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Copyright of Elektronik Industrie is the property of Hüthig GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Formation of interlayer connections in semiconductor and printed circuit board packaging can be accomplished by filling vias using three additive component electrolytic copper deposition. One of the essential additives that enables filling performance, bis-(3-sulfopropyl) disulfide (SPS) oxidized during electrolysis to give 1,3-propane disulfonic acid (PDS). In order to further elucidate the plating chemistry and improve performance, the electrochemical effects and the effects of PDS content in the electrolyte on resulting copper deposits were investigated. The crystallite structure and crystal structure transitions were investigated using X-ray diffractometry and the influence on physical properties of the deposit by internal strain analysis and extensibility. Combustion-infrared absorption spectrometry was used to determine the C and S content in the respective deposits. In all examinations, PDS content in the electrolyte was found to influence plating performance and deposit characteristics. The results suggested that PDS masked SPS and that co-deposition of PDS affected the deposit physical properties. [ABSTRACT FROM AUTHOR]

This study investigates the effects of printed circuit board (PCB) thickness on adjustable fountain and conventional wave soldering. The pin-through-hole (PTH) vertical fill is examined with three PCBs of different thicknesses (i.e., 1.6, 3.1, and 6.0 mm) soldered through adjustable fountain and conventional wave soldering at conveyor angles of 0° and 6°. The vertical fill of each PCB is the focus. The PTH solder profile is inspected with a non-destructive X-ray computed tomography scanning machine. The percentages of the PTH vertical fill of both soldering processes are also estimated and compared. The aspect ratio of the PCB is also investigated. Experimental results reveal that adjustable fountain wave soldering yields better vertical fill than conventional wave soldering. The vertical fill level of adjustable fountain wave soldering is 100%, 90%, and 50% for the 1.6, 3.1, and 6.0 mm PCB thickness, respectively. FLUENT simulation is conducted for the vertical fill of the solder profile. Simulation and experimental results show that the PTH solder profiles of the two soldering processes are almost identical. The effect of PCB thickness on PTH voiding is also discussed. [ABSTRACT FROM AUTHOR]

ABSTRACT This article reports a high gain millimeter-wave substrate integrated waveguide (SIW) antenna using low cost printed circuit board technology. The half elliptic slots which can provide small shunt admittance, low cross polarization level and low mutual coupling are etched on the board surface of SIW as radiation slots for large array application. Design procedure for analyzing the characteristics of proposed radiation slot, the beam-forming structure and the array antenna are presented. As examples, an 8 × 8 and a 32 × 32 SIW slot array antennas are designed and verified by experiments. Good agreements between simulation and measured results are achieved, which shows the 8 × 8 SIW slot array antenna has a gain of 20.8 dBi at 42.5 GHz, the maximum sidelobe level of 42.5 GHz E-plane and H-plane radiation patterns are 22.3 dB and 22.1 dB, respectively. The 32 × 32 SIW slot array antenna has a maximum measured gain of 30.05 dBi at 42.5 GHz. At 42.3 GHz, the measured antenna has a gain of 29.6 dBi and a maximum sidelobe level of 19.89 dB and 15.0 dB for the E-plane and H-plane radiation patterns. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:709-718, 2015. [ABSTRACT FROM AUTHOR]

In this paper, a new analytical model introduced extracting from datasheet of a MOSFET and developed a MATLAB code for simulating a MOSFET driver circuit is proposed in the literature to observe the ringings of its output for capacitively loaded case. The output waveform is studied only for high-to-low transition. Gate drive resistance, wiring parasitics of the printed circuit board layout, and the characteristic properties of the MOSFET affect both the delay time of the MOSFET to become ON and performance of the driver circuit. Also, voltage stress of the MOSFET and therefore safe operating range for the circuit all depend on these effects. These effects are all considered in the design stage. The simulation results obtained from CST Design Studio software are compared with the results of experimental work. The analytical modeling results solved in the MATLAB are found congruent with the simulation results and experimental results as well. The simulation work showed that developed MATLAB code along with extracted models from datasheets has less convergence problems and also requires less simulation time. [ABSTRACT FROM AUTHOR]

ABSTRACT A compact small-size LTE/WWAN planar printed antenna for ultrathin smartphone application is presented, which achieves two wide operating bands of 647-972 MHz and 1605-2770 MHz to cover LTE (LTE700/2300/2500) and WWAN (GSM850/900/1800/1900/UMTS2100) bands. A feeding strip and an inverted M-shaped parasitic shorting strip are combined to form the proposed coupled-fed antenna with a simple structure and small size of 15 × 36 mm2. So it can be easily printed on the circuit board and it is convenient to adjust antenna performance. At the same time, a rectangular notch on the circuit board not only can be used to place the battery for ultrathin smartphone application but also changes the ground plane current path to achieve a better impedance matching, especially in the low-band (698-960 MHz). Moreover, the proposed antenna allows tighter integration of multiple electronic components, such as USB, microphone. In addition, the design process and measured results of the proposed antenna are also provided below. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2116-2120, 2015 [ABSTRACT FROM AUTHOR]

This article describes about an instrument and method for aroma based quality detection of Basmati and other aromatic rice varieties. It comprises few modules such as odour delivery module, sniffing module, water bath module and computing module. Odour handling module helps to deliver odour to the sensor array; a sniffing unit comprising a sensor array module that includes a eight number of metal oxide semiconductor sensors assembled on a printed circuit board, said printed circuit board fitted into a sensor chamber; a water bath module for preparing rice sample, said water bath module including a heater attachment to facilitate cooking; a computing module to quantify the aroma data acquired by sensors; data acquisition module etc. Principal Component Analysis (PCA) implemented for clustering the data sets acquired from sensor array. Also data generated from sensor array was fed to Probabilistic Neural Network (PNN), Back-propagation Multilayer Perceptron (BPMLP) and Linear Discriminant Analysis (LDA) for identification of different rice varieties. Finally, for aroma quantifying, pure-quadratic response surface methodology model used with mean square error (MSE) 0.0028. [ABSTRACT FROM AUTHOR]

In this paper, a novel meander–spiral coil (MSC) was designed as an eddy-current sensor (ECS) probe, which has small sensing area and spot size, nearly no limitation of mounting space, and can perform better than the regular-spiral coil (RSC). The results of the finite-element analysis show that the MSC has a magnetic active area that was only a quarter of that of the RSC. The MSC has much smaller inductance and resistance than the RSC, though the former has high sensitivity similar to the latter. These types of spiral coils were manufactured by printed circuit board technology and tested, which proves that the MSC has a small sensing range. Owing to MSC’s small magnetic active area and high performance, this type of spiral coil is suitable for applications in sensor arrays and micro-electromechanical systems. Furthermore, using the MSC, ECSs have the potential to be used for micro-gap measurement, accelerometers, and pressure measurement applications, as in the case of capacitive sensors. Moreover, ECSs are inherently immune to environmental contaminations. [ABSTRACT FROM AUTHOR]

Production planning and control of the printed circuit board (PCB) assembly includes several decisions dealing with, for example, grouping of PCB jobs, allocation of PCB batches to machine lines, sequencing of batches and load balancing of lines. The production time of a PCB job for a given placement machine is a key factor in this context and it must be quickly and accurately estimated, possibly millions of times in a single planning task, to avoid erroneous decisions. The commonly used nominal tact time-based estimators are very rough and the machine simulators too slow. Therefore, the purpose of this study is to give better machine-specific estimators that avoid the construction the actual machine control program. Two new estimators are proposed for gantry machines, one based on the information given by the manufacturer about the operations of the placement head, and the other on the regularised least-squares regression method trained with a set of PCB placement jobs. In practical evaluation with 95 PCB jobs, the mean absolute percentage error of the first and second methods are 3.75% and 6.52%, respectively, while that of the tact time-based approach is more than 17%. This indicates a great potential of the proposed methods as production time estimators. [ABSTRACT FROM AUTHOR]

The wettability between solder and substrate is a very important issue in reliability of soldering process. The contact angle θ is used to measure the degree of wetting. The contact angle of lead-free alloy Sn-3 % Ag-0.5 % Cu (wt%) was measured, as a function of temperature, for three different commercial surface finish substrates used in printed circuit boards (PCB): Sn, NiAu and Organic Solderability Preservative (OSP). The measurements were performed by the sessile drop method in two different atmospheres: high vacuum and inert gas. In high vacuum the results showed that on substrates of NiAu and OSP the solder started spreading suddenly at 225 °C and in Sn substrate the contact angle decreases slightly with temperature. In inert gas atmosphere the results showed different behaviours: the contact angle between molten solder in OSP and NiAu substrates is sensitive to temperature; and, in Sn substrate, the contact angle does not change with temperature. The NiAu and OSP substrates showed a better degree of wettability than Sn substrate, in inert atmosphere. [ABSTRACT FROM AUTHOR]

In this paper, an evaluation board with a built-in 25 Gb/s PRBS source was developed for testing high frequency probe (pogo pin) in time domain. The high frequency probes in semiconducting testing field are one of convincing contact elements selections. A commercial clock-data-recovery (CDR) chip was used to design the PRBS source. The 25 Gb/s PRBS signal with 14.2 ps rise time, 15.6 ps fall time, and 14.2 ps time jitter can be generated from our evaluation board. Some printed circuit board (PCB) layout techniques were used to design the 25 Gb/s evaluation board. The advantages of our 25 Gb/s evaluation board for testing high frequency probe have low cost, small size, and light weight. [ABSTRACT FROM AUTHOR]

In this paper, a smaller and cheaper novel Subminiature Modular Plug-in Mini (SMPM) connector has been used to replace a K-type connector. The SMPM connector is installed on the top of printed circuit board (PCB) and soldering with an electrode to reduce the trace of a microstrip and to maintain the high frequency performance. Three designs of the PCB electrode have been simulated and verified experimentally. The optimized impedance mismatch of the soldering point between a SMPM connector and the PCB electrode is controlled within a range of ±2-Ohm. The 3-dB bandwidth of the whole setup including two SMPM connectors and a 2.5-cm long microstrip is above 25-GHz. This optimization can be used in designing high-speed PCB for the application of 100GBASE Ethernet. [ABSTRACT FROM AUTHOR]

We report a novel ionic wind generator in which many single ionic wind generators are tightly integrated in parallel on printed circuit boards (PCBs). Experimental measurements demonstrate that the device produces an enhanced volumetric air flow by virtue of a large cross-sectional area. Although the parallel connection of multiple generators causes interference between parallel air jets, which degrades the wind speed, we reduce the interference with a shielding layer between the corona and collector electrodes. The proposed design for integrating multiple ionic wind generators on PCBs offers the potential for applications in cooling small electrical devices with the intrinsic characteristics of ionic wind generators, which are motionlessness, silence, and compactness. [ABSTRACT FROM AUTHOR]

The adhesion strength of the interface between copper foil and resin is an important technological parameter for applications in microelectronics. In this study, a new brown oxidation solution of copper foil, including the recipe composition and reliability tests, was fully discussed. We provided an overview of brown oxidation process used in the semi-flexible printed circuit boards production industry by investigating the brown oxide film. The morphology of the copper oxide film was changed from lamellar structure to honeycomb structure with the increasing of oxidation time. The peel adhesion strength of the Cu/polyimide laminates was increased from about 2–16 N/cm by altering the immersion time and the concentration of inhibitors in brown oxidation solution. Scanning electron microscopy, peel tests and X-ray diffraction indicated that the higher adhesion strength was resulted from the rougher surface and the proper etching depth of copper foil, which was caused by chemical reactions on the interface surface of copper foil. [ABSTRACT FROM PUBLISHER]

A model of copper scrap management at country level is proposed, taking all copper scrap collection streams into account, with their associated environmental impacts and costs. The method is applied to the treatment of printed wiring boards (PWB) in France. Considering the initial physical properties and composition of this scrap, seven flowsheets are constructed for the production of refined copper. Then, depending on the number of PWB treated in each processing chain, the production rate, energy consumption, operating cost and environmental impacts are evaluated. Three bi-objective optimizations are conducted based on the NSGA II multi-objective genetic algorithm: production versus energy consumption, production versus operating cost and production versus environmental impacts. Pareto fronts are obtained for each optimization, giving the set of non-dominated solutions. Then the decision support tool TOPSIS is used to find the best compromise solution for waste management. [ABSTRACT FROM AUTHOR]

This paper presents reflection-type phase shifters (RTPSs) with very high figure-of-merit (FoM) and low insertion-loss variation, achieving up to 360^\circ relative phase shifts. Two compact topologies are proposed. They were implemented at the working frequency of 2 GHz on a printed circuit board technology. The reflection loads are based on the use of one transmission line loaded by varactors, forming L- or \pi-type networks. An automatic procedure is given to design the electrical length and the characteristic impedance of the transmission line of the reflection loads as well as the output impedance of the 3-dB branch-line coupler in order to get phase shifters with the highest possible FoM. Measurement results of the first L-type network RTPS showed a relative phase shift of 201^\circ for only 0.54 dB \pm \0.09 dB of insertion loss, leading to a FoM of 319^\circ/dB. A relative phase shift of 385^\circ was achieved for the \pi-type network RTPS with insertion loss of only 0.98 dB \pm \0.58 dB, leading to an FoM of 246^\circ/dB. In both cases, simulation and measurement results fit very well. Moreover, the return loss over a 10% bandwidth is always better than 10.9 dB for the first RTPS and better than 12.3 dB for the second one, respectively. The comparison with previous works shows more compact reflection loads with electrical performance equal to the state-of-the-art. [ABSTRACT FROM PUBLISHER]

Length-matching is an important technique to balance delays of bus signals in high-performance printed circuit board (PCB) routing. Existing routers, however, may generate very dense meander segments. Signals propagating along these meander segments exhibit a speedup effect due to crosstalk between the segments of the same wire, thus leading to mismatch of arrival times even under the same physical wire length. In this paper, we present a post-processing method to enlarge the width and the distance of meander segments and hence distribute them more evenly on the board so that crosstalk can be reduced. In the proposed framework, we model the sharing of available routing areas after removing dense meander segments from the initial routing, as well as the generation of relaxed meander segments and their groups for wire length compensation. This model is transformed into an ILP problem and solved for a balanced distribution of wire patterns. In addition, we adjust the locations of long wire segments according to wire priorities to swap free spaces toward critical wires that need much length compensation. To reduce the problem space of the ILP model, we also introduce a progressive fixing technique so that wire patterns are grown gradually from the edge of the routing toward the center area. Experimental results show that the proposed method can expand meander segments significantly even under very tight area constraints, so that the speedup effect can be alleviated effectively in high-performance PCB designs. [ABSTRACT FROM PUBLISHER]

The method by which high-technology product manufacturers balance profits and environmental performance is of crucial concern for governments and enterprises. To examine the environmental performance of manufacturers, the present study applied Fuzzy-DEMATEL model to examine environmental performance of the PCB industry in Taiwan. Fuzzy theory was employed to examine the environmental performance criteria of manufacturers and analyse fuzzy linguistics. The fuzzy-DEMATEL model was then employed to assess the direction and level of interaction between environmental performance criteria. The core environmental performance criteria which were critical for enhancing environmental performance of the PCB industry in Taiwan were identified and presented. The present study revealed that green design (a1), green material procurement (a2), and energy consumption (b3) constitute crucial reason criteria, the core criteria influencing other criteria, and the driving factors for resolving problems. [ABSTRACT FROM AUTHOR]

This paper presents the results of humidity testing of weak organic acids (WOAs), namely adipic, succinic, glutaric, dl-malic, and palmitic acids, which are commonly used as activators in no-clean solder fluxes. The study was performed under humidity conditions varying from 60% relative humidity (RH) to ∼99%RH at 25°C. The following parameters were used for characterization of WOAs: mass gain due to water adsorption and deliquescence of the WOA (by quartz crystal microbalance), resistivity of the water layer formed on the printed circuit board (by impedance spectroscopy), and leakage current measured using the surface insulation resistance pattern in the potential range from 0 V to 10 V. The combined results indicate the importance of the WOA chemical structure for the water adsorption and therefore conductive water layer formation on the printed circuit board assembly (PCBA). A substantial increase of leakage currents and probability of electrochemical migration was observed at humidity levels above the RH corresponding to the deliquescence point of WOAs present as contaminants on the printed circuit boards. The results suggest that use of solder fluxes with WOAs having higher deliquescence point could improve the reliability of electronics operating under circumstances in which exposure to high humidity is likely to occur. [ABSTRACT FROM AUTHOR]

We present a microfluidic read-out platform concept for miniaturized radio-frequency identification (RFID) tags that will help identifying natural underground sources. Designed microfluidic platform has embedded spiral reader antennas for data communication via near field magnetic coupling. To enable near field magnetic coupling with the reader antennas at reasonably low frequencies, we developed electrically ultrasmall (380 $\mu $ m $\times 380 \mu $ m $\times 15 \mu $ m with resonance $\sim 0.75$ GHz) on-chip antennas. Concept feasibility was proven by a set of experiments. First, data communication between an RFID reader and a printed circuit board-level passive tag was demonstrated through miniaturized antennas. Second, coupling between passive reader and on-chip antennas was shown inside the fluidic environment. In addition, a chip separation mechanism was introduced to the platform to prevent cross-coupling events between RFID tags. [2014-0043] [ABSTRACT FROM AUTHOR]

This article presents two new cavity-backed slot antennas utilizing substrate-integrated waveguide technology and offering high gain. Radiation performances of the proposed antennas are experimentally and numerically evaluated. Using two slots backed by a circular cavity, one can improve antenna gain by 2 dB over the gain of a single-slot antenna. Then a 2 × 2-slot antenna array backed by two cavities is presented, which offers a gain of 9.2 dBi, which is 4.2 dB and 2.2 dB higher than the gain of single- and two-slot antennas, respectively. All the proposed antenna structures are made on a single-layer substrate, and a low-cost printed circuit board process is used for fabrication. [ABSTRACT FROM PUBLISHER]

A central aspect of surface mount technology (SMT) systems is the assembly of printed circuit boards (PCBs) which requires the resolution of many optimization problems. One of these problems arises when assembling many types of PCBs on a single machine. In this case, the main goal becomes the minimization of the setup times. That is, the time required to modify the feeder rack in order to have all components needed by the next type of PCB to be assembled. Achieving such a minimization goal will provide the system with improved productivity and flexibility capabilities. In order to minimize the setup time, we propose a genetic algorithm that uses a group-based representation with a series of specialized genetic operators. A set of 90 instances is proposed as a test bed for the single machine many-types of PCB problem. The proposed algorithm accomplishes the best known result for a benchmark instance of the problem and outperforms, in terms of assembly time, a well known heuristic on the set of proposed instances. [ABSTRACT FROM AUTHOR]

Cemented carbide micro-drills (0.1 to 0.3 mm in diameter) wear down or break casually while drilling micro-holes in printed circuit boards (PCBs). This study focused on the interaction between cemented carbide and PCB and its effects on PCB micro-drilling. The results indicated that two-body abrasive wear and three-body abrasive wear occurred on the flank face and the chisel edge of micro-drills. Heat generated during friction softened the resin from PCB and friction chips, which were then pressed to cover the surface of cemented carbide and filled the grooves on the surface. The resin adhered to the flank face of micro-drills and made the wear rate of micro-drills slow down. However, the resin of the PCB can also adhere to the tip and the helix flute of micro-drills at high temperature, which may damage the chip removal during micro-drilling and the hole location accuracy. [ABSTRACT FROM AUTHOR]

Online transformer monitoring and protective relaying require voltage sensors with fast response and high precision. Traditional devices, such as resistive and capacitive dividers, have disadvantages in measuring transient voltage, e.g., oscillation, narrow bandwidth, and large size. This paper introduces a new D-dot probe for transient measurement. The difference input circuit structure is presented on the basis of the operating principle of the D-dot probe. Paralleled multiple electrodes are applied to gain the mutual capacitance value of the probe to achieve a large divide ratio and make the probe work in a self-integrating mode. Pspice simulation is conducted to find a way to minimize probe error. The probe is manufactured into printed circuit boards (PCB). The steady state linearity and transient response of the probe are tested. Results show that the probe has fast response and broad bandwidth. [ABSTRACT FROM AUTHOR]

This paper aims to analyse the design techniques of differential transmission lines loaded with metamaterials. Specifically, complementary split-ring resonators were etched on the ground plane of a microstrip transmission line in order to mitigate both differential- and common-mode propagation in differential signalling. Several prototypes were manufactured and characterised in printed circuit boards. The topologies under test were measured and compared as radiofrequency interference filters, taking into account frequency response, signal integrity, and near- and far-field radiation impact with regard to a reference (solid ground) board. [ABSTRACT FROM AUTHOR]

Micromachining technologies are becoming prominent for the fabrication and growth of microproducts like microchip, switches, printed circuit board, micro-sensors, chemical micro-reactors, and micro-fluidic systems like air lubricated bearing etc. Electrochemical micromachining (EMM) is an important micromachining technology due to specific advantages like no tool wear, absence of stress, no heat-affected zone, high MRR, bright surface finish, and ability to machine complex shapes regardless of hardness. Microfeatures were generated on SS-304 stainless steel by EMM. Major difficulties in sharp and accurate microfeature generation is the localization of current during machining and consequently, the overcut and taper formation in vertical wall. To reduce overcut and taper angle of microfeatures, machining zone was simulated with a conical micro tool of taper angle 13° and normalized current density along the cross-section of microchannel was calculated from the distribution of equipotential lines. The maximum current density was found at the exit side of the microchannel and from this simulated data it was predicted that taperless slot generation was possible with conical micro tool. Later on, it was verified by practical experiments for the generation of through, taper-less microfeatures. This paper aims at reducing taper angle, overcut, corner deviation of microfeatures like microchannels, bands of microprofiles etc. The experimental study of process parameters such as pulse frequency of applied voltage, micro tool feed rate, electrolyte concentration, and depth of sinking by micro tool were conducted for the investigation and analysis of their effects on material dissolution. Finally, it has been shown that both conical and straight micro tool can be used for generation of taperless microslots. After the proper selection of process parameters, microfeatures were machined. [ABSTRACT FROM AUTHOR]

Sales forecasting is very beneficial to most businesses. A successful business needs accurate sales forecasting to understand the market and sales trends. This paper presents a novel sales forecasting model by integrating support vector regression (SVR) and bat algorithm (BA). Since the accuracy of SVR forecasting mainly depends on SVR parameters, we use BA for tuning these parameters because Bat is a newly introduced algorithm and has many parameters. In order to find the best set of BA parameters Taguchi method was utilized. We validated our model on four known UCI datasets. Then we applied our model in printed circuit board (PCB) sales forecasting case study. We compared the accuracy of the proposed model with Genetic algorithm (GA)-SVR, particle swarm optimization (PSO)-SVR, and classic-SVR. The experimental results show that the proposed model outperforms the others. To ensure the robustness of our proposed model, sensitivity analysis was also done using our model to find out the effects of dependent variables values on sales time series. [ABSTRACT FROM AUTHOR]

Electroless Cu plating is a key process to provide electrically conductive layers on insulating substrates for the subsequent Cu electroplating of printed-circuit boards (PCBs). Recently introduced substrate materials are prone to spontaneous delamination failure (blistering) of the electroless layer during deposition. A higher Ni content in electroless Cu baths prevents delamination failure by increasing the internal tensile stress in the Cu layer. This effect is achieved by suppressing Cu self-diffusion through the incorporation of small amounts of Ni in the grain boundaries and the grain boundary junctions. Whether the hydrogen gas evolved inevitably during electroless Cu deposition and potentially trapped in the deposit may cause blistering is still under debate. Here we test this hypothesis by quantifying the generated hydrogen gas volume during Cu deposition in baths with Ni concentrations between 0 and 1000 ppm, and observing the rate of blister formation in the deposit. We find a constant molar ratio of 0.65 ± 0.05 mol H2/mol Cu independent of the Ni content in the bath, in contrast to a systematic and substantial change of the blister probability. From this lack of a correlation between the blister rate and hydrogen evolution, we rule out hydrogen evolution as a determining factor for blister formation. [ABSTRACT FROM AUTHOR]

Copyright of Elektronik Industrie is the property of Hüthig GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT Substrate integrated nonradiative dielectric (SINRD) waveguide fabricated directly on printed circuit board (PCB) or metalized dielectric layer, with its excellent performances of simplifying fabrication process and minimizing mechanical errors, is vitally essential at the microwave and millimeter-wave frequencies. In this article, a transition of coplanar waveguides (CPW) to the SINRD waveguides based is presented, providing effective interconnects for compactly and flexibly integrating the planar-CPW-based devices with the SINRD waveguide circuits. It is found that simulated results are in good agreements with the measured results, which proves the promising future of the SINRD waveguide of PCB version in the area of millimeter-wave hybrid integrated systems. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:898-900, 2017 [ABSTRACT FROM AUTHOR]

Printed circuit board (PCB) windings are convenient for many applications given their ease of manufacture, high repeatability, and low profile. In many cases, the use of multistranded litz wires is appropriate due to the rated power, frequency range, and efficiency constraints. This paper proposes a manufacturing technique and a semianalytical loss model for PCB windings using planar litz structure to obtain a similar ac loss reduction to that of conventional windings of round wires with litz structure. Different coil prototypes have been tested in several configurations to validate the proposal. [ABSTRACT FROM AUTHOR]