Double Meander Research Articles

Methodology for substantiating the parameters of navigation signals with double meander modulation for local navigation systems based on land pseudo-satellites

Formulation of the problem. The development of local navigation systems based on land pseudo-satellites in order to solve the problem of insufficient noise immunity of global navigation satellite systems determines the relevance of the improvement of the theory of multicriteria synthesis of new types of navigation signals. Purpose. Ensuring high accuracy and continuity of navigation-time definitions with the level of out-of-band radiation reduced to compliance with electromagnetic compatibility requirements and an acceptable decrease in the energy efficiency of transmitters by developing a methodology for substantiating the parameters of navigation signals with double meander modulation for local navigation systems based on land pseudo-satellites. Results. The use of navigation signals with double meander modulation in local navigation systems based on land pseudo-satellites is proposed, and their advantages over currently used signals are shown. A methodology of multi-criteria substantiating of navigation signal parameters has been developed, taking into account spectral, correlation characteristics, as well as the effect of reducing the level of out-of-band radiation of land radio transmitting devices in order to ensure electromagnetic compatibility requirements on the time characteristics of the signal. Practical significance. The obtained results can be used by specialists in the field of local and global radio navigation systems when considering the introduction of new types of navigation signals that ensure high quality indicators of tracking their parameters, as well as the application of new and existing navigation signals in local navigation systems based on land pseudo-satellites.

Integrating RF MEMS Switch on Array Antenna to Achieve Reconfigurability in Wideband Application

Reconfigurable multi-band antennas are highly used for commercial as well as military purposes as a single antenna could be reconfigured dynamically to send and the receive multiple signals of different frequency simultaneously. In this work an antenna array is designed and integrated with RF MEMS shunt capacitive switch over it, for the applications of S,C,X-band in the frequency range of 2-12GHz. A membrane that can move freely over a coplanar waveguide serves as the MEMS switch. Here, a double meander tuned dual beam arrangement is used to increase switch isolation. Electrostatic mechanisms are used for actuators due to their low power requirements, compact design, and quick switching. By the simulation result, The beam starts to bend from 0.60793mm to 0.4116mm at the voltage 1.78492mV to 57.7382mV and it provides capacitance at 1.435pF to 1.597nF. It was noticed that the insertion loss (S21) and the return loss (S11) of a MEMS switch are around -0.079 dB and 20.618 dB correspondingly, in order to have a good switching characteristic in the up state. The switch has an insertion loss (S21) of -31.307 dB and return loss (S11) of about -0.256 dB in the up state thus exhibiting good switch characteristics. The RF MEMS shunt capacitive switch is integrated on the predesigned antenna array the dynamically shifting of the switch from on state to off state helps achieving the reconfigurability in the antenna array. Such antennas are applicable in spaceborne radar, communication satellites, unmanned aerial vehicles, unmanned aircraft system and various other communication as well as sensing applications.

Algorithms for searching and detecting navigation signals with double meander modulation with a different number of spectral components

One of the main directions of improving the accuracy characteristics of navigation equipment of consumers of global navigation satellite systems is the use of new types of navigation signals, in particular, signals with double meander modulation. However, these signals have a relatively high level of closely spaced side lobes of the autocorrelation function, which makes it difficult to solve the problem of unambiguous measurements during search and tracking. To conduct a study of the noise immunity of algorithms for searching and detecting navigation signals by double meter modulation. Analytical expressions are obtained for calculating the total envelope at the detector output using four and two spectral components of a navigation signal with double meander modulation. It is revealed that the detection algorithm using four spectral components of a signal with double meander modulation to form the total envelope has better noise immunity than the detection algorithm using two spectral components. It is shown that the detection algorithm using two spectral signal components with double meander modulation, due to the simplicity of implementation, ensures compatibility with the existing navigation equipment of consumers of global navigation satellite systems. As a result of mathematical modeling, the dependences of the probability of the search ending with the correct detection on the signal/interference ratio are obtained. The presented research results can be used by specialists in the field of satellite radio navigation in the modernization of global navigation satellite systems, as well as in the development of advanced navigation equipment for consumers working with signals with double meander modulation.

Monitoring of Surgical Wounds with Purely Textile, Measuring Wound Pads – II. Detection of Bacterial Inflammation by Measurement of Wound Tissue Temperature

Aims: This study was executed to aquire basic knowledge on relations between design characteristics and the quality of measurements, as well as the optimization of the design of purely textile, measuring wound dressings for the detection of wound tissue warming as an indicator for (bacterial) inflammation. Background: The normal healing of surgical skin wounds may be disrupted by complications, by far the most common being post-operative bacterial infections. Objective: The temperature of the wound and its surroundings – the main indicative parameter for the onset of bacterial inflammation – can be determined and shown by means of functionalized, purely textile wound dressings with measuring capability when used as part of a measuring and assistance system. The textile sensors comprise insulated electrical wires stitched onto a textile backing designed as double meander, which is appropriate for the detection of temperature, moist, and rectangular transverse elongation (indicating inflammation, bleeding or seroma discharge, and tissue volume increase as a sign of haemorrhage (into the tissue) or seroma formation). Methods: Major design parameters are diameter of the electrical conductor (wire) / distance between an electrical conductor and the nearest (parallel) conductor / spacing of the embroidered seams (upper thread loops) along a conductor / number of meander loops, and length, width, and area of the double meander sensor array. Results: Skin temperature rises a few degree Celsius resulting in differences in ohmic resistance in the order of a few parts per thousand. The ohmic resistance of the electrical sensor wire as measurement for the temperature under the dressing solely depends on the length of the wire. Neither the spacing between the sections of wire nor the spacing of the upper thread has any detectable direct effect on the determination of the temperature. Conclusion: To improve measuring accuracy, sensor wires as thin as possible should be used for two reasons: (1) because their ohmic resistance is higher, simplifying measurement, and (2) because they can be stitched closer together in wound dressings, enabling a longer sensor wire to be used in the area of interest.

Design and evaluation of micro-heater geometries for MEMS-based ozone gas sensor through a theoretical modeling

Green House Gases (GHGs) such as ground-level ozone are an important component of smog. In addition to destroying health and crops, it has an impact on climate change and the mortality rate of humans. It is known to cause over 150,000 pre-mature deaths every year and millions of cases of chronic diseases particularly in children and elderly. In this light, the efficiency of MEMS based Ozone Gas Sensor is an important parameter to be optimized. This paper illustrates the design, simulation, and evaluation of a micro-heater that is a vital component of the gas sensor. Simulations suggest that the meander spiral geometry offers a better temperature distribution over the sensor surface, thereby increasing the sensor contact area. 83.75 K/V is the sensitivity of the structures compared, 4 times more than the single meander and 1.5 times more than the double meander and spiral geometries.

Formation of a navigation signal with double meander modulation

Formation of a navigation signal with double meander modulation

Double Meander Dipole Antenna Array with Enhanced Bandwidth and Gain

In this paper, a new design of high gain and wide bandwidth microstrip patch antenna array containing double meander dipole structure is proposed. Two in-phase resonant frequencies in the Ku-band (12–18 GHz) could be achieved in the double meander dipole array structure, which lead to enhance impedance bandwidth without costing extra design section. Besides, further enhanced gain of 2 dBi of the array over the entire operating frequency range has been achieved by introducing a double-layer substrate technique. The proposed antenna has been fabricated using the E33 model LPKF prototyping PCB machine. The measurement results have been performed, and they are in very good agreement with the simulation results. The measured –10 dB impedance bandwidth indicates that the array provides a very wide bandwidth which is around 30% at the center frequency of 15.5 GHz. A stable gain with a peak value of 10 dBi is achieved over the operating frequency range. The E- and H-plane radiation patterns are simulated, and a very low sidelobe level is predicted. The proposed antenna is simple and has relatively low-profile, and it could be a good candidate for millimeter wave communications.

Design of Compact Dual-band High-gain Planar Antenna for WLAN

A compact dual-band planar antenna with high gain for WLAN application is presented. The antenna fed by CPW is composed of T-type feed and double C-type meander line, which generate the higher and lower operation bands respectively. DGS structure in CPW ground broadens the bandwidths of high frequency. Through electromagnetic simulator software simulation and analysis, the overall size is 30×15.25×1.6mm. The simulation results show that the proposed antenna can operate in 2.35∼2.52GHz and 3.85∼6.14GHz, which cover the WLAN operating bands of IEEE 802.11n and 802.11a/b/g. The gain is 1.42dBi at 2.45GHz, and 4.42dBi at 5.2GHz, and 5.38dBi at 5.8GHz, respectively. The radiation patter of the antenna is omnidirectional and has higher gain.

Low-power printed micro-hotplates through aerosol jetting of gold on thin polyimide membranes

We report on patterning of miniaturized gold (Au) based micro-hotplates reaching high temperature at lower power consumption than ever reported using aerosol jet printing. Efficient heating (i.e. ~12 °C/mW) was achieved by reducing the effective heating area and the thickness of the polyimide substrate. Au nanoparticles solution was used for printing heaters of two different sizes, i.e. 500 × 500 μm2 and 150 × 150 μm2. These double meander heaters were patterned on a 50 μm-thick polyimide substrate implementing 5 μm-thick membranes using laser etching. Finite element simulations were used to optimize the thermal design of the devices. They exhibit a power consumption at 250 °C of 39 mW and 22 mW for the larger and smaller heater design, respectively. These results indorse the significance of aerosol jet printing process at high resolution to realize high temperature and power efficient micro-hotplates on foil for applications such as; in portable gas and chemical sensors, thermal metrology and mapping, localized heating, thermal actuators and microfluidics etc.

The neolithic burials of Changis‑sur-Marne Les Pétreaux (Seine‑et‑Marne) in their regional context in the Paris Basin

Between 1995 and 2004 quarrying by the aggregate extraction company Cemex over an area of seventy hectares in the double meander of Armentieres upstream of Meaux provided an exceptional opportunity to investigate a site located in the floodplain of the lower Marne valley. This very large preventive excavation area revealed multiple traces of occupation of a site occupied intermittently from the 5th millennium BC to the 4th century AD. Ten burials figure among the remains uncovered; they were excavated and dated to the Middle Neolithic II period. Such features remain a rare find in the northern half of France and are presented here in detail. A synthesis, which sets the site of Changis in its Middle Neolithic regional context concludes the article.

Dual-band LTCC antenna based on 0.95Zn2SiO4-0.05CaTiO3 ceramics for GPS/UMTS applications**Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20133718120009), the Natural Science Foundation of Shandong Provence, China (Grant Nos. ZR2013FQ002 and ZR2014FQ006), the China Postdoctoral Science Foundation (Grant No. 2014M551935), the Qingdao Municipality Postdoctoral Science Foundation, China, and the Scientific Research

In this paper, we present a compact low-temperature co-fired ceramic (LTCC) dual-band antenna by using the electromagnetic coupling effect concept for global positioning system (GPS) and universal mobile telecommunication system (UMTS) applications. The overall dimension of the antenna is 8.6 mm × 13.0 mm × 1.1 mm. It consists of double meander lines and a via hole line. The top meander line operates at the upper band, and the bottom radiating patch is designed for the lower band. The via-hole line is employed to connect the double meander lines. Because of the effect of the coupled line, total dimension of the proposed antenna is greatly reduced. With the 2.5: voltage standing wave ratio (VSWR) impedance bandwidth definition, the lower and upper bands have the bandwidths of 110 MHz and 150 MHz, respectively. The proposed antenna is successfully designed, simulated, and analyzed by a high frequency structure simulator (HFSS). And the antenna is manufactured by using the 0.95Zn2SiO4-0.05CaTiO3 ceramics (εr = 7.1, tanδ = 0.00038) that is prepared by ourselves. The results show that the antenna is compact, efficient, and of near omnidirectional radiation pattern.

소형 미앤더 2-층 모노폴 안테나의 특성분석

In this paper, we present a low profile 2-layered meander built-in monopole antenna for portable RFID reader using FDTD(Finite Difference Time Domain) method. The input impedance, return loss, and VSWR in the frequency domain are calculated by Fourier transforming the time domain results. The double meander 2-layer structure is used to enhance the impedance matching and increase the antenna gain. The measured bandwidth of the antenna is 0.895 GHz ~ 0.930 GHz for a S11 of less than -10dB. The measured peak gain of proposed low profile RFID built-in antenna is 2.3 dBi. And the proposed built-in antenna for portable RFID reader can offers relatively wide-bandwidth and high-gain characteristics, in respectively. Experimental data for the return loss and the gain of the antenna are also presented, and they are relatively in good agreement with the FDTD results. This antenna can be also applied to mobile communication field, energy fields, RFID, and home-network operations, broadcasting, and other low profile mobile systems.

The correlation functions of single elements of the modulating functions of double complex meander noise-like navigation signals (alternative binary offset carrier modulated signals)

The correlation characteristics of elements of complex meander pseudo-random sequences (PRSs) are analyzed. These sequences are the basis for forming double complex meander (DCM) noise-like signals (alternative binary offset carrier modulated signals—AltBOC signals) applied in new-generation satellite radio navigation systems (in particular, the European Galileo and Chinese Bei-Dou/Compass systems). Analytical expressions are obtained for the correlation functions (CFs) of single complex meander symbols (MSs) and for the cross CFs (CCFs) of the sine and cosine components of complex MSs. Formulas for the CFs of single elements of the modulating functions (MFs) of an elementary (two-component) AltBOC signal and a four-component AltBOC signal are derived for typical values of multiplicity coefficient Nm (Nm = 2 and 3). Plots of CFs and CCFs are depicted, and the properties of these functions are discussed. The Fourier transform is applied to obtain the energy spectra of single MSs of an elementary AltBOC signal and a complete four-component AltBOC signal. In the examples, the attention is focused on AltBOC signals with the AltBOC (15, 10) modulation and the repetition rate of PRS elements fs = 10 fref = 10.23 MHz, where the reference frequency is fref = 1.023 MHz.

Resonant multimeander‐metasurfaces: A model system for superlenses and communication devices

AbstractWe study the optical properties of single and double meander meta surfaces (MMS). A strong and resonant photon–plasmon coupling in single and double structures is found. The effect can be used to mimic bulk negative index materials with a promise for lower optical losses. Based on the optical properties of the MMS structures the application fields reach from near/far field lenses to communication devices. The strong photon–plasmon coupling effects pave the route for dense optical/plasmonic integration.

미앤더 라인을 이용한 RFID 태그용 원형 루프 안테나의 소형화

본 논문에서는 UHF 대역(<TEX>$908.5{\sim}914$</TEX> MHz)에 사용되는 RFID 태그용 소형 안테나를 원형 루프 안테나로 설계 및 제작하였다. 원형 루프 구조를 미앤더 라인 구조로 변형시킴으로써 원형 루프 안테나의 소형화를 가능하게 하였다. 2단 미앤더 라인 구조를 이용한 소형 원형 루프 안테나의 경우, 안테나 직경이 40 mm로 일반 원형 루프 안테나에 비해 83%의 크기 축소율을 얻었으며, <TEX>$S_{11}$</TEX>, -11.9 dB, -10 dB 대역폭 12 MHz(1.3%), 최대 이득 -1.18 dBd의 특성을 얻었다. 또한 알루미늄으로 코팅된 과자 봉지와 같은 평면형 도체에 부착 가능하도록 태그 안테나를 2단 미앤더 라인 구조를 이용하여 반파장 원형 루프 안테나에 적용시킨 반파장 소형 원형 루프 안테나를 고안, 제작하였다. 이 안테나는 접지면을 제외하고 92.1%의 크기 축소율을 얻었으며, <TEX>$S_{11}$</TEX> -16.5 dB, -10 dB 대역폭 48MHz(5%), 최대 이득 -0.58 dBd의 특성을 얻었다. 방사 패턴은 z-y면에서 무지향성 패턴 특성을 나타내었다. 이로써 본 논문에서 제안된 미앤더 라인 구조의 원형 루프 안테나가 RFID 태그 안테나의 소형화에 적합함을 확인하였다. In this paper, the miniaturized radio frequency identification(RFID) tag antennas used in UHF band<TEX>$(908.5{\sim}914MHz)$</TEX> are designed and fabricated by using the circular loop antenna(CLA). Miniaturization of CLA was possible to transform the structure of circular loop into the structure of meander line. In the case of double meander line CLA is reduced up to 83% compared with the general type CLA. The <TEX>$S_{11}$</TEX>, -10 dB bandwidth, and gain of double meander line CLA were -11.9 dB, 12 MHz(1.3%), and -1.18 dBd. Also, a small half-wavelength CLA using double meander line is designed and fabricated for flat snack bag coated aluminum. The antenna is reduced up to 92.1% except ground. It shows the <TEX>$S_{11}$</TEX> of -16.5 dB, -10 dB bandwidth of 48 MHz(5%) and gain of -0.58 dBd. The radiation pattern shows omni-directional pattern in z-y plane(x-axis pol.). Through this result, we can confirm that miniaturized type CLAs using meander lines are suitable for miniaturized RFIB tag antennas with the UHF band.

Linear Variable Reluctance (VR) Micro Motors With Compensated Attraction Force: Concept, Simulation, Fabrication and Test

This paper reports on optimized fabrication technologies for electromagnetic actuator systems and their characterization. These actuators consist of three-dimensional microstructures of increasing complexity like electroplated micro coils, flux guidances, insulation and planarization layers. The microstructures are fabricated by UV depth lithography using AZ9260, electrodepositable photo resist and Epon SU-8. Electroplated nickel iron and copper is used for the generation of flux guidance and coils. The magnetic flux is generated and guided in plane by a three dimensional double meander coil wound around laterally toothed stator poles. The traveller's comb shaped poles reach in between the stator poles and, therefore, are attracted from both sides. Thus, the attraction forces exceeding thrust, common to any VR-motor concept, are eliminated. The micro actuator was simulated, fabricated and successfully tested.

Brownian excursion area, Wright’s constants in graph enumeration, and other Brownian areas

This survey is a collection of various results and formulas by different authors on the areas (integrals) of five related processes, viz. Brownian motion, bridge, excursion, meander and double meander; for the Brownian motion and bridge, which take both positive and negative values, we consider both the integral of the absolute value and the integral of the positive (or negative) part. This gives us seven related positive random variables, for which we study, in particular, formulas for moments and Laplace transforms; we also give (in many cases) series representations and asymptotics for density functions and distribution functions. We further study Wright’s constants arising in the asymptotic enumeration of connected graphs; these are known to be closely connected to the moments of the Brownian excursion area. The main purpose is to compare the results for these seven Brownian areas by stating the results in parallel forms; thus emphasizing both the similarities and the differences. A recurring theme is the Airy function which appears in slightly different ways in formulas for all seven random variables. We further want to give explicit relations between the many different similar notations and definitions that have been used by various authors. There are also some new results, mainly to fill in gaps left in the literature. Some short proofs are given, but most proofs are omitted and the reader is instead referred to the original sources.

COMPACT RING MONOPOLE ANTENNA WITH DOUBLE MEANDER LINES FOR 2.4/5 GHZ DUAL-BAND OPERATION

A novel compact ring monopole antenna with double meander lines is proposed for wireless local area networks (WLAN) applications in IEEE 802.11b/g/a systems. The designed antenna, fed by a 50 Ω microstrip transmission line, is only 32 mm in height and 16 mm in width. By introducing a horizontal and a vertical branched strips to a closed rectangular strip ring, the proposed antenna can generate two separate impedance bandwidths. Prototypes of the proposed antenna have been constructed and tested. The obtained impedance bandwidths reach about 12% for the 2.4 GHz band and 45.3% for the 5 GHz band, which meet the required bandwidth specification of 2.4/5 GHz WLAN standard. Also, good radiation performance and antenna gain over the two frequency ranges have been obtained.

Tail estimates for the Brownian excursion area and other Brownian areas

Brownian areas are considered in this paper: the Brownian excursion area, the Brownian bridge area, the Brownian motion area, the Brownian meander area, the Brownian double meander area, the positive part of Brownian bridge area, the positive part of Brownian motion area. We are interested in the asymptotics of the right tail of their density function. Inverting a double Laplace transform, we can derive, in a mechanical way, all terms of an asymptotic expansion. We illustrate our technique with the computation of the first four terms. We also obtain asymptotics for the right tail of the distribution function and for the moments. Our main tool is the two-dimensional saddle point method.

Preparation of periodic structures by meander type liquid phase epitaxy

The growth of nanostructures by epitaxial growth from a narrow slot of the melt shaped into a meander form is described. Basic types of the meander shapes enable the realization of conditions when the growing layer is composed of thin segments of some material (single meander liquid phase epitaxy — SM LPE) or two materials (double meander liquid phase epitaxy — DM LPE). This configuration has been used experimentally for the preparation of structures of GaInAsPInP. There is a clear correlation between the increase of the full width at half maximum (FWHM) of photoluminescence (PL) peaks and the value of the barrier melt carry-over. The methodology of determination of the melt carry-over values has been created, as well as the quantitative theory enabling the description of the consequent changes of melt composition.