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1 – 10 of over 1000
Article
Publication date: 21 June 2019

Chang Fei Yee, Muammar Mohamad Isa, Azremi Abdullah Al-Hadi and Mohd Khairuddin Md Arshad

This paper aims to analyze the negative impact of surface mount (SMT) pad and imperfect via structure such as stub, pad, non-functional pad (NFP) and anti-pad on the signal…

221

Abstract

Purpose

This paper aims to analyze the negative impact of surface mount (SMT) pad and imperfect via structure such as stub, pad, non-functional pad (NFP) and anti-pad on the signal integrity at 40 Gbps transmission on printed circuit board (PCB) due to impedance mismatch or discontinuity. The optimized modeling of via and SMT structures is performed to achieve minimal impedance mismatch and insertion loss less than 10 dB for six-inch full path transmission line between transmitter and receiver on PCB at Nyquist frequency 20 GHz.

Design/methodology/approach

This work is split into two phases. The first phase involves optimization of via and SMT structures in three-dimensional electromagnetic (3DEM) simulation using Hyperlynx Via Wizard and Keysight EMPro software, respectively, followed by analysis of time domain reflectometry (TDR) and insertion loss (Sdd21). Whereas, in the second phase, full path hybrid mode simulation involving vias for signal layer transition, a 6-inch PCB channel and SMT pads is performed using Keysight ADS software to observe the TDR, Sdd21 and eye diagram at 40 Gbps transmission.

Findings

Imperfect via and SMT structures have a negative effect on signal reflection and attenuation. The optimized via and SMT minimizes the impedance mismatch by 81 per cent and insertion loss by 4.5 dB, ultimately enlarging the eye diagram opening to achieve minimal data loss at receiver with 40 Gbps transmission.

Originality/value

The results of original empirical research work on signal integrity analysis that optimizes the PCB channel design to achieve 40 Gbps signal transmission are presented in this study. It serves as a reference guide for high-speed PCB layout design.

Details

Circuit World, vol. 45 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 11 May 2012

Martyn Gaudion

The purpose of this paper is to discuss nickel gold plating of PCB traces and its adverse effects on signal integrity, and to explore the other key drivers in optimising yields…

273

Abstract

Purpose

The purpose of this paper is to discuss nickel gold plating of PCB traces and its adverse effects on signal integrity, and to explore the other key drivers in optimising yields and controlling PCB processes that impinge on signal integrity.

Design/methodology/approach

The paper is a response to requests from PCB fabricators to explain why the losses on impedance controlled traces on PCBs were sometimes higher than expected.

Findings

While nickel is acceptable on short lengths of pad to accommodate gold plating, plating the whole trace length is generally not good practice from a digital signal integrity perspective. In addition, with the fastest serial transmission rates in the 10 to 20 GHz region and long serial words in some situations designers may need to consider both the associated high and low frequency performance.

Originality/value

With the development of ultra high speed digital bus architectures, PCB fabricators will appreciate the need to add an understanding of the drivers of insertion loss (base material loss tangent data, foil roughness and copper cross sectional areas) to their existing experience of architectures with minimal losses.

Article
Publication date: 12 August 2021

Chong Wang, Yingjie Wang, Kegu Adi, Yunzhong Huang, Yuanming Chen, Shouxu Wang, Wei He, Yao Tang, Yukai Sun, Weihua Zhang, Chenggang Xu and Xuemei He

The purpose of this paper is to establish an accurate model to quantify the effect of conductor roughness on insertion loss (IL) and provide improved measurements and suggestions…

183

Abstract

Purpose

The purpose of this paper is to establish an accurate model to quantify the effect of conductor roughness on insertion loss (IL) and provide improved measurements and suggestions for manufacturing good conductive copper lines of printed circuit board.

Design/methodology/approach

To practically investigates the modified model of conductor roughness, three different kinds of alternate oxidation treatments were used to provide transmission lines with different roughness. The IL results were measured by a vector net analyzer for comparisons with the modified model results.

Findings

An accurate model, with only a 1.8% deviation on average from the measured values, is established. Compared with other models, the modified model is more reliable in industrial manufacturing.

Originality/value

This paper introduces the influence of tiny roughness structures on IL. Besides, this paper discusses the effect of current distribution on IL.

Content available

Abstract

Details

Circuit World, vol. 37 no. 4
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 5 January 2024

Divya Shree M. and Srinivasa Rao Inabathini

This paper aims to present the simulation, fabrication and testing of a novel ultra-wide band (UWB) band-pass filters (BPFs) with better transmission and rejection characteristics…

Abstract

Purpose

This paper aims to present the simulation, fabrication and testing of a novel ultra-wide band (UWB) band-pass filters (BPFs) with better transmission and rejection characteristics on a low-loss Taconic substrate and analyze using the coupled theory of resonators for UWB range covering L, S, C and X bands for radars, global positioning system (GPS) and satellite communication applications.

Design/methodology/approach

The filter is designed with a bent coupled transmission line on the top copper layer. Defected ground structures (DGSs) like complementary split ring resonators (CSRRs), V-shaped resonators, rectangular slots and quad circle slots (positioned inwards and outwards) are etched in the ground layer of the filter. The circular orientation of V-shaped resonators adds compactness when linearly placed. By arranging the quad circle slots outwards and inwards at the corner and core of the ground plane, respectively, two filters (Filters I and II) are designed, fabricated and measured. These two filters feature a quasi-elliptic response with transmission zeros (TZs) on either side of the bandpass response, making it highly selective and reflection poles (RPs), resulting in a low-loss filter response. The transmission line model and coupled line theory are implemented to analyze the proposed filters.

Findings

Two filters by placing the quad circle slots outwards (Filter I) and inwards (Filter II) were designed, fabricated and tested. The fabricated model (Filter I) provides transmission with a maximum insertion loss of 2.65 dB from 1.5 GHz to 9.2 GHz. Four TZs and five RPs are observed in the frequency response. The lower and upper stopband band width (BW) of the measured Filter I are 1.2 GHz and 5.5 GHz of upper stopband BW with rejection level greater than 10 dB, respectively. Filter II (inward quad circle slots) operates from 1.4 GHz to 9.05 GHz with 1.65 dB maximum insertion loss inside the passband with four TZs and four RPs, which, in turn, enhances the filter characteristics in terms of selectivity, flatness and stopband. Moreover, 1 GHz BW of lower and upper stopbands are observed. Thus, the fabricated filters (Filters I and II) are therefore evaluated, and the outcomes show good agreement with the electromagnetic simulation response.

Research limitations/implications

The limitation of this work is the back radiation caused by DGS, which can be eradicated by placing the filter in the cavity and retaining its performance.

Practical implications

The proposed UWB BPFs with novel resonators find their role in the UWB range covering L, S, C and X bands for radars, GPS and satellite communication applications.

Originality/value

To the best of the authors’ knowledge, for the first time, the authors develop a compact UWB BPFs (Filters I and II) with BW greater than 7.5 GHz by combining reformed coupled lines and DGS resonators (CSRRs, V-shaped resonators [modified hairpin resonators], rectangular slots and quad circle slots [inwards and outwards]) for radars, GPS and satellite communication applications.

Details

Microelectronics International, vol. 41 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 June 2000

K. Wiak

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines;…

Abstract

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 21 September 2020

Sandhya Ramalingam, Umma Habiba Hyder Ali and Sharmeela Chenniappan

This paper aims to design a dual mode X-band substrate integrated waveguide (SIW) bandpass filter in the conventional SIW structure. A pair of back-to-back square and split ring…

Abstract

Purpose

This paper aims to design a dual mode X-band substrate integrated waveguide (SIW) bandpass filter in the conventional SIW structure. A pair of back-to-back square and split ring resonator is introduced in the single-layer SIW bandpass filter. The various coupling configurations of SIW bandpass filter using split square ring slot resonator is designed to obtain dual resonant mode in the passband. It is shown that the measured results agree with the simulated results to meet compact size, lower the transmission coefficient, better reflection coefficient, sharp sideband rejection and minimal group delay.

Design/methodology/approach

A spurious suppression of wideband response is suppressed using an open stub in the transmission line. The width and length of the stub are tuned to suppress the wideband spurs in the stopband. The measured 3 dB bandwidth is from 8.76 to 14.24 GHz with a fractional bandwidth of 48.04% at a center frequency of 11.63 GHz, 12.59 GHz. The structure is analyzed using the equivalent circuit model, and the simulated analysis is based on an advanced design system software.

Findings

This paper discusses the characteristics of resonator below the waveguide cut-off frequency with their working principles and applications. Considering the difficulties in combining the resonators with a metallic waveguide, a new guided wave structure – the SIW is designed, which is synthesized on a planar substrate with linear periodic arrays of metallized via based on the printed circuit board.

Originality/value

This study has investigated the wave propagation problem of the SIW loaded by square ring slot-loaded resonator. The electric dipole nature of the resonator has been used to achieve a forward passband in a waveguide environment. The proposed filters have numerous advantages such as high-quality factor, low insertion loss, easy to integrate with the other planar circuits and, most importantly, compact size.

Details

Circuit World, vol. 48 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 30 April 2018

Prithivi Rajan V. and Punitha A.

This paper aims to design a radio frequency micro-electro-mechanical system (RF MEMS)-based phase shifter using chamfered coplanar waveguide (CPW) transmission line (t-line) with…

Abstract

Purpose

This paper aims to design a radio frequency micro-electro-mechanical system (RF MEMS)-based phase shifter using chamfered coplanar waveguide (CPW) transmission line (t-line) with open-circuit interdigital metal–air–metal (ID MAM) capacitors.

Design/methodology/approach

The proposed phase shifter achieves maximum differential phase shift with low loss at Ku band. The phase shifter is built with one switchable fixed-fixed beam (MEMS switch) on chamfered CPW t-line in series with two planar open-circuit ID MAM capacitors. An equivalent circuit model for the proposed phase shifter is derived, and its parameters are extracted using an electromagnetic (EM) solver.

Findings

The MEMS switch is actuated using an electrostatic method with the calculated residual stress of 44.26 MPa. The fabricated phase shifter exhibits low insertion loss, close to 0.14 dB at 17 GHz, with the maximum phase shift of 15.06°. The return loss is greater than 23 dB between 12 and 18 GHz.

Originality/value

This phase shifter presents a promising solution for low loss applications in the Ku band with a maximum phase shift. As the maximum phase shift of 15.06° is achieved for a unit cell with low insertion loss, the phase shifter is found to be feasible for modern electronically tunable phased arrays used for satellite communication and radar systems.

Details

Circuit World, vol. 44 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 3 June 2020

Bahar Tasar, Keti Ventura and Ural Gokay Cicekli

The purpose of this paper is to investigate the effects of capacity decisions regarding the number of servers/chefs and tables on identifying a change in the number of…

1480

Abstract

Purpose

The purpose of this paper is to investigate the effects of capacity decisions regarding the number of servers/chefs and tables on identifying a change in the number of wait-related anxious customers, customer losses and customers served to meet the waiting time standards of an actual upscale restaurant.

Design/methodology/approach

The authors applied a simulation model to present the consequences of restaurant capacity decisions based on waiting time standards. Arena Simulation Software, licensed by Rockwell Automation, was used for modeling and identifying distributions of the data set provided by the restaurant. An experiment was designed for an upscale restaurant with existing five servers/chefs and 50 tables by changing these resources to measure the changes in customers' wait-related anxiety and other service performance indicators.

Findings

The results showed that an additional server/chef on weekends decreases the daily average number of anxious customers by nearly 33% and increases the daily average number of customers served by nearly 3% and has a little positive effect of decreasing customer losses. Table insertion for high- and low-requested seating areas had an only positive effect on decreasing customer losses.

Originality/value

In this study, the service capacity is dependent on waiting time, and it is addressed to study the relationship with customers' wait-related anxiety, which is a subjective metric. This study developed a point of view for identifying anxious customers whose waiting times are much longer than their cooking and delivery duration expectations regarding their meal preferences in the cooking stage and waiting experiences in the service entry.

Details

British Food Journal, vol. 122 no. 9
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 12 April 2018

Shouxu Wang, Xiaolan Xu, Guoyun Zhou, Yuanming Chen, Wei He, Wenjun Yang, Xinhong Su and Yongshuan Hu

As a common transmission line, the microstrip line plays an important role in high-speed circuits. The purpose of this paper was to investigate the effects of the circuit design…

232

Abstract

Purpose

As a common transmission line, the microstrip line plays an important role in high-speed circuits. The purpose of this paper was to investigate the effects of the circuit design of microstrip lines on the signal integrity (SI). In addition, the influence of the type and thickness of the solder resist ink on SI was analyzed to provide guidance for the related producing process design of printed circuit boards (PCBs).

Design/methodology/approach

Microstrip line properties consisting of shape, line-width/line-space ratio, reference layer design and as-covered solder resist ink were designed to measure the insertion loss (S21) in high-speed PCB.

Findings

The study showed that the insertion loss (S21) of straight, meander, snake-shaped and wavy microstrip lines was approximately consistent. A microstrip line with width/space ratio less than 0.96 is necessary, as the differential line closing produces a mutual interference. Reference layer including the discontinuous area should be repaired by adjusting the microstrip line parameters. With regard to the solder resist ink, the insertion loss of novel solder resist ink decreased by 0.163 dB/in at 12.9 GHz and 0.164 dB/in at 14 GHz, compared with traditional solder resist ink. Accordingly, the insertion loss effectively improved at a lower thickness of solder resist.

Originality/value

This paper demonstrated that the common designing factors of line shape, line/space ratio, reference layer and solder resist influence microstrip line SI in the significant reference of designer-making PCB layout.

Details

Circuit World, vol. 44 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

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