Showing papers in "Progress in Electromagnetics Research C in 2019"
TL;DR: In this article, a dual band circular microstrip patch antenna with an elliptical slot for future 5G mobile communication networks is presented, which has resonating frequencies of 28 GHz and 45 GHz, with bandwidths of 1.3 GHz and 1 GHz, respectively.
Abstract: This paper presents a dual band circular microstrip patch antenna with an elliptical slot for future 5G mobile communication networks. The antenna has resonating frequencies of 28 GHz and 45 GHz, with bandwidths of 1.3 GHz and 1 GHz, respectively. Efficiency of the antenna is 85.6% at 28 GHz and 95.3% at 45 GHz. The return loss at 28 GHz is −40 dB, with maximum gain of 7.6 dB while at 45 GHz return loss is −14 dB with maximum gain of 7.21 dB. The antenna is designed on a Rogers RT5880 (lossy) substrate with dielectric constant of 2.2 and loss tangent (tan δ) of 0.0013. The antenna has a compact size of 6× 6× 0.578 mm3. Array configuration is used to achieve 12 dB gain, required for mobile communication. The proposed array has resonance frequencies of 28 GHz, 34 GHz and 45 GHz with maximum gain of 13.5 dB and radiation efficiency of 98.75%. Centre series fed technique is used for the excitation of array. SAR value of array antenna obtained at 28 GHz is 1.19 W/kg, at 34 GHz is 1.16 W/kg, and at 45 GHz is 1.2 W/kg. CST Microwave Studio, a 3D simulating tool, is used for the antenna design and calculation of the antenna parameters along with the SAR analysis.
91 citations
TL;DR: In this paper, the authors introduced new compact microstrip line fed dual-band printed MIMO antennas resonating at 28 GHz and 38 GHz which are appropriate for 5G mobile communications.
Abstract: This paper introduces new compact microstrip line fed dual-band printed MIMO antennas resonating at 28 GHz and 38 GHz which are appropriate for 5G mobile communications. The first design in this work is a two-element conventional rectangular microstrip patch antenna with inset feed intended for 28 GHz and 38 GHz bands. The second design is symmetric dual-band two-element MIMO slottedrectangular patches via microstrip inset fed lines. The dual-band response is attained from inverted I-shaped slots inserted in main patches. The third design is symmetric dual-band four-element MIMO antenna with inverted I-shaped slotted rectangular patches. A slot formed DGS is inserted in the partial rectangular ground plane. The substrate size is 55× 110 mm2, while the introduced antennas have very modest planar configurations and inhabit an insignificant area which make them fit easier within handset devices for the forthcoming 5G mobile communications. Better return losses and larger bandwidths are realized. The MIMO antennas have low mutual coupling without using any added constructions. The antenna systems offer appropriate values of directivity, gain, and radiation efficiency with anticipated reflection and correlation coefficient characteristics which are seemly for 5G mobile applications. The antenna systems are fabricated by a photolithography process that uses optic-radiation to copy the mask on a silicon slab by the aid of photoresist layers and measured using Vector Network Analyzer ZVA 67 (measures up to 67 GHz frequency) with a port impedance of 50 Ω.
82 citations
TL;DR: In this paper, a semi-elliptical patch that is fed by a tapered microstrip line is proposed to give wide impedance bandwidth from 2.4 GHz to more than 12 GHz.
Abstract: This paper introduces a novel MIMO UWB antenna with dual notches. The proposedantenna is based on Quasi Self Complementary (QSC) method to give wide impedance bandwidthfrom 2.4GHz to more than 12 GHz. The proposed antenna consists of a semi-elliptical patch that isfed by a tapered microstrip line. The antenna is designed on an FR-4 substrate with compact size20mm × 15mm × 1.5mm. The dual notched bands are achieved by using a square ring printed on thebottom of the substrate to reject WiMAX at 3.6 GHz. Also, a C-shaped slot is etched in the radiatingpatch to reject interference with the WLAN band at 5.8 GHz. In the proposed MIMO antenna, theisolation reduction is achieved utilizing diversity technique to minimize the mutual coupling betweenthe antennas. The isolation between MIMO elements is more than 20 dB. The envelope correlationcoefficient (ECC), diversity gain (DG), total active reflection coefficient (TARC), furthermore, channelcapacity loss (CCL) are measured and calculated. The proposed antenna is designed, simulated, andmeasured. A good agreement is shown between the experimental and simulated results.
34 citations
TL;DR: In this article, a silica-based highly nonlinear photonic crystal fiber of near infrared window was explored for propagating light towards the near-infrared wavelength region; it was demonstrated that it is possible to generate high power wide supercontinuum spectrum using 2.5 ps input pulses at 1.06 μm, 1.30 μm and 1.55 μm center wavelengths.
Abstract: This research explores a silica based highly nonlinear photonic crystal fiber of near infrared window; solid silica core photonic crystal fiber is suitable for propagating light towards the near-infrared wavelength region. Full vector finite difference method is used for numerical simulation, by solving the generalized nonlinear Schrödinger equation with the split-step Fourier method to show that the design exhibits high nonlinear coefficient, near zero ultra-flattened dispersion, low dispersion slope and very low confinement losses. It is demonstrated that it is possible to generate high power wide supercontinuum spectrum using 2.5 ps input pulses at 1.06 μm, 1.30 μm and 1.55 μm center wavelengths. It is observed that supercontinuum spectrum is broadened from 960 nm to 1890 nm by considering center wavelengths of 1.06 μm, 1.31 μm, and 1.55 μm into silica based index guiding highly nonlinear photonic crystal fiber. Furthermore, immensely short fiber length of 1m at center wavelengths of 1.06 μm, 1.31 μm and 1.55 μm is possible using the proposed highly nonlinear photonic crystal fiber. The generated high power wide supercontinuum spectrum is applicable as a laser light source in near infrared band.
31 citations
TL;DR: In this article, the effects of incident wave angular power spectrum (APS) distribution and user hand effect on the envelope correlation coefficient (ECC) of a two-port MIMO antenna operating in the sub 6GHz LTE-U frequency band were studied.
Abstract: This paper studies the effects of incident wave angular power spectrum (APS) distribution and user hand effect on the envelope correlation coefficient (ECC) of a two-port MIMO antenna operating in the sub 6GHz LTE-U frequency band. APS of uniform and Gaussian distributions are used with different Gaussian angular spread (AS) values, i.e., 10◦, 30◦, 50◦, and 70◦. A prototype was fabricated, and three-dimensional radiation patterns of the antenna elements were measured in an anechoic chamber from 4 to 6GHz in both cases of free space and when the prototype is held in data mode using a hand phantom. An algorithm to calculate ECC from the complex data of far field radiation pattern with different APS distributions is explained in detail. Results show that user hand presence increases ECC between ports compared with free space, whose increase is more obvious under Gaussian APS. ECC values under uniform APS is practically zero over the entire frequency range except at frequencies close to 6 GHz, where the highest ECC values are 0.13 and 0.16 in free space and with user hand, respectively. However, Gaussian APS with different ASs shows a significant impact of the ECC. With narrow AS of 10◦, ECC at some incident directions can be as high as 0.84 (in free space) and 0.92 (with user hand), and the mean ECC values under this AS are 0.25 (in free space) and 0.37 (with user hand). ECC values keep decreasing as AS gets wider, with the maximum ECC at AS = 70◦ observed to be 0.23 and 0.34 in free space and with user hand, respectively, whereas the mean ECC values are close to uniform APS. Statistical distribution of the ECC showed good agreement with exponential distribution, with a better agreement between measured ECC and exponential distribution observed in free space with wider AS.
31 citations
TL;DR: In this paper, a compact ultra-wideband (UWB) multiple-input multiple-output (MIMO) spatial diversity antenna with dual band-notches designed on an FR4 substrate is proposed and experimentally investigated.
Abstract: In this paper, a compact ultra-wideband (UWB) multiple-input multiple-output (MIMO) spatial diversity antenna with dual band-notches designed on an FR4 substrate is proposed and experimentally investigated. The antenna consists of two radiating elements fed by two tapered microstrip lines. Two inverted L-shaped slits are used to introduce notches at WLAN (5.15–5.85 GHz) and IEEE INSAT/Super-Extended C-band (6.7–7.1 GHz). An isolation of more than 15 dB is achieved through the whole working band (2.9–10.8 GHz) by introducing a T-shaped decoupling structure on the ground plane. Furthermore, the envelope correlation coefficient (ECC), diversity gain (DG), multiplexing efficiency, TARC, peak gain and radiation patterns of the MIMO antenna are also discussed. The simulated and measured results show that the proposed UWB MIMO antenna is a good candidate for UWB diversity applications.
25 citations
TL;DR: In this article, the effect of the presence of a resonator defect on the transmission behavior, phase, and phase time of a one-dimensional photonic comb-like structure was studied.
Abstract: This work describes a theoretical study of filters using a defect in one-dimensional photonic comb-like structure. This photonic comb-like structure is constituted by finite or infinite segments which have negative permeability and grafted in each site by a finite number of lateral branches (play the role of the resonators), which consists of a negative permittivity. Numerical results exhibit the permissible bands which are separated by gaps (forbidden band). These gaps originate not only from the periodicity of the system but also from the resonance states of the grafted lateral branches. We study the effect of the presence of a resonator defect on the transmission behavior, phase, and phase time. The electromagnetic band structure shows that there is a defect mode in the gap. The transmission rate and the reduced frequency of this mode are related to the variation of defect length. Similarly, we calculate, for the first time, the quality factor evolution of this defect mode when the defect length varies. This structure can be used as a new optical filter in the microwave range with a high factor of quality and of transmission.
25 citations
TL;DR: A novel reconfigurable filtering antenna with three tunable states used for IoT applications using the combination of a hairpin filter and an open loop filter in the structure with the switching of p-i-n diodes is presented.
Abstract: This paper presents a novel reconfigurable filtering antenna with three tunable states used for IoT applications. The frequency reconfigurability is achieved using the combination of a hairpin filter and an open loop filter in the structure with the switching of p-i-n diodes. The open-loop filter structure provides two narrow band states at 2.4 GHz and 7.8 GHz, and the hairpin filter provides a single narrow band state at 10.4 GHz. The frequency reconfiguration is obtained without compromising the compact size of the designed circuit along with the targeted frequency bands at lower WLAN (2.47 GHz), WiMAX (3.42 GHz), INSAT C-band (7.18 GHz), fixed/mobile satellite service in X-band (8.4 GHz), direct broadcast service in Ku-band (12.14 GHz) applications. The prototype is constructed on an FR4 substrate and tested for validation in an anechoic chamber. The designed antenna provides excellent radiation characteristics and considerable gain at resonant frequencies. The proposed reconfigurable antenna is also tested using the CDAC Cmote device in the real-time environment and found more suitable for the IoT based communication applications.
22 citations
TL;DR: In this paper, the problem of shielding an infinitesimally thin perfectly conducting circular disk against a vertical magnetic dipole is solved in an exact form through the application of the Galerkin method in the Hankel transform domain.
Abstract: The problem of the shielding evaluation of an infinitesimally thin perfectly conducting circular disk against a vertical magnetic dipole is here addressed. The problem is reduced to a set of dual integral equations and solved in an exact form through the application of the Galerkin method in the Hankel transform domain. It is shown that a second-kind Fredholm infinite matrix-operator equation can be obtained by selecting a complete set of orthogonal eigenfunctions of the static part of the integral operator as expansion basis. A static solution is finally extracted in a closed form which is shown to be accurate up to remarkably high frequencies.
20 citations
TL;DR: In this paper, a wearable antenna for wireless body area network (WBAN) that operates at the 2.45 GHz medical band is proposed, which is enabled by coplanar waveguide, and the impedance bandwidth of the antenna is expanded by combining a circular slot with asymmetric slots.
Abstract: This paper proposes a wearable antenna for Wireless Body Area Network (WBAN) that operates at the 2.45 GHz medical band. The antenna is enabled by coplanar waveguide, and the impedance bandwidth of the antenna is expanded by combining a circular slot with asymmetric slots. In order to reduce the radiation of the antenna back lobe and improve the antenna gain, a new 2×2 Artificial Magnetic Conductor (AMC) is designed and loaded under the monopole antenna. The radiation of antenna back lobe is effectively reduced due to the addition of AMC reflector. Also, the front-to-back ratio of the demonstrated antenna is higher than 20 dB, achieving a forward gain of 7.47 dBi and Specific Absorption Rate (SAR) lower than 0.15 W/kg, in the ISM band. For further research, the antenna is fabricated and tested, showing a strong agreement between simulation and measurement. Meanwhile, the antenna has stable performance under the bending condition, meeting the practical application requirements of wearable equipment.
19 citations
TL;DR: A general synthesis approach is proposed for reflectarrays using second order Phoenix cells using an original spherical representation that transforms the optimization domain in a continuous and unbounded space with reduced dimension.
Abstract: A general synthesis approach is proposed for reflectarrays using second order Phoenix cells. It relies on an original spherical representation that transforms the optimization domain in a continuous and unbounded space with reduced dimension. This makes the synthesis problem simpler and automatically guarantees smooth variations in the optimized layout. The proposed mapping is combined with an Artificial Neural Network (ANN) based behavioral model of the cell and integrated in a min/max optimization process. Bi-cubic spline expansions are used to decrease the number of variables. As an application, a contoured beam for space communication in the [3.6–4.2] GHz band is considered. The gain improvement compared to an initial Phase Only synthesis (POS) is up to 1.62 dB at the upper frequency. Full-wave simulation of the final array is provided as a validation.
TL;DR: In this article, the authors investigated the performance of triple band-notched multiple input multiple output (MIMO) antenna for ultra wideband (UWB) communication and found that the radiation efficiency of the radiator is more than 80% over the entire UWB frequency range.
Abstract: This paper investigates the performance of compact triple band-notched Multiple Input Multiple Output (MIMO) antenna for Ultra-Wideband (UWB) communication. Open-ended quarter wavelength slots are inserted on the radiators. These slots are used to obtain notch bands at WiMAX/C band, WLAN band and the X-band Satellite Communication System that ranges in 3.3–4.2 GHz, 5– 6GHz, and 7.2–8.6 GHz, respectively. An I-shaped stub extends from the ground surface to minimize mutual coupling among radiating elements. Mutual coupling and Envelope Correlation Coefficient are found less than −15 dB and 0.2, respectively. The diversity characteristics like Mean Effective Gain Ratio and Total Active Reflection Coefficient are found around 1 dB and less than −10.5 dB respectively. The radiation efficiency of the radiator is more than 80% over the entire UWB frequency range. The proposed antenna is designed with the overall dimensions of 23 × 40 × 1.6 mm3.
TL;DR: In this article, a parasitic element structure is proposed to reduce the mutual coupling in a miniaturized microstrip dual-band MIMO antenna, which resonates at (7.6 to 8.16 GHz) and 600 MHz (13.8 to 14.2 GHz) for Ku band applications.
Abstract: In this article, a parasitic element structure is proposed to reduce the mutual coupling in a miniaturized microstrip dual-band Multiple-Input Multiple-Output (MIMO) antenna, which resonates at (7.8 GHz) for X-band and at (14.2 GHz) for Ku band applications. The design of the primary antenna consists of two identical radiators placed on a 24 × 20 mm2 Fr-4 substrate, which are excited by orthogonal microstrip feed lines. In addition, a single complementary split ring resonator (S-CSRR) is used to improve the performance of proposed antenna. Simulation and measurement were used to study the antenna performance, including reflection coefficients, coupling between the two input ports, radiation efficiency, and the radiation pattern. The measured results show that the proposed antenna achieves two operating bands with impedance bandwidths (|S11| ≤ −10 dB) of 560 MHz (7.6 to 8.16 GHz) and 600 MHz (13.8 to 14.4 GHz) and mutual coupling (|S12| < −26 dB), which are suitable for X/Ku band applications.
TL;DR: In this paper, a new compact broadband circular fractal antenna is presented to simultaneously cover the operations in S-, C-, X-, and Ku-bands, and the proposed broadband antenna features small size of 38×36×1.4 mm3 and nearly omnidirectional radiation patterns that make it excellent candidate for integration in broadband wireless communication systems.
Abstract: A new compact broadband circular fractal antenna is presented to simultaneously cover the operations in S-, C-, X-, and Ku-bands. Fractal geometry of the radiator including an iterative circular patch with a square slot, a modified feed-line with step technique, and slot-loaded semi-circular ground plane is used to achieve a broad impedance bandwidth more than 151% from 3 to 21.5 GHz (|S11| < −10 dB). The simulation results are verified by experimental measurements. Measured data are in good agreement with the simulated results. The frequencyand time-domain characteristics of the antenna including impedance matching, far-field patterns, gain, group delay, and fidelity factor are presented and discussed. The proposed broadband antenna features small size of 38×36×1.4 mm3 and nearly omnidirectional radiation patterns that make it excellent candidate for integration in broadband wireless communication systems.
TL;DR: In this paper, a compact multiple-input-multiple-output (MIMO) antenna with very high isolation is proposed for ultrawideband (UWB) applications.
Abstract: A compact multiple-input-multiple-output (MIMO) antenna with very high isolation isproposed for ultrawideband (UWB) applications. The antenna with a compact size of 30.1 × 20.5mm) consists of two
TL;DR: In this paper, a wideband antenna is designed systematically based on characteristic mode analysis (CMA), which consists of a rectangle, a semi-annular ring, and a microstrip line.
Abstract: In this paper, a wideband antenna is designed systematically based on characteristic mode analysis (CMA). The antenna consists of a rectangle, a semi-annular ring, and a microstrip line. The radiating behavior and resonant frequencies of the radiating element are analyzed by using first four characteristic modes. First two modes only have wideband behavior and are excited by CPW feeding technique. The proposed antenna is printed on a low cost FR4 substrate with a size of 35×50×1.6 mm3 and impedance bandwidth ranging from 1.6 to 3.8 GHz for the applications of GSM, DCS, LTE, and WIMAX. To validate the proposed approach, the wideband antenna is fabricated and tested. A wide impedance bandwidth of 81% with |S11| < −10 dB is achieved for both simulation and measurement results.
TL;DR: In this paper, a modified square spiral antenna (MSSA) is proposed for achieving a miniaturized quad-band microstrip patch antenna (MPA) suitable to be used for 915-MHz (UHF band), 2.45-GHz (2395-2510 MHz), band 3: 3.5GHz (3470-3550 MHz), and band 4: 5.8-GHz(5698-5900 MHz).
Abstract: In this paper, a new design approach is presented for achieving a miniaturized quad-band microstrip patch antenna (MPA) suitable to be used for 915-MHz (UHF band), 2.45and 5.8-GHz (ISM band), and 3.5-GHz (WiMAX band). The proposed antenna is called modified square spiral antenna (MSSA) which is composed of a modified dual-arm square spiral patch strip structure and a taperedground plane with coplanar wave-guide (CPW)-fed configuration to feed this antenna, all printed on the top side of an FR4 substrate. The proposed antenna is designed through intermediate systematic design steps of antennas starting from a conventional strip-fed rectangular MPA and ending by achieving MSSA. A CST Microwave Studio (CST MWS) is used to model the designed antenna, and simulation results, in terms of return loss (S11), realized peak gain and efficiency, besides radiation patterns, are obtained. To validate the design concept, the antenna structure is fabricated, and the simulated and measured S11 results nearly coincide with each other. The proposed antenna is characterized by miniaturized size of 28 × 28 mm2, and based on measured −10-dB S11 result, MSSA has four bands, band 1: 915 MHz (872–929 MHz), band 2: 2.45-GHz (2395–2510 MHz), band 3: 3.5-GHz (3470–3550 MHz), and band 4: 5.8-GHz (5698–5900 MHz).
TL;DR: In this article, a fixed-frequency beam steering method using a single patch antenna controlled by only one electronically tunable component is proposed, where a ground-etched slot loaded with one varactor diode is tuned to be capacitive, resonant, or inductive.
Abstract: In this paper, we propose a convenient fixed-frequency beam steering method, using a single patch antenna controlled by only one electronically tunable component. The antenna is based on coupled-mode patch antenna (CMPA) [1] that is capable to scan the beam as the function of frequency. A ground-etched slot loaded with one varactor diode is tuned to be capacitive, resonant, or inductive. In order to test broader tuning range, two kinds of varactors with the ranges of 9.24 pF–1.77 pF and 2.67 pF–0.63 pF are implemented respectively. By analyzing how the loaded slot affects the cavity modes and fields, we demonstrate how the voltage bias tunes the frequency responses and steers beam of the antenna. Perturbed by the loaded slot, the frequency response of the antenna shifts from center frequency of 2.35 GHz with the bandwidth of 4.26% down to the band centered at 2.3 GHz with the bandwidth of 4.35%. The maximum scanning range is realized at around 2.29 GHz where the measured main beam continuously scans from −34◦ to +32◦ when the varactor with lower tuning range is used and biased. Meanwhile, the main beam of 2.35 GHz scans from +32◦ to +54◦ when the higher-range varactor is biased. The proposed single-element antenna is able to maintain high gain and efficiency that are comparable to a regular patch antenna with same size and substrate.
TL;DR: In this article, a hexagonal-shaped multiple-input multiple-output (MIMO) patch antenna is presented, which covers the S band (2-4 GHz), WLAN (2400-2480 MHz & 5150-5350/5725-5875 MHz), UWB (3.1-10.6 GHz), and X band (8-12 GHz) applications.
Abstract: In this paper, a hexagonal-shaped multiple-input multiple-output (MIMO) patch antenna is presented. It covers the S band (2–4 GHz), WLAN (2400–2480 MHz & 5150–5350/5725–5875 MHz), UWB (3.1–10.6 GHz), and X band (8–12 GHz) applications. The proposed structure is simulated and fabricated on an FR4 substrate with overall dimensions of 0.186λ0 × 0.373λ0 and separation of two patches with a distance of 0.053λ0 (where λ0 is the wavelength at 2GHz). The single UWB patch is antenna derived from the triangular-shaped edge cuttings in the bottom of the rectangular patch antenna with a partial and defected ground. The proposed MIMO structure produces simulated results from 2GHz to 13.3 GHz and measured results from 2.1 GHz to 12.9 GHz, with good agreement. The proposed structure resonates at 3.4 GHz, 5.8 GHz, 10.2 GHz, and 11.8 GHz. The isolation is improved to above 20 dB by placing an E-shaped tree structure and parasitic element in most of the band. The radiation efficiency and peak gain values are 78–94% and 1.4–6.6 dB, respectively. Diversity performance of the proposed structure is verified with low envelope correlation coefficient (ECC < 0.04), high diversity gain (DG > 9.985), and acceptable total active reflection coefficient (TARC < −10 dB) values.
TL;DR: In this article, a new compact microstrip low-pass filter with ultra-wide stopband characteristics is presented, which combines DGS-DMS along with quasi octagonal resonators to achieve compact size and ultra wide stopband suppression level.
Abstract: In this paper, a new compact microstrip low-pass filter (LPF) with ultra-wide stopband characteristics is presented. The combinations of DGS-DMS along with quasi octagonal resonators are employed in the design of the proposed filter to achieve compact size and ultra-wide stopband suppression level. The proposed filter has been designed, simulated, optimized and tested. The design procedure is validated using the commercial full-wave EM MoM simulator Microwave Office. Simulated as well as measured results of low-pass filter exhibit sharp roll-off (ξ) of 19 dB/GHz and creating transmission zero at around 7.8 GHz with attenuation level −54 dB. The measurement results show good agreement with the simulations. The cutoff frequency of the proposed low-pass filter is 2.4 GHz with the insertion loss less than 0.3 dB. The ultra wide stopband with over 20 dB attenuation extended from 3.42 GHz to 12 GHz. The spurious passband suppression up to six harmonics (5fc) is achieved for the proposed design. The addition of two parasitics DGS elements in the ground plane leads to suppression of the undesired harmonics und thus to improve the stopband. The size of the whole structure is less as (0.44λg × 0.26λg) with λg = 68 mm. The proposed filter is useful for microwave L band, GPS system, and RADAR applications.
TL;DR: This paper presents the design and analysis of a dual-band circularly polarized (CP) microstrip patch antenna for WLAN and vehicular communication applications and the measured results are found in good agreement with simulated results.
Abstract: This paper presents the design and analysis of a dual-band circularly polarized (CP) microstrip patch antenna for WLAN and vehicular communication applications. In this antenna, an L-shaped slot is cut, and a square parasitic patch with diagonally opposite corners cut is loaded in offset beneath to monopole antenna to realize dual-band CP response with wideband response. The antenna exhibits dual-band CP response at 2.45 GHz (WLAN) and 5.9 GHz (Vehicular) having 20.45% and 15.73% of simulated impedance bandwidth and 6.84% and 14.16% of axial ratio bandwidth for WLAN and Vehicular band, respectively. The measured impedance bandwidth (S11 < −10 dB) is 19.43% and 12.73% for WLAN and vehicular band, respectively. The antenna design is simple and fabricated using an economical glass epoxy FR4 substrate with size of 45 × 40 mm2. The measured results are found in good agreement with simulated results. The proposed antenna is analyzed using transmission line equivalent circuits, and the details are presented and discussed.
TL;DR: In this article, a Ridge Substrate Integrated Waveguide (RSIW) multiple band bandpass filter embedded with an octagonal shape Complementary Split Ring Resonator (CSRRs) is proposed.
Abstract: In this research paper, a Ridge Substrate Integrated Waveguide (RSIW) multiple band bandpass filter embedded with an octagonal shape Complementary Split Ring Resonator (CSRRs) is proposed. The electrically coupled octagonal shape CSRR is placed interdigitally in RSIW using transverse coupling technique to improve multiple passband bandwidths. The filter exhibits a highly selective multiple electric or magnetic or bianisotropic mode for different frequencies. The analysis for spurious band suppression has been done by direct method. The prototype configuration of quarterwavelength octagonal CSRR resonators introduces band suppression at all odd harmonics. The proposed structure of filter with dimension 1.36λg × 0.52λg excluding feed port is fabricated. Full wave structure simulated results are compared with measurement ones. The measured passband frequencies and their calculated respective central frequency (f0), fractional bandwidth (FBW) are in close agreement with the simulated result. The spurious higher order harmonics are observed as suppressed. The filter can be utilized to suppress interference from LAN, WLAN, GSM, WiMAX and variable stopband for ISM interference.
TL;DR: In this paper, a triple frequency band notch antenna with fractal and two via edge located (TVEL) structures near the feed line is proposed to achieve the desired frequency band-notch characteristics over WiMAX, WLAN and satellite downlink communication.
Abstract: A compact ultra-wideband (UWB) antenna with triple band-notch characteristics is proposed. The proposed antenna employs fractal and two via edge located (TVEL) electromagnetic band gap (EBG) structures near the feed line to cause triple frequency band notch characteristics over WiMAX (3.3 to 4.0 GHz), WLAN (5.1 to 5.8 GHz), and satellite downlink communication (7.2 to 7.8 GHz) frequency bands. The proposed antenna is designed and fabricated on a 24×24×1.6 mm3 FR4 substrate. It offers impedance bandwidth (VSWR < 2) from 2.9 to 11.2 GHz except over the notched bands. The antenna has nearly omnidirectional radiation patterns and steady gain over the desired UWB. The measured results agree with the simulated ones.
TL;DR: In this paper, a broadband flexible RFID sensor tag antenna with a T matching network is proposed to detect the concentration of aqueous solutions, which is based on a printed dipole whose arms are loaded with circular disk patches.
Abstract: In this paper, we present a broadband flexible RFID sensor tag antenna to detect the concentration of aqueous solutions. The proposed RFID tag antenna sensor with a T matching network is based on a printed dipole whose arms are loaded with circular disk patches. The structure is printed on a Kapton polyimide flexible substrate. The sensing mechanism of the RFID tag antenna is based on the change of sensitivity of the RFID tag antenna that occurs with the variation of aqueous solution concentration. The proposed sensor is designed using CST Microwave studio, and its various parameters are optimized in order to have a broadband impedance matching that covers the entire RFID band (860– 960 MHz). The experimental setup is small, rapid, contactless, and inexpensive. Results are presented for NaCl and sugar aqueous solutions with concentrations ranging from 0% to 80%.
TL;DR: This paper presents design analysis of a compact CPW-fed Wearable Textile Antenna with Dual Band notched characteristics for UWB applications and its performance is measured and compared with the simulated ones.
Abstract: This paper presents design analysis of a compact CPW-fed Wearable Textile Antenna with Dual Band notched characteristics for UWB applications. The proposed wearable textile antenna is designed on two different dielectric substrates; leather and denim with copper foil as conducting element. The performances of the designed textile antenna are compared on two substrates. Band-notched filtering characteristics are achieved by inserting semicircular split ring resonators on the conducting element. The first notch band is obtained from 2.3–2.5 GHz for Bluetooth application band, and the second notch band is obtained from 3.3–3.6 GHz for WiMAX application band. The simulated and measured frequency results show that the antenna has an impedance bandwidth of 1.8–10 GHz and reflection coefficient less than −10 dB, except at the two eliminating bands. The proposed antenna is designed and simulated using Ansys HFSS Electromagnetic Simulator. The prototype of the antenna has been developed on the denim substrate, and its performance is measured and compared with the simulated ones.
TL;DR: In this paper, the authors proposed an ultrathin triple band microwave absorber using a miniaturized metamaterial structure for near-unity absorption characteristics, which achieved the highest absorption values of 99.04, 99.62, and 99.33% at the frequencies of 4.25 GHz, 8.35 GHz, and 11.06 GHz, respectively.
Abstract: This article discusses about the design and development of an ultrathin triple band microwave absorber using a miniaturized metamaterial structure for near-unity absorption characteristics. In order to design a miniaturized metamaterial (MTM) absorber unit cell with triple band response, two resonators, named as Structure-I and Structure-II, are configured within the single unit cell. The geometrical proportions of the suggested resonators have been chosen in such a manner so that Structure-I can contribute one absorption band while Structure-II can contribute two absorption bands. Therefore, the combination of two resonators offers triple band response with the highest absorption values of 99.04%, 99.62%, and 99.33% at the frequencies of 4.25 GHz, 8.35 GHz, and 11.06 GHz, respectively. Additionally, the suggested absorber unit cell claims miniaturization with total electrical size of 0.156λ0 × 0.156λ0 × 0.014λ0, where λ0 corresponds to the free-space wavelength at the first peak absorption frequency of 4.25 GHz. Additionally, the electric field and vectored surface current distribution along with the input impedance graph has been used to discuss the absorption methodology of the suggested structure. Further, the MTM belongings of the suggested structure have been illustrated with the dispersion curve.
TL;DR: In this paper, the authors proposed a new method based on spatial cumulants for estimating the parameters of multiple near-field and far-field sources, which leads to a significant reduction in computational complexity.
Abstract: The authors propose a new method based on spatial cumulants for estimating the parameters of multiple near-field and far-field sources. The Toeplitz property used in some studies is not applicable to fourth-order statistics to separate sources components. Therefore, in this paper, a method is proposed to compute output cumulants of specified sensors in special arrangements, by which the components of the near-field and the far-field sources are effectively separated using differencing. The angle and range estimations, as well as the classification of the sources, are obtained based on the data from two spatial cumulant matrices. One of them contains the angle information of all sources, and the other only contains the information of near-field sources. The parameters extraction algorithm is based on the ESPRIT technique; therefore, the proposed method does not require any spectral search. This leads to a significant reduction in computational complexity. Unlike some approaches, the proposed method does not suffer from array aperture loss. Also, the parameters pairing procedure is done automatically. Analysis and simulation results confirm the good performance of the proposed method in terms of computational complexity, estimation accuracy, correct classification of signals, and aperture loss.
TL;DR: The proposed statistical hybrid model is the synthesis of the well-validated deterministic hybrid model and a set of well-known statistical distributions widely used in communications literature such as Gaussian, Lognormal, Wald, Weibull and Gumbel statistical distributions.
Abstract: This pair of papers proposes a new approach towards the channel modeling of transmission and distribution broadband over power lines (BPL) networks either on the theoretical or on the practical basis. The proposed statistical hybrid model is the synthesis of the well-validated deterministic hybrid model and a set of well-known statistical distributions widely used in communications literature such as Gaussian, Lognormal, Wald, Weibull and Gumbel statistical distributions. In this paper, the theoretical framework of the statistical hybrid model, as well as the flowchart of the statistical hybrid model, is analytically presented.