedure is illustrated by an application of the method to a standard coaxial cable probe, a permittivity range of interest in the food industry and, as an empirical model, the well-known "lumped capacitor model." [ABSTRACT FROM AUTHOR]

A new type of rectangular coaxial cable, operating from 28 to 48 GHz, was designed and fabricated with thick SU8 photoresist technology. Two pairs of bent quarter-wavelength supporting stubs were proposed to reduce the lateral dimension of the structure. A size reduction of 40% was achieved by using the bent supporting stubs design as compared with a similar one with straight supporting stubs design. An average insertion loss of 0.36 dB across the bandwidth of 28-48 GHz was achieved, with return loss of better than - 14 dB. The use of bent supporting stubs did not compromise its microwave performance. The component is, therefore, particularly appealing for integrated components such as complex couplers or Butler matrix, where overall size reduction (with no loss of performance) and cost saving can be substantial. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1443–1446, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23377 [ABSTRACT FROM AUTHOR]

Patched leaky coaxial cable (PLCX) is proposed as an alternative to the conventional leaky cable for wireless links in a complex environment. It is expected to have the capability of adjusting the coupling between the cable and the environment and give smoother electric field coverage. In this paper, the radiation characteristics of the PLCX with general inclined patches are studied by a hybrid method that involves the finite-difference time-domain (FDTD) method for the near-field computation and the mode expansion method for the transformation of near field to far field. In the method, the space around the patched leaky cable is divided into two regions by an artificial closed cylindrical surface that is incorporated with the FDTD lattice surface when implementing the FDTD iteration. The field distribution on the artificial surface is obtained after the implementation of the FDTD method. Meanwhile, the field outside the artificial boundary is expanded in terms of the Floquet modes with coefficients to be determined. By matching the field expressed by modes and the field obtained from the FDTD method at the artificial boundary, a matrix equation with unknown coefficients is obtained. Solving this matrix equation, the expansion coefficients are known, and the field outside the artificial boundary is ready to be obtained. [ABSTRACT FROM AUTHOR]

Requirements for patient safety and a high interference rejection ratio in medical equipment create a demand for effective isolation devices. A system scale approach that uses capacitive coupling for power and signal isolation is presented. In addition, we describe the development of an instrumentation system prototype that applies microwaves for power exchange and bidirectional data transfer across the isolation barrier. The system consists of an isolated transducer unit, a central unit, and a single coaxial cable between the units. The isolation capacitance is as low as 1.6 pF, inclusive of the digital data transfer and power exchange up to 600 mW of isolated direct current (dc) power. The system is suitable for line-powered biopotential measurements and it is shown that reducing the isolation capacitance from 180 to 1.6 pF improves the power line rejection by 30 dB in a typical electrocardiogram (ECG) measurement setup. [ABSTRACT FROM AUTHOR]

In video-on-demand (VOD) systems, a number of sophisticated architectures have been proposed to provide instantaneous services through the use of multicast technology. Most of the architectures focus on minimizing bandwidth requirements under the assumption that clients play from beginning to end, but this assumption is not suitable for Time-shifted TV. Moreover, they have been proposed on an IP network, and failed to make full use of the broadcasting property of Hybrid Fiber Coaxial (HFC) network. In this paper, we propose a novel delivery scheme, named as piecewise patching (PP), to tackle these problems. The piecewise patching scheme provides the video data for the users in a piecewise mode instead of a whole patching stream which includes all missing data. The former user can utilize the data from the later users' patching stream whose playback time is in advance of the former user's patching stream. In the proposed scheme, each client receives the data simultaneously from arbitrary channels which broadcast the same content. Simulation results show that the proposed scheme improves the performance of Time-shift TV service significantly in terms of total server bandwidth requirement. [ABSTRACT FROM AUTHOR]

A dual Ka-band rectangular coaxial line fed cavity backed patch antenna fabricated by a sequential surface micromachining process with ten structural layers is presented in this letter. The antenna bandwidth is 4.1% around 36 GHz, with gain and radiation efficiency of 5.7 dBi and 95%, respectively. The lower band is characterized with 5.1% bandwidth around 28 GHz and a monopole-like radiation pattern with 5.1 dBi maximum gain. Analysis and design are conducted with a finite element code and good agreement with measurements is demonstrated [ABSTRACT FROM AUTHOR]

Television cabling distributions have hitherto been constructed by coaxial cables. Their transmission capacity has not been sufficiently utilized. They transmitted only television channels. Considerable efforts have been made to utilize their bandwidth more effectively for the transmission of not only television channels but also voice, Internet and various interactive supplementary services. EUB has been designed to serve this purpose, as a supplementary device for television sets. [ABSTRACT FROM AUTHOR]

We present a new approach to the problem of radiation by a coaxial line into a half-space. We obtain boundary-integral equations for the current densities over the walls of the coax and its opening to the half-space. Using the modes of the coax for basis and testing functions, we convert the integral equations to an infinite system of linear equations, the unknowns being the coefficients of the current density expansions. We demonstrate how, by solving a small subsystem, we can obtain the fields everywhere in space. [ABSTRACT FROM AUTHOR]

The complexity of a turbo equalizer based on the Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm is manageable only for mildly dispersive channels having a small amount of memory. To enable turbo equalization of highly dispersive channels, we propose the soft-feedback equalizer (SFE). The SFE combines linear equalization and soft intersymbol-interference cancellation. Its coefficients are chosen to minimize the mean-squared error (MSE) between the equalizer output and the transmitted sequence, under a Gaussian approximation to the a priori information and the SFE output. The resulting complexity grows only linearly with the number of coefficients, as opposed to the quadratic complexity of previously reported minimum-MSE structures. We will see that an SFE-based turbo equalizer consistently outperforms another structure of similar complexity, and can outperform a BCJR-based scheme when complexity is taken into account. [ABSTRACT FROM AUTHOR]

The in-home network is a crucial system for ubiquitous multimedia environments. In order to provide economical and effective high data rate transmission, we propose a transmission scheme based on the multi-carrier technique. We employ a coaxial cable channel as the transmission medium deployed for cable television (CATV). Through experiments, we show that it is possible to transmit a signal centered at 1.2 GHz with 528 MHz bandwidth without giving severe interference to the CATV system. With this observation, we propose an orthogonal frequency division multiplexing (OFDM)-based transmission scheme motivated by successful implementation of multiband OFDM (MB-OFDM) as the short range wireless transmission medium. The proposed OFDM-based system with several elementary techniques specialized in the coaxial cable for home network (CoHoNet) can achieve robust transmission over several experimental channel realizations with low power consumption. [ABSTRACT FROM AUTHOR]

The methods for calculating the capacitance and inductance of the leaky coaxial cable are proposed. The characteristic impedances of the closed and leaky sections of the periodically slotted leaky coaxial cable are obtained from the capacitance and inductance. The reflection coefficient of the leaky coaxial cable is then obtained by a method in which the input impedance at the input terminal of the cable is calculated from the impedance at the end terminal of the cable by an iterative procedure. The methods are verified by comparing the numerical results with theoretical results of the non-slotted coaxial cable. [ABSTRACT FROM AUTHOR]

A folded loop antenna for handsets has already been introduced and shown as one of the balance-feed antennas for handsets, which is very effective at mitigating the antenna performance degradation owing to body effects. In order to meet the requirements for the latest handsets such as small size and wideband characteristics, a folded loop antenna is modified to have wider band characteristics. A folded loop antenna has a self-balanced structure so that the current on the ground plane (GP) can be reduced even though an antenna is fed by an unbalanced line such as coaxial cable. The antenna, which is introduced here, is also expected to maintain this effect. In the analysis, the electromagnetic simulator based on the method of moments (MoM) is used. Also design parameters, which are useful in practical operation, are found. An example of a wideband antenna, which has a self-balanced effect, is designed based on these parameters. In addition, antenna characteristics such as VSWR, the current distributions and the radiation patterns are shown. As a result, it has been confirmed that the antenna has wideband characteristics and a self-balanced effect. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a new high-resolution reflectometry technique that operates simultaneously in both the time and frequency domains. The approach rests upon time-frequency signal analysis and utilizes a chirp signal multiplied by a Gaussian time envelope. The Gaussian envelope provides time localization, while the chirp allows one to excite the system under test with a swept sinewave covering a frequency band of interest. This latter capability is of particular interest when testing communication cables and systems. Sensitivity in detecting the reflected signal is provided by a time-frequency cross-correlation function. The approach is verified by experimentally locating various types of faults, located at various distances, in RG 142 and RG 400 coaxial cables. [ABSTRACT FROM AUTHOR]

High Temperature Superconducting (HTS) cables have been recently studied because of low loss and compactness, compared with conventional copper cables. We, so far, analyzed current distributions in a single-phase coaxial cable with and without shield current. Three-phase cables are usually composed of the three single-phase cables. However, a tri-axial cable, composed of concentric three phases, has more advantages compared with the three coaxial cables, because of reduced UTS tapes and leakage field. We derive equations governing layer current and current density distributions in the tri-axial cable considering other phases. The current and current density distributions are described as explicit functions of cable construction parameters, such as radius, twist pitch and twist direction. We calculate the homogeneous current and current density distributions by choosing adequate cable construction parameters. [ABSTRACT FROM AUTHOR]

In this paper, we propose a closed-form equation and a novel design procedure for suppressing the space harmonics and coupling loss of a radiated-mode leaky coaxial cable (LCX). The LCX with periodic principal slots is analyzed using Floquet theory, and its radiation usually contains higher radiation harmonics that may cause an uneven coupling loss. A closed-form equation is derived to determine the orders of the harmonics being suppressed. Consideration of the resonant points makes it possible to choose the operating-frequency range of the antenna from the passband region, where the level of the resonant points is low. The proposed design procedure, which leads to the suppression of the higher radiation harmonics and longitudinal loss, features the use of additional slots with unequal pitches. A sample LCX antenna is designed, fabricated, and tested at 1800 MHz using the proposed procedure. The measurement results for the coupling loss agree well with the simulation results. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 338–342, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20817 [ABSTRACT FROM AUTHOR]

This paper describes an experimental study for NO, decomposition using repetitive streamer discharges produced by reciprocal traveling wave voltage pulse from a direct-grounded coaxial cable. When the cable is charged and then grounded at one end of the cable without any resistance, a reciprocal traveling voltage pulse is repeatedly applied to a barrieretype reactor at the opposite end with a change in its polarity. High-speed photographs of discharge light indicated that the voltage oscillation caused by one switching induced alternate propagation of positive and negative streamers with a very high frequency. The 50% streamer initiation voltage with the reciprocal pulse generator was much smaller than that with a single pulse generator having a matching resistance. The reason for the difference in the 50% voltage was explained by the effect of pre-charging to the dielectric barrier. In the case of the reciprocal pulse, a large number of space charges were accumulated on the barrier surface during the cable charging, so that the field strength in the gap was strongly enhanced after the polarity reversal. In the test of NO removal from a flue gas, high NO removal ratio was obtained under the low applied voltage when the reciprocal pulse generator was used. Removal weight of NO per unit discharge energy in the reciprocal pulse generator was lower than that in the single pulse generator. However, the total efficiency calculated with the stored energy in the reciprocal pulse generator gave a better performance. [ABSTRACT FROM AUTHOR]

Quarter wavelength coaxial line cavities are commonly used structures in constructing diplexer and band pass filters at the Very and Ultra High Frequencies (V-UHF). Despite its wide use of this structure, design rules of selecting geometrical details concerning the input/output feeding points are determined in each case experimentally, which is a tiresome process. In order to achieve an accurate and reliable design and to avoid cut and paste to achieve fine tuning of resonance at the desired frequency and matching at the input/output lines a field analysis is implemented to develop accurate design rules. In this context the effect of feeding structure geometrical details as well as inner-outer conductor gaps are examined. Furthermore, in order to achieve an additional control of the filter bandwidth the use of a tapered coaxial line is also examined and computed. The performance of various structures is examined and design curves are provided to ease the work of designer. [ABSTRACT FROM AUTHOR]

An numerical model to calculate the inter-layer current distributions and the AC losses in co-axial multi-layer cable conductors was developed. The inter-layer current distributions and the AC losses in 4-layer cables were numerically calculated for various combinations of twist pithes and twist directions of the cables. With the numerical model, the twist pitch combinations to equalize the inter-layer current distribution and to reduce the AC loss were also investigated. The analytical results showed the remarkable dependence of the losses and the current distributions on the twist pitches and the directions of the cables. The optimized cable structures were discussed by the numerical results. [ABSTRACT FROM AUTHOR]

Reducing AC losses, cable size and cost of HTS tapes are required for the practical application of HTS power transmission line. We have theoretically investigated the relationship between AC losses and cable parameters such as layer radius and twisting pitch and direction in coaxial multi-layer HTS cable using our developed simulation method and revealed that the larger number of HTS tapes and twisting pitch are desirable for reduction of AC losses. In this paper we investigated influence of twisting pitch and direction on cable size and total amount of HTS tapes under a condition of constant AC losses. The diameter of each layer and total amount of HTS tapes in the cable with the same twisting direction are much smaller than those of alternate twisting direction. The cable with the same tape current would be better than that of the same layer current because of the smaller difference of the number of tapes per layer. In the cable with the same tape current, cable size decreases with the number of layers in spite of almost the same amount of total HTS tapes in the whole cable. In cable design, we cannot handle the restrictions of AC loss and load factor individually; it would be difficult to satisfy both the conditions of low AC loss and high load factor. AC losses could be reduced by increasing critical current of HTS tape without the restriction of load factor, while AC losses increases with the critical current with the restriction of load factor. [ABSTRACT FROM AUTHOR]

Miniature rectangular coaxial transmission line (with a 300 × 300 μm outer conductor) is simulated, fabricated, and tested up to the Ka band. It is made by the electrochemical fabrication (EFAB™) of nickel such that the center conductor is supported primarily by ≈λ/4 stubs that also establish a resonant passband. The minimum insertion loss of a 1.67-cm-long test structure is found to be 1.74 dB at the passband center of 29 GHz. This is within 0.57 dB of the lowest insertion loss predicted by full-wave numerical simulations, indicative of the high precision and smooth surface morphology of the EFAB process. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 365–368, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11383 [ABSTRACT FROM AUTHOR]

Discusses the use of coaxial cable in high-definition video transmission in the United States. Bandwidth standards;Common return loss values; High-definition applications bandwidth.

The near fields produced by a perforated coaxial cable (where the perforations can have an arbitrary shape, and where the spacing between perforations is very small compared to the wavelength in the cable) is here determined by a numerical integration of the axial currents which flow on the outside surface of the cable's outer conductor. It is first shown that these currents consist of three components, namely, a forward-going current having a phase velocity equal to that in the cable, and forward- and backward-going currents having (for all practical purposes, for convential cable-jacketing materials and thickness) the phase velocity of light. The magnitude and phase of the latter currents cannot be readily determined a priori since they depend on the cable's mounting environment, as discussed. Rather, empirical values can be found to fit the circumstances, and to predict the near fields so as to agree with measured values. As such, this model is a phenomenological one, and it shows that the near fields produced, on a line parallel to the cable, are, in general, quite oscillatory in nature. Because of the small slot spacing, this type of cable produces usable near fields over a very broad frequency range (e.g., hundreds of kilohertz to about 3 GHz), and is employed for two-way communication both indoors and outdoors. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 101–105, 2000. [ABSTRACT FROM AUTHOR]

A coaxial line to a rectangular waveguide junction, backed by an iris-coupled cavity, is analyzed using a new approach based on the five-cavity moment method. The scattering matrix of the junction is obtained by combining the mode-matching method and an interpolation technique. The computed results are checked for orthogonality and unitary conditions, and are verified against experimental results. The proposed structure and the analysis method will be useful in the design of extracted pole filters, diplexers, and multiplexers. © 1998 John Wiley & Sons, Inc. Int J RF and Microwave CAE 8: 20–26, 1998. [ABSTRACT FROM AUTHOR]

A method for evaluating the admittance of a radial-line/coaxial-line junction as seen from the coaxial line is presented. The method is based on the magnetic vector potential, the TEM approximation in the coaxial line, and rotationally symmetric E-type modes in the radial line. The method is simpler and more straightforward than the Fourier transformation. When the radial line is terminated by arbitrary impedance, the admittance of the junction is obtained. The result is equivalent to that of Williamson. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 19: 160–164, 1998. [ABSTRACT FROM AUTHOR]

Denoting g(x + iy) = 1 / αβ sn²(x + iy, k0) - A / sn²(x + iy, k0) - A/β′ A = 1 + α / 1 - α/β′ and k²0 = (1 - α/β) / (1 + α)² we find an equipotential of constant electric intensity to form a new type of TEM transmission line for industrial applications. [ABSTRACT FROM AUTHOR]

The special cases of a general coaxial rectangular line with square outer conductor and inner cross conductor of equal arms are solved analytically by means of conformal transformations. [ABSTRACT FROM AUTHOR]

Since coaxial cables have excellent electromagnetic shielding characteristics, they are widely used as interconnecting cables for digital information equipment. However, since braided lines are used in the shield layer of most coaxial cables, if an RF current flows, a noise voltage (normal mode noise) is induced between the core wire and the braided wire by electromagnetic coupling. Electromagnetic noise is also radiated from the common mode current of the braided shield. It has been considered that ferrite core loading is effective for reduction of the electromagnetic noise, and such loading is frequently used. In this article, in order to study whether ferrite core loading is effective in reducing normal mode noise, the normal mode noise generated by the braided shield current is analyzed with respect to the core loading location. Next, a formula for the noise-reduction effect due to ferrite core loading is derived and its validity is demonstrated experimentally. © 1998 Scripta Technica, Electron Comm Jpn Pt 1, 82(2): 1–10, 1999 [ABSTRACT FROM AUTHOR]