Layer PCB Research Articles

A High Gain Circularly Polarized Slot Antenna Array for 5G Millimeter-Wave Applications

An air-filled substrate-integrated waveguide (AF-SIW) circularly polarized (CP) 1 × 8 mm wave antenna array is presented for fifth-generation (5G) applications. The presented slot antenna array consists of three layers of PCB and one layer of aluminum, which serve as the AF-SIW feeding network and the metal cavity radiation element, respectively. The CP characteristic is achieved by the use of an S-shaped aluminum radiation cavity on the top of the AF-SIW feeding network. The air-filled substrate-integrated waveguide technique is unitized to achieve high radiation efficiency. A wide input impedance bandwidth of 18.4% is obtained for the proposed antenna scheme, ranging from 34.5 GHz to 41.5 GHz, with a peak gain of 18 dBic. As for CP characteristic, the proposed antenna possesses a wide 3 dB axial ratio (AR) bandwidth, which is 16.4% (36.5 GHz to 43 GHz). The antenna scheme is fabricated and measured to verify the potential application as well as the promising performance. The measured results of the 1 × 8 antenna array shows that the wide AR as well as the input impedance are simultaneously achieved, which coincide well with the simulated results. Also, the measured results indicate that the proposed antenna scheme might be a good candidate for future mobile applications.

The DUNE Far Detector Vertical Drift Technology. Technical Design Report

DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including themystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model.The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolutionrequired to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise.In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D.Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered.This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals.

A Monte Carlo study to evaluate and optimise the angular dependence of the Octa – A 2D silicon array detector used for dosimetry in stereotactic radiotherapy

PurposeA detector assembly based on a 2D silicon array sensor, Octa, was previously demonstrated to be accurate for small field relative dosimetry. Experimental studies showed angular dependence of the response that has also variations with the field size. A Monte Carlo simulation model was developed and used in this work to study how the detector assembly's components contribute to the observed angular dependence. MethodsGeant4 was used as the Monte Carlo code. A detailed model of the Octa detector and its packaging was placed in the centre of a solid water phantom with the central sensitive volumes (SVs) located at the isocentre and irradiated at polar angles from 0 to 180° (the beam was normal to the detector plane at 0°). Phase-space files from the IAEA database were used to model a CyberKnife X-ray beam with collimator diameters of 5, 10, and 15 mm. Reference simulations were compared with previous experimental results. To investigate the impact of the assembly's materials, simulations were conducted by iteratively substituting the non-water-equivalent materials of certain components with solid water. In terms of geometry, the influence of the dimensions of an air gap on top of the SVs and the silicon substrate thickness were investigated. ResultsPresence of the silicon surrounding the detector's SVs caused the highest decrease in energy deposition – up to (27 ± 1)%. Thickness of the air gap placed on top of the SVs had no effect at angles below 90°, but for 90–180°, it showed the largest impact on the variation in angular dependence between fields of different sizes – from (6 ± 2)% for 1 mm gap to (24 ± 2)% for 2 mm gap. The variation in the silicon substrate thickness and the air gap's lateral length, as well as presence of the PCB layer did not show significant influence on the angular response. ConclusionFurther development of the detector assembly's design can be driven by mechanical robustness to provide reliability for clinical routine without sacrificing angular dependence. Current design is recommended for use at angles 0–90°: it has shown independence of the angular response from small field size variation and it was previously optimised to be correction-free in output factor measurements. The air gap dimensions are recommended as the main variable parameters for optimisation for further studies when small X-ray beams are measured by the detector positioned in axial plane.

Dual Coupled Inductors With Controllable Integrated Leakage Inductance and CM Noise Suppression for CF-DAB Converter

A dual coupled inductors (DCI) structure is proposed, which integrates the two dc inductances, a high frequency transformer and a leakage inductance into two standard EE cores. And the dc inductance and leakage inductance can be accurately controlled by designing the number of PCB windings and the air gap length. Consequently, a DCI DAB converter is derived by the derivation process of the DCI structure. Furthermore, to suppress the CM noise, an improved PCB winding coupled inductor structure is proposed to reduce the parasitic capacitance. The proposed improved coupled inductor structure is obtained by the exchanged PCB layers and misaligned PCB windings. Finally, the validity of the proposed topology and design is verified by experimental results from a 1-kW laboratory prototype.

Design of 98.8% Efficient 400-to-48-V $LLC$ Converter With Optimized Matrix Transformer and Matrix Inductor

Data centers have seen a rapid increase in power consumption in recent years, and the 48 V power architecture has gained popularity due to its efficiency. However, the cost of efficient power supplies remains challenging due to their complicated magnetic designs. The search for efficient and cost-effective power supplies continues. This paper focuses on the implementation of the DC-DC stage of the power supply unit for the 48 V data center bus architecture. In this paper, we present a design process for a high-efficiency, high-power-density 3 kW 400 V to 48 V LLC converter for use in data centers. Through optimization of the matrix transformer's geometry, turn number, and resonant frequency, we achieve superior efficiency and power density compared to state-of-the-art designs. To address challenges with the printed circuit board PCB-based inductors, we propose the use of a resonant matrix inductor, which reduces the number of stacked PCB layers, simplifies the winding implementation, and lowers the AC loss. By integrating the matrix inductor with the matrix transformer, we create a modular and scalable magnetic structure suitable for a wide range of voltages and currents. We also introduce EMI shielding for the matrix transformer with a full-bridge rectifier, resulting in an 18 dB reduction in common-mode noise. The prototype achieved a peak efficiency of 98.8% and a power density of 600 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> , demonstrating the effectiveness of the proposed design.

Electrostatic separation process of metal/plastic granular mixtures using a horizontal rotating disk

A rotating disk electrostatic separation device was developed and studied for the separation of mm-size metal and plastic particles. The device is constituted by two helical concentric electrodes build up on the top side of a simple layer PCB, and supplied by two high voltage amplifiers delivering square, DC and AC waveform signals. The separation mechanism is based on an electro-adhesion force applied on metal particles and an air suction force for recovering the plastic particles. The obtained results as functions of the voltage level, the rotating speed, and the suction force confirmed the high separation performance in terms of recovery and purity rates which reached values of 95 and 100%, respectively.

Enhanced throughput and clean laser drilling with a sacrificial polymer layer

Laser micromachining is the chosen method for vertical interconnect access point (VIA) formation in flex PCB layers. Even so, this method suffers from several inherent physical issues as a result of the intense localized heating causing strong Marangoni convection and the buildup of recast along the VIA upper crater walls while also scattered particle debris and oxidation of copper across the surface. The mitigation of the height and radius of this recast layer is critical for the following build-up process and device functionality and reliability. This is currently a major technology inhibitor to the adoption of flex PCBs for high-power electronics. In this study, we present experimental results showing the use of engineered sacrificial layers that coat the surface of the flex PCB substrate during the laser micromachining process. Optimization of this engineered sacrificial layer resulted in a major improvement in recast quality and debris control as well as reducing the oxide formation while increasing the laser drilling efficiency, attributable to increased surface pressure on the substrate. In this paper, we describe the methods and materials used in the development of sacrificial layers and show the positive impact it achieves on improving and modifying the plasma characteristics throughout the overall laser drilling process.

Active attitude control for microspacecraft; A survey and new embedded designs

Novel technologies and design techniques of the active attitude control systems (ACS) for microspacecraft are briefly covered in this survey. Electric propulsion (EP) thrusters for satellites orbit correction and interplanetary vehicles acceleration have recently emerged as the focal point and front subject in propulsion fields due to their low mass, low cost and high specific impulse. Therefore, micro propulsion thrusters are explored for small satellites in terms of its performance, lifetime and future prospects. The focus of the review is at the center of research published in the last few years and state-of-the-art design concepts in terms of control, reliability, fault analysis and response to failure has been discussed for reaction wheels and magnetorquers. Finally, novel embedded planar magnetorquers which are integrated inside the internal layers of PCB for providing attitude maneuverability to various small satellites are discussed and simulated for critical tasks such as damping the initial angular velocities after vehicle launch. As the proposed magnetorquers are integrated in the form of copper traces, thermal analyses are done to maintain the temperature gradients.

Octa-OAM-mode SIW slot antenna on two PCB layers with simple feeding networks

ABSTRACT This paper demonstrates the design and simulation analysis in association with fabrication measured results of an orbital angular momentum (OAM) substrate integrated waveguide (SIW) slot antenna working at 10 GHz in X band. Simple feeding networks including 90° hybrid couplers are introduced to excite traveling waves inside four separated circular resonators radiating eight OAM modes beams. The antenna is composed of two PCB layers where the circular resonators and feeding networks are located, respectively. The measured results including S-parameters and radiation patterns are in good agreement with the simulation results in HFSS.

Solar-powered IoT based smart hydroponic nutrition management system using FARM

Good nutrition and water conditions are significant in a hydroponic system. Nutrients in hydroponic systems are periodically re-mixed to target the right amount of TDS. The TDS amount needs to be regularly measured after the weather changes, namely temperature, humidity, light intensity, and rainfall. The research proposes developing a solar-powered Internet of Things (IoT) based Smart Hydroponic Nutrition Management System using Fuzzy Association Rule Mining (FARM). The system consists of an IoT connected to a TDS (Total Dissolved Solids) sensor, a relay module connected to two 5v mini pumps that supply AB Mix nutrients, and a solenoid valve to supply water. The IoT system is also connected to sensors for temperature and humidity, light intensity, and rainfall to record the causes of weather changes that cause changes in TDS in hydroponic water. FARM is used to extract fuzzy association rules (FAR) from IoT sensors. The system targets a TDS of 1200 for leafy plants such as lettuce. The system prototype was developed in a small 5×7cm single layer PCB using the wire-wrapping technique. The test results produce a standard deviation of 2.345 for the TDS average of 1196.17 and threshold 50. In one week of evaluation, three times of rain and four times of hot weather were considered to change the TDS, and seven actions of the relay module were carried out. FARM has extracted fuzzy rules with average support of 0.401 and confidence of 0.826.

A PCB‐stacked air‐filled Luneburg reflector lens antenna for 5G millimeter wave applications

AbstractA wideband Luneburg reflector lens antenna with multi‐beam scanning performance is proposed for 5G millimeter wave (MM‐wave) applications. The proposed lens antenna consists of two groups of PCBs, four feed antennas, and a reflector. Holes are drilled with various radius in each layer of PCB (except the top and the bottom layers), so the air spacing between the two groups of PCBs changes discretely, which realizes the graded refractive index (GRIN) of the Luneburg lens. Owing to the utilization of the reflector, the size of the proposed lens is reduced by half compared to the conventional cylinder Luneburg lens, and the aperture efficiency is enhanced since the radiation aperture is reduced. The measured −10 dB impedance bandwidth covers 32–38 GHz with isolations better than 19 dB. The radiation beams demonstrate an azimuthal scanning range of 20–66 deg. It is a good candidate for 5G MM‐wave applications.

A Planar W-Band Large-Scale High-Gain Substrate-Integrated Waveguide Slot Array

A W-band large-scale substrate-integrated waveguide (SIW) cavity-backed slot array for high-gain applications is presented in this communication. The proposed antenna consists of a compact 16-way power divider and a 32 × 33 slot array. The 16-way power divider at the bottom-layer PCB provides equal-amplitude and alternative-phase excitation for 32 SIWs on the top layer PCB, and each of them supports 33 radiation slots. The loss along with the complexity of the feeding network is reduced by the implementation of alternative-phase excitation. To demonstrate the proposed slot array, a 4 × 33 slot array excited by a two-way power divider is designed first. Then, the 4 × 33 slot array is extended to a 32 × 33 slot array by a 16-way power divider. To verify the proposed slot array, the designed array is fabricated and measured. The measured peak gain, radiation, and aperture efficiencies are 30.88 dBi, 42%, and 22.8% at 93.2 GHz, respectively. The proposed high-gain antenna is an excellent candidate for the high-frequency millimeter-wave (mm-wave) wireless system.

Fractal Hilbert sensor to detect partial discharge on transformer

The design of fractal Hilbert sensor is presented in this paper. The sensor is intended to detect partial discharge (PD) in transformer insulation. The fractal Hilbert sensor designed using 4 order fractal and etching on single layer PCB board. The Hilbert fractal type is chosen as this type of sensor can be built on smaller area compare to other types. The sensor overall dimension is limited to 5x5 cm as it is proposed to be use to detect the PD presence in transformer. The sensor sensitivity is tested using a closed type TEM cell. After the sensitivity of the sensor is tested the sensor then applied to detect the PD signals emitted by void PD defect model. The results show the sensor has sensitivity as high as 10 dB. The sensor also has capability to detect the PD signals generated by the PD defect source. The waveforms captured by the sensor show the sensors can capture high frequency pulse generated by the PD source. Keywords: Partial Discharge (PD), Fractal Hilbert Sensor UHF, Sensor Sensitivity

Empty substrate‐integrated waveguide phase inverter in millimetre‐wave band application

In this Letter, a novel empty substrate-integrated waveguide (ESIW) phase inverter (PI) applied in millimetre-wave has been proposed. ESIW PI, based on the structural symmetry design, is made of four parts: top cover, middle layer, ESIW PCB, and bottom layer. Owing to the reversed-phase transmission channel, the phase difference between the two outputs is absolutely equal to 180°. The simulation and measurement results are in a good agreement. In the entire Ka band, the return losses, insertion losses and amplitude imbalance of ESIW PI are better than 12.7, 2.66, and 0.64 dB ± 0.6 dB, respectively. Besides, the phase difference is within 180.5° ± 2.9° in the same frequency band. In addition, the input and output ports are located in the identical circuit plane, which is easy to integrate with other devices and components.

Radiation Pattern Reconfigurable FM Antenna

In this work, a radiation pattern reconfigurable antenna design using compact printed spiral monopoles that operates at 102 MHz is reported. The proposed antenna changes its radiation behaviour that responds towards a desired direction with the use of RF switches. The antenna is printed on a 76.6mm × 50mm PCB layer providing more than 20MHz bandwidth at -10 dB threshold and is easily fabricated with low manufacturing cost. The antenna was also simulated on 500mm × 500mm ground plane that represents the roof top of a vehicle.

16- Layer PCB Channel Design with Minimum Crosstalk and Optimization of VIA and TDR Analysis

A transparent interconnects on a 16 layer PCB stack-up with a 100 Ω differential impedance with interconnects is proposed in this paper. To minimize the differential crosstalk, a differential spacing is maintained between interconnects. The transmitter and receiver are demonstrated as Input Buffer Information Specification (IBIS) models. An IBIS model describes the V-I characteristics information about the particular buffer. To provide better channel performance, the interconnect Via structures are optimized in this paper. To observe the channel performance in the frequency domain, S-parameter analysis is performed. To view BER plots, eye diagram and bathtub curve analysis is implemented. To observe the impedance with respect to the propagation delay of the channel, Time Domain Reflectometer (TDR) analysis is performed. Debugging and impedance discontinuity correction are performed using TDR analysis. ADS 9 (Advanced Design System) simulation software is used in this paper.

Low insertion loss of surface mount device low pass filter at 700 MHz

The paper involved with the design, simulation and fabrication of 6th order elliptical-based Surface Mount Device (SMD) LPF with cutoff frequency at 700 MHz. Fabricated LPF is consisted of four PCB layers which components of SMD are soldered on the top layer. Another three layers is for grounding and shielding, power supply and grounding void. The four layers is crucial to avoid interference between components. The research has find out that the momentum simulation is definitely required to improve the signals response compared to a normal simulation by ADS software. The comparison between momentum simulated versus measured and normal simulated versus measured is 0.2 dB and 29 dB correspondingly. Such huge difference leads to conclusion that momentum simulation is saving time without having much struggles and efforts to get optimum readings. The Proposed SMD LPF has a very low insertion loss of 0.965dB with a transition region of 195 MHz which is good steepness to avoid any image frequency.

A compact dual‐band filtering antenna for wireless local area network applications

A printed dual-band filtering antenna with decent frequency selectivity at 2.45 and 5.2 GHz for wireless local area network (WLAN) applications is developed. The filtering antenna is compact, which comprises a tapped feed line, two dual-band stub-loaded open-loop resonators, and a dual-band bended monopole. It can be easily printed on a single layer PCB substrate with low profile and low cost. The entire structure is very simple compared with the previously reported dual-band filtering antennas that requiring multi-layer structures. The monopole functions as not only a radiator, but also the last resonator of a dual-band filter. The developed antenna exhibits good frequency selectivity and out-of-band suppression. In addition, the two operation bands can be adjusted relatively individually. The proposed antenna is optimized and fabricated. The experimental results show it has good frequency selectivity at both 2.45 and 5.2 GHz, wide bandwidth 11.8% and 7.8%, and excellent out-of-band suppression.

Wideband horn antenna based on multi‐substrate layer technology

A metal horn antenna fed by a co-planner waveguide with ground (CPWG) is designed and fabricated. To integrate and connect other active elements of the system, the CPWG is designed by multi-substrate PCB technology. A transition in the PCB layer concatenating the CPWG and the microstrip line has provided a continuous structure to lead the electric field from RF circuit into the horn. A ridge waveguide is used to widen the bandwidth. The simulated and measured results show that the proposed antenna has a broad impedance bandwidth of 33.1% (from 20.5 to 28.6 GHz) for |S 11|<–10 dB and the radiation patterns also satisfy the requirements over the bandwidth.

The PANDA barrel-TOF detector at FAIR

The barrel-Time-of-Flight detector is one of the outer layers of the multi-layer design of the PANDA target spectrometer. PANDA, which is being built at the FAIR facility, will use cooled antiprotons on a fixed Hydrogen or nuclei target, to study broad topics in hadron physics. The detector is designed to achieve a time resolution below 100 ps and provides the interaction times of events as well as the particle ID. The B-TOF is designed with a minimal material budget in mind mainly consisting of 5 mm thin plastic scintillator tiles read out by a serial connection of 4 SiPMs. The signal transmission is embedded in large 16 layer PCB in micro strip lines. We will first review the detector concept which is described in the TDR then some more recent developments, with a study of different PCB layouts for signal transmission, the readout with the TOFPET2 ASIC and its performance and presenting the results of a study on the influence of the scintillator thickness on the time resolution.