Analytical solution of higher order modes of a dielectric-lined eccentric coaxial cable

Author(s):  
Mehdi Gholizadeh ◽  
Farrokh Hojjat Kashani

Abstract This study provides an analytic method for the calculation of the cutoff frequencies and waveguide modes of a partially filled eccentric coaxial cable. The method is based on the expressions of the involved electromagnetic fields in bipolar coordinate systems and the validity range of the solution is discussed. It is shown how the waveguide geometry and dielectric parameters may be selected to engineer the lined waveguide's spectral response. Numerical results are included which show good agreement with the corresponding results from full-wave simulations by commercial software.

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1259
Author(s):  
Dmitry Kozlov ◽  
Irina Munina ◽  
Pavel Turalchuk ◽  
Vitalii Kirillov ◽  
Alexey Shitvov ◽  
...  

A new implementation of a beam-steering transmitarray is proposed based on the tiled array architecture. Each pixel of the transmitarray is manufactured as a standalone unit which can be hard-wired for specific transmission characteristics. A set of complementary units, providing reciprocal phase-shifts, can be assembled in a prescribed spatial phase-modulation pattern to perform beam steering and beam forming in a broad spatial range. A compact circuit model of the tiled unit cell is proposed and characterized with full-wave electromagnetic simulations. Waveguide measurements of a prototype unit cell have been carried out. A design example of a tiled 10 × 10-element 1-bit beam-steering transmitarray is presented and its performance benchmarked against the conventional single-panel, i.e., unibody, counterpart. Prototypes of the tiled and single-panel C-band transmitarrays have been fabricated and tested, demonstrating their close performance, good agreement with simulations and a weak effect of fabrication tolerances. The proposed transmitarray antenna configuration has great potential for fifth-generation (5G) communication systems.


2018 ◽  
Vol 16 ◽  
pp. 123-133
Author(s):  
Fabian Ossevorth ◽  
Ralf T. Jacobs ◽  
Hans Georg Krauthäuser

Abstract. A full wave description of a thin wire structure, that includes mutual interactions and radiation, can be obtained in closed form with the so-called Transmission Line Super Theory or a refined variant of this method that utilises perturbation theory. In either procedure, a set of mixed potential integral equations is solved for the currents that propagate along a wire. With the perturbation approach, no iteration is required to approximate the initial current distribution on the wire. This procedure will be applied to solve multi-wire problems. The theory will be derived and computed results will be shown to be in good agreement with method of moment computations.


2019 ◽  
Vol 8 (1) ◽  
pp. 82-90
Author(s):  
L. K. Warne ◽  
S. Campione ◽  
R. S. Coats

This paper considers plane wave coupling to a transmission line consisting of an aerial wire above a conducting ground. Simple circuit models are constructed for the terminating impedances at the ends of the line including radiation effects. We consider the following load topologies: open circuit, short circuit, and grounded rods. Results from the transmission line model with these loads show good agreement with full-wave simulations.  


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Rahmani Faouzi ◽  
Amar Touhami Naima ◽  
BelbachirKchairi Abdelmounaim ◽  
Aknin Noura ◽  
Taher Nihade

This work presents the design and analysis of a beam switching antenna for VANET, Wi-Fi, and WiMAX wireless communication systems. The proposed reconfigurable antenna is powered by a coaxial cable and consists of a circular patch, six fish-shaped radiating elements, and a circular planar ground. The antenna was constructed on a Rogers RT5880 substrate. Its dimensions are as follows: 0.81λ0 × 0.81λ0 × 0.03λ0. It performs six reconfigurable operating states, at the same frequency, by controlling the activation and deactivation of six PIN diodes to change the beam’s direction. A theoretical equivalent circuit model of the antenna is extracted. A progressive analysis of improving the antenna characteristic performances is provided. The bandwidth of the proposed antenna is 9.07% (measured), 9.62% (simulated), and 9.31% (theoretical). The designed antenna has a maximum gain of 9.57 dB for all pattern states and a superior efficiency ratio from 85% to 95% over the operating range (5.54 GHz–6.10 GHz). The proposed reconfigurable antenna is fabricated. Measured, simulated, and theoretical results are given and show good agreement, including reflection coefficient (S11) and radiation patterns.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Mohammad Reza Khawary ◽  
Vahid Nayyeri ◽  
Seyed Mohammad Hashemi ◽  
Mohammad Soleimani

This paper presents a novel ultracompact narrow bandpass filter with high selectivity. The proposed filter is composed of cascading two basic cells. Each cell is basically a microstrip line loaded with a quasiplanar resonator and series gaps which can be fabricated using a standard multilayer printed circuit board technology. The structure is analyzed through an equivalent circuit and full-wave simulations. The simulation results are compared with experimental measurements demonstrating a good agreement between them. The measurement indicates that the realized bandpass filter at the center frequency of 1 GHz has a fractional bandwidth of 2.2%. Most importantly, in comparison with other similar recent works, it is shown that the proposed filter has the smallest size.


2019 ◽  
Vol 11 (08) ◽  
pp. 765-773
Author(s):  
Gaoya Dong ◽  
Weimin Wang ◽  
Yuanan Liu

AbstractA series of compact filtering power dividers (FPDs) with simple layouts are proposed based on coupling topology. The structure of the presented FPD1 is composed of three resonators and one isolating resistor. These FPDs can be designed based on coupling matrix filter theory. A half-wave transmission line is employed in FPD2 to introduce a transmission zero (TZ) locating at 1.27f0. The FPD3 is designed by replacing quarter-wave transmission lines in FPD2 with quarter-wave coupled lines, which will produce a TZ locating at 1.96 f0 and extend upper stopband bandwidth. For verification, three FPDs centered at 2.45 GHz are fabricated and measured. All measured results are in good agreement with the full-wave simulation results.


2014 ◽  
Vol 6 (6) ◽  
pp. 611-618 ◽  
Author(s):  
Yung-Wei Chen ◽  
Hung-Wei Wu ◽  
Yan-Kuin Su

In this paper, a new multi-layered triple-passband bandpass filter using embedded and stub-loaded stepped impedance resonators (SIRs) is proposed. The filter is designed to have triple-passband at 1.8, 2.4, and 3.5 GHz. The 1st and 2nd passbands (1.8/2.4 GHz) are simultaneously generated by controlling the impedance and length ratios of the embedded SIRs (on top layer). The 3rd passband (3.5 GHz) is generated by using the stub-loaded SIR (on bottom layer). Using the embedded SIR, the even modes can be tuned within very wide frequency range and without affecting the odd modes. Therefore, the design of multi-band filters with very close passbands can be easily achieved and having a high isolation between the passbands. The filter can provide the multi-path propagation to enhance the frequency response and achieving the compact circuit size. The measured results are in good agreement with the full-wave electromagnetic simulation results.


2001 ◽  
Vol 49 (7) ◽  
pp. 1304-1309 ◽  
Author(s):  
G. Panariello ◽  
L. Verolino ◽  
G. Vitolo

1969 ◽  
Vol 47 (24) ◽  
pp. 2763-2777 ◽  
Author(s):  
C. T. Tindle ◽  
E. Vogt

A comparison is made between the R-matrix and S-matrix theories of low-energy compound nucleus resonances for the particular case of two-level interference. The (p,γ) and (p,n) cross sections of 14C for proton energies between 0.7 and 1.5 MeV are analyzed using both theories. The 15N compound nucleus in this region exhibits strong two-level interference. The two theories provide equally good fits to the data, but the parameters describing the compound-nucleus levels are quite different. A general analytic method of relating the two sets of parameters is derived and shown to give good agreement with the results obtained by curve-fitting procedures. Remarks are made concerning the general behavior of the parameters under strong interference conditions and also on the inclusion of many channels into the analysis.


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