Groove Guides Research Articles

Comparative study of three kinds of fibula cutting guides in reshaping fibula for the reconstruction of mandible: An accuracy simulation study in vitro

ObjectivesIn order to get predictable reassembling and higher accuracy in the reconstruction of the mandible, we designed three kinds of fibula cutting guides: (1) Two-edge wide groove guide (WGG); (2) Two-edge narrow groove guide (NGG); and (3) One-edge guide (OEG). The purpose of this study was to compare the accuracy of fibula remodelling using the three kinds of fibula cutting guides above in a simulation procedure in vitro. Materials and methodsCutting and reshaping of fibula analogs were guided by the three kinds of guides mentioned above. Then the fibula segments were glued together and scanned with CT, and finally the 3D accuracy of fibula reshaping was compared to the virtual plan. ResultsComparisons were made with regard to planned versus actual fibula segment length and angle projections in 3 planes. There were no significant differences in length change among the WGG group, NGG group and OEG group. There were very significant differences in angle projections in 3 planes between every 2 of the 3 groups. Conclusions3 kinds of guides do not affect the length of fibula segments. Two-edge narrow groove guides (NGG) caused the smallest error among the 3 kinds of guides. The error caused by two-edge wide groove guide (WGG) was similar to that caused by one-edge guide (OEG). The conclusion was in consistent with the referred groove-restriction-effect in the section of discussion. Clinical relevanceWe suggest that the two-edge narrow groove guide (NGG) is the superior choice for fibula cutting in reconstruction of the mandible.

Nanoimprint Mold for 2.5 Tbit/in.2 Directed Self-Assembly Bit Patterned Media with Phase Servo Pattern

We demonstrate the mold fabrication and replication process for the production of 0.8 and 2.5 Tbit/in.2 directed self-assembly bit patterned media (DSA-BPM). These devices are fabricated with 33 and 17 nm dot pitch patterns using the microphase segregation structure of polystyrene–poly(dimethylsiloxane) as an etching mask template. The self-assembled dot arrays are simultaneously ordered on both the circular tracks for the data area and the arbitrary marks for the servo area by DSA using groove guides. We fabricated the Si mold with dot pillars of 19.3 nm height for the 2.5 Tbit/in.2 DSA-BPM from the poly(dimethylsiloxane) dot mask. We also demonstrated the nickel mold replication of the 0.8 Tbit/in.2 DSA-BPM by electroforming from the Si mold.

Analysis of Excitations for a Groove Guide Resonator at 10 GHz by means of the FDTD Method

Various excitations of a new groove guide resonator working in the X-band (8 GHz – 12 GHz) are investigated by means of numerical simulations. For the numerical simulations the Finite-Difference Time-Domain method is used. The groove guide resonator, modelled both with and without excitation structures, is discretised in space. The results in the time domain are then transformed into the frequency domain in order to obtain the resonance frequency spectrum. Comparison between simulations with and without excitations shows the effect of the excitations on the resonance frequency spectrum. The results are compared with those of previous analytical methods.

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.

An Improvement for Calculating Precision of Arbitrary Groove Guide

The calculating precision of a new Fourier's expansion-differential method presented by us for analyzing the arbitrarily shaped groove guide is improved in this paper. Through calculating and analyzing the guide wavelengths of the typically several groove guides, the correctness of the new method is verified. A new type of similar V-groove guide is presented and analyzed by using the new method in detail. The obtained results are of important significance for enriching guide theory, analysis and calculation of guide performances in practical engineering applications for millimeter waves.

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.

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.

A new Fourier's expansion-differential method for analyzing groove guide with arbitrary shape

A new Fourier's expansion-differential method for analyzing groove guide with arbitrary shape is firstly presented in this paper. It is convenient to solve practical application problems of arbitrary groove guides. The calculated results of the guide wavelengths of typical groove guides are in good agreement with ones in references, and its computing precision is fairly high. Hence the computational correctness of the new method is verified. The new method has the advantages of clear conception, direct-viewing expression, simple and easily feasible computation, etc. So it is of important application values for enriching groove guide theory and is solving actual engineering application problems for millimeter waves.

Field Patterns in Asymmetrical Double Groove Guide by Finite Element Method

The electromagnetic power coupling in asymmetrical double-groove guide is 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 is distributed with a concentration of energy in the wide groove region, while the electromagnetic field of the first higher-order TE mode is distributed with a concentration of energy in the narrow groove region. The results in this paper have important values in design of groove guide power coupler for millimeter wave applications.

The Analysis of Post-Mount in W-Band Circular Groove Guide

Finite-difference time-domain (FDTD) method is used to calculate the driving-point impedance of the circular groove guide diode mount. A simple way is proposed to approximate the curvilinear metal boundary of circular groove guide. Discrete equations are obtained from the Ampere's law and Faraday's law. Perfectly matched layer (PML) is applied on the open boundary of circular groove guide. At last program is made to obtain the field components. The driving-point impedance can be achieved from the ratio of the Fourier transform of the voltage and the Fourier transform of the current. The cutoff frequency and field pattern of the dominant mode are also obtained with well agreement with the theoretical results, this verifies the validity of the FDTD program.

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 Aperture Field of Circular Groove Guide Horn Antenna by Using FD-TD Method

This paper presents an instance of using FD-TD method to analyze the aperture field of circular groove guide horn antenna. This process is one part of a hybrid method to solve the radiation field of aperture antenna. To verify the calculated aperture field the radiation pattern is computed from it and compared with the measured one. Good agreement is reached.

Circular Groove Guide Coupled with High-Q Cavity

The structure of circular groove guide coupled with high-Q cavity is studied. As a new type of millimeter wave component, it can be used for wavemeter and highly stabilized circular groove guide oscillator. The design and analysis of the novel structure are given in this paper.

Conchoid of Nicomedes and Limacon of Pascal as Electrode of Static Field and as Waveguide of High Frequency Wave

Groove guides have sharp corners in the guide proper so are not low loss and high power carrying wave guides. Proposed has been a groove rectangular waveguide with rounded internal angles [1]. However, the latter is not practical in having the infinite arms. Let us try the Conchoid of Nicomedes and Limacon of Pascal to see how can they be boundaries of static fields or high frequency waves. Also has been proposed the pentagon waveguide [2] for the high power transmission in high frequency. Yet we feel that we have very limited forms of waveguides, so we study the existing curves to see whether we can find some better guides such as rounded corner rectangular waveguide and others by starting from the boundary curves of p = a/ cos φ + l and p = a cos φ + l.

The Characteristic Equation of Corrugated Circular Groove Guide

Using the mode matching technique and neglecting the space harmonics, the characteristic equation of corrugated circular groove guide is given.

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.

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.

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.

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.

The groove guide as an interaction structure for a microwave FEL

Microwave FELs need a waveguide to confine the radiation and to control the group velocity of the radiation. If the electron bunches are short (some tens of ps), the control of the group velocity allows the FEL to operate in different regimes (steady-state or superradiant) [1].The Groove Guide (GG) is a low loss, laterally open structure; it consists of two parallel conducting planes with two grooves trapping the electromagnetic energy. The dimensions of the GG are of the order of some wavelengths, and, differing from the “standard” oversized waveguide, the GG supports a single TE01-like mode, if suitably designed.Moreover, the electromagnetic energy density, trapped by the grooves, is higher than in the rectangular oversized guide, for the same amount of power flowing, leading to a stronger coupling between the electrons and the radiation.In this paper the advantages of using a GG as a FEL interaction structure are discussed. Experimental measurements and characterization in the Ka band of prototypes of straight section, bend, transition from/to standard WR-28 rectangular waveguide are presented.