Showing papers in "Electromagnetics in 2015"
TL;DR: Comparisons of the proposed time-domain reflectometry/teaching–learning-based optimization approach results with measurements reveal that this approach has a high potential and is very effective for wiring network diagnosis.
Abstract: Time-domain reflectometry has proven to be one of the best methods for wiring network diagnosis, and it can easily be applied to the detection and localization of defects, while only requiring one access point to the wiring network. In this article, a novel approach combining the time-domain reflectometry response extracted from vector network analyzer measurements and the teaching–learning-based optimization technique is developed and applied to the diagnosis of wiring networks. The proposed approach consists of two steps. In the first step, propagation along the cables is modeled using the forward model. In the second step, teaching–learning-based optimization is used to solve the inverse problem to deduce physical information about the defects in the wiring network. The proposed approach has been successfully tested on several cases and for different configurations. Comparisons of the proposed time-domain reflectometry/teaching–learning-based optimization approach results with measurements reve...
28 citations
TL;DR: In this article, the frequency response of a first-order bandpass frequency selective surface is obtained for various angles of incidence, and principles of operation, detailed synthesis procedure, and designing guideline for this type of frequency selective surfaces are presented and discussed.
Abstract: This article introduces analytical formulas to obtain frequency response for a periodic array of hexagon metallic patches and strip cells. The validity of analytic expressions obtained from analysis is verified using full-wave simulations. The formulas are then employed for designing a first-order bandpass frequency selective surface. The proposed frequency selective surface is composed of a periodic array of metallic patches separated by thin air gaps backed by a wire mesh having the same periodicity. The array of metallic patches and the wire mesh constitute a capacitive surface and a coupled inductive surface, respectively, which together act as a resonant structure in the path of an incident plane wave. The frequency response of the proposed frequency selective surface is obtained for various angles of incidence. Moreover, principles of operation, detailed synthesis procedure, and designing guideline for this type of frequency selective surface are presented and discussed in this article.
19 citations
TL;DR: In this article, a single-layer broadband circularly polarized reflectarray with subwavelength double-ring elements is presented, which can obtain a better circular polarization performance compared to conventional λ/2 elements.
Abstract: A single-layer broadband circularly polarized reflectarray with subwavelength double-ring elements is presented in this article. Compared to conventional λ/2 elements, the subwavelength one can obtain a better circular polarization performance. Then, by using angular rotation technique, a reflectarray with this type of elements is designed and implemented. The fabricated reflectarray demonstrates excellent performance of 40% 3-dB axial ratio bandwidth and 19.1% 1-dB gain bandwidth, respectively. Moreover, the highest aperture efficiency can reach as large as 50%.
12 citations
TL;DR: The modified T-match and meander-line techniques were utilized to enhance the impedance of the tag antenna so that it is not only compatible with an integrated circuit chip but also operable in the ultra-high-frequency radio frequency identification international standard bandwidth.
Abstract: Ultra-high-frequency radio frequency identification is widely used in logistics and inventory management due to its compact size, distant readability, and speedy response. Nevertheless, current readability distance of the existing ultra-high-frequency radio frequency identification does not satisfy the requirements of certain applications, giving rise to research works to improve upon the present technology. Therefore, the focus of this article is to develop a compact wideband passive tag antenna operable in the entire ultra-high-frequency radio frequency identification band of 860–960 MHz. The impedance bandwidth, i.e., |S11| (dB), of the proposed tag antenna was set at less than –10 dB. The modified T-match and meander-line techniques were utilized to enhance the impedance of the tag antenna so that it is not only compatible with an integrated circuit chip (NXP G2XL; NXP Semiconductors, 2012) but also operable in the ultra-high-frequency radio frequency identification international standard band...
10 citations
TL;DR: In this paper, a new mathematical model of a major hysteresis loop and a simple procedure for the formation of first-order and higher-order reversal curves are proposed.
Abstract: In this article, a new mathematical model of a major hysteresis loop and a simple procedure for the formation of first-order and higher-order reversal curves are proposed. The applicability of the model has been tested by comparison with measured results, obtained with electrical steel and ferrite cores, and simulation results obtained with the Preisach model. Very good agreement has been found between simulated and measured major and minor hysteresis loops, as well as first-order and higher-order reversal curves.
10 citations
TL;DR: In this paper, two miniaturized microstrip tri-band bandpass filters with tri-mode resonators are presented, and a pseudo-interdigital structure is introduced to realize size reduction.
Abstract: Based on open stub-loaded dual- and tri-mode resonators, two miniaturized microstrip tri-band bandpass filters with good performance are presented. A pseudo-interdigital structure is introduced to realize size reduction. The 0° feed network is applied to create at least one transmission zero near the passband edge of each passband, resulting in high rejection and selectivity. The mode-splitting technique is used by combining two multi-mode resonators with electrical coupling, and the split two modes generate one passband. For demonstration, two tri-band bandpass filters with dual- and tri-mode resonators are implemented, respectively. The simulated and measured results are presented and show good agreement.
9 citations
TL;DR: In this article, a microstrip unit cell element with a simple structure is presented for designing circularly polarized reflectarray that converts a linearly polarized incident field into a radiated circularly polarised field.
Abstract: A novel microstrip unit cell element with a simple structure is presented for designing circularly polarized reflectarray that converts a linearly polarized incident field into a radiated circularly polarized field. The unit cell element consists of a circular patch with two orthogonal slots etched in it. A parametric study was carried out using CST Microwave Studio (Computer Simulation Technology, worldwide) on the unit cell element to evaluate the effect of the unit cell’s salient parameters. This unit cell element was used to design and implement a prime focus array, which had 3-dB gain bandwidth and 3-dB axial-ratio bandwidth equal to 7.6 and 8.6%, respectively.
9 citations
TL;DR: In this paper, a compact microstrip bandpass filter with controllable passband center frequencies is presented based on a short stub-loaded stepped-impedance resonator.
Abstract: Based on a short stub-loaded stepped-impedance resonator, a novel compact microstrip bandpass filter with controllable passband center frequencies is presented. To obtain dual-passband characteristics, dual-mode short stub-loaded stepped-impedance resonator and novel quad-pole-splitting techniques are investigated. The single passband is split into two with a notch when two resonators are employed, and dual passbands of a close band could be realized. It was found that the filter exhibits two desirable close passbands, an adjustable fractional bandwidth, and wide upper-stopband response. Moreover, the compact size of the proposed structure can be achieved. Good agreement between the measured and simulated results is shown.
8 citations
TL;DR: In this article, a double-ridged horn antenna is designed to have fewer parts that reduce the possibility of performance reduction due to the production process, and the effects of the E-plane sidewalls on antenna performance are examined.
Abstract: In this article, a 2–18-GHz double-ridged horn antenna is designed, and the effects of the E-plane sidewalls on antenna performance are examined. The modifications implemented in the shape of the ridges cause a better voltage standing wave ratio over the whole frequency band. The double-ridged horn antenna is designed to have fewer parts that reduce the possibility of performance reduction due to the production process. The antenna is modeled using commercial 3D electromagnetic simulation software, CST Microwave Studio (Computer Simulation Technology, Germany). After the simulations, a prototype of the designed model is manufactured and tested. The measurement results are in good agreement with the simulation results. The results show that the antenna has low side-lobe levels with a voltage standing wave ratio less than 1.85 (typically 1.5) over the entire frequency band. The method outlined in this article can be used to design a double-ridged horn antenna as a test antenna in electromagnetic com...
7 citations
TL;DR: In this paper, the equivalent dipole moment method is employed to accelerate the marching-on-in-degree method for the time-domain combined field integral equation, where each element can be viewed as a dipole model when the distance between the source and the testing basis functions is beyond a threshold distance.
Abstract: In this article, the equivalent dipole moment method is employed to accelerate the marching-on-in-degree method for the time-domain combined field integral equation. Each element can be viewed as a dipole model when the distance between the source and the testing basis functions is beyond a threshold distance. In this way, the impedance matrix elements of each order can be easily computed by a simple procedure, and the computational time is reduced significantly for transient electromagnetic scattering. Numerical results are presented to demonstrate the efficiency of the proposed method for electromagnetic scattering from perfect electric conductor objects.
6 citations
TL;DR: In this paper, a new method based on the subdivision of the integration path and using the double exponential quadrature formula is introduced to alleviate overlapping branch cuts and apply the array scanning method to structures with an arbitrary spatial period.
Abstract: The problem of aperiodic excitation of periodic structures with periods larger than a half-wavelength is revisited. A large number of antennas and other electromagnetic wave propagation problems fall within this category. Because of overlapping branch cuts, the conventional path deformation techniques employed in application of the array scanning method for this type of problem fail when the period is larger than a half-wavelength. A new method based on the subdivision of the integration path and using the double exponential quadrature formula is introduced to alleviate this problem and apply the array scanning method to structures with an arbitrary spatial period. To demonstrate the application of the new method and to validate the results, reflection and transmission coefficients of a frequency selective surface excited by a single electric dipole are calculated. Near fields of the frequency selective surface with aperiodic excitation are obtained and compared with those of a commercial electrom...
TL;DR: In this article, a novel approach to get new high-order nonstandard finite-difference time-domain methods is proposed by using different coefficients in electric field and magnetic field update equations, schemes up to order (2, 8) are derived.
Abstract: A novel approach to get new high-order nonstandard finite-difference time-domain methods is proposed. By using different coefficients in electric field and magnetic field update equations, schemes up to order (2, 8) are derived. These new methods maintain comparable accuracy to the conventional high-order finite-difference time-domain counterparts while a reduction in computational cost is achieved. The dispersion and anisotropic behaviors of these new methods are investigated. Some numerical examples are studied to examine the accuracy and efficiency of the new method.
TL;DR: An exact closed-form technique is employed to calculate the cutoff wavenumbers of a conducting circular waveguide loaded with two circular dielectric cylinders in this paper, where an analytical expression of the hybrid modes is derived in terms of cylindrical coordinates of the geometry.
Abstract: An exact closed-form technique is employed to calculate the cutoff wavenumbers of a conducting circular waveguide loaded with two circular dielectric cylinders. An analytical expression of the hybrid modes is derived in terms of cylindrical coordinates of the geometry. The addition theorem of Bessel functions is used to transfer the electromagnetic fields from one coordinate system to another to apply the boundary conditions. A MATLAB (The MathWorks, Natick, Massachusetts, USA) code is developed to solve the system of equations and produce the cutoff wavenumbers for different geometrical parameters. The present problem can be extended to model a circular waveguide loaded with multiple dielectric cylinders that resembles a petroleum-carrying pipeline. A professional High Frequency Structure Simulator (HFSS; ANSYS, Inc., Canonsburg, PA, USA) is used to solve this model and to determine the ratio of the multi-phase fluid.
TL;DR: In this paper, a technique to realize controllable multiple band rejection notches in high-order miniaturized ultra-wideband filters employing the E-shaped microstrip structure was presented.
Abstract: This article, for the first time, presents a technique to realize controllable multiple band rejection notches in high-order miniaturized ultra-wideband filters employing the E-shaped microstrip structure. In this technique, the filter circuit is composed of a double layer substrate where on the bottom layer the main filter circuit uses a cascaded E-shaped microstrip; the structure is developed and on the top layer the notches circuit employs a square-loop shape, where the structure is etched. These two filter circuits are capacitively coupled using overlapping microstrip lines. To demonstrate the technique and design process, several examples are designed, fabricated, and measured. One particular example is a fifth-order ultra-wideband bandpass filter with multiple rejection notches in which each notched band has a second-order stopband response. The filter size is very small, about 5.7 mm × 6.5 mm × 0.63 mm, excluding the feeding ports.
TL;DR: A new procedure for the design of dual-band monopole antennas operated in wireless local area network bands is presented, using the binary particle swarm optimization and the discrete Green's function method to achieve proper topology of the antenna.
Abstract: This article presents a new procedure for the design of dual-band monopole antennas operated in wireless local area network bands. The binary particle swarm optimization and the discrete Green’s function method are combined to achieve proper topology of the antenna without any prior knowledge about the antenna configuration. The discrete Green’s function method is implemented using parallel programming to accelerate the design procedure. Two antennas with symmetric and asymmetric topologies are designed and fabricated. The experimental results show the validity of the design algorithm.
TL;DR: In this article, a modified stepped-impedance resonator is proposed for a dual-band bandpass filter for wireless local area network (WLAN) applications, which consists of two pairs of proposed novel step-imping resonators, one of which is embedded in the other to obtain two passbands.
Abstract: A compact dual-band bandpass filter based on a modified stepped-impedance resonator is presented in this article. The conventional low-impedance stub of stepped-impedance resonator is replaced by a closed rectangular loop. The proposed filter consists of two pairs of proposed novel stepped-impedance resonators, one of which is embedded in the other one to obtain two passbands. Five transmission zeros can be generated near the passbands for enhanced frequency selectivity and band-to-band isolation. The center frequencies and bandwidths of the two passbands can be controlled by adjusting the geometric dimensions of the proposed stepped-impedance resonator. To demonstrate the proposed method, a 2.4-/5.2-GHz dual-band bandpass filter for Wireless Local Area Networks (WLAN) application has been designed, fabricated, and measured. The circuit only occupies 0.07λg × 0.09λg.
TL;DR: In this paper, a high-frequency method for the prediction of radar cross-section of coated targets with extremely electrically large size in the terahertz band in free space is presented.
Abstract: This article presents a high-frequency method for the prediction of radar cross-section of coated targets with extremely electrically large size in the terahertz band in free space To consider the scattering characteristics of the coated targets with a rough surface in the terahertz band, taking into account the effect of surface roughness, the reflection coefficients on the smooth coating surface can be modified; the equivalent electric and magnetic currents on the surface can then be corrected by the modified reflection coefficients to obtain the electric and magnetic induced current densities on the rough coating surface Therefore the physical optics method, which was combined with the graphical electromagnetic computing method and improved using the partition display algorithm, can be used to solve the scattered fields, and the radar cross-section of the coated targets with a rough surface in the terahertz band can then be obtained Numerical results for several coated targets, such as the m
TL;DR: In this paper, a differential dual-frequency patch antenna using a coupling feed is proposed, which is composed of a radiation patch with two U-shaped slots, two differential I-shaped feeding aluminum blocks, and a ground.
Abstract: A novel differential dual-frequency patch antenna using a coupling feed is proposed. The proposed antenna is composed of a radiation patch with two U-shaped slots, two differential I-shaped feeding aluminum blocks, and a ground. Two resonant frequencies are realized by two slots in the radiation patch. The lower resonant frequency is mainly controlled by the dimension of the radiation patch. The upper resonant frequency is mainly determined by the length of the slots. The two I-shaped feeding aluminum blocks can broaden the bandwidth of the proposed antenna. Simulated and measured results agree well. Measured results show that this proposed antenna can operate at 1.03 and 1.75 GHz with fractional bandwidths of 7.0% and 19.6%, respectively. This proposed antenna can operate with symmetrical radiation pattern, high gain, and low cross-polarization.
TL;DR: In this paper, an improved element pattern reconstruction method is introduced to calibrate the mutual coupling effect of antenna arrays, and its applications in wide-angle direction-of-arrival estimation are presented.
Abstract: An improved element pattern reconstruction method is introduced to calibrate the mutual coupling effect of antenna arrays, and its applications in wide-angle direction-of-arrival estimation are presented. In this method, direction-of-arrival estimations and a calibration matrix are achieved by alternate iteration. The improved method can achieve a more accurate calibration matrix and direction-of-arrivals with less calculation time and iterations than the joint estimation methods for direction-of-arrivals and calibration matrix. Additionally, the angle ranges of direction-of-arrival estimations can be widened by this method for practical antenna arrays. The validity was verified by some numerical examples with a microstrip antenna array.
TL;DR: In this article, a two-dimensional analysis model for predicting eddy current loss in a winding flux-switching permanent magnet under an open-circuit was presented, which is obtained by solving Poisson and Laplace equations in polar coordinates for each domain.
Abstract: This article shows a two-dimensional analysis model for predicting eddy current loss in a winding flux-switching permanent magnet under an open-circuit. The finite-element method is used for electrical machine design; however, this numerical method is always time consuming. Depending on the geometry, the mesh quality of the finite-element method should be high, and thus the finite-element method is more time consuming for special electrical machines. To solve this problem, a sub-domain model using Fourier analysis is improved for a flux-switching permanent magnet machine. It is obtained by solving Poisson and Laplace equations in polar coordinates for each domain, i.e., the magnet, air gap, rotor and stator slots, as well as external region. The model accounts for the influence of interaction between the stator slots and air gap, as well as rotor slots and air gap. Magnetic field distribution, flux linkage, back-electromotive force, cogging torque, and eddy current loss waveforms are derived from ...
TL;DR: In this paper, a theoretical extension of a plane wave integral representation to account for fields inside a reverberation chamber with an arbitrary lossy configuration was developed, which can explain a general over-moded RRC with the anisotropy condition; each of the six complex field components possesses non-zero mean values and different variances from one another.
Abstract: This article develops a theoretical extension of a plane wave integral representation to account for fields inside a reverberation chamber with an arbitrary lossy configuration. It is shown that the presented development can explain a general over-moded reverberation chamber with the anisotropy condition; i.e., each of the six complex field components possesses non-zero mean values and different variances from one another. It is found that the ensemble average of the absolute square of the total field can satisfy the homogeneity property (i.e., being independent of position), despite the correlation between the angular spectrum components of the received field. To the of the best authors knowledge, a detailed physical explanation of a high-loss reverberation chamber based on this extended plane wave integral formulation is not currently available due to the difficulty finding a homogeneity property. The theoretical expressions and physical explanations can not only provide fresh insights into the ...
TL;DR: In this paper, a modified interdigital coupling structure by using quarter and half-wave resonators alternately, and a narrowband bandpass filter operating at X-band has been designed proving the feasibility of the proposed structure.
Abstract: This article presents a modified interdigital coupling structure by using quarter- and half-wave resonators alternately, and a narrowband bandpass filter operating at X-band has been designed proving the feasibility of the proposed structure. The weak coupling required for narrowband filter is realized by arranging five quarter- and half-wave resonators alternately. In this article, simulated and measured result for a narrowband filter with fifth-order Chebyshev response is proposed. The filter is fabricated on 0.508-mm-thick Rogers RO4350B (Chandler, AZ, USA) with dielectric constant 3.66 using standard photolithography technique. Configurations produce very small and compact filter size, at 28.30 × 10.63 mm2. The simulated frequency responses have demonstrated a good narrowband property from 9.84 to 10.25 GHz (3-dB bandwidth), which is a fractional bandwidth of 4.1% at the center frequency, 10 GHz. The measured passband insertion loss is less than 4.56 dB and the passband return loss is better t...
TL;DR: In this paper, a broadband circularly polarized slot antenna fed by a coplanar waveguide, with simple layer geometry, is introduced. But the performance of the proposed antenna is limited by the 3dB axial ratio bandwidth.
Abstract: This article is introducing a novel broadband circularly polarized slot antenna fed by a coplanar waveguide, with simple layer geometry. A simple design procedure, made of seven stages, is extended to achieve the required performances. The antenna consists of two linked rectangular slots and two asymmetrical L-shaped slots embedded in opposite corners of stair-shaped ground plane with two conducting rectangles that are added to the ground plane in conjunction with a U-shaped strip. This strip is protruded into the slot from the signal line of the coplanar waveguide. By using the U-shaped patch and two conducting rectangles, two orthogonal electric fields with quadrature phase difference, it is possible to excite a circularly polarized wave. The proposed antenna, with a size of 45 × 45 × 0.8 mm3 is enabled to operate across 1.9 to 4.5 GHz with a fractional impedance bandwidth of 81.25%; for S11 less than –10 dB. The 3-dB axial ratio bandwidth is enclosed by the voltage standing wave ratio ≤ 2 imped...
TL;DR: In this article, a compact multi-mode bandpass filter with high selectivity and a wide stopband is proposed by introducing a triple-mode resonator into a dual-mode RF resonator.
Abstract: A compact multi-mode bandpass filter with high selectivity and a wide stopband is proposed in this article. The quintuple-mode resonator is proposed by introducing a triple-mode resonator into a dual-mode resonator. Due to the intrinsic characteristic of the proposed resonator, two transmission zeros are created at both sides of the passband for enhancing selectivity. Furthermore, two transmission zeros are generated by the input and output feed lines, leading to sharp skirts and a wide stopband. The simulated responses show a 3-dB fractional bandwidth of 25.8% at the central frequency (2.4 GHz). Measurement results agree well with the simulated results.
TL;DR: The excellent agreement between simulated and measured results shows that the proposed power divider can realize required functions with good matching, low insertion loss, fine isolation, and wide bandwidth.
Abstract: An impedance-transforming coupled-line Wilkinson power divider with port isolations and extensions is proposed in this article. It is composed of a coupled line section, an isolation resistor, and three extended transmission lines at each port for physical isolation and convenient installation. By substituting additional transmission lines for the three port extensions and introducing coupled lines, the power divider achieves suppressed insertion loss with enhanced physical output isolation. Closed-form design equations are successfully derived and verified. The excellent agreement between simulated and measured results shows that the proposed power divider can realize required functions with good matching, low insertion loss, fine isolation, and wide bandwidth.
TL;DR: In this article, the potential ability of an annular probe antenna as a feed in a cylindrical waveguide is presented to produce circular polarization; scientific concepts are presented about this ability.
Abstract: This article presents a new technique to excite a waveguide as a feed for a satellite antenna in low Earth orbit. In the first step, the potential ability of an annular probe antenna as a feed in a cylindrical waveguide is presented to produce circular polarization; scientific concepts are presented about this ability. Also, a method is studied to determine the dyadic Green function inside the cylindrical waveguide when an arbitrary probe is embedded in the waveguide. In the second step, according to Poynting’s theorem, the radiation power for the annular probe in the waveguide is calculated. Subsequently, the probe impedance due to the radiation power is determined in the waveguide. Another requirement is the creation of a wide radiation pattern that is realized by a corrugated ground plane installed on the aperture of the waveguide; this structure is known as a choke ring antenna. As the elevation angle increases, the choke ring antenna gain increases until the maximum gain for a certain elevati...
TL;DR: Considering a practical application scenario where six-bit phase shifters are employed, the peak side-lobes have been suppressed significantly by employing the genetic algorithm and a significant improvement is achieved.
Abstract: An efficient approach based on the combination of two-dimensional Woodward–Lawson analytical method and differential evolution optimization algorithm is developed for the synthesis of irregularly shaped radiation patterns based on four-dimensional planar arrays. Owing to the time-modulation of four-dimensional arrays, the ripples in the coverage area and the side-lobe levels are suppressed effectively. By combining the two-dimensional Woodward–Lawson method and differential evolution algorithm, the optimized time sequences and element excitations can be obtained. Radiation efficiency of time-modulated planar arrays also has been optimized and a significant improvement is achieved. Considering a practical application scenario where six-bit phase shifters are employed, the peak side-lobes have been suppressed significantly by employing the genetic algorithm. Numerical examples are presented to demonstrate the effectiveness and flexibility of the proposed approach.
TL;DR: In this article, an iterative physical optics model was proposed to solve the extra-large-scale (e.g., larger than 1,000 square lambda) electric electromagnetic scattering problem on a wind-driven sea surface at a low grazing angle directed against a shore-based radar with an Iterative Physical Optics model.
Abstract: This article proposes to solve the extra-large-scale (e.g., larger than 1,000 square lambda) electric electromagnetic scattering problem on a wind-driven sea surface at a low grazing angle directed against a shore-based radar with an iterative physical optics model. In order to accelerate the convergence of the iterative physical optics model and improve its robustness, the forward–backward methodology and its modification with under-relaxation iteration are developed first to simulate the rough sea surface scattering. Meanwhile, according to the scattering characteristics of rough sea surface, the local iteration methodology and the fast far-field approximation in the matrix-vector product are proposed to reduce greatly the computational complexity. Through these techniques, this model can solve effectively the extra-large-scale electric scattering problem from the randomly rough sea surfaces.
TL;DR: The theory of distributions of L. Schwartz is a very useful and convenient way for the analysis of physical problems since physical distributions, especially charge distributions yielding the discontinuity of the potential and boundary conditions, can be correctly described in terms of mathematical distributions as mentioned in this paper.
Abstract: The theory of distributions of L. Schwartz is a very useful and convenient way for the analysis of physical problems since physical distributions, especially charge distributions yielding the discontinuity of the potential and boundary conditions, can be correctly described in terms of mathematical distributions. To obtain the charge distributions, the distributional form of the Laplacian is applied to the Poisson’s equation; therefore, for the correct representations and interpretations, the distributional forms and their proper applications are very important. In this article, it is shown that the distributional form of the Laplacian has been presented by Schwartz and also others with a missing term, leading to confusing and wrong results mathematically, and as a result electromagnetically; and the revised, correct, and complete distributional representations of the Laplace operator, the Poisson equation, and double layers, defined as the dipole layer and equidensity layer, are obtained and pres...
TL;DR: In this paper, a planar printed monopole antenna with broadband characteristics in both axial and impedance is proposed and experimentally studied, and the measured results show a -10dB S11 bandwidth of 69.6% from 3.60 to 7.47 GHz and a 3-dB axial ratio bandwidth of 27.9% from 4.72 to 6.25 GHz.
Abstract: A new circular polarization planar printed monopole antenna with broadband characteristics in both axial and impedance is proposed and experimentally studied. By inserting a vertical slot into the left ground plane and cutting a horizontal slit in the right ground plane, the impedance bandwidth of the antenna is enlarged, and its wide axial ratio bandwidth is achieved. The measured results show a –10-dB S11 bandwidth of 69.6% from 3.60 to 7.47 GHz and a 3-dB axial ratio bandwidth of 27.9% from 4.72 to 6.25 GHz. The radiations of antenna exhibit a right-hand circular polarization in the +z direction and a left-hand circular polarization in the opposite direction. Moreover, a parametric study of the design is carried out.