Analysis for a Novel Cocoon-Shaped Groove Guide with Method of Lines

An arbitrarily cross-sectional groove guide is analyzed by using the method of lines and its characteristic equations are gives for TE and TM modes. Some numerical results show that correctness of the method of lines compared with the relevant results in the references is verified, and it is convenient to solve groove guide with arbitrary shape in practical application problems. A novel cocoon-shaped groove guide is firstly presented and its transmission characteristics are analyzed and discussed. The new type of cocoon-shaped groove guide has the good performances. The obtained results are of important application values in theoretical studies and practical applications of groove guides for millimeter waves.     

Analysis of Loss and Dispersion Characteristics for Groove Guides with Arbitrary Groove Profiles by an Equivalent Active Transmission Line Method*

Loss and dispersion characteristics of groove guide are two practically important factors in the design for millimeter wave system consisting of groove guide. In this paper, a new method is presented for analyzing loss and dispersion characteristics of the groove guides with arbitrary groove cross-sections. The method is based on the combination of an equivalent active transmission line equation and the staircase approximation. Numerical results of dispersion and attenuation properties for some groove guides with different groove profiles are given. The effectiveness and practicality of the present analysis are confirmed by the data given in the literature.*Supported by the National Natural Science Foundation of China (No. 60171019) and (No. 60371010)     

Finite-element analysis of dispersion and loss characteristics of groove guide with arbitrary shapes

The dispersion and loss characteristics of groove guide with arbitrary shapes are analyzed with high-order finite element method. The effectiveness and the reliablity of the method are verified by the experiments and the results obtained by other methods. Groove guides with various groove shapes, such as rectangular, triangular, parabolic, elliptic and cosine functions, are investigated systematically. The calculating results show that the dispersion of groove guide with different groove shape is almost the same, however, the loss characteristics is rather different; among them, V-shape groove guide has the lowest loss which is about half of the rectangular one. All the curves and the data given in this paper can be used in designing elements and circuits of the groove guide.     

Transmission characteristics of several kinds of closed groove waveguides for millimeter waves

An advantage of closed groove guide over open groove guide is attended. In this paper, the several kinds of closed groove guides including the trapezoidal-, elliptic- and parabolic-groove guides as new types of millimeter wave transmission lines are presented. Their dispersion and cut-off characteristics of the dominant mode are analysed and compared with ones of the closed V-and circular- groove guides by using the equivalent network method. The obtained results have important meaning in theoretical studies and actual applications of groove waveguides.     

Analytic method of arbitrary cross section open groove guide

Groove guide is one of the waveguides that have been used at millimeter and submillimeter waveband. This paper analyzes arbitrary groove guides by means of the eigen-weighted boundary integral equation method that uses the eigenfunctions of a fictitious regular boundary as weighting functions. In comparison with the theoretical and experimental results published, the numerical results for rectangular, circular and V-groove guides using this method are exact enough with fast convergence and less calculation.The Project Supported by National Natural Science Foundation of P.R. China     

On the Main Mode of Trapezoidal-Groove Guide By Finite Element Method

In this paper, the propagation properties such as the dispersion characteristics, cut-off wavelength, guide wavelength and field distribution for the main mode of trapezoidal-groove guide are analysed by using the finite element method. The dispersion is very low, and the field distribution in a trapezoidal-groove guide is similar to that of rectangular one. The results have important values in design, manufacture, and application of groove guides.     

Analysis for dispersion characteristics of trapezoidal-groove waveguide

In this paper, the dispersion characteristics of the main mode for the trapezoidal-groove guides are analysed by using the approach of equivalent network with transverse resonance. The relationship curves between guide wavelength, phase constant and guide dimensions, frequency are obtained. The characteristics have important values in design, manufacture and application of groove guides.     

Analyzing Semicircular Groove Guide with the Conformal Mapping Technique

Semicircular groove guide is a kind of waveguide for millimeter waves. In this paper, a conformal mapping technique is used to analyze it. Several semicircular groove guides are calculated with the method. It is shown that their cutoff wavelength calculated by the method are very close to those calculated by the transverse resonance method.     

Analysis of dispersion characteristics of groove guides with mode-matching method

Groove guide is widely recognized as one of the most promising millimeter wave transmission structures. In this paper, the mode-matching method is used to analyse the dispersion characteristics of single and asymmetrical double groove guides, and the unified formulae of Nth-order approximation dispersion equations are presented. Based on this analysis, a general program for calculating the dispersion characteristrics of single and asymmetrical double groove guides has been completed. Some comparisons between the results obtained by present method and published data show that very good agreement has been seen. The effectiveness and the reliability of the given formulae and program are thus verified.     

Network analyses for transmission characteristics of several kinds of curve-shaped groove waveguides

In this paper, the several kinds of the novel curve-shaped groove guides including the whole elliptic-, whole cosine- and hyperbolic-groove guides as the new millimeter wave transmission lines are presented. The dispersion, cut-off and band characteristics of the dominant mode for the several kinds of the curve-shaped groove guides are analysed by using the equivalent network method with transverse resonance. The obtained results have important values in their theoretical studies and actual applications of the curve-shaped groove waveguides.     

Coupling performance of closed double circular groove guide

Double circular groove guide is a simple structure which can be used to construct directional coupler. In this paper, the coupling property of two uniformly coupled circular groove guides is studied based on the transverse resonance analysing results of closed double circular groove guide.The project supported by National Natural Science Foundation of P.R. China     

An improved solution to the dominant mode properties of groove guides of general cross section

An improved solution to the dominant mode properties of groove guides of general cross section is presented in this paper. A novel differential equation is formulated and solved by numerical integration technique. Numerical results for single V-groove guide show good agreement with available measured values. Calculated results for the cutoff wavelengths of semicircular-groove and trapezoidal-groove guides are presented.     

Finite Element Analysis of the Dominant Mode Variation in Groove Guide

In this paper, the dominant mode in groove guide is analyzed by finite element method. For the guide with a shallow groove, the electric field lines (abbreviated as E lines) are perpendicular to the parallel plate, which is different from the literatures, and the dominant mode distribution is irrelevant to the groove width; for the guide with a narrow but deeper groove, the E lines are parallel to the plate region, which represents the characteristics of lower attenuation, for the guide with a deeper and wider groove, a complicated E lines are obtained. These results reveal that the dominant mode distribution in groove guide is varied, which replenish our understanding of groove guide, and the results have important values in design, manufacture, and application of groove guide.     

An Active Transmission Line Solution for Loss Characteristics of the Groove Guide

The analysis of loss characteristics for groove guide is one of the most practically important problems in millimeter wave system consisting of groove guide. In this paper, the calculation of the skin loss for the modes in the groove guide is ended to the solution of an active equivalent transmission line equation. The effectiveness and the reliability of the present method are verified by comparison between the present results and those given in the literature.     

Field Patterns in Double Circular-Groove Guide by Finite Element Method

The electromagnetic power coupling in symmetrical and asymmetrical double circular-groove guides have been analyzed by finite element method (FEM) in this paper. The electrical field patterns of the dominant mode and the first higher-order TE mode have been presented. The electromagnetic field of the dominant mode distributes with a concentration in the two grooves and the region between grooves as well for symmetrical double circular-groove guide, while it distributes with a concentration in the groove with larger radius for the asymmetrical double circular-groove guide. The electrical field patterns of the first higher-order TE mode in symmetrical and asymmetrical double circular-groove guide are also presented. The figures in this paper have important values in design of circular-groove guide power coupler for millimeter wave applications.     

ANALYSIS OF ARBITRARILY TRAPEZOIDAL-GROOVE GUIDE WITH THE CONFORMAL MAPPING METHOD

The arbitrarily open trapezoidal-groove guide is analyzed with the conformal mapping technique. A new formula is given for the evaluation of one fundamental parameter associated with the technique. The relationship between the cut-off wavelength for the dominant mode and the geometry of the guide structure is studied; dispersion characteristic of the groove guide is also given. Some numerical results are shown to be in good agreement with both experimental data and the results of the finite element method (FEM). Moreover, it is testified that dispersion of the trapezoidal-groove guide is low. The obtained results are significant for the design and application of the open trapezoidal-groove guide for millimeter waves.     

Analysis of the mono-groove NRD waveguide and antenna

In this paper, an improved structure of symmetric groove nonradiative dielectric (GNRD) guide, the mono groove NRD (MGNRD) guide is presented, which keeps the similar performances of the symmetric groove structure, but is more easy to fabricate in millimeter waveband. The dispersion characteristics of the MGNRD is analysed using the transverse resonance method, then a MGNRD leaky-wave antenna is constructed, calculated and tested. The theoretical and experimental data are agreement with each other, and shows a attractive prospect for application.This article is supported by the State Natural Science Foundation of China.     

The novel boundary integral equation method for solving arbitrary cross-section waveguides

A novel method for solving arbitrary cross-sectionn waveguides is presented. The novel method is a modification of the eigen-weighted boundary integral equation method; the EWBIEM is modified by using the eigenfunction of a fictitious regular boundary as weighting function, whose eigenvalue may be the known value, and meanwhile using the domain-bases. To confirm the validity of the novel method, numerical analysis are presented for circular groove guide as an example.The Project Supported by National Natural Science Foundation of P.R. China     

LEAKY CHARACTERISTICS OF A NEW MILLIMETER WAVE ANTENNA BASED ON GROOVE GUIDE WITH AN ASYMMETRIC CONDUCTOR STRIP

A new millimeter wave leaky wave antenna is presented in this paper, which is a modification of the groove guide with an asymmetric conductor strip by introducing a dielectric slab into the conductor plane region of the groove guide antenna. The leakage property of the new antenna is carefully examined through calculations of an equivalent network, which is developed here with taking into account the coupling between different modes to guarantee the calculating accuracy. It has been found that the new leaky wave antenna is of larger leakage constant than that for the original groove guide antenna because of the introduction of the dielectric slab. Extensive numerical results of the leakage characteristics are given to establish useful guidelines for the design of the new type groove guide leaky wave antenna.     

The solution of the characteristic equation of circular-rectangular groove guide

Circular-rectangular groove guide is a new type of structure we have presented for coupling between circular groove guide and rectangular groove guide. In this paper, as the continuity of our previous work, the characteristic equation of circular-rectangular groove guide has been solved and the numerical results have been given and discussed.The Project Supported by National Natural Science Foundation of P. R. China