Meander Line Research Articles

An Ultra‐Compact Spoof Surface Plasmon Polariton Transmission Line and Its Signal Integrity Analysis

An ultra‐compact spoof surface plasmon polariton (UCSSPP) transmission line (TL) based on a meander line is proposed, which can achieve almost the same transmission performance as the conventional rectangular‐groove SSPP TL, but the linewidth is greatly reduced by more than 40%. The coupling effect between two UCSSPP TLs in different line arrangements has been well studied, revealing that excellent crosstalk suppression can be achieved when two TLs are arranged back‐to‐back, while strong coupling occurs when they are arranged face‐to‐back or face‐to‐face. The signal integrity of back‐to‐back UCSSPP TLs is analyzed and demonstrated, which shows that the signal integrity can be greatly improved compared with microstrip (MS) TLs. In addition, based on the principle of mode mismatch, MS and UCSSPP TLs are arranged alternately to solve the mutual coupling problem in multi‐line systems. In contrast, benefiting from the strong coupling of face‐to‐face UCSSPP TLs, an ultra‐miniaturized SSPP coupler working at 9 GHz is designed, whose size can be reduced by over 75% compared with conventional MS coupler. The measurement results show good agreement with full‐wave simulations, indicating that the proposed UCSSPP TL has significant advantages in signal integrity and device miniaturization over previously reported SSPP TLs.

A Low-Profile Compact Meander Line Telemetry Antenna with Low SAR for Medical Applications

A low-profile Compact Meander Line Telemetry Antenna (CMLTA) operating at 402.5 MHz for the Medical Implant Communication System (MICS) band medical applications is introduced. The proposed antenna focuses specifically on pacemaker telemetry applications. The meander line technique with an open loop configuration and simple transmission line feeding mechanism has been used for achieving the compact design. Based on the theory of surface current distribution, the proposed technique provides the opportunity to increase the electrical dimensions while decreasing the physical dimensions of the antenna. Further design optimization is carried out to optimize the overall antenna size to a maximum volume of 4080 mm3. By introducing CMLTA, the size of the antenna is reduced by 79% as compared to the previous work. The proposed antenna demonstrated satisfactory performance with 10 dB bandwidth of 6.17%, a maximum gain of -22 dBi and an EIRP of -25.28 dBi. The analysis of Specific Absorption Rate under premise use of 1 W input power provided the maximum 1 g and averaged 10 g SAR of 74.7 W/kg and 17.7 W/kg, respectively, demonstrating a satisfactory level according to the IEEE standard safety guidelines. Fabrication and measurements are carried out where measured results are found to be in good agreement with the simulated results. With the optimized dimensions, satisfactory gain, EIRP, and SAR performance, the proposed CMLTA is deemed suitable for pacemaker telemetry applications for effective communication.

A Compact, Ultra-Wideband, Transformer-Based Quadrature Signal Generation Network in 45 nm CMOS SOI for 5G Applications

In this article, we present an ultra-wideband, fully-differential quadrature signal generation network for 5G applications. The ultra-wideband network is composed of a passive balun and cascaded transformer-based quadrature hybrid. Passive balun converts a single-ended signal to differential with minimum insertion loss, and transformer-based quadrature hybrids are cascaded to suppress I/Q imbalance over an ultra-wide bandwidth. The coupling coefficient of the transformer-based quadrature hybrid is enhanced by adopting vertically stacked multiturn transformer topology to extend operation bandwidth and reduce passive loss and chip area. A novel layout and signal routings are proposed to reduce passive loss, undesired magnetic coupling and I/Q imbalance, making meander lines for phase matching unnecessary. The proposed ultra-wideband quadrature signal generation network is designed in GlobalFoundries 45 nm CMOS SOI process with a core area of 845 μm × 495 μm. The output I/Q magnitude mismatch is less than 0.5 dB from 16 to 60 GHz, and phase mismatch is less than 2° from 16.5 to 54.7 GHz. The input return loss is lower than −10 dB from 22 to 45 GHz, and signal loss varies from 5.74 to 7.4 dB (including 1:2 power splitting and loss from passive balun). The effective image rejection ratio (IRR) is calculated based on I/Q mismatch and is higher than 40 dB from 21.5 to 53.5 GHz.

Comparison of Time Responses of a Meander Line Turn to Ultrashort Pulse Excitation

The article presents the results of calculating time responses of a meander line (ML) turn to pulse excitation. The responses were calculated at the ML nodes analytically and numerically, and demonstrated coincidence. Besides, the created prototype of the ML turn was measured and showed good qualitative and acceptable quantitative agreement with the simulation results. Analytical models were found to be promising since they may significantly accelerate the design of such MLs in contrast to numerical methods which provide costly multivariate simulation of the time response during optimization.

Circularly Polarized Miniaturized Implantable Antenna for Leadless Pacemaker Devices

A compact circularly polarized (CP) implantable antenna working at 915 MHz, at the industrial, scientific, and medical (ISM) band, is developed in this article. The proposed radiator is based on a fully planar and low-profile patch antenna with a ground plane and different slots but without any via holes, which makes the structure a good candidate for implantable devices. The circular polarization is achieved by means of introducing a surrounding and asymmetrical U-shaped structure. A meander line has been included in the inside of the U-shaped structure to increase the electrical length of the antenna without increasing its mechanical dimensions. An impedance bandwidth of 18.9% from 810 to 980 MHz and an axial ratio of 17.2% from 850 to 1010 MHz have been achieved. The proposed antenna has a compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.2\times 5.6\times0.25$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , which seems to be the smallest antenna over the recently reported implantable antennas. In addition, the proposed antenna achieves a relatively high gain value of −23 dBi.

Design of Flexible Meander Line Antenna for Healthcare in Wireless Body Area Network Systems.

A flexible meander line monopole antenna (MMA) is presented in this paper. The antenna can be worn for on-and off-body applications. The overall dimension of the MMA is 37 mm x 50 mm x 2.37 mms, The MMA was manufactured and measured, and the results matched with simulation results. The MMA design shows a bandwidth of up to 1282.4 (450.5) MHz and provides gains of 3.03 (4.85) dBi in two operating bands, respectively, showing omnidirectional radiation patterns in free space. While worn on the chest or arm, bandwidths as high as 688.9 (500.9) MHz and 1261.7 (524.2) MHz, and the gains of 3.80 (4.67) dBi and 3.00 (4.55) dBi were observed. The experimental measurements of the read range confirmed. Clinical Relevance- Wireless Medical Body Area Network (WMBAN) technology allows for continuous monitoring and analysis of patient health data to improve the quality of healthcare services.

Reconfigurable Compact Size Power divider with Low Insertion Loss and Meander Line

Reconfigurable Compact Size Power divider with Low Insertion Loss and Meander Line

Analysis of the pulse signal propagation in a turn of a meander line of two segments based on lattice diagrams

The analysis of the propagation of a pulse signal in a turn of a meander line of two segments is carried out. For this purpose, the plotting of lattice diagrams for the even and odd modes is carried out, as well as their subsequent comparison with the time responses to the pulse excitation in each node of the line. A complete coincidence of the amplitudes and arrival times of pulses obtained by different methods was obtained.

Multi-band propagation of spoof surface plasmon polaritons by its high-order modes

Compact dual-band and tri-band bandpass filters (BPFs) based on high-order modes of spoof surface plasmon polaritons (SSPPs) are proposed. By using the meander line technique, the electrical size of the proposed SSPP structure was reduced by 68% compared with the traditional rectangular-grating SSPP structure. The high-efficiency passbands are excited by high-order modes of SSPPs. Therefore, dual-band and tri-band BPFs are designed by using two and three high-order modes of SSPPs, respectively. In addition, a notched band is obtained by loading three complementary split-ring resonators (CSRRs) on the bottom layer of the tri-band BPF. Thus, a quad-band BPF is achieved.

A Dual-Polarized Frequency-Selective Rasorber With a Switchable Wide Passband Based on Characteristic Mode Analysis

This study proposes a dual-polarized frequency-selective rasorber (FSR) with a switchable wide passband. The FSR is made up of two layers: the first is a lossy frequency-selective surface (FSS), which is made up of meander lines and lumped resistors that absorb energy. The position of the lumped resistors can be determined via characteristic mode analysis. Another layer is a lossless FSS with PIN diodes for the reconfigurable function. The lossless FSS is made up of three layers for a wide passband. When PIN diodes are turned off, the absorption bands in the lower band vary from 2.73 to 3.76GHz, while the upper band ranges from 6.07 to 7.94 GHz. Meanwhile, the reflect band with a value greater than −3 dB spans the frequency range from 4.21 to 5.88 GHz. When the PIN diodes are turned on, the passband with insertion loss less than −1 dB extends from 3.82 to 5.3 GHz. At the same time, the absorption band ranges from 5.9 to 7 GHz. Due to the nonlinearity of PIN diodes, there is a certain difference between the simulated and the measured results. Also, we analyzed the influence of the inductance value of PIN diodes on the whole structure.

Via-based miniaturized rasorber using graphene films

In this work, we present a miniaturized wideband rasorber with good angular stability using via-based metal–graphene structure. The rasorber consists of a compact lossy layer, a frequency-selective surface layer, and an air spacer in the middle. The metal–graphene structure in the lossy layer achieves a tiny period due to multiple metal vias connected with meander lines and open stubs. The graphene resistive films printed on the surface by screen-printing technology realize omnidirectional planar resistors for broadband absorption. The 1-dB transmission band of the rasorber is from 7.27 to 8.01 GHz and the 10-dB reflection band is from 2.54 to 8.58 GHz. Due to its miniaturized unit cell, both the transmission and absorption performance is stable with a large-angle incident wave. The ultra-miniaturized rasorber is fabricated and measured, which demonstrates a wide bandwidth of 108.6% and a small period of 0.05λL with great angular stability, making it a good candidate for bi-station stealth radome applications.

Analytical Models and Conditions for Optimal Protective Meander Lines

Analytical Models and Conditions for Optimal Protective Meander Lines

A Planar Low-Profile Meander Antenna Design for Wireless Terminal Achieving Low RF Interference and High Isolation in Multi-Antenna Systems

In this article, a meander line internal antenna used for wireless terminal is proposed. The current of this antenna is mostly distributed on the antenna radiator itself, rather than on the main board of the wireless device. As a result, the chance of having radio-frequency (RF) interference issues, which usually result in receiver desensitization in wireless radios, can be significantly reduced. The antenna has good radiation performance in the vertical polarization with a low physical profile, compared with the existing antenna designs for typical wireless terminals. The antenna has efficiency similar to the monopole antenna with much less reference/ground plane dependence, achieving lower RF interference, which is demonstrated by the noise coupling measurements in a predefined digital clock - antenna configuration. Furthermore, the mutual coupling (i.e., isolation) between two such antennas is studied and the envelope correlation coefficient between the two antennas is found to be low. A router assembled with the two proposed antennas is tested, and the total isotropic sensitivity is found lower compared with monopole antennas, due to the characteristics of low RF interference and high isolation of the proposed antenna.

A Novel Meander Line Metamaterial Absorber Operating at 24 GHz and 28 GHz for the 5G Applications

Fifth generation (5G) communication systems deploy a massive MIMO technique to enhance gain and spatial multiplexing in arrays of 16 to 128 antennas. In these arrays, it is critical to isolate the adjacent antennas to prevent unwanted interaction between them. Fifth generation absorbers, in this regard, are the recent interest of many researchers nowadays. The authors present a dual-band novel metamaterial-based 5G absorber. The absorber operates at 24 GHz and 28 GHz and is composed of symmetric meander lines connected through a transmission line. An analytical model used to calculate the total number of required meander lines to design the absorber is delineated. The analytical model is based on the total inductance offered by the meander line structure in an impedance-matched electronic circuit. The proposed absorber works on the principal of resonance and absorbs two 5G bands (24 GHz and 28 GHz). A complete angular stability analysis was carried out prior to experiments for both transverse electric (TE) and transverse magnetic (TM) polarizations. Further, the resonance conditions are altered by changing the substrate thickness and incidence angle of the incident fields to demonstrate the functionality of the absorber. The comparison between simulated and measured results shows that such an absorber would be a strong candidate for the absorption in millimetre-wave array antennas, where elements are placed in proximity within compact 5G devices.

Design of a Flexible T-Matched Feed UHF RFID Tag Antenna

Abstract A flexible radio frequency identification (RFID) tag antenna with a T-match feeder is proposed in this paper. The T-match feed acts as the conjugate network matching of the tag antenna and 0.99 of power transfer coefficient was achieved. By incorporating a meander line and capacitive tip loading technique, the compact size is realized with a wide bandwidth of 44MHz that can cover the RFID spectrum allocated for the Malaysia region, from 919 to 923 MHz. The proposed antenna is printed on the flexible polyethene terephthalate (PET) substrate with a dimension of 90mm × 24mm × 0.143mm. By employing 4W EIRP power, the detection distance of 29.15m in free space. The proposed meandered line and capacitive tip loading tag antenna with T-match feed line is beneficial to be part of the RFID systems because of their compactness, wide bandwidth and high-power transfer coefficient.

Reconfigurable Polarization Converter Using Liquid Metal Based Metasurface

A multifunctional reconfigurable metasurface based on liquid metal injection is presented. The reflective flexible material metasurface formed by two switchable microfluidic layers&#x2014; the top layer comprising an array of meandered half-rings and the lower layer, straight meander lines&#x2014;can be reconfigured into four states. The proposed metasurface becomes a reflector with emptied channels, whereas it exhibits linear-to-circular polarization conversion (or linear-to-cross-polarization conversion) properties when the top (or bottom) layer is filled with a liquid metal alloy. Upon normal excitation of linearly u/v-polarized waves and activation of the bottom layer, the metasurface reflects cross v/u-polarized waves in the frequencies from 9.83 to 17.42 GHz (53&#x0025; bandwidth) with a polarization conversion ratio (PCR) of at least 90&#x0025;. On the other hand, the metasurface operates as a linear-to-circular polarizer (for u/v-polarized waves) over 8.97&#x2013;11.30 GHz (23&#x0025; bandwidth), reflecting left- or right-hand circularly polarized waves. To verify the polarization conversion performance, a <inline-formula> <tex-math notation="LaTeX">$25\times 25$ </tex-math></inline-formula> element metasurface array is fabricated and measured. The experimental results confirm the simulation results over the 8&#x2013;12 GHz test band. The compactness, structural flexibility, and multifunctionality of the proposed metasurface make it a suitable candidate for modern integrated antenna array systems.

Oldest leaf mine trace fossil from East Asia provides insight into ancient nutritional flow in a plant\u2013herbivore interaction

The Late Triassic saw a flourish of plant–arthropod interactions. By the Late Triassic, insects had developed all distinct strategies of herbivory, notably including some of the earliest occurrences of leaf-mining. Herein we describe exceptionally well-preserved leaf-mine trace fossils on a Cladophlebis Brongniart fern pinnule from the Momonoki Formation, Mine Group, Japan (Middle Carnian), representing the oldest unequivocal leaf-mines from East Asia. The mines all display a distinctive frass trail—a continuous meandering line, which later becomes a broad band containing spheroidal particles—demonstrating larval development. Although the shapes of the frass trails are generally comparable to those of Lepidoptera or Coleoptera, they cannot be unequivocally assigned to a specific extant leaf-mining taxon. Furthermore, elemental analyses by X-ray fluorescence (XRF) reveals that the frass trail comprises phosphate coprolites. The quantitative variations in P, S, and Si between coprolites and leaf veins may reflect physiological processes (e.g., consumption, absorption, and excretion) mediated by plant chemicals. Our findings reinforce the idea that leaf-mining had become a pervasive feeding strategy of herbivorous insects by the Late Triassic.

VHF/UHF wideband slim monopole antenna with meander line loading and slot-modified ground designed by characteristic mode analysis

VHF/UHF wideband slim monopole antenna with meander line loading and slot-modified ground designed by characteristic mode analysis

5.8 GHz BAND Wi-Fi AND IoT APPLICATIONS ANTENNA DESIGN

Due to the increase in internet-connected devices in daily life, the compact embedded wireless device becomes necessary to meet multiple frequency-based applications on a common platform. Reconfigurability is a good solution for improving device utility in many technical interfaces. Wireless compatibility between different devices over the Internet reveals the importance of the antenna unit. Internet of Things (IoT) based applications requires integration with wireless communication technologies to obtain application data. In this study, a meander-shaped microstrip patch antenna in the 5.8 GHz band is proposed for use in IoT applications. The dimensions of the antenna are 40 x 15 x 1.6 mm3. The antenna design consists of a full circle, a semicircle, and a meander line. In the antenna design, FR-4 has been used as the substrate material, and copper has been used as a conductor on the upper and lower surfaces. Performance parameters have been investigated in the proposed antenna design. In addition, a parametric study is presented to investigate the flexibility of the antenna. The results show that gain and yield can be improved by adjusting the dimensions of the rectangular ground plane. As a result of the improvements, the terminated antenna, return loss below -20 dB in the 5.8 GHz band, 700 MHz wide operating band, 4.35 dBi realized gain, 5.3 dBi directivity, -0.9188 dB radiation efficiency and -0.9445 dB total efficiency have been obtained. In addition, the proposed antenna also operates in the 4.5 GHz, 7 GHz, and 8.5 GHz bands as multi-band.

A miniaturized planar meander line antenna for UHF CubeSat communication

The use of LoRa (Long Range) wireless communication as an Internet-of-Things (IoT) protocol has great potential. This technology works in the unlicensed ISM band and covers all the globe with different frequencies, which can improve the wide and rapid spread of information. To obtain global IoT coverage using LoRa, the use of satellite networks is mandatory. The development of nanosatellites, mostly in the CubeSat form factor, for communication applications in general and LoRa communication in particular, is currently increasing. To date, these satellites usually use linear wire deployable antennas for communication. However, deployable mechanical systems present the risk of failure during the mission. In fact, one-unit CubeSat geometry allows a very small space (10 cm * 10 cm * 0.06 cm) for the antenna. Since the size of the antenna is proportional to wavelengths, the antenna size is a large problem for low frequencies, especially in the UHF band. For this reason, planar antennas are an attractive solution for CubeSat communications. This work presents the design of a miniaturized printed monopole meander line antenna working at a frequency of 920 MHz. The novelty of the design is obtained by placing the meander line and the ground plane onto similar sides of the antenna. The meander line allows reduction of the antenna size by a factor of λ/5 for the selected operating frequency. The structure of this proposed antenna has a low profile, and a small size of 50 * 80 * 1.635 mm 3 or about 0.153λ 0 * 0.245 λ 0 . It has an S11 magnitude of –33.53 dB obtained by simulation and S11 magnitude of −19 dB obtained through experimental measurements. The simulation results also show that the proposed meander line antenna will produce an omnidirectional radiation pattern and a maximum gain of 1.8 dB.