Advanced Electromagnetics (E-Journal)
Not a member yet
299 research outputs found
Sort by
Comparative Study of the Accuracy of Analytical Inductance Formulae for Square Planar Spiral Inductors
No full textIn the design of radio frequency (RF) microelectronic integrated circuits (IC’s) and of antennas for short-wave radio frequency identification (RFID) and telemetry systems, planar spiral coils are important components. Many approximate analytical formulae for calculating the inductance of such coils can be found in the literature. They can simplify the problem of designing inductors to a predefined inductance considerably. But the error statistics given by different authors cannot be compared because they are based on different or unknown domains of definition. Hence, it is not possible to decide which formula is best in a given case by merely studying the literature. This paper compares the maximum relative errors of six of some of the most cited formulae in the literature. To all formulae, the same domains of definition are applied. Each of them spans all four dimensions of the parameter space. Precise inductances are obtained numerically with the help of the free scientific and industrial standard software FastHenry2 and used as reference values to calculate the errors of the formulae. It has been found that the alleged maximum errors reported by some authors are far too optimistic. Only two formulae feature small enough errors to be useful in circuit design. The method and the domains of definition applied in the present study may also prove useful for the assessment of future formulae
New Compact Microstrip Filters Based on Quasi Fractal Resonator
No full textThis paper presents new microstrip devices as single band bandpass and multi band bandstop filters. The proposed filters use slotted patch microstrip resonator based on quasi fractal geometry, simulated by AWR12 software package. Both filters have quasi elliptic frequency response, designed at centre frequency of 2.437 GHz for bandpass filter and at band frequencies of 2.434, 4.032, 4.976 and 5.638 GHz GHz respectively, for multi bandstop filter. All filters are employed using RT/Duroid 6010.8 LM substrate of dielectric constant and 1.27 mm dielectric thickness. Simulation results show that the designed quasi fractal bandpass filter has very narrow fractional bandwidth of 0.38 % which is very rare in microstrip filter design. On the other hand, the projected bandstop filter offers multi narrow rejection bands that is useful in broadband wireless schemes influencing from fixed interferences. Both filters present satisfactory S11 and S21 responses besides smallness properties that stand for interesting features of the newest wireless applications. The simulated and measured frequency responses for both designed filters are in good agreement
A New Lowpass Filter Unit Cell with Sharp Roll-off and Improved Stopband Performance in Coplanar Waveguide Technology
No full textIn this paper, a new compact unit cell for a coplanar waveguide (CPW) lowpass filter (LPF) is proposed. By combining a pair of coupled parallel stepped impedance resonators (SIRs) and high impedance short stubs in the CPW line, a fifth-order elliptic lowpass filter unit cell (LUC) is designed. The extra transmission zero introduced by parallel coupled SIRs is used to extend the stopband and increase the roll-off rate. The characteristics of the proposed LUC is investigated to achieve a sharp roll-off and a wide stopband. The measured results are in accordance with the simulated results. It has an insertion loss less than 0.9 dB from dc to 6 GHz, and a wide -15 dB stopband from 7.5 to 18 GHz. In addition, the filter dimensions are as small as 4.9 mm × 8.7 mm, that is, 0.046λg2, where λg is the guided wavelength at the cut-off frequency. The filter structure is simple and easy to fabricate as well
Analytical Approximation for the Inductance of Circularly Cylindrical Two-Wire Transmission Lines with Proximity Effect
No full textThe paper describes a simple analytical approximation for the inductance of two-wire transmission lines of circularly cylindrical wires with proximity effect. It yields precise results up to very high frequencies, and also at all interaxial distances between the wires above some limit. Its accuracy is established by comparison to numerical computations and to measurements. It is shown that the proximity effect cannot be neglected unless the interaxial distance between the wires amounts to at least four wire diameters. Further, images of the current distribution in various situations are discussed
Compact Uniplanar Multi Feed Multi Band ACS Monopole Antenna Loaded With Multiple Radiating Branches for Portable Wireless Devices
No full textThis research article presents, a compact 0.19 λ x 0.32 λ size ACS fed printed monopole wideband antenna loaded with multiple radiating branches suitable for LTE2300/WiBro, 5 GHz WLAN and WiMAX applications. The proposed triple band uniplanar antenna encompasses of C shaped strip, L shaped strip, rectangular shaped strip and a lateral ground plane. All the radiating strips and ground plane are etched on the 26 × 15 m size low cost FR4 epoxy substrate. This designed geometry evoked three independent reonances at 2.3 GHz, 3.5 GHz and 5.5 GHz with precise impedance matching over each operating band. The reflection coefficient ( ) response of the presented antenna demonstrates three distinct resonant modes associated with -10 dB bandwidths are about 2.24-2.40 GHz, 3.38-3.83 GHz and 5.0-6.25 GHz respectively. From the study, it is also observed that the proposed design works perfect with microstrip as well as CPW feedings. Hence the designed Multi Feed Multi Band (MFMB) antenna can be easily deployed in to any portable wireless device that works for 2.3/3.5/ 5 GHz frequency bands
Design of Compact Dual-band Fractal Monopole Antenna with Virtually Extended Ground Plane
No full textAchieving a particular response to serve multiple wireless applications is regarded as the primary demand in our modern age because of the considerable development of the communication devices. In this paper, a compact monopole antenna with reduced ground plane has been suggested to meet the requirements of the dual-band WLAN applications. The antenna miniaturization has been carried out in employing two techniques. Initially, the fractal geometry has been applied to the antenna radiating element. Two-sided Koch fractal curves up to the third iteration have been used to increase the path of electrical current on the surface of the radiating element which is in the form of a square with dimensions. To gain more miniaturization, the antenna ground plane has been further reduced by using different lengths of two open-ended parallel stubs to form a virtually extended ground plane. This supportive technique has been adopted as a tuning means to control the path of the electrical currents exciting the resulting resonances. The proposed antenna and has been printed on an FR-4 substrate with a thickness of 1.6 mm and 4.4 relative dielectric constant and is fed by 50-ohm microstrip feed line. The resulting antenna dimensions are of about 19.1 mm × 19.1 mm. A parametric study has been carried out, and the results reveal that the proposed antenna offers a dual-band performance with a considerable ratio of resonant frequencies covering the existing 2.4/5.2/5.8 GHz WLAN applications, besides many other communication services
Symmetric surface waves along a metamaterial dielectric waveguide and a perfectly conducting cylinder covered by a metamaterial layer
No full textExistence of symmetric complex waves in a metamaterial dielectric rod and a perfectly conducting cylinder of circular cross section covered by a concentric layer of metamaterial, a metamaterial Goubau line, is proved. Analytical investigation and numerical solution of dispersion equations reveal several important properties of running waves inherent to open metal-metamaterial waveguides which have not been reported for waveguides filled with standard media
A Prototype Model Design of Wide Band Standard Reference Rod-Dipole antenna for 3-Axis EMC Measurement with hybrid Balun for 0.9 to 3.2GHz
No full textEvery electronics equipment must deal with EMC test. The testing laboratory of electronics equipment for radiation emission must have accurate calibrated antennas. The field strength of total radiated radio frequency is average of all incident signals at given point, this incident spinals originates from various directions. In order to measure three components of all electric field vectors, a tripole antenna is most beneficial over conventional antenna because of it responds to signal coming from multi directions. This paper presents novel three axis wide band calculable rod-dipole antenna with hybrid balun for the range of 900MHz to 3.2GHz frequencies, the proposed antenna is small in size and good electrical characteristics, the Important parameters measured and verified with designed values. Return loss S11 more than -10dB within the frequency range 900MHz to 3.2GHz. The result of this articles are evident that, efficient construction of antenna with low cost, light weight module applicable for EMC pre-compliance test at open field site
Probabilistic Assessment of Lightning Related Risk of Transmission Lines Based on Frequency Dependent Modeling of Tower-Footing Grounding System
No full textThis paper presents a probabilistic evaluation, based on Monte-Carlo method, for the estimation of insulation risk of failure of overhead transmission lines (TLs). The proposed method takes into account the wide-band model of tower-footing grounding system. The wide-band model of grounding system in frequency domain is obtained by the method of moment solution to the governing electrical field integral equations. The electrical parameters of soil are considered to be either constant or frequency dependent. The time-domain representation of the grounding system is inferred through pole-zero characterization of its associated frequency response. The case of a typical 400-kV transmission line is modelled in EMTP_RV with the tower-footing grounding system integrated with the transmission line (TL) system. The results of the paper show that the failure risk of transmission lines is affected by the grounding system model. This effect is more pronounced when the soil electrical parameters are assumed to be frequency dependent
Design and Implementation of Multiband Microstrip Patch Antenna for Wireless Applications
No full textMultiband phased array antennas are required for today’s multi-function communication applications. Generally Microstrip antenna arrays like Kotch array, Sierpinski array are used, but in some circuits where space is limited, arrays are not used. Therefore, to achieve the multiband operation with limited space, an antenna is designed with E-shaped in combination with split ring resonator to achieve the multiband operation. The simulation and experimental results show that the proposed antenna operates at four different frequencies, 1.8GHz, 3.6GHz, 4.53GHz and 5.73GHz, which can be used for different wireless applications like GSM 1800 (1.71– 1.78 GHz), WiMAX (3.4-3.69GHz) -IEEE 802.16 standards, Wi-Fi/WLAN (5.15-5.82 GHz). All the simulation results like resonant frequency, return loss, radiation patterns and fabricated antenna measured result is presented in this paper. The antenna is simulated using CST 2014 software