Abstract—A multifunctional meander line polarizer is described. The polarizer is capable of eﬀecting conversions between linear and circular polarization and between left-hand and right-hand circular polarization. It can also cause arbitrary rotation of linear polarization, including converting a wave from horizontal polarization to vertical. The polarizer is analyzed by the spectral domain approach.
H-plane Spiro Meander Line Uniplanar Compact EBG (HSMLUC-EBG) as shown in Figure 14 has been created by modifying the E-SMLUC-EBG. Dimension of the unit cell of modiﬁed structure (H- SMLUC-EBG) by increasing the length of spiral line of E-SMLUC-EBG is shown in Table 5. H-coupling in antenna develops between non-radiating edges, hence the capacitance between antenna and EBG gets decreased. To compensate this, we have increased the length of spiral line so that resonant frequency remains unchanged. Behavior of the combination of three unit cells of the proposed H-SMLUC-EBG has
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Meander line antenna has been considered desirable on flight vehicles to reduce drag and mini- mize aerodynamic disturbance; however, the antenna design and performance analysis have made mostly by trial-and-error. An inductor model by simulating the meander line sections as electrical inductors and the interconnecting radiation elements as a quasi-monopole antenna is developed to analyze the antenna performance. Experimental verifications of the printed meander line antennas embedded in composite laminated substrates show that the inductor model is effec- tive to design and analyze. Of the 4 antennas tested, the discrepancy of resonant frequency in simulation and experiment is within 4.6%.
Abstract—In this paper, a symmetrically structured meander line antenna placed around a T-shaped junction with truncated ground planes is proposed for wearable applications. The designed antenna has a percentage bandwidth of 69.04% covering the GSM 1800 band industrial scientiﬁc and medical (ISM) 2.4–2.5 GHz band, 4G LTE band 7 (2.5–2.69 GHz). The antenna is compact in nature with a size of 30 × 40 × 1.6 mm 3 . SAR reduction is achieved without the attachment of any additional unit. It is found that the application of designed truncated ground planes around positions of high electric ﬁeld (E-ﬁeld) region is an eﬀective solution for reduction of Speciﬁc Absorption Rate (SAR) signiﬁcantly through ﬁeld cancellation technique. Maximum temperature elevation due to electromagnetic wave absorption has also been computed. The antenna is simulated over a homogenous human dry skin model as well as over a head model. The proposed design is fabricated and measured, and it is found to be compatible for real world applications while considering its miniaturization, radiation patterns and SAR limitations.
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While ACO-based techniques display a natural suitability for the constructive design meth- ods of meander line antennas, they are unlikely to be the only effective approaches to this problem. This is particularly true when the “problem” is to explore the performance envelope in the wider design space, not just optimise a specific antenna for a specific purpose. For these studies, using a diverse range of construction methods and optimisation algorithms is neces- sary to ensure a diversity of trial solutions and adequate coverage of the design space. To this end, later work investigated the efficacy of other, algorithmically-diverse techniques. Gomez- Meneses, Randall and Lewis  used another nature inspired technique referred to as extremal optimization (EO). As EO is an iterative, rather than constructive, heuristic, and handles per- mutations poorly, the antenna construction process was adapted to a knapsack problem in which antenna segments are selected for inclusion. This creates an extremely rich space of solutions compared to that explored by the ACO implementation, including antennas with “parasitic” elements that are not connected to the main antenna path. The results revealed that the EO algorithm had similar performance to ACO on the smaller grids (up to size 7), but dropped off, particularly in terms of resonant frequency, on larger grid sizes. Representing the problem as a binary selection problem is an ongoing area of research, with Hettenhausen, Lewis, Thiel and Shahpari  investigating the use of a binary Multi-Objective Particle Swarm Optimization algorithm (MOPSO) to explore the general design space of electrically- small, planar antennas using a representation of them as made up of a number of square patches. Preliminary experiments have shown some promising results in terms of the diversity of the design space explored but have, to date, not exceeded the performance envelope estab- lished by the original ACO studies.
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wireless systems such as GSM, DCS and UMTS While many moveable communications system uses a simple antenna with a matching circuit (Soltani et al. 2011); (Lakhtakia 2006), it may result in reduced efficiency, when designed much smaller in order to suit into compact devices (Shafie et al . 2010); (Liao et al . 2010).Therefore a meander line antenna is presented here to produce a triple- band frequency without any harmonics at a resonance frequencies of 0.9 GHz, 1.8 GHz and 2.1 GHz.
Abstract—A slotted meander line printed monopole antenna for low frequency applications of 878 MHz is presented. The novelty of the design is obtained by evaluating numerous slots and meander line that produces a new structure of double E-shaped meander line antenna backed by a defected partial ground plane. The operating frequency of the conventional printed monopole antenna is greatly reduced by the presence of the slots and meander line which lead to the reduction of the antenna size. The size reduction of 70% compared to the conventional reference antenna is achieved in this study. The antenna has a simple structure and small antenna size of 46 . 8 mm × 74 mm or 0 . 137 λ 0 × 0 . 217 λ 0 . The
In this paper, a novel meander line microstrip log-periodic dipole antenna for dual-polarized radar systems is presented and optimized, working in the reference frequency band 2–8 GHz. The speciﬁc interest is focus on its dual polarization, wide impedance band, reduced cross-polarization components, high isolation between the input ports providing the polarization diversity and suitable scanning capabilities. This paper is organized as followings: in Section 2, the geometry and design of the proposed antenna are presented. The accuracy of designed parameter values and veriﬁcation of the proposed antenna are carried out with measurements in Section 3. Finally, conclusions are brieﬂy shown in Section 4.
Abstract—In this paper, a complementary meander line split-ring resonator (C-MLSRR) model is proposed, and its equivalent circuit model is given. Prototypes of microstrip lines loaded with C-MLSRR with and without series capacitive gaps are designed, which exhibit a negative permittivity behavior (without series capacitive gaps) and a left-handed behavior (with series capacitive gaps), respectively, at two different frequencies. The application of the C-MLSRRs in compact dual band (i.e., 2.52 GHz and 5.35 GHz) notch filter for wideband application is presented to highlight the unique features of the C- MLSRRs.
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separation between the antenna elements is desired to restrict the surface wave. Hence could not be of use for miniature design. However, Chang et al.  and Zhao et al.  proved that the addition of decoupling and matching network in a miniature design could reduce mutual coupling between antenna elements. Ghosh et al.  introduced meander line resonator to achieve mutual coupling of only upto − 10 dB. Ray et al.  designed printed antenna consisting of two substrates placed one below the other and separated by air gap in-between. This separation resulted in decreasing the coupling between the two patches. D. Guha and J. Y. Siddiqui  obtained attractive tunability characteristics of printed antenna with an air gap in between the substrate and the ground plane. Li et al.  designed a defected ground structure (DGS) for reducing mutual coupling but in such a device increment was experienced in back-radiation or decrement in front-to-back ratio. Signiﬁcant front-to-back radiation ratio was accomplished through the use of metal-backed substrates [17, 18]. Antennas printed on metal-backed substrate have limited eﬃciency and bandwidth as the radiated ﬁeld from the image of antenna’s electric current cancels out the radiated ﬁeld from the antenna current itself. In this case, input impedance matching of the antenna becomes diﬃcult as the presence of perfectly electric conductor (PEC) ground plane results in signiﬁcant increases in the stored electromagnetic energy of the antenna. A possible solution to circumvent this diﬃculty is to use artiﬁcial perfectly magnetic conductor (PMC). Unlike PEC surface, PMC surface allows for the placement of parallel electric currents in their close proximity. The input impedance matching of the antenna becomes easier in case of PMC surface, as the radiated ﬁelds add up in-phase. PMC surface however suﬀers from low overall antenna eﬃciency as they tend to become lossy and absorb the antenna near-ﬁeld energy. Mosallaei and Sarabandi  utilized the three properties of RIS to minimize mutual coupling eﬀect between the antenna and its image, enhance bandwidth, miniaturize antenna size and improve front-to-back ratio. The three properties of RIS substrate include total power reﬂection, spatial distributed image representation and ability to store electric or magnetic energy. In MLA, the conductors are folded back and forth to make the overall antenna shorter . Their beneﬁts include, lightweight, small-size, easy to integrate, low fabrication cost and potential for low speciﬁc absorption rate (SAR).
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Meander antenna is electrically small antenna .The design of meander line antenna is a set of horizontal and vertical lines. Combination of horizontal and vertical lines forms turns. Number of turns increases efficiency increases. In case of meander line if meander spacing is increase resonant frequency decreases. At the same meander separation increase resonant frequency decreases. The meander line element consists of vertical and horizontal line so it formed a series of sets of right angled bends. The polarization of antenna depends on radiations from the bend. The spacing between two bends is very vital, where if the bends are too close to each other, then cross coupling will be more, which affects the polarization purity of the resultant radiation pattern.
First of all, before the project was conducted, the literature review was done by gathering information about existing ordinary antennas. Information regarding the project taken from books, journals and internet resources for better understanding and to find solutions or options. As for next step, the design of parasitic meander line antenna was studied. The process of designing antenna using parasitic element was analyzed. Then, get used to the software and basic skills of it. The software or simulator that used is Microwave Studio CST of Microwave Office. The parameters that obtained from simulation are the frequency, return loss, directivity, gain, bandwidth, radiation pattern and polarization .
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Finally, I would also like to extend our utmost gratitude to all the lecturers of University Technical Malaysia Malacca (UTeM) for their guidance and patience. Their teachings have thought me that education and knowledge are vital in life if we wish to succeed. DUAL LAYER SLOTTED MEANDER LINE ANTENNA DESIGN
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Parallel matching stub is applied here to demonstrate the performance of impedance-matched conventional meander line antenna, whose configuration is shown in Fig. 1 (MLA2). A shorting pin is employed to connect the parallel stub to the ground plane. These two MLAs are modeled and simulated in ANSYS HFSS software package, and their primary structural parameters are listed in Table 1 with other relevant parameters given as: the thickness of FR4 dielectric substrate (ε r = 4.4) h d = 1.6 mm;
We can control the properties of meander line resonators by varying the dimension. Three dominant dimensions are the length of horizontal wires (deﬁned as l in Fig. 1), the width of wires (deﬁned as w in Fig. 1) and the gap between wires (deﬁned as g in Fig. 1). The length of wires mainly decides the equivalent inductance of the structure. Once it grows, the inductance increases, making the resonant frequency lower down. The gap between wires aﬀects the resonant frequency as well, since the gap size inﬂuences the inductance of the perpendicular wires. When the gap size increases, the resonant frequency decreases. The width of wires also inﬂuences the equivalent inductance. By widening the wires, we could decrease the inductance and increase the resonant frequency. Some simulation results have proved these analyses, as shown in Fig. 4.
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Common design of antenna faced some issues regarding the size because a bigger size of antenna will not only make it costly, but also have difficulties to fit in a device. In order to overcome the problem, a meander line antenna would be one of the suitable methods to be used to design a low profile antenna. Meander line antenna is chosen because it is able to reduce or miniaturize the size of antenna. It is smaller in size and very flexible to be shifted or relocated .
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The driving current for the EMATs is provided using an adapted Ritec RAM-5000 pulser-receiver. The signal pulse used for the meander line designs was a 2 MHz, 7 cycle sinusoid. The racetrack design for transmission was powered by a 3 cycle pulse, also at 2 MHz for most of this work, however, the optimal signal strength for the design was found to be at 1 MHz. For improved signal detection, all the data shown in this work has been processed to show only the signal power; a more in depth explanation of the technique can be found in previous work by the authors . This has been calculated by cross-correlating the raw data with a synthetic signal designed to mimic the generation signal, taking the absolute value of the output, to extract the signal wave packet, and then squaring it to give a power. The synthetic signal, G, was generated as follows:
Since there are errors inherent in our determination of the dielectric constant and especially the loss tangent, in Fig. 13, we show the response of the meander line for the lossless and lossy cases, but this time, the losses have been increased to 0.05 and 0.09 for the frequency ranges 0–8 GHz and 8–16 GHz, respectively. This simulation (Fig. 13) is intended to give a very qualitative perspective on the effect of having higher losses in the transmission line system. Clearly observed, from the results presented in Fig. 13, that as the losses of the transmission line system increase, the more the output pulse deviates from that of the ladder-dominated response that characterizes the lossless system. Notice the DC offset seen before the arrival of the pulse (in Figs. 12 and 13) is a typical characteristic of the meander line and is due to the synchronous coupling that results in premature arrival of some pulse energy.
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In this article, a compact (25.4 mm × 25.4 mm×0.762 mm) electrically small, low profile dual band antenna is presented. Multifunctional compact planar versions are introduced by appropriately four meander line elements. These antenna can be used for dual band [GPS L1 and Global star (GS)] linear polarization application. The performance characteristics of the proposed dual band antenna is investigated by Finite Element Method based 3D electromagnetic simulator ANSYS Ansoft High Frequency Structure Simulator (HFSS).
Meander line antennas were commonly for UHF tags, due to the characteristics of high gain, omni-directionality, planarity and relatively small surface size . However, the length-to-width ratio limited as 5 : 1 was proposed . Recently, the half-Sierpinski fractal antenna was introduced with a small length-to-width ratio (< 2 : 1) . The inductive impedance of tag antenna was necessary for matching the capacitive terminations of chip IC, thus the tuning apparatus was proposed [5, 9–11, 18]. H-shaped meandered- slot antennas with the performance of broadband and conjugate impedance matching were developed for on-body applications [15, 16]. The ceramic patch antenna mountable on metallic objects was proposed . The compact microstrip antenna with Koch curve was presented . On the other hand, the self-complementary dipoles were introduced for the performance of wideband, high impedance and balun [20–27].
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