Full multimodal analysis of an open rectangular groove waveguide

In this paper, a full multimodal analysis of an open rectangular-shaped groove waveguide is presented for both TE and TM modes. The method of solution involves the formulation of the problem in terms of an integral-equation representation to which a Galerkin approximation, which incorporates the anticipated singularities at the edges of the guide, is then applied. The method proves to be extremely accurate and numerically efficient to compute, and results are presented for both the lower and higher order modes     

Field theoretical CAD of open or aperture matched T-junctioncoupled rectangular waveguide structures

The rigorous computer-aided design of rectangular waveguide structures coupled by open or rectangular iris loaded E- or H-plane T-junctions is described. The design theory is based on the full wave mode-matching method for the key-building-block T-junction element associated with the generalized S-matrix technique for composite structures. The waveguide structures may be arbitrarily composed of the T-junction and already known key-building-block elements (such as the double step and the septum discontinuity) combined with homogeneous waveguide sections between them. The E- or H-plane T-junction effect, large apertures, finite iris or septum thicknesses, and higher-order mode interactions at all step discontinuities are rigorously taken into account. Typical design examples, like rectangular iris coupled T-junctions, narrow-stopband waveguide filters, high return loss E-plane T-junction diplexers, an elliptic function E-plane integrated metal insert filter and a simple ortho-mode transducer demonstrate the efficiency of the method. The theory is verified by measurements     

Determination of admittance of coaxial-line/rectangular waveguide junction

An analytical approximate method to determine the admittance of a coaxial-rectangular waveguide junction is presented. The accuracy of the method is verified experimentally.     

矩形波导结中多介质柱散射特性边界元法分析

应用边界元法数值分析了n个端口矩形波导结中加载多介质柱的散射特性,对介质柱所在区域和除去介质柱后的空气区域分别用单连域和多连域问题的边界元法进行了分析。为了验证此方法的正确性,编制了一个通用的计算机程序,对几个算例进行了计算,结果与文献值一致。     

Choice of collocation nodes used in the analysis of an open rectangular dielectric waveguide

The collocation method applied for the electrodynamic analysis of an open rectangular dielectric waveguide is considered. The mathematical apparatus of the correlation theory is used to choose the distribution of collocation nodes. The dispersion equation for the fundamental mode of the structure is solved, the convergence of the solution is investigated, and the electromagnetic-field components on the medium interface are calculated.     

Analysis of coaxial-line/rectangular waveguide junction with dielectrically sheathed probe

The analysis of a coaxial line/rectangular waveguide junction is presented for the case where the centre conductor is sheathed in a dielectric. Expressions for the current distribution and the admittance of the junction are presented. A comparison of theoretical and experimental results show the theory to be very accurate.<>     

Coupling of an open resonator and a rectangular waveguide through a smooth waveguide transition

Under investigation is a coupling element for coupling an open resonator to a rectangular waveguide and consisting of a smoothly irregular waveguide section conjugate to a narrow slot in a mirror, A technique for the determination of the coupling Q-factor is proposed and good agreement between calculations and experimental results is obtained. Based on such a coupling element, an open resonator has been well matched with a waveguide and made retunable in a wide frequency range without coupling adjustment..     

圆形槽波导到矩形波导结的有限元分析

设计基于圆形槽波导的元件经常会用到圆形槽波导到矩形波导结.应用有限元法(FEM)分析了N端口波导结.采用完全匹配层(PML)将槽波导的开放边界截断为有限区域,然后对圆形槽波导到矩形波导结的散射特性进行了数值计算,得出的散射参量为圆形槽波导振荡器输出结构的优化设计提供了依据.     

A simple and rigorous analysis of the transmission properties of asector horn junction in a rectangular waveguide

Rigorous representations of expansion with a modal function, reflection, and transmission coefficients for the electromagnetic field at the junction between a sector horn and a rectangular waveguide are obtained. So far, this problem has been approximately treated by limiting the mode number of the electromagnetic field expansion or the flare angle of the horn. The electromagnetic fields at the discontinuity are expanded by a modal function of integer order. As a result, rigorous solutions are simply obtained by the orthogonality of a trigonometric function without any qualification. By using the numerical results calculated from these representations with strict accuracy, the transmission properties at the junction between a sector horn and a rectangular waveguide are examined in detail     

Modal analysis of open groove waveguide

A self-contained analysis for lower-order modes in the open groove waveguide is presented. By adopting an approximate form for the fields in the outer region of the guide and then performing the remainder of the analysis rigorously, closed-form results for the fields and modal equation are obtained. The analysis shows a simple transverse network representation that can be compared with that obtained by A.A. Oliner and P. Lampariello (ibid., vol.33, no.9, p.755-64, 1985). Universal dispersion curves, obtained numerically for the dominant mode, are presented     

Mode-matching analysis of a shielded rectangular dielectric-rod waveguide

Rectangular cross-sectional dielectric waveguides are widely used at millimeter wavelengths. In addition, shielded dielectric resonators having a square cross section are often used as filter elements; however, there is almost no information available on the effect of the shield. Rectangular or square dielectric waveguide is notoriously difficult to analyze because of the singular behavior of the fields at the corners. Most published analyses are for materials with a low dielectric constant, and do not include the effects of a shield. This paper describes a numerically efficient mode-matching method for the analysis of shielded dielectric-rod waveguide, which is applicable to both low and high dielectric-constant materials. The effect of the shield on the propagation behavior is studied. The shield dimensions may be selected such that the shield has a negligible effect so that results can be compared with free-space data. The results are verified by comparison with several sets of published data, and have been confirmed by measurement for a nominal /spl epsiv//sub r/ of 37.4.     

有限元\\边界元混合算法分析波导裂缝阵列天线

研究了一种分析波导裂缝阵列天线的方法。将有限元-边界元混合算法（FE-BI）应用于波导裂缝阵列天线的计算中,建立理论分析模型,计算波导裂缝上的等效磁流,进而求解整个天线阵列的远场辐射特性。为了检验这种方法的正确性,将所得的数值计算结果与测试值进行了比较,结果表明：FE-BI法可以作为计算波导裂缝阵列天线的一种有效的方法。     

Modes of crossed rectangular waveguide

The cutoff frequencies and modal fields of dually polarized crossed rectangular waveguide are calculated numerically and the cutoff frequencies verified experimentally. Symmetry arguments and group theory are used to explain mode degeneracies and mode splitting. The single mode bandwidth is 38 percent of center frequency for both polarizations when the guide dimensions are chosen appropriately. For applications where symmetric excitation is assured, bandwidths in excess of 2:1 can be obtained.     

Higher-order node-based TDFEM for transient electromagnetic analysis in rectangular waveguide

Higher-order Time Domain Finite Element Method (TDFEM) based on the nodal inter- polation is proposed for two-dimensional electromagnetic analysis. The detailed algorithms of the method are presented firstly, and then the accuracy, CPU time and memory consumption of the higher-order node-based TDFEM are investigated. The high performance of the presented approach is validated by numerical results of the transient responses of Transverse Electric (TE) field and Transverse Magnetic (TM) field in a rectangular...     

Modal transforms in rectangular waveguide

Transformation matrices that allow conversion between normalised s-parameters in TE_z/TM_z, TE_x/TM_x and TE_y/TM_y format are presented. The transforms are simple to implement and are essential when comparing results expressed in terms of different modal solutions     

Slot-mode propagation in rectangular waveguide

A previously observed discrepancy in the near-field pattern of a leaky-wave rectangular-waveguide antenna has been attributed to the presence of a second mode, in addition to the well known perturbed-waveguide mode. In this letter, a quantitative investigation of the properties of this so called slot mode is reported, and it is revealed that the cutoff frequency decreases with slot height and is strongly sensitive to it, in contrast to the other leaky-wave modes. Experimental observations of leaky-wave radiation at S band frequencies from a slotted Q band rectangular waveguide substantiate the theoretical predictions.     

Attenuation in corrugated rectangular waveguide

The attenuation characteristics of two corrugated rectangular waveguides propagating the dominant hybrid mode are shown to be significantly better over a wide bandwidth than those for a plain guide propagating the TE10 mode.     

Artificially integrated synthetic rectangular waveguide

A synthetic rectangular waveguide (SRW), which consists of two electrical sidewalls and two parallel periodical structures placed at the top and bottom surfaces of the waveguide, is presented. The SRW is made by multilayered integrated circuit processes, which typically have large ratios of SRW lateral dimensions to substrate thickness. Two theoretical methods, finite-element method and deembedding of composite structure consisting of SRW and mode converters, are applied to investigate the propagation characteristics of the SRW. Application of the dispersion characteristics of the two-dimensional periodical structures coupled with appropriate mode converter designs leads to results in SRW designs supporting TE/sub 10/, TM/sub 00/, and TM/sub 10/ modes. Measurements and the two theoretical approaches indicate that the slow-wave factor is 4.9 and Q-factor is 260 at 6.85 GHz for the TE/sub 10/ mode propagation with a cutoff frequency of 4.10 GHz (0.348 factor of cutoff frequency of conventional rectangular waveguide using the same material and dimensions). The theoretical data show the TM/sub 00/ mode to have a slow-wave factor of 1.8, Q-factor of 187.6 at 11.4 GHz, and cutoff frequency of 10.2 GHz. The TM/sub 10/ mode has a slow-wave factor of 1.98, Q-factor of 187.6 at 12.5 GHz, and cutoff frequency of 10.4 GHz.