scholarly journals Investigation of the Leaky-Wave Characteristics of a Cylindrical Dielectric Rod Using the Coefficient Matrix of the System of Characteristic Equations and Davidenko’s Method

Author(s):  
Ersoy Kelebekler
Author(s):  
Shixiao Xiao ◽  
Lianwu Yang

Abstract In this paper, a leaky-wave antenna (LWA) with wide scanning angle and low cross-polarization is proposed based on a T-type folded substrate-integrated waveguide (FSIW). Transverse slots with a sinusoidal distribution pattern are etched on the surface of the FSIW so that transmission lines with slow-wave characteristics can excite and radiate −1 order harmonics. The length of the transverse slot affects the dispersion characteristics of the transmission line, and the sinusoidal modulation period controls the operating range of the LWA. In the frequency range of 8.3–15 GHz, the proposed LWA achieves a wide scanning ranging from backward −42° to forward +68° continuously. The cross-polarization of the beam is also kept at less than −30 dB during this scanning. A prototype is fabricated and measured to confirm the design, and the measured results show an agreement with the simulated one.


2003 ◽  
Vol 37 (6) ◽  
pp. 457-458
Author(s):  
Yun-Qi Fu ◽  
Guo-Hua Zhang ◽  
Dun-Bao Yan ◽  
Nai-Chang Yuan

2007 ◽  
Vol 73 ◽  
pp. 15-27 ◽  
Author(s):  
Hamidreza Dalili Oskouei ◽  
Keyvan Forooraghi ◽  
Mohammad Hakkak

2019 ◽  
Vol 30 ◽  
pp. 11003
Author(s):  
Vasiliy A. Malakhov ◽  
Irina V. Malakhova ◽  
Artyom S. Nechaev ◽  
Artyom A. Nikitin ◽  
Yulia V. Raevskaya

Excitation experiment technique of the E01 leaky wave in a round open dielectric waveguide is given. Experimental research results of the E01 leaky wave characteristics of a round open dielectric waveguide are presented.


Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ersoy Kelebekler

Abstract Open dielectric waveguides are structures used to guide electromagnetic energy in integrated circuits above the cutoff or as leaky wave antennas propagating the energy transversely out of the waveguide in a narrow region below the cutoff. In this study, the related operating regions for the hybrid EH modes of a cylindrical dielectric rod were obtained analytically. Analyses of the leaky wave characteristics of the hybrid EH modes for various radii of the rod and various dielectric constant values were performed. The guided modes existing above the cutoff with a pure real propagation constant, and the leaky wave modes existing below the cutoff with a complex propagation constant, were obtained from the coefficient matrix of the characteristic equations system of the structure using the bisection method and Davidenko’s method, respectively. Additionally, the guided modes of the structure were obtained and designated in the light of previous studies in the literature. The results show that the frequency spectrum of the antenna mode region increases as the value of the dielectric constant and the radius of the dielectric rod decrease. In addition, a circular dielectric with a smaller radius and dielectric constant had a larger frequency spectrum in the leaky wave antenna applications.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 621-629
Author(s):  
Yingsong Zhao ◽  
Cherdpong Jomdecha ◽  
Shejuan Xie ◽  
Zhenmao Chen ◽  
Pan Qi ◽  
...  

In this paper, the conventional database type fast forward solver for efficient simulation of eddy current testing (ECT) signals is upgraded by using an advanced multi-media finite element (MME) at the crack edge for treating inversion of complex shaped crack. Because the analysis domain is limited at the crack region, the fast forward solver can significantly improve the numerical accuracy and efficiency once the coefficient matrices of the MME can be properly calculated. Instead of the Gauss point classification, a new scheme to calculate the coefficient matrix of the MME is proposed and implemented to upgrade the ECT fast forward solver. To verify its efficiency and the feasibility for reconstruction of complex shaped crack, several cracks were reconstructed through inverse analysis using the new MME scheme. The numerical results proved that the upgraded fast forward solver can give better accuracy for simulating ECT signals, and consequently gives better crack profile reconstruction.


2003 ◽  
Vol 13 (5-6) ◽  
pp. 475-498 ◽  
Author(s):  
K. Pianthong ◽  
B. E. Milton ◽  
M. Behnia

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