An efficient integral equation technique for the analysis of arbitrarily shaped capacitive waveguide circuits

Abstract

In this contribution a new and efficient integral equation formulation is presented for the analysis of arbitrarily shaped capacitive waveguide devices. The technique benefits from the symmetry of the structure in order to reduce the dimensions of the problem from three to two dimensions. For the first time, this technique formulates the waveguide capacitive discontinuity problem as a 2‐D scattering problem with oblique incidence, combined with an efficient calculation of the parallel plate Green's functions. The numerical method allows the efficient evaluation of the electromagnetic fields inside the analyzed structures. Results for different practical capacitive waveguide devices are successfully compared with commercial software tools for validation of the proposed theory. Finally, a novel low‐pass filter implementation based on circular conducting posts has been proposed. The field contour lines in the critical gaps of the new structure are curved due to the use of rounded posts. This could result in improved power handling capabilities with respect to standard corrugated low‐pass filters.

On the analysis of capacitive rectangular waveguide discontinuities close to arbitrarily shaped conducting and dielectric posts

“…The posts can be metallic or composed of homogeneous dielectric material. This formulation is an extension of the numerical techniques reported in previous articles for the analysis of rectangular waveguide structures Quesada Pereira et al [11], Quesada Pereira et al [12], Quesada Pereira et al [13]. We must emphasize that the treatment of metallic and homogeneous posts in the vicinity of a step discontinuity with capacitive symmetry is addressed for the first time in this paper.…”

“…It is important to note that the capacitive symmetry of all geometrical elements (invariant along the x-axis), for the problem under study, except for the excitation, is analyzed following the same strategy presented in Quesada Pereira et al [11], Quesada Pereira et al [12]. As explained in those works, the system of integral equations is transformed into the spectral domain for a spatial harmonic corresponding to the fundamental TE 10 mode of the rectangular waveguide exciting the problem (k x = π/a).…”

“…The systems of integral equations described in Section 2 is solved using the MoM following a similar implementation as the one proposed in Quesada Pereira et al [11], Quesada Pereira et al [12], Quesada Pereira et al [13]. Other powerful alternative procedures for the efficient numerical solution of integral equations can be found in Mirzaee and Samadyar [21], Mirzaee and Alipour [22], Mirzaee and Hadadiyan [23], Mirzaee and Hoseini [24], Mirzaee and Hadadiyan [25].…”

Novel Spatial Domain Integral Equation Formulation for the Analysis of Rectangular Waveguide Steps Close to Arbitrarily Shaped Dielectric and/or Conducting Posts

“…An alternative technique to these previous techniques is the integral equation formulated in the spatial domain (Perez Soler et al, 2007;Quesada Pereira et al, 2006, 2011. The advantage of this technique is that it can treat more general structures composed of complex-shaped metallic posts or homogeneous material Radio Science 10.1002/2017RS006429 bodies, once the relevant Green's functions of the problem are efficiently computed in the spatial domain.…”

Integral-Equation Formulation for the Analysis of Capacitive Waveguide Filters Containing Dielectric and Metallic Arbitrarily Shaped Objects and Novel Applications

“…Among the useful available numerical methods, this paper uses an integral equation formulation to develop a new software tool for the efficient analysis of this class of components. Recently, an integral equation formulation for this purpose was proposed in [7], [8]. The efficiency of the method relies on the reduction of the structure to a 2D scattering problem with oblique angle of incidence.…”