PCB Size Research Articles

Performance evaluation of planar dipole antenna for smart home applications

In a Smart Home wireless module, the antenna generally occupies one-third of the total circuit advances in the Internet of Things (IoTs). Dipole antenna comes in various shapes, but the planar antenna is the most suitable and attractive design for the IoTs application in Smart Homes because it is smaller in size and has a thin profile, making it suitable for mounting on portable equipment. In this research, two antennae, Meandered Dipole and Wideband Planar Antenna, were designed using Advance Design System (ADS) software on a PCB size of 18.8 mm × 43.2 mm, FR4 substrate with 4.6 dielectric constant and 0.8 mm thickness using copper metal as the conducting element. The transmission line has designed width of 1.25 mm, resulting in a typical line impedance of 50 Ω. A comparison of the analysis of simulation and measurement results from feeding port 1 of the Meandered PIFA Antenna shows a better performance of 95.43% efficiency with a gain of 2.54391dBi and a return loss of −24.49 dB at resonant frequency of 2.4 GHz than that from feeding port 2 whose efficiency was only 73.99%. Whereas, the wideband planar antenna shows an average bandwidth of 93.91% from 1.3 to 2.4 GHz. This range covers the GPS applications, the 2.4 GHz ISM band, and the general WCDMA and the LTE 3GPP bands useable for smart home and IoT applications. The proposed antenna provides low power operation, extended range and compact, cost-effective designs to support vendor's customers, and make quality of life smarter and more economical with the use of the smart home device.

A 93.4% efficiency 42cc type-C power delivery adaptor with PMOS integration power line extension method

This paper presents a dc-link capacitor reduction method with P-MOS integrated control method. When compared with SCR chopping method, this novel method can easily integrate the auxiliary switch and control function circuits into one simple chip. Furthermore, the P-MOS control ground can be directly connected onto bus ground. This connection method is convenient to integration and easy drive. The theoretical analysis and detailed control method is given. Furthermore, one ultra-high efficiency GaN-based 65W prototype is made to verify it. The results show that with 27uF*4 bulk caps and integration control method, efficiency can achieve 93.4% at 90VAC with the PCB size 44*31*31mm, 42.3cc under the same dc-link capacitance. Dynamic and EMI performance are also verified. This method is suitable to commercial controller integration for ultra-density and high-efficiency type-c power delivery (PD) applications.

An Analytic Hierarchy Process for Selecting Battery Equalization Methods

Batteries have been the predominant energy storage system used in electric vehicles. Battery packs have a large number of cells that develop charge, thermal, and capacity imbalances over time, limiting the power, range, and lifetime. Electronic battery management and state of charge (SoC) equalization methods are necessary to mitigate such imbalances. Today, it is possible to find a wide range of battery equalization methods in the literature, but how to decide which of these methods should be applied in practice? This paper compares 24 SoC equalization circuits that are typically found in automotive applications. We employ an analytic hierarchy process (AHP) approach to rank these equalization circuits according to multiple decision criteria (energy efficiency, equalization speed, implementation and control simplicity, hardware size, and total price). We also prepared a survey to collect design preferences from multiple battery balancing experts from around the world in order to better understand the relative importance of different criteria. The obtained results confirm that automotive engineers continue to favor passive balancing methods because of their low price, small PCB size, and implementation simplicity—despite the energy efficiency benefits of active balancing.

Design a CRLH Antenna for MIMO Applications with Single and Dual Band

A design of MIMO antenna with four elements each one consists of two polarized ports is proposed in this research. The design of each elements based on ZORA which is applied to get the advantage of band frequency flexibility. The proposed MIMO antenna is operated as a single and dual band by adjusting a ground structure. The resonance frequency is 3.9 GHz for single band with bandwidth 1 GHz (3.4–4.4) GHz at -10 dB with −27 dB isolation. The resonance frequencies for dual band are 4.95 and 7 GHz with bandwidth 1.23 GHz (4.03–5.26) GHz and 410 MHz (6.88–7.29) GHz at −10 dB and less than −12 dB isolation for both bands. The obtained size of FR-4 PCB for single band is 77 × 150 mm2 while 82 × 150 mm2 for dual band which are suitable for future smartphone.

Study of hygroscopic expansion of anode readout boards of gaseous detectors based on FR4

The problem of hygroscopic expansion of FR4 based large-size PCBs is discussed using the example of Micromegas detector. The readout electrodes of the detector located on the anode printed circuit board assumed to have precise dimensions. During the production and delivery process, the readout PCB is exposed to different temperature and humidity conditions. As a result, the PCB size differs from the nominal one at the moment of assembly of the detector. The problem appears to be relevant for any other large-size gaseous detectors with the readout structure based on FR4. The swelling of two test PCB samples during water absorption is studied. The size of the samples is 650× 500× 0.5 mm3. Both samples have copper strips on one side. The second side is naked on sample 1 and fully covered with a copper layer on sample 2. The elongation of the samples from dry conditions to 50% RH is measured. The influence of the copper layers on the absorption rate and the value of equilibrium elongation is discussed. It is shown that elongation of sample 1 follows the Fick's law while the absorption process in sample 2 is more complicated. The coefficient of linear hygroscopic expansion of sample 1 is measured and discussed.

X-Band Microstrip Bandpass Filter Design using Square Loop Resonator and Defected Ground Structure

Filter is an important part in telecommunication system including in radar system. To get the better performance in selecting the signal, a ftlter must have a good Q-Factor. In this paper, an investigation of a ftlter design for synthetic radar has been successfully done. This ftlter has been designed to work at x-band using square loop resonator (SLR). A Defected Ground Structure (DGS) has been implemented to this work to increase the Q-factor of the ftlter. The result of measurement getting that the center frequency at 9.51 GHz with the bandwidth 610 MHz and PCB size of this ftlter is 22 mm x 16 mm.

Tutorial: Design of High-Speed Nano-Scale CMOS Mixed-Voltage Digital I/O Buffer With High Reliability to PVTL Variations

Ever since the reliability issues caused by I/O (input/output) compatibility among chips fabricated using different processes were raised during mid-2000, on-silicon mixed-voltage I/O buffer with wide voltage tolerance has been considered a better solution than using signal level converters to shrink PCB size, number of discretes, and power consumption. However, various external voltages on I/O pad result in body effect, leakage, hot-carrier degradation, and gate-oxide overstress in stacked transistors of mixed-voltage I/O. What even worse is that slew rate (SR) was also found deteriorated by PVT (Process, Voltage, Temperature) variations. A complete mixed-voltage I/O buffer design flow using nano-scale CMOS processes will be introduced in this tutorial based on previously developed buffers. Besides circuit design methodology, the reliability design consideration for the buffers, including ESD, PVT detection, and slew rate auto-adjustment will be discussed as well.

Ultrawideband Circularly Polarized Antenna With Shared Semicircular Patches

A low-profile ultrawideband antenna of circular polarization (CP) is proposed in this communication. This antenna consists of two layers of Rogers RT/Duroid 5880 PCB board of 0.79 mm thickness. The size of the top PCB is 54.6 mm ×54.6 mm, and four pairs of semicircular patches are printed on both its top and bottom sides. This top PCB is placed 10.5 mm above the bottom PCB, which is 95 mm ×95 mm in size. On the top side of the bottom PCB is a 1-to-4 microstrip feeding network with 90° phase difference between the adjacent ports, while the ground plane is on its bottom side. The top PCB is supported by four small trapezoid-shaped PCB boards at the center of its four edges, respectively. A slot line is printed on each trapezoidal PCB to feed the patches. Both the simulation and measurement results show that this low-profile antenna has a very wide 10 dB return loss bandwidth from 2.9 to 9 GHz. Meanwhile, lower than 3 dB axial ratio can be achieved from 3 to 7.8 GHz and its right-hand circular polarized (RHCP) gain is higher than 8 dBic. The good performance of this antenna can justify that it is a promising candidate for indoor positioning applications that require CP.

Detection of PCB Soldering Defects using Template Based Image Processing Method

In this study, a predefined template-based image processing system is proposed to automatically detect of PCB soldering defects that negatively affect circuit operation. The proposed system consists of a prototype, a camera, an image processing method and inspect process. The prototype is produced using a plastic material, depending on the focal length of the camera and the PCB size. Image processing step comprises two steps. Firstly, solder joints are determined using Fuzzy C-means clustering algorithm. Then, the center of each joint is determined. In the next step, a joint template is created that contains solder joints information. This joint template contains information about the effects of touching other joints for each joint. In this way, the inspection of soldering defects is getting shorter. Finally, each joint is only inspected for the joints specified in the template. The proposed method is evaluated on 85 real PCB image with 4250 soldering joints.

Next Generation Chip Embedding Technology for High Efficient Mid Power Modules

Abstract Embedding active dies into the substrate is fulfilling integration requirements for modern communication devices, and furthermore embedding was shown to have beneficial effects on electrical performance and thermal dissipation, especially for mid power modules (from a few hundred watts to 5kW) [1–3]. It comes with strong advantages as the power modules operate at higher frequencies (MHz range) and aim to apply smaller capacitors and inductors. This approach reduces the overall PCB size and weight from system point of view. These beneficial effects were observed especially for embedded power dies that were already mounted in a lead frame cavity when embedding [3]. In this paper we shall report the development of embedded technologies for power modules mounted in a lead frame cavity and compare electrical performance, thermal dissipation and reliability results with conventional PQFN packaging [3]. We shall also report electrical performance in various operation frequency ranges from a few kHz to MHz to address the benefit on high switching frequency power modules for SiC or GaN applications. We will also address if the EMI effect can be eliminated by using chip embedded technology instead of wire bonding connection from driver to gate pad of power MOSFET chip. We will conclude that the challenges of electrical performance and thermal dissipation required for today's power modules can successfully be overcome by next generation power modules based on lead frame chip embedding.

Low‐noise inducing Rx for human body communication

A low-noise inducing receiver (Rx) for human body communication is proposed. By minimising switching noise from the digital circuit of the Rx and coupling of the signal to the Rx ground, stable and reliable communication was accomplished even when the transmitter (Tx) and the Rx were attached to the human body. A prototype Tx and Rx were implemented with a PCB size of 5 × 6 cm. They were tested with this low-noise inducing Rx design and accomplished a data rate of 1 Mbits/s without any cyclic redundancy check (CRC) error.

Flex-DIMM – A New High Density Module Form Factor

The Dual In-Line Memory Module (DIMM) has remained relatively unchanged for the past two decades, with exception of an increase in PCB size, I/O pads and layer count. A new generation called Flex-DIMM is introduced by replacing the rigid-PCB substrate with a thin, bifurcated, flexible circuit that enables several improvements; including a thinner cross-section, better signal integrity with lower layer count, better thermal dissipation and ability to be directly mated to the surface of a motherboard. Originally intended for RDIMM applications, the new module may be an ideal solution for clustered microservers.

Wireless Spintronics Modulation With a Spin Torque Nano-Oscillator (STNO) Array

This letter presents a spin RF-direct modulation using a frequency division multiplex (FDM) with a spin torque nano-oscillator (STNO) array. For the proposed modulation, two STNO are bonded at each branch of a T-junction on a PCB, where a high pass filter (HPF) and a low pass filter (LPF) are connected on each branch of the T-junction to transmit the modulated signal into one antenna. Each STNO modulates by on-off keying (OOK) with digital data directly after setting on the separation of channels for two STNOs into 700 MHz, one STNO at 3.5 GHz frequency and the other at 4.2 GHz, with consideration of the minimum sensitivity and interference related with isolation between channels. A data rate of up to 400 Kbps is obtained at a distance of 10 mm, and the dc power consumption is 3 mW per STNO, including logic circuit operation. The PCB size is as small as 28 × 27 mm, including the 4.2 × 2.1 mm STNO array.

Bandwidth Enhancement and Size Reduction of Microstrip‐Fed Folded‐Slot Antenna

ABSTRACTA microstrip‐fed half‐wavelength folded‐slot antenna that is cut at the finite ground plane edge for bandwidth enhancement as well as size reduction of the conventional folded‐slot antenna is proposed. The antenna is fabricated within limited space of 35 mm × 12 mm on a 35 mm × 35 mm substrate, which is about the size of typical PCB for of RF modules used in wireless communication systems. The measured impedance bandwidth (S11 ≤ −10 dB) and maximum antenna gain over the passband are 92.5% (2.63∼7.27 GHz) and 4.69 dBi, respectively. The measured radiation patterns are similar to those of the conventional folded‐slot antennas and are stable across the pass band. These properties and its compact structure render the proposed antenna suitable for applications in various wireless communication systems. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2248–2251, 2013

2.4GHz 지그비 모듈용 소형화된 폴디드 슬롯 안테나

A microstrip-fed miniaturized folded-slot antenna that is cut at the finite ground plane edge for the size reduction is proposed as a ZigBee module operating in the 2.4 GHz frequency band, as specified by the IEEE standard 802.15.4. The antenna is fabricated within space limited to on a substrate, which is about the PCB size of a typical wireless ZigBee module. The measured impedance bandwidth and antenna gain are 2.37~2.49 GHz and 2.4 dBi respectively. The measured radiation patterns are similar to conventional folded-slot antennas and are also stable across the pass band. These properties and its compact structure help in making the antenna suitable for ZigBee module.

The Implementation of Sub-1GHz Wireless Personal Area Monitoring System

This paper presents the development of a brand new hardware framework of low-cost, tiny and power-efficient wireless monitoring system. The framework of this wireless personal area monitoring system (WPAMS) includes sub-1GHz RFID interrogator subsystem, antenna subsystem and passive RFID transponder subsystem. Compare to other interrogators, sub-1GHz interrogator achieves larger communication range and suffers fewer reflections in the indoor space. The sophisticated commercial transponder can be easily embedded in the personal belongings without any battery inside. In addition, a lightweight three-pass authentication process helps to form a simple point-to-point short-range identification network which makes our monitoring system is superior to other monitoring systems using active communication technologies, such as Bluetooth, ZigBee, UWB, Wi-Fi, and so on. Six experimental scenarios have been developed to demonstrate the performance on item-level identification. By connecting +5.7/5.5dBi right-hand circularly polarized commercial antennas and +1.7dBi linear polarized antenna, under 1 watt power limitation, the proposed WPAMS has successfully identified all the items within 2-meter range. The current PCB size of interrogator is 2-inch×3.25-inch×0.25-inch and can be reduced in the near future.

The Performance Comparison of Sub-1GHz Wireless Personal Area Monitoring Systems

This paper presents a brand new hardware framework of wireless personal area monitoring system (WPAMS) in order to form a point-to-point simply connected personal area identification network with the applications of ubiquitous monitoring personal valuable belongings. The WPAMS consists of sub-1GHz radio frequency identification (RFID) interrogator subsystem, antenna subsystem and passive RFID transponder subsystem with salient features of low-cost, tiny and power-efficient. The hardware frameworks of two commercial interrogator prototypes have been identified and simulated. With the connection of 5.7dBi right-hand circularly polarized antenna and in the adherence of local power regulation (within 1watt), the identified range of all types of commercial transponders from sideward and upward directions can be reached to 2 meters. The current PCB size of interrogator is 88mm45mm and can be reduced in the near future.

Design of Low Power Wideband Low Noise Amplifier for Software Defined Radio at 100 MHz to 1 GHz

Abstract This paper describes the design of wideband low noise amplifier (LNA) for mobile software defined radio (SDR) application which targeted to be applied in two-way communication mobile system architecture. The technical specification was deduced from the TIA-603 C standard receiver system sensitivity and intermodulation. The proposed LNA exhibit low power consumption and adopts a negative feedback wideband amplifier topology, operated from 100 MHz to 1 GHz which covers the whole Land Mobile FM Communication Equipment (136 - 941 MHz) frequency band. The proposed topology solve the RF tracing problem inherited in the targeted frequency and also the problem of economically impractical PCB size rendered by other wideband amplifier methods. The Advanced Design System software is used to perform the simulations. The measured result show the proposed LNA has a stable gain of more than 15 dB, noise figure less than 1.5 dB, Sn and S22 less than -10 dB, with current consumption of 8 mA from voltage supply at 1.8 V.

Complementary pattern method to reduce mutual coupling in metamaterial antennas

A complementary pattern (CP) for multiple antennas in order to reduce mutual coupling between antenna elements is proposed and investigated. The proposed CP is comprised of meandered transmission lines between antennas on FR4 (ɛr=4.6) substrate. The multiple antennas are a printed embedded type based on composite right/left handed (CRLH) metamaterial transmission lines. In order to validate the CP effects, simulation and measurement results for both the with-CP case and the without-CP case in metamaterial antennas are compared. The CP is presented as an equivalent circuit. Through parametric studies, the optimal dimension of CP is determined. The return loss, isolation, radiation patterns of each plane, measured peak gain and current distributions are provided. By calculating the envelope correlation coefficient between two antennas, the authors also demonstrate the effect of the CP in a metamaterial antenna. The total PCB size is 21.5×50 mm2 with 1 mm thickness, and the antenna space is 21.5×10 mm2. The resonant frequency with good isolation value is 3.3 GHz. Since the metamaterial antenna and CP consist of transmission lines, the proposed structures are compatible with other radio frequency (RF) devices.

확장성이 고려된 IEEE-802.15.4 기반의 저전력 범용 센서노드 설계 및 제작

Low power consumption sensor network platform (sensor node) for sensor networking with IEEE 802.15.4 protocol was fabricated. The sensor node used ceramic bar type antenna for increasing RF signal performance and decreasing PCB size occupied by antenna. The communication range of the fabricated sensor node was about <TEX>$20{\sim}30$</TEX> m in open environment with 915 MHz frequency bandwidth and well supported by Tiny OS. The sensor node have good connectivity with various external devices by RS-232, I2C, analogue and digital expansion board, hence, this sensor node can be applied to various applications in wireless sensor network and ubiquitous sensor network.