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This study presents an analytical-based solution of electromagnetic plane wave scattering from a finite number of general-shaped grooves in a perfectly conducting plane. The formulation, for the near as well as far-field, is based on Fourier-integral representation of the scattered field and stair-case approximation of the grooves' fields. An efficient formulation of the scattering matrix based on hierarchical and modular formulations, which combines the boundary conditions between fields in groove layers and upper half space is demonstrated. The scattering matrix construction consists of two levels of matrices. The first level of matrices is the individual grooves scattering matrices and the coupling matrices between grooves. The second level of the matrices contains all the geometrical and physical parameters of the grooves as well as the incident field. The near and far-field results of finite rectangular and isosceles right triangle (IRT) grooves are in excellent agreement with a solution from high frequency simulation software, a finite-element simulator and previously published results. The proposed method is able to optimise finite asymmetric gratings for optical and terahertz applications. [ABSTRACT FROM AUTHOR]

An algorithm is presented for efficient computation of electromagnetic interactions between a large number of sources in electrically small problems. The algorithm is based on a plane-wave expansion of the free-space Green's function. The expansion consists of both propagating and evanescent plane waves, and is stable at low frequencies. The algorithm is used in the iterative solution procedure of the method of moments to reduce the computational complexity of solving the matrix equation. It reduces the complexity of the matrix–vector multiplication from O(N2) to O(N log N). The numerical results verify the validity and efficiency of the algorithm in solving large-scale and low-frequency problems. [ABSTRACT FROM AUTHOR]

An efficient model parameter extraction (PE) approach and a linear calibration method in the framework of the space mapping technique for electromagnetic (EM) optimisation of microwave filters is presented. A correct formulation for the PE is proposed that allows the use of simple approximate models. In this technique, knowledge of the reflection function of the EM model is efficiently used to iteratively calibrate an existing approximate model of the filter. The use of a reflection function in this approach eliminates the need for the direct modelling of all the complex unknown EM effects in the microwave filter during the PE step. A number of guidelines are also presented to improve the uniqueness of the solution. The validity of the method is verified by the design and optimisation of two filters. In all cases, very good convergence and robustness are achieved with a minimum number of EM simulations. [ABSTRACT FROM AUTHOR]

A design method for a millimetre-wave amplifier using accurate and scalable models extracted from the measured S-parameters of each circuit component is presented. The amplifier was fabricated using low-cost CMOS technology. The measured results show that the figure of merit of the fabricated amplifier – taking into account gain, noise figure, power consumption and size – is 177 which verifies the ability of the presented method for millimetre-wave amplifier design. The sensitivity of the amplifier performance with respect to the design parameters is also presented. [ABSTRACT FROM AUTHOR]

A high sensitivity sensor with a simple structure is presented for analysis of (bio)chemicals in liquid or solution form. The proposed technique is based on the travelling-wave whispering gallery resonance perturbation method in the millimetre-wave range. The resonance modes are launched inside a dielectric disk through coupling into a dielectric image waveguide. The top surface of the disk is used as the sensing area where the resonance mode interacts with the sample. Theoretical analysis and experimental results for the proposed sensor are discussed. [ABSTRACT FROM AUTHOR]